Ophthalmology by Prof Anis Sir PDF

1 Contents: Chapter: 1. Ocular anatomy Page: 1 – 4 Chapter: 2. Eyelid Page: 5 - 22 Chapter: 3.Lacrimal drainage system Page: 23 – 35 Chapter: 4. Orbit Page: 36 – 4...

1 Contents: Chapter: 1. Ocular anatomy Page: 1 – 4 Chapter: 2. Eyelid Page: 5 - 22 Chapter: 3.Lacrimal drainage system Page: 23 – 35 Chapter: 4. Orbit Page: 36 – 49 Chapter: 5. Dry eye Page: 50 – 57 Chapter: 6. Conjunctiva Page: 59 – 82 Chapter: 7. Cornea Page: 83 - Chapter: 1. Ocular Anatomy The eye is the organ of sight situated in the orbital cavity. It is almost spherical in shape and is about 2.5 cm in diameter. The volume of an eyeball is approximately 7 cc. The space between the eye and the orbital cavity is occupied by fatty tissue. The bony wall of the orbit and the fat helps to protect the eye from injury. Structurally the two eyes are separate but they function as a pair. It is possible to see with only one eye, but three-dimensional vision is impaired when only one eye is used specially in relation to the judgment of distance. Fig: 1.1 Structure of the eye  2  Structure of the Eye The eyeball has three layers namely: 1) The outer fibrous layer—Sclera and cornea 2) The middle vascular layer—Iris, ciliary body and choroid 3) The inner nervous tissue layer—Retina.  Interior of the Eyeball The structures inside the eyeball are: 1) Aqueous humor 2) Lens 3) Vitreous.  Accessory Structures of the Eye 1) Eyebrows 2) Eyelids and eyelashes 3) Lacrimal apparatus 4) Extraocular muscles of the eye. 5) Conjunctiva 6) Orbital fat  Structure of the eye 1) The Outer Fibrous Layer  Sclera: The sclera or white of the eye forms the firm, fibrous outermost layer of the eye. It maintains the shape of the eye and gives attachment to the extraocular muscles. It is about 1 mm thick. The sclera becomes thin (sieve-like membrane) at the site where the optic nerve pierces it. It is called Lamina cribrosa. Fig: 1.2. Schematic diagram of three layers of the eyeball  3  Cornea: Cornea forms the anterior 1/6 of the eye. The transparent, ellipsoid, anterior part of the eyeball is known as the cornea. It is the main refracting surface of the eye. The dioptric power is + 43 ± 1  Limbus: The junction of cornea and sclera is known as the limbus. There is a minute arcade of blood vessels about 1 mm broad present at the limbus.  2. The Middle Vascular Layer:  Iris: Iris is a coloured, free, circular diaphragm with an aperture in the center—the pupil. It divides the anterior segment of the eye into anterior and posterior chambers which contain aqueous humor secreted by the ciliary body. It consists of endothelium, stroma, pigment cells and two groups of plain muscle fibers, one circular (sphincter pupillae) and the other radiating (dilator pupillae).  Ciliary body: Ciliary body is triangular in shape with base forwards. The iris is attached to the middle of the base. It consists of non-striated muscle fibers (ciliary muscles), stroma and secretory epithelial cells. It consists of two main parts, namely pars plicata and pars plana.  Choroid: Choroid is a dark brown, highly vascular layer situated between the sclera and retina. It extends from the ora serrata up to the aperture of the optic nerve in the sclera.  3. The Inner Nervous Tissue Layer  Retina: Retina is composed of ten layers of nerve cells and nerve fibers lying on a pigmented epithelial layer. It lines about 3/4 of the eyeball. Macula lutea is a yellow area of the retina situated in posterior part with a central depression called fovea centralis. It is the most sensitive part of retina.  Interior of the eyeball  Aqueous Humor Both anterior and posterior chambers contain a clear aqueous humor fluid secreted into the posterior chamber by the ciliary epithelium. It passes in front of the lens, through the pupil into the anterior chamber and returns to the venous circulation through the canal of Schlemmn’s situated in the angle of anterior chamber.  Lens: Lens is a transparent, circular, biconvex structure lying immediately behind the pupil. It is suspended from the ciliary body by the suspensory ligament or zonule of Zinn. It is enclosed within a transparent capsule.  Vitreous: Vitreous is a transparent, colorless, inert gel which fills the posterior 4/5 of the eyeball. It contains few hyalocytes and wandering leucocytes. It consists of 99% water, some salts and mucoprotein.  Accessory structures of the eye 1) Eyebrows 2) Eyelids and eyelashes 3) Lacrimal apparatus 4) Extraocular muscles of the eye. 5) Conjunctiva  4 6) Orbital fat  Eyebrows Eyebrows are two arched ridges of the supraorbital margins of the frontal bone. Numerous hairs (eyebrows) project obliquely from the surface of the skin. They protect the eyeball from sweat, dust and other foreign bodies.  Eyelids and Eyelashes The eyelids are two movable folds of tissue situated above and below the front of each eye. There are short curved hairs, the eyelashes situated on their free edges. The eyelid consists of:  A thin covering of skin  Three muscles—the orbicularis oculi, levator palpebrae superioris and Müller’s muscles  A sheet of dense connective tissue, the tarsal plate  A lining of the conjunctiva.  Lacrimal Apparatus: Lacrimal apparatus consists of:  Lacrimal gland and its ducts  Accessory lacrimal glands  Lacrimal canaliculi  Lacrimal sac  Nasolacrimal duct The tears are secreted by the lacrimal gland and accessory lacrimal glands. They drain into the conjunctival sac by small ducts. The tears then pass into the lacrimal sac (via the two canaliculi), nasolacrimal duct and finally into the nasal cavity (inferior meatus).  Extraocular Muscles of the Eye The eyeballs are moved by six extrinsic muscles, attached at one end to the eyeball and at the other to the walls of the orbital cavity. There are four straight and two oblique muscles. They consist of striated muscle fibers. Movement of the eyes to look in a particular direction is under voluntary control but co-ordination of movement needed for convergence and accommodation to near or distant vision is under autonomic control. The extraocular muscles of the eye  The medial rectus rotates the eyeball inwards.  The lateral rectus rotates the eyeball outwards.  The superior rectus rotates the eyeball upwards.  The inferior rectus rotates the eyeball downwards.  The superior oblique rotates the eyeball so that the cornea turns in a downward and outward direction.  The inferior oblique rotates the eyeball so that the cornea turns upwards and outwards.  Blood supply to the eye Arterial Supply The eye is supplied by the short (about 20 in number) and long ciliary (2 in number) arteries and the central retinal artery. These are branches of the ophthalmic artery, which is one of the branches of the internal carotid artery.  5 Venous Drainage: Venous drainage is done by the short ciliary veins, anterior ciliary veins, 4 vortex veins and the central retinal vein. These eventually empty into the cavernous sinus.  Nerve supply to the eye The eye is supplied by three types of nerves, namely motor, sensory and autonomic.  The Motor Nerves i. The third cranial nerve (oculomotor) ii. The 4th cranial nerve [trochlear]: It supplies the superior oblique muscle. iii. The 6th cranial nerve [abducens]: It supplies the lateral rectus muscle. iv. The 7th cranial nerve [facial]: It supplies the orbicularis oculi muscle.  The Sensory Nerve i. The 5th cranial nerve [trigeminal]: The ophthalmic division supplies the whole eye.  The Autonomic Nerves 1. The sympathetic nerve supply is through the cervical sympathetic fibers to:  Iris—Dilator pupillae muscle  Ciliary body  Müller’s muscle in the lids  Lacrimal gland. 2. The parasympathetic nerve supply originates from the nuclei in the midbrain. It gives branches to:  Iris—Sphincter pupillae muscle  Ciliary body  Lacrimal gland. Chapter: 2. Eyelid  Basic concepts of eyelid  What is an eyelid?  Layers of eyelid  Glands of the eyelid  The Outer Canthus  The inner Canthus  Blood supply  Nerve supply  Blood Supply  Lymphatic Drainage  Function of eyelid Classification of Eyelid diseases  Inflammatory diseases of eyelid  Diseases of lid margin:  Blepharitis  Diseases of lid glands:  Chalazion  Stye or External hordeolum  6  internal hordeolum  Tumors of the eyelid:  Benign tumor Benign epidermal tumour  Squamous cell papilloma  Seborrheic keratosis  Actinic keratosis Benign pigmented lesions  Freckle  Congenital melanocytic naevus  Acquired melanocytic naevus Benign adnexal tumour  Syringoma  Pilomatricoma Miscellaneous benign tumour Capillary haemangioma Port-wine stain Pyogenic granuloma Neurofibroma  Malignant tumor  Basal cell carcinoma  Squamous cell carcinoma  Sebaceous gland carcinoma  Disorders of the eyelashes  Misdirected lashes  Eyelash ptosis  Trichomegaly  Madarosis  Poliosis  Other eyelid disorder  Ptosis  Ectropion  Entropion  Congenital malformations of eyelid  Epicanthic folds  Telecanthus  Blepharophimosis, ptosis and epicanthus inversus syndrome  Epiblepharon  Congenital entropion  Coloboma  Cryptophthalmos  Euryblepharon  Microblepharon  Ablepharon  7  Basic concepts of eyelid:  What is an eyelid? An eyelid is a thin fold of skin that covers and protects the human eye. Layers of the eyelid Eyelid has 7 layers, from anterior to posterior a) Skin b) Subcutaneous areolar tissue c) Striated muscle (Orbicularis Oculi) d) Submascular areolar tissue e) Fibrous layer f) Smooth muscle (Muller’s muscle) g) Conjunctiva Fig: 2.1. Cross-section of the upper eyelid a) Skin  The eyelid is primarily made of skin. It is the thinnest skin in the body and is less than 1 mm thick. b) Subcutaneous areolar tissue:  It is very loose and contains no fat. It is thus readily distended by oedema or blood c) Layers of striated muscle:  It consists of orbicularis Oculi and levator palpebrae superioris (LPS) muscle. Orbicularis Oculi is supplied by zygomatic branch of facial nerve. It closes the eyeball. Therefore, in paralysis of facial nerve there occurs lagophthalmos (is the inability to close the eyelids completely) which may be complicated by exposure keratitis. LPS is supplied upper division of oculomotor nerve. LPS opens the eyeball d) Submascular areolar tissue:  It is a layer of loose connective tissue. The nerves and vessels lie in this layer. Therefore, to anaesthetize lids, injection is given in this plane. e) Fibrous layer:  8  It is the framework of the lids and consists of two parts: the central tarsal plate and the periphery septum orbitale. f) Layer of non-striated muscle fibers:  It consists of the palpebral muscle of Muller which lies deep to the septum orbitale in both lids. In the upper lid it arises from the fibers of LPS muscle; and is inserted on the peripheral margins of the tarsal plate. It is supplied by sympathetic fibers. g) Conjunctiva:  It is the thin transparent layer of tissue that lines the inner portion of the lids is called palpebral conjunctiva. Fig: 2.2 Cross-section of the lower eyelid Glands of the eyelid  There are 3 types of gland in the eyelid: a) Meibomian gland: They are modified sebaceous glands found in the tarsal plates. The cells of which synthesize lipids (meibum) that form the outer layer of the tear film. b) Glands of Zeis: These are modified sebaceous glands associated with eye lash follicles. c) Glands of Moll, also known as ciliary glands, are modified apocrine sweat glands that are found on the margin of the eyelid.  The Outer Canthus The outer or lateral angle of the palpebral fissure is called the outer canthus.  The Inner Canthus The inner or medial angle of the palpebral fissure is called the inner canthus. A semilunar fold, the plica semilunaris with an elevation called the caruncle is situated in the inner canthus.  Blood Supply It is supplied by the ophthalmic and lacrimal arteries by their medial and lateral branches. The venous drainage is through the ophthalmic vein.  Nerve Supply  The 7th nerve supplies the orbicularis oculi muscle. The 3rd nerve supplies the levator palpebrae superioris. The sympathetic nerves supply the Muller’s muscle.  The sensory supply is by the ophthalmic division of the 5th cranial nerve.  Lymphatic Drainage  9  The preauricular and the submaxillary lymph nodes  Functions of eyelid a) Protect the eye from foreign matter, such as dust, dirt, and other debris, b) It also protects from bright light that might damage the eye. c) When we blink, the eyelids also help spread tears over the surface of eye, keeping the eye moist and comfortable. d) The eyelashes help filter out foreign matter, including dust and debris, and prevent these from getting into the eye  Eyelid diseases  Inflammatory diseases of eyelid  Blepharitis: Blepharitis is a chronic inflammation of the lid margins.  Etiology: 1. It follows chronic conjunctivitis due to Staphylococcus in debilitated children usually who are living in poor hygienic conditions. 2. Parasites such as Demodex folliculorum, Phthiriasis palpebrarum, crab louse, head louse also cause blepharitis.  Types  Squamous blepharitis  It is due to abnormal metabolism and seborrhea. It is usually associated with the dandruff of the scalp.  Numerous white coloured small scales accumulate among the eyelashes.  The eyelashes fall out readily but are replaced without distortion.  On removal of the scales, the underlying surface is hyperemic.  Ulcerative blepharitis:  It is an infective condition. The yellow crusts glue the lashes together.  On removing the crusts, there are small ulcers seen around the bases of the lashes. These ulcers bleed easily.  The eyelashes fall out being replaced by misdirected lashes.  Symptoms Involvement is usually bilateral and symmetrical. Symptoms of either form of blepharitis include  foreign body or burning sensation,  excessive tearing,  itching,  photophobia,  redness of the eye,  blurred vision,  frothy tears,  Dry eye or crusting of the eyelashes on awakening. Symptoms are usually worse in the mornings although in patients with associated dry eye they may increase during the day  Sequelae  10  Trichiasis—this condition is due to misdirected eyelashes.  Tylosis—there is thickening or hypertrophy of the lid margin.  Madarosis—Absence of or scanty eyelashes as a result of destruction of the hair roots.  Ectropion—there is eversion of the lid margin due to the contraction of the scar tissue.  Epiphora—constant watering of the eyes occurs as a result of ectropion which may lead to eczema of the skin.  DIFFERENCES BETWEEN SQUAMOUS AND ULCERATIVE BLEPHARITIS SQUAMOUS ULCERATIVE BLEPHARITIS BLEPHARITIS Clinical features Scales White, fine and dry Yellowing, coarse, and sticky Ulceration Absent Present Bleeding Absent Present Loss of eyelashes Few and temporary Permanent and almost all lashes are involved Course Mild Progressive Complications Occasional Usual and serious  Treatment  Local—the local treatment should be energetic in the ulcerative form. i. Removal of scales, crusts and diseased lashes is done by bathing the lid margin with 3% sodium bicarbonate lotion. ii. Epilation of loose and diseased eyelashes is advised. iii. Antibiotic drops and ointment are applied after culture and sensitivity.  General i. Improvement of general health and personal hygiene should be done. ii. Dandruff of the scalp is adequately treated.  Diseases of lid glands: Followings are the diseases are lid glands i. Chalazion ii. Internal Hordeolum iii. External Hordeolum/Stye  Chalazion:  A chalazion (meibomian cyst Plural: Chalazia) is a sterile chronic granulomatous inflammatory lesion (Lipogranulomas) of the meibomian gland, caused by retained sebaceous secretions. Histopathology shows a lipogranulomatous chronic inflammatory picture. When it is acute occasionally secondary infection is called Internal Hordeolum  Treatment of chalazion:  Conservative: At least a third of Chalazia resolve spontaneously so observation may be appropriate, especially if the lesion is smaller.  Hot compress application several times daily may aid resolution, particularly in early lesions.  Steroid injection: (Triamcinolone Acetonide) into or around the lesion has been reported to give similar resolution rates to incision and curettage in case of small chalazia. It may be preferred for marginal lesions or lesions close to structures such as the lacrimal punctum because of the risk of surgical damage.  11 Fig: 2.3. A. Chalazion. Fig: 2.3. B. Stye  Surgery: Following local anaesthesia infiltration, the eyelid is everted with a specialized clamp (Fig: 2.4); the cyst is incised vertically through the tarsal plate and its contents are curetted.  Why we give vertical incision? If we give horizontal incision all the ducts of Meibomian gland will be injured which causes deficiency of lipid layer of precorneal tear film  Fate of chalazion  Spontaneous resolution  May remain same size.  May be infected  Undergo fibrosis  May burst into conjunctival or skin surface Fig: 2.4. Chalazion clamp Fig: 2.5. Chalazion curette  Internal Hordeolum Acute inflammation of the meibomian gland of the eyelid is called Internal Hordeolum. Staphylococcus aureus is the infectious agent in most cases.  Treatment of Internal Hordeolum:  Oral antibiotics are required for significant bacterial infection,  Hot compress application several times daily  Analgesic & anti ulcerant if needed  External Hordeolum/Stye  12 An external hordeolum or styes is an acute Staphylococcal infection of the glands of Zeis or Moll. It resembles a pimple and is tender to touch. It is most likely to form near the edge of the eye, where the eyelashes meet the eyelid. The condition is more common in children. Staphylococcal organisms are the most common causes of eyelid infections, but other organisms may be involved.  Treatment of Internal Hordeolum: and External Hordeolum/Styes In many cases, external hordeolum/styes will go away on own; only hot compression and epilation of the lash (If styes arise from the lash follicle) is sufficient. But when it doesn’t response with this treatment systemic antibiotic and topical antibiotic is required. Differences between chalazion & Styes Chalazion Stye Diseases of the meibomian gland. Diseases of the glands of Zeis or Moll Chronic granulomatous inflammation It is an acute condition Usually painless It is painful Located away from the lid margin Located closed to the eyelid margin Usually surgical intervention is needed Usually conservative treatment is needed.  Tumors of the eyelid: Benign epidermal tumour Squamous cell papilloma Seborrheic keratosis Actinic keratosis Benign pigmented lesions (Not discuss here) Freckle Congenital melanocytic naevus Acquired melanocytic naevus Benign adnexal tumour (Not discuss here) Syringoma Pilomatricoma Miscellaneous benign tumour Capillary haemangioma Port-wine stain Pyogenic granuloma (Not discuss here) Neurofibroma  Malignant tumour Rare predisposing conditions: (Not discuss here) Basal cell carcinoma Squamous cell carcinoma Keratoacanthoma: (Not discuss here) Sebaceous gland carcinoma Lentigo maligna and melanoma: (Not discuss here) Merkel cell carcinoma: (Not discuss here)  13 Kaposi sarcoma: (Not discuss here)  Benign epidermal tumour Squamous cell papilloma Seborrheic keratosis Actinic keratosis  Squamous cell papilloma: is a very common benign epithelial tumour with a variable clinical appearance, hyperkeratotic lesions similar to a cutaneous horn. The incidence increases with age; at least some cases result from human papilloma virus infection. Treatment usually involves simple excision, but other options include cryotherapy and laser or chemical ablation.  Seborrheic keratosis: Seborrheic keratosis (basal cell papilloma) is an extremely common slowly growing lesion found on the face, trunk and extremities of elderly individuals. The differential diagnosis includes pigmented basal cell carcinoma  Actinic keratosis: Actinic (solar, senile) keratosis is a common slowly growing lesion that rarely develops on the eyelids  Miscellaneous benign tumour Capillary haemangioma Port-wine stain Pyogenic granuloma Not discuss here Neurofibroma  Capillary haemangioma (strawberry naevus) Capillary haemangioma (strawberry naevus) is one of the most common tumors of infancy. It is three times more common in boys than girls. It presents shortly after birth It is unilateral, raised bright, red lesion usually in the upper lid; a deeper lesion appears purplish. Ptosis is frequent. The lesion blanches on pressure and may swell on crying. There may be orbital extension. Histopathology shows proliferation of varying-sized vascular channels in the dermis and subcutaneous tissue.  Port-wine stain Port-wine stain (naevus flammeus) is a congenital malformation of vessels within the superficial dermis. About 10% have associated ocular or CNS involvement, including Sturge–Weber and other defined syndromes Fig: 2. 6. A. Strawberry naevus Fig: 2.6. B Port wine stain  14  Neurofibroma Neurofibroma: Cutaneous neurofibromas are benign nerve tumors, usually nodular or pedunculated, that can be found anywhere on the skin. Plexiform neurofibromas typically present in childhood as a manifestation of neurofibromatosis type 1 with a characteristic S-shaped deformity of the upper eyelid. Treatment of solitary lesions involves simple excision but removal of the more diffuse plexiform lesions may be difficult.  Tumors of the eyelid: Malignant  Basal cell carcinoma  Squamous cell carcinoma  Sebaceous gland carcinoma  Basal cell carcinoma BCC is the most common human malignancy and typically affects older age groups. BCC is by far the most common malignant eyelid tumour, accounting for 90% of all cases. It most frequently arises from the lower eyelid. The tumour is slowly growing and locally invasive but non-metastasizing. Tumors that recur following incomplete treatment tend to be more aggressive. Fig: 2.7. Squamous cell carcinoma  Squamous cell carcinoma: SCC is a much less common, but more aggressive tumour than BCC with metastasis to regional lymph nodes. The tumour may exhibit perineural spread to the intracranial cavity. SCC accounts for 5–10% of eyelid malignancies and may arise de novo or from pre-existing actinic keratosis or carcinoma in situ (Bowen disease, intra epidermal carcinoma)  Sebaceous gland carcinoma (SGC) Sebaceous gland carcinoma (SGC) is a very rare, slowly growing tumour that most frequently affects the elderly, with a predisposition for females. It usually arises from the meibomian glands. In contrast to BCC and SCC, SGC occurs more commonly on the upper eyelid where meibomian glands are more numerous.  Disorders of the eyelashes  Trichiasis or misdirected lashes  Eyelash ptosis  Trichomegaly  Madarosis  15  Poliosis  Trichiasis or misdirected lashes: It is commonly due to inflammation such as chronic blepharitis or herpes zoster ophthalmicus, but can also be caused by trauma, including surgery such as incision and curettage of a chalazion. It causes constant irritation and corneal abrasion. Removal of the offending eyelash called epilation is the treatment  Eyelash ptosis: Eyelash ptosis refers to a downward sagging of the upper lid lashes. The condition may be idiopathic or associated with floppy eyelid syndrome, or long- standing facial palsy.  Trichomegaly: Trichomegaly is excessive eyelash growth.  Madarosis is the term used for the loss of lashes.  Poliosis: is a premature localized whitening of hair, which may involve the lashes and eyebrows  Other eyelid disorder  Ptosis  Ectropion  Entropion  Ptosis: (from Greek Ptosis “Blepharoptosis) Ptosis: (from Greek Ptosis “Blepharoptosis) is a drooping of the upper eyelid. Fig: 2.8. Ptosis 1) Congenital  Simple: This is the commonest form. The presence of congenital ptosis should be confirmed by comparing the photographs taken during childhood. It is usually, but not invariably, bilateral, and is due in most cases to defective development of the muscles. Simple congenital ptosis is an isolated condition, but congenital ptosis is called complicated when there is an associated maldevelopment of the surrounding structures.  Complicated—associated with ocular motor anomalies, blepharophimosis syndrome and Marcus Gunn ptosis 2) Acquired  Neurogenic  Myogenic  Aponeurotic  Mechanical  16 Neurogenic ptosis is caused by an innervational defect such as third nerve paresis and Horner syndrome. Myogenic ptosis is caused by a myopathy of the Levator Palpebrae Superioris (LPS) muscle itself Acquired myogenic ptosis occurs in myasthenia gravis, myotonic dystrophy and progressive external ophthalmoplegia. Aponeurotic or involutional ptosis is caused by a defect in the Levator aponeurosis. Acquired ptosis is most commonly caused by aponeurotic ptosis. Mechanical ptosis is caused by the gravitational effect of a mass or by scarring at upper eyelid.  Ectropion: It is a condition in which the lid margin rolls outwards. Fig: 2.9 Ectropion before and after surgery  Types 1) Involutional (age-related) ectropion affects the lower lid of elderly patients. It occurs due to:  Horizontal lid laxity  Lateral canthal tendon laxity,  Medial canthal tendon laxity, 2) Mechanical ectropion: It occurs as a result of thickening of the conjunctiva, e.g. as in trachoma stage IV. 3) Cicatricial ectropion: It may be due to several conditions such as chronic conjunctivitis, blepharitis, injury, burns, ulcers, etc. 4) Paralytic ectropion: It occurs due to the paralysis of orbicularis oculi muscle.  Symptom: The most common symptom is constant watering of the eyes.  Signs  Conjunctiva becomes dry in appearance and thickened in texture.  Chronic conjunctivitis may be present due to exposure of the conjunctiva and cornea.  Corneal ulcer may develop (exposure keratitis).  Treatment: Surgery is the treatment of choice  Entropion: (Fig: 2. 12) Entropion is a malpositioned resulting in inversion of the eyelid margin.  Congenital entropion  Acute spastic entropion  Involutional entropion  Cicatricial entropion  17 Fig: 2.10. Trichiasis Fig: 2.11. Entropion  Symptoms: Occur due to rubbing of cilia against the cornea and conjunctiva and are thus similar to trichiasis. These include foreign body sensation, irritation, lacrimation and photophobia.  Complications: These are similar to trichiasis.  Symblepharon It is a condition of adhesion of the lids to the globe.  Etiology: It is due to the formation of raw surfaces upon two opposite spots of the palpebral and bulbar conjunctiva, causing adhesion during the healing process. It is often due to:  Burns due to heat or caustics  Ulcers  Diphtheria  Operations.  Congenital malformation of eyelids  Epicanthic folds  Telecanthus  Blepharophimosis, ptosis and Epicanthus inversus syndrome  Epiblepharon  Congenital entropion  Coloboma  Cryptophthalmos  Euryblepharon  Microblepharon  Ablepharon Fig: 2.12. Epicanthic fold  Epicanthic folds are bilateral vertical folds of skin that extend from the upper or lower lids towards the medial canthi.  18  Telecanthus: It consists of increased distance between the medial canthi due to abnormally long medial canthal tendons. It should not be confused with hypertelorism in which there is wide bony separation of the orbits. Fig: 2.14 Telecanthus Fig: 2.15: Hypertelorism Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) BPES is a condition that mainly affects development of the eyelids. People with this condition have a narrowing of the eye opening (blepharophimosis), droopy eyelids (ptosis), and an upward fold of the skin of the lower eyelid near the inner corner of the eye (epicanthus inversus). In addition, there is an increased distance between the inner corners of the eyes (Telecanthus). Because of these eyelid abnormalities, the eyelids cannot open fully, and vision may be limited. Fig: 2.16. Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES)  Epiblepharon: Epiblepharon comprises an extra horizontal fold of skin stretching across the anterior lid margin. The lashes are directed vertically. When the fold of skin is pulled down the lashes turn out and the normal location of the lid becomes apparent. Treatment is not required in the majority of cases because spontaneous resolution with age is usual.  Coloboma: An eyelid coloboma is a full-thickness defect of the eyelid. No lid appendages or accessory structures are usually seen within the coloboma.  19 Fig: 2.17. Epiblepharon Fig: 2.18. Coloboma  Cryptophthalmos is a rare congenital anomaly in which the skin is continuous over the eyeball with absence of eyelids. It is the failure of eyelid separation can be associated with maldevelopment of the underlying cornea and microphthalmia. Cryptophthalmos usually occurs on both sides. Fig: 2. 19. Cryptophthalmos  Euryblepharon is a rare congenital anomaly in which there is symmetrical enlargement of the palpebral aperture associated with large eyelids.  20 SCA: 1  A lady of 20-year-old came to you with a nodular swelling in the upper eyelid. According to her statement it was started 2-month-before with pain, redness and swelling, after using systemic antibiotic (oral) symptoms went off, but the swelling is persisting which is cosmetically not accepted to her a) What is the diagnosis? 0.5 b) What is the pathogenesis of this lesion? 1.5 c) What is your treatment 1.5 SCA: 2 a) Draw and label the structures of upper eyelid 2.5 b) What are the functions of eyelid? 1.0 SCA: 3 a) What is chalazion? 1.0 b) What is Stye? 1.0 c) What is the difference between these two? 1.5 SCA: 4 a) What is chalazion? 1.0 b) What is the fate of chalazion? 1.0 c) Write down the treatment of chalazion 1.5 SCA: 5 a) What is entropion? 1.0 b) What are the symptoms? 1.0 c) How to manage? 1.5 SCA: 6 a) What are the malignant tumors of the eyelid? 1.5 b) Which one is the most common? 1.0 c) Which one is common in upper lid? 1.0 SCA: 7 a) What is blepharitis? 0.5 b) What are the types? 1.0 c) How will you manage a case of blepharitis? 2.0 SCA: 8 a) What are the glands of the eyelid? 1.0 b) What are they secreting? 1.0 c) Name 3 diseases of these lid glands 1.5 SCA: 9 a) What is ptosis? b) What are the types of ptosis? c) Discuss any one of it? Write short notes on: a) Chalazion b) Internal Hordeolum c) Stye/External Hordeolum d) Ptosis  21 e) Ectropion f) Entropion g) Blepharitis h) Trichiasis i) Madarosis j) Telecanthus MCQ: 1  Following are the functions of eyelid: a) Protect the eye from foreign matter. b) It also protects from bright light. c) it keeps the eye moist d) it has some antibiotic action e) it is the first defense action of eye MCQ: 2  Followings are the layers of the eyelid a) skin b) areolar tissue c) epithelial layer d) fatty layer e) conjunctiva MCQ: 3  Fibrous layer of the eyelid has the following structures: a) nerves and blood vessels b) tarsal plate c) Septum orbitale. d) muscle of Muller e) levator palpebrae superioris (LPS) MCQ: 4  Followings are the glands of the eyelid a) meibomian gland b) glands of Zeis c) sweet gland d) goblet cell e) glands of Moll, MCQ: 5  Fate of chalazion a) spontaneous resolution b) may turn into malignancy c) may be infected d) undergo fibrosis e) may burst into conjunctival or skin surface MCQ: 6  Followings are correct:  22 a) trichiasis: Inward rolling of the eyelid b) ectropion: Outward rolling of the eyelid c) ptosis: Drooping of the lower lid d) Epicanthic folds are bilateral vertical folds of skin that extend from the upper or lower lids towards the medial canthi. e) Telecanthus: Increased distance between the medial canthi MCQ: 7  Blepharitis a) inflammation of the lid glands b) it is a common disease c) maintenance of hygiene is key-point of treatment d) it is usually unilateral e) it is 2 types Answer of MCQ: 1) T, T, T, F, T. 2) T, T, F, F, T 3) F, T, T, F, F. 4) T, T, F, F, T. 5) T, F, T, T, T, 6) F, T, F, T, T, 7) F. T. T. F. F.  23 Chapter: 03. Lacrimal drainage system  Basic concepts of the lacrimal drainage system  Secretory portion  The lacrimal-glands  Accessory Lacrimal Glands  The Excretory part:  The puncta  The canaliculi  The lacrimal sac &  The nasolacrimal duct  Watering 1) Dacrocystitis  Risk factors of dacryocystitis  Pathophysiology  Chronic dacryocystitis: Symptoms and Signs  Sac Patency Test: How to perform?  Inferences of SPT  Chronic dacryocystitis: Treatment  Complication of chronic dacryocystitis  What is DCR & DCT?  Primary external dacryocystorhinostomy  Primary endonasal/endoscopic dacryocystorhinostomy  Endo laser DCR  Contraindication of DCR Surgery  Congenital NLD obstruction  Sign  Differential diagnosis  Treatment  SCA & MCQ  Basic concepts of the lacrimal drainage system Lacrimal apparatus is the ocular adnexa (accessory part). Functionally, it is divided into two portions. 1) Secretary part & 2) Excretory part Secretory systems consist of the following:  lacrimal gland: reflex secretion  accessory lacrimal gland: basic secretion  The lacrimal-glands: (Fig: 3.1) These are serous glands situated at the upper and outer angle of the orbit, in a depression known as the fossa for the lacrimal gland. Each gland is approximately the size and shape of an  24 almond. It is composed of secretory epithelial cells. Anteriorly the gland is divided into two parts—the upper orbital part and the lower palpebral part. The ducts of the lacrimal gland which are about 12 in number open in the fornix of the upper lid. The glands secrete tears composed of water, salt and lysozyme, a bactericidal enzyme. The gland has two portions.  The larger orbital – portion and  The smaller palpebral orbital - portion. Only the palpebral lobe can be visualized in the superior fornix on lid eversion. Thus, disease processes that solely affect the orbital lobe may not manifest until later.  Blood supply:  Artery supply: Lacrimal artery, branch of ophthalmic artery.  Venous drainages: Ophthalmic Vein.  Lymphatic drainage: Joins that of conjunctiva & drain into the preauricular lymph nodes.  Nerve supply:  Sensory nerve: The lacrimal branch of the ophthalmic division of the 5th nerve.  Sympathetic supply: The carotid plexus of the cervical sympathetic.  Secretomotor fibers: These are derived from the facial nerve via the sphenopalatine ganglion.  Accessory Lacrimal Glands (Fig: 3.1) These are very small glands of exactly the same structure as the lacrimal glands.  Glands of Krause: These are about 20 in number in the upper lid and about 8 in the lower lid situated within the stroma of the conjunctiva mainly near the fornix.  Glands of Wolfring: These are few in number situated near the upper border of tarsal plate. Fig: 3.1 Lacrimal and Accessory lacrimal gland  The Excretory part consists of the following  The puncta  The canaliculi  The lacrimal sac &  25  The nasolacrimal duct  Punctum: (plural puncta) There are two puncta in each eye, located at the posterior edge of the lid margin, at the junction of the lash-bearing lateral five-sixths (pars ciliary) and the medial non-ciliated one-sixth (pars lacrimalis). Normally they face slightly posteriorly and can be inspected by everting the medial aspect of the lids. 8 mm Fig: 3.2. Excretory part  The canaliculi: Pass vertically from the lid margin for about 2 mm (ampulla). They then turn medially and run horizontally for about 8 mm the superior and inferior canaliculi usually unite to form the common canaliculus, which opens into the lateral wall of the lacrimal sac. A small flap of mucosa (Rosen Müller valve) overhangs the junction of the common canaliculus and the lacrimal sac prevents reflux of tears into the canaliculi.  The lacrimal sac It is a cystic structure lined with columnar epithelium. It is situated in the lacrimal fossa formed by the lacrimal bone and the frontal process of the maxilla. It is about 15 mm in length and 5 mm wide when distended. The portion of the sac above the opening of the canaliculi is known as the fundus. The sac is continuous with the nasolacrimal duct inferiorly. In dacryocystorhinostomy (DCR) operation an anastomosis is created between the sac and the nasal mucosa to bypass an obstruction in the nasolacrimal duct.  26  The nasolacrimal duct: It is 12–18 mm long and is the inferior continuation of the lacrimal sac. It opens into the inferior nasal meatus, lateral to and below the inferior turbinate. The opening of the duct is partially covered by a mucosal fold (valve of Hasner).  Watering: Watering of the eye is a general term it is divided into two other names:  Epiphora: It means watering due to any obstruction in draining passage of the tear.  Lacrimation It means excessive secretion of tear There are two types of lacrimation:  Physiological: Emotional. Some gas & fumes, during onion peeling.  Pathological: Any pathological condition, such as foreign body in the eye. Conjunctivitis. Corneal ulcer. Acute congestive glaucoma. Acute anterior iridocyclitis.  Dacryocystitis Infection of the lacrimal sac is usually secondary to obstruction of the nasolacrimal duct. It may be acute or chronic and is most commonly staphylococcal or streptococcal.  Risk factors of dacryocystitis  Usually, related to nasolacrimal duct obstruction.  Nasal pathologies like nasal septum deviation, rhinitis and inferior turbinate hypertrophy on the same side.  Female is also a known risk factor for the development of this infectious condition due to narrow duct diameter.  The presence of dacryoliths at various levels of the lacrimal drainage system.  The occurrence of acute dacryocystitis being more prevalent with increasing age.  Pathophysiology: Dacryocystitis usually occurs because of obstruction of the nasolacrimal duct. The obstruction may be an idiopathic inflammatory stenosis (primary acquired nasolacrimal duct obstruction) or it may be secondary to trauma, infection, inflammation, neoplasm, or mechanical obstruction (secondary acquired lacrimal drainage obstruction). Obstruction of the nasolacrimal duct leads to stagnation of tears in a pathologically closed lacrimal drainage system which can result in dacryocystitis.  Chronic dacryocystitis: Symptoms and Signs  History of watering more than 6 months  Associated chronic conjunctivitis  Eyelashes are matted  Regurgitation of fluid (may be turbid, pus like) when pressing over the sac region.  Sac Patency Test: How to perform?  27  Topical anesthetic drops are instilled into the conjunctival cul-de-sac.  3 or 5 cc syringe filled with distilled water mounted on 24G/26G lacrimal cannula is used.  A gentle outward traction is applied on the lower eyelid laterally. This makes the lower canaliculi horizontal and aids in smooth syringing.  The subject is asked to look upwards for proper visualization of both the puncta.  The punctum is dilated with Nittleship’s punctum dilator.  The cannula is inserted and fluid is injected slowly.  Regurgitation (if any) is noted and presence of fluid in nose/pharynx is confirmed from the subject. Fig: 3.3: Nittleship’s punctum dilator. Fig: 3.4. Bowman’s lacrimal probe Fig: 3.5. Syringing through lower punctum  Inferences of SPT  Freely patent: When fluid is reported by the subject in the pharynx without reflux from either canaliculus.  Partial obstruction or a narrow duct (functional block): When fluid is not reported in the throat, occlude the opposite punctum and then syringe with pressure. If patent it indicates partial obstruction or a narrow duct (functional block).  28  Anatomical block: If not it means an anatomical block.  Total Common Canalicular Block CCB): When immediate regurgitation is noted from the opposite punctum.  Canalicular block: When fluid regurgitates from the same punctum. Irrigate from opposite punctum to check patency of rest of the lacrimal drainage apparatus.  When turbid fluid comes from both puncta: There is block in the lacrimal sac or NLD.  Chronic dacryocystitis: Treatment Surgery is the treatment of choice in chronic dacryocystitis. We can do:  DCR (Dacryocystorhinostomy) OR  DCT (Dacryocystectomy) Choice of surgery depends upon the age of the patient and general physical condition. If patient is aged and more than 65-year-old and debilitated, we usually go for DCT in spite of DCR  Complication of chronic dacryocystitis: If untreated there is  Chronic/recurrent conjunctivitis  Chronic/recurrent corneal ulcer  It may turn into acute on chronic dacryocystitis From acute on chronic dacryocystitis there is chance of:  Lacrimal abscess  Lacrimal fistula  Mucocele  Orbital cellulitis  Facial cellulitis  Cavernous sinus thrombosis  What is DCR & DCT?  DCR: It is an anastomosis or bypass operation, in which a communication is made between the medial wall of the lacrimal sac and the lateral wall of the nasal mucosa by cutting the intervening bones at the level of middle meatus. (Frontal process of Maxilla and Lacrimal bone)  DCT is a destructive surgery in which the lacrimal sac is removed, where there is watering persisted as before but recurrent infection is overcome.  DCR Surgery Preoperative investigation:  CBC  RBS  BT, CT (because in DCR operation we have to cut the nasal mucosa, which is highly vascular with numerous capillaries, so if BT, CT is abnormal there is chance of profuse  29 bleeding, for this reason when the patient is a young lady we do not do surgery during her menstrual period)  X- ray PNS (to exclude nasal pathology)  X- ray chest (P/A view) not routinely  ECG, if more than 40 year or any cardiac history  Primary Options for DCR Primary external dacryocystorhinostomy-  Advantages of the external approach include excellent success rates, reported to be up to 90%. A large osteotomy is created with direct visualization of lacrimal sac abnormalities, Direct suturing of the nasolacrimal sac and lateral nasal mucosal flaps allow for optimal apposition and primary intention healing of the flaps to create the bypass system.  Disadvantages: include a visible scar compared to the internal approach. Primary endonasal/endoscopic dacryocystorhinostomy  Advantages of the internal, or endonasal, approach include lack of a skin incision. This can be an option for the pediatric population or in younger patients without skin creases that could camouflage a scar.  Data suggests a slightly lower success rate than the "traditional" technique.  SURGERY: Anesthesia:  DCR may be performed under monitored sedation or general anesthesia based on the surgeon and patient’s preference. The patient may typically be discharged home on the same day. Local anesthesia, using an equal mixture of 2% lidocaine and 0.5% bupivacaine, with 1: 100,000 epinephrine is infiltrated into the medial canthus, lower lid incision site, and nasal mucosa.  Nasal packing: Nasal packing soaked in 4% cocaine, lidocaine, or afrin (Oxymetazoline) provides additional nasal anesthesia and mucosal vasoconstriction to the middle meatus. Meticulous hemostasis is crucial to a successful DCR surgery Fig: 3.6. Nasal pack is giving with the help of Fig: 3.7. Curvilinear skin incision Thuticum nasal speculum and Tilley’s forceps  DCR: Technique (External DCR):  30  A curvilinear skin incision is made with a surgical marking pen at the level of the medial canthal tendon and extending into the thin skin of the lower lid for 10-12 mm and 8 mm medial to the Medial palpebrae ligament  The patient’s face is prepared and draped in the usual sterile fashion. The skin is incised with a 15-blade scalpel  The orbicularis oculi muscle fibers are separated until the periosteum of the anterior lacrimal crest is identified.  The incision should be lateral to the angular vessels to avoid bleeding.  The periosteum along the anterior lacrimal crest is incised from the level of the medial canthal tendon extending inferiorly, and the periosteum widely elevated.  The periorbita and lacrimal sac is similarly elevated posterior laterally off the lacrimal sac fossa.  The fossa is next carefully perforated where the bone thins at the suture line between the thicker frontal process of the maxilla and the adjacent thinner lacrimal bone.  A high-speed drill are used (due to unavailability we use DCR trephine) to remove the bone of the lacrimal fossa, inferiorly to the lacrimal duct at the inferior orbital rim, and anteriorly past the anterior lacrimal crest.  A bony ostium measuring approximately 15mm is removed.  A 0-0 Bowman probe is passed into the lacrimal sac to tent the sac medially, and Westcott scissors are used to open the lacrimal sac from the duct to the fundus, with relaxing incisions at both ends.  Any abnormal scar overlying the opening of the common canaliculus, lacrimal sac stones, foreign bodies, or masses are removed if present. Fig: 3.8. Lacrimal mucosal flap Fig: 3.9. Nasal mucosal flap  Lacrimal sac opened to create a flap.  A corresponding incision is made in the nasal mucosa, to create anterior only, or anterior and posterior flaps  A corresponding nasal mucosal flap is elevated.  The lacrimal sac flaps are meticulously anastomosed to the nasal mucosal flaps after silicone tubes are passed into the canaliculi and through the DCR ostium.  31 Lacrimal mucosal flap Nasal mucosal flap Fig: 3.10. Silicon tube introducing  The silicone tubes are placed through the new ostium and the flaps sutured together with 6/0 chromic catgut  After suturing the flaps together to create the new pathway into the nose, the orbicularis muscle and skin are closed in layered fashion.  The anterior limb of the medial canthal tendon is also re suspended if released earlier.  The silicone tubes are tied and left long in the nasal vestibule to facilitate office removal later. The tubes may be removed anywhere from 4 weeks to several months after surgery. Surgical follow up  Following surgery, the patient is discharged home if stable and instructed to rest for one week, without heavy lifting, exercise, or strenuous activity that may induce bleeding.  Hot drinks and food should be avoided for the first 12-24 hours postoperatively in order to decrease the risk of epistaxis caused by heat-induced nasal vasodilation.  Ice/cold compresses are placed on the incision site for 48 hours while awake to minimize swelling and bruising.  The patient’s head should remain elevated at all times at a 45-degree angle and the patient instructed to avoid nose blowing for one week to decrease the risk of hemorrhage.  Skin sutures are removed one week postoperatively if nonabsorbable sutures were used,  The silicone tube is removed typically at 4-8 weeks after surgery. Complication per-operative  Hemorrhage: Chance of hemorrhage during incision if we injured the angular vein. Another source is during cutting bones and during making nasal mucosal flap.  Injury to the internal opening of the common canaliculus when opening the sac  Cerebrospinal fluid leak due to penetration of the cribriform plate  Injury to the canaliculi from improper probing  Injury to the orbital contents from rongeurs or drill  Shredding of the lateral nasal mucosa due to improper bone removal  Failure to completely open the inferior portion of the lacrimal sac, resulting in a lacrimal stump syndrome.  Failure to adequately drain and remove a lacrimal sac diverticulum  32  Complication: Postoperative  Hemorrhage  Infection  Incomplete improvement, persistent tearing  Early loss of the silicone tube  Fibrosis occlusion of the ostium  Synechiae between the middle turbinate, nasal septum, or lateral wall & need for additional surgery  Sinusitis  Contraindication of DCR Surgery Absolute contraindication:  Atrophic rhinitis  Malignancy in the sac region Relative contraindication:  Nasal polyp  DNS  Acute dacryocystitis  Endo laser DCR With the advent of nasal endoscopes, endoscopic DCR is becoming popular. In this procedure, a nasal endoscope is used to visualize the lacrimal sac through the nasal cavity. The bone covering the lacrimal sac is nibbled out. The medial wall of the sac is incised or excised, facilitating drainage of tears into the nasal cavity. This procedure avoids scarring. The advantages include lesser peri-operative morbidity, and no scar. Data suggests a slightly lower success rate than the "traditional" technique. Advantages:  No scar  Less bleeding  Less chance to injury of the surrounding structures  Less comorbidity Disadvantages:  Reducer success rate  More recurrence  Congenital NLD obstruction The lower end of the nasolacrimal duct, in the region of the valve of Hasner, is the last portion of the lacrimal drainage system to canalize, with complete patency most commonly occurring soon after birth, when the valve is not open after birth there is blockage of NLD  Congenital Nasolacrimal duct obstruction: Signs  Epiphora and matting of eyelashes may be constant or intermittent, and may be particularly noticeable when the child has an upper respiratory tract infection;  33  If there is frank bacterial conjunctivitis may be treated with a broad-spectrum topical antibiotic.  Gentle pressure over the lacrimal sac may cause mucopurulent reflux.  Congenital Nasolacrimal duct obstruction: Differential diagnosis  Differential diagnosis includes other congenital causes of a watering eye, such as  punctal atresia; it is important to exclude  congenital glaucoma,  chronic conjunctivitis (e.g. chlamydial),  keratitis and  Uveitis.  Congenital Nasolacrimal duct obstruction: Treatment Massage of the lacrimal sac has been suggested as a means of rupturing a membranous obstruction by hydrostatic pressure. The index finger is initially placed over the common canaliculi to block reflux, and then rolled over the sac, massaging downwards. Probing: If the baby is not recover within 12 months we can go for probing under general anaesthesia. Sometimes one probing is not sufficient there may need repeated probing. Most of the baby is cure with probing. There is 1% chance of persistent blocking. In this case s/he may need DCR surgery after few years. SCA: 1  A 40-year-old man presented with painful swelling and redness over the right lacrimal sac area. He had history of watering in right eye for the last 2 years. a) What is your clinical diagnosis? 1.0 b) How will you treat the patient? 2.0 c) What suggestion will you give to this patient? 0.5 SCA: 2  An 18 month-old baby presented with persistent watering and mild discharge from both eyes since birth. a) What is your possible diagnosis? 0.5 b) What are the differential diagnoses? 1.0 c) How will you manage the case? 2.0 SCA: 3 a) What is DCR? 1.0 b) What are the contraindications of DCR surgery? 1.5 c) What are the sources of per-operative bleeding in DCR surgery? 1.0 SCA: 4 a) What are the signs and symptoms of acute dacryocystitis? 1.0 b) How will manage a case of acute dacrocystitis? 1.5 c) Is surgery indicated or contraindicated during acute attack? Why? 1.0  34 SCA: 5 a) How will you perform Sac patency test? 2.0 b) What is the interpretation? 1.5 SCA: 6 a) What is DCR? 1.0 b) What is DCT? 0.5 c) What is the difference between these two? 2.0 SCA: 7 a) Draw and label the anatomy of lacrimal apparatus b) Mention the pathway of tear c) How will you manage a case of acute dacryocystitis?  Write short notes on: a) SPT b) Lacrimal gland c) Accessory lacrimal gland d) Endolaser DCR e) Anesthetic used in DCR surgery f) DCT MCQ: 1  In chronic dacryocystitis a) it is a painful condition b) DCR is the choice of surgery c) in surgery, anastomosis is done at the level of inferior meatus d) atrophic rhinitis is not a contraindication for surgery e) patient complains of watering MCQ: 2  In dacryocystorhinostomy the following bones are cut a. frontal process of maxilla b. frontal bone c. body of the sphenoid bone d. lacrimal bone e. ethmoid bone MCQ: 3  Followings are the relative contraindication of DCR surgery: a) nasal polyp b) deviated nasal septum c) atrophic rhinitis d) malignancy in sac region e) chronic dacrocystitis MCQ: 4 3 June 2019  35  Followings are the secretary parts lacrimal apparatus: a) common canaliculi b) lacrimal gland c) gland of Wolfring d) nasolacrimal duct e) lacrimal sac , MCQ: 5  Followings are the signs and symptoms of chronic dacryocystitis: a) chronic conjunctivitis b) eyelashes are matted c) pain d) swelling e) regurgitation of fluid (may be turbid, pus like) when pressing over the sac region. MCQ: 6  Following are the absolute contraindication of DCR surgery a) nasal polyp b) deviated nasal septum c) atrophic rhinitis d) malignancy in sac region e) acute dacryocystitis. MCQ: 7  Following are the correct statements: a) the lacrimal gland is pear shaped b) number of gland of Wolfring is more than gland of Krause c) the lacrimal sac is 10 – 12 mm long d) the nasolacrimal duct is 10 mm long e) lacrimal gland is situated in the fossa for the lacrimal gland. Answer MCQ 1) F, T, F, T, T 2) T. F. F. T. F 3) T, T, F, F, F, 4) F, T, T, F, F 5) T, T, F, F, T 6) F, F, T, T, F 7) F, F, T, F, T 3 June 2019  36 Chapter: 4. Orbit  Basic concepts of orbit  Roof  Lateral wall  Floor  Medial wall  The superior orbital fissure  Optic foramen and canal  The inferior orbital fissure  Exophthalmos & Proptosis  Aetiological basis of proptosis  Unilateral proptosis in adults  Unilateral proptosis in children  Bilateral proptosis  Measurement of proptosis:  History  Thyroid Eye Disease  Clinical features  soft tissue involvement  lid retraction  proptosis  restrictive myopathy  Optic neuropathy.  Investigations  Treatment  Infection  Preseptal cellulitis  Introduction  Diagnosis  Treatment  Orbital cellulitis  Introduction  Clinical features  Complications  Causes  Investigation 3 June 2019  37  Treatment  SCA  MCQ  Answer of MCQ  Basic concepts of Orbit The two orbits are two pyramidal-shaped bony cavities situated on either side of the nose or midline of face. The apex is represented by the optic foramen and the base by the orbital margins of the frontal and maxillary bones. The average volume of orbit is approximately 30 cc. The surfaces of each orbit (roof, floor, medial and lateral wall) are composed of seven bones: ethmoid, frontal, lacrimal, maxillary, palatine, sphenoid and zygomatic bones. The thinnest of these bones is the lamina papyracea over the ethmoid sinuses along the medial wall. Fig: 4.1. Bony orbit The roof consists of two bones: a) the lesser wing of the sphenoid and b) the orbital plate of the frontal bone. A defect in the orbital roof may cause pulsatile proptosis due to transmission of cerebrospinal fluid pulsation to the orbit. 3 June 2019  38 The lateral wall also consists of two bones: a) the greater wing of the sphenoid and b) the zygomatic. The floor consists of three bones: a) the zygomatic, b) maxillary and c) palatine. The posteromedial portion of the maxillary bone is relatively weak and may be involved in a ‘blowout’ fracture. The orbital floor also forms the roof of the maxillary sinus so that maxillary carcinoma invading the orbit may displace the globe upwards. The medial wall consists of four bones: a) maxillary, b) lacrimal, c) ethmoid and d) sphenoid. The lamina papyracea, which forms part of the medial wall, is paper-thin and perforated by numerous foramina for nerves and blood vessels. Orbital cellulitis is therefore frequently secondary to ethmoidal sinusitis.  The superior orbital fissure is a slit linking the cranium and the orbit, between the greater and lesser wings of the sphenoid bone; through it pass numerous important structures.  The superior portion contains the a) lacrimal, b) frontal and c) trochlear nerves, and d) the superior ophthalmic vein.  The inferior portion contains the a) superior and inferior divisions of the oculomotor nerve, b) the abducens and nasociliary nerves, and c) Sympathetic fibers from the cavernous plexus.  Inflammation of the superior orbital fissure and apex (Tolosa–Hunt syndrome) may therefore result in a multitude of signs including ophthalmoplegia and venous outflow obstruction.  Optic foramen and canal: Optic canal (5-10 mm long): It is located in the lesser wing of sphenoid. It transmits following structures:  Optic nerve and its meninges  Ophthalmic artery  Sympathetic nerves.  Optic foramen: It is the orbital end of optic canal. It measures 6 mm in diameter.  The inferior orbital fissure lies between the greater wing of the sphenoid and the maxilla, connecting the orbit to the pterygopalatine and infratemporal fossae. Through it run  the maxillary nerve, 3 June 2019  39  the zygomatic nerve and  branches of the pterygopalatine ganglion, as well as  the inferior ophthalmic vein. Fig: 4.2. Superior orbital fissure and optic foramen  Exophthalmos & Proptosis: Exophthalmos is defined in Dorland's Medical Dictionary as an "abnormal protrusion of the eyeball; also labeled as proptosis." Proptosis in the same reference is defined as exophthalmos. Another resource suggests that the terms exophthalmos and proptosis can be used to describe eyes appearing to bulge out of the face due to an increase in the volume of the tissue behind the eyes. Proptosis can describe any organ that is displaced forward, while exophthalmos refers to only the eyes. Proptosis can include any directional forward displacement Henderson reserves the use of the word exophthalmos for those cases of proptosis secondary to endocrinological dysfunction. Therefore, this dictum will be followed, and non–endocrine-mediated globe protrusion will be referred to as proptosis and exophthalmos will be reserved for protrusion secondary to endocrinopathies.  The etiological basis of proptosis can include: 1) Thyroid eye disease 2) Infections  Preseptal cellulitis  Bacterial orbital cellulitis  Rhino-orbital mucormycosis 3) Non-infective inflammatory disease  Idiopathic orbital inflammatory disease (IOID)  Orbital myositis  Acute dacryoadenitis  Tolosa–Hunt syndrome  Wegener granulomatosis 4) Non-neoplastic vascular abnormalities 3 June 2019  40  Cavernous sinus thrombosis  Carotid–cavernous fistula 5) Cystic lesions  Dacryops  Dermoid cyst  Sinus mucocoele  Encephalocoele 6) Vascular tumour  Varices  Lymphangioma  Capillary haemangioma  Cavernous haemangioma 7) Lacrimal gland tumour  Pleomorphic lacrimal gland adenoma  Lacrimal gland carcinoma 8) Neural tumour  Optic nerve glioma  Optic nerve sheath meningioma  Plexiform neurofibroma  Isolated neurofibroma 9) Lymphoma 10) Rhabdomyosarcoma 11) Metastatic tumour  Adult metastatic tumour  Childhood metastatic tumour  Orbital invasion from adjacent structures  Proptosis in adults unilateral is often due to an  Thyroid eye diseases  Orbital cellulitis  Idiopathic orbital inflammatory disease (IOID)  Cavernous sinus thrombosis  Carotid–cavernous fistula  Optic nerve sheath meningioma  Pleomorphic lacrimal gland adenoma  Lacrimal gland carcinoma  Optic nerve sheath meningioma  metastatic tumour (Note: The most common cause of unilateral proptosis in children is orbital cellulitis and in adult thyroid ophthalmopathy)  In children, unilateral proptosis is often due to an  orbital cellulitis 3 June 2019  41  rhabdomyosarcoma,  retinoblastoma,  capillary hemangioma,  dermoid cyst,  glioma of the optic nerve, and  metastatic disease.  Bilateral Proptosis  Developmental anomalies of the skull—Oxycephaly (tower skull).  Endocrine exophthalmos, both thyrotoxic and thyrotrophic.  Inflammatory lesions—Cavernous sinus thrombosis.  Tumours—lymphosarcoma, lymphoma, pseudotumor, etc.  Lipodystrophies—Xanthomatosis, diabetic exophthalmic dysostosis (Hand-Schüller- Christian Disease). (Note: The most common cause of bilateral proptosis in children is neuroblastoma and leukemia and in adult thyroid ophthalmopathy)  Measurement of proptosis: The proptosis can be measured with a plastic rule resting on the lateral orbital margin, or with the exophthalmometer using a similar principle. Commonly, a binocular exophthalmometer (e.g. Hertel) is employed, using visualization of the corneal apices to determine the degree of ocular protrusion from a scale. Readings greater than 20 mm are indicative of proptosis and a difference of 2–3 mm or more between the two eyes is suspicious regardless of the absolute values.  History A meticulous history of the patient's ocular and systemic systems is the key in establishing a diagnosis. The ophthalmic history should address the duration and the rate of onset of the proptosis. The patient should be queried about pain, change in visual acuity or refraction, diplopia, and decreased fields of vision. Transient visual loss or blackout periods may signify optic nerve compromise and may call for rapid intervention. Complaints of foreign body sensation or dry gritty eyes are symptoms that may indicate corneal decompensation. In performing a thorough medical history and a review of systems, the ophthalmologist should consider orbital involvement secondary to systemic pathology. Past trauma and family history also may aid in the diagnosis.  Thyroid eye disease (TED) Clinical features: TED typically proceeds through a congestive (inflammatory) stage in which the eyes are red and painful; this tends to remit within 1–3 years and only about 10% of patients develop serious long term ocular problems. A fibrotic (quiescent) stage follows in which the eyes are white, although a painless motility defect may be present. Clinical features broadly can be categorized into 1) soft tissue involvement, 2) lid retraction, 3 June 2019  42 3) proptosis, 4) restrictive myopathy 5) optic neuropathy. 1) Soft tissue involvement Symptoms. Grittiness, red eyes, lacrimation, photophobia, puffy lids and retrobulbar discomfort. Signs may include: a) Epibulbar hyperaemia. This is a sensitive sign of inflammatory activity. Intense focal hyperaemia may outline the insertions of the horizontal recti. b) Periorbital swelling is caused by oedema and infiltration behind the orbital septum; this may be associated with chemosis and prolapse of retroseptal fat into the eyelids c) Tear insufficiency and instability is common. 2) Lid retraction Retraction of upper and lower lids occurs in about 50% of patients with Graves’ disease. Symptoms. Patients may complain of a staring or bulging eyed appearance, difficulty closing the eyes and ocular surface symptoms. Signs a) The upper lid margin normally rests 2 mm below the limbus. Lid retraction is suspected when the margin is either level with or above the superior limbus, allowing sclera to be visible (‘sclera show’) b) The lower eyelid margin normally rests at the inferior limbus; retraction is suspected when sclera shows below the limbus. c) The Dalrymple sign is lid retraction in primary gaze (Fig. 3.8B). d) The Kocher sign describes a staring and frightened appearance of the eyes which is particularly marked on attentive fixation (Fig. 3.8C). e) The von Graefe sign signifies retarded descent of the upper lid on downgaze (lid lag – Fig. 3.8D 3) Proptosis, Symptoms are similar to those of lid retraction. Signs. Proptosis is axial, unilateral or bilateral, symmetrical (Fig. 3.9A) or asymmetrical (Fig. 3.9B), and frequently permanent. Severe proptosis may compromise lid closure and along with lid retraction and tear dysfunction can lead to exposure keratopathy, corneal ulceration and infection 4) Restrictive myopathy: Between 30% and 50% of patients with TED develop ophthalmoplegia and this may be permanent. Ocular motility is restricted initially by inflammatory oedema, and later by fibrosis.  Symptoms. Double vision, and often discomfort in some positions of gaze.  Signs, in approximate order of frequency: 3 June 2019  43 Elevation defect (Fig. 3.10A) caused by fibrotic contracture of the inferior rectus, may mimic superior rectus palsy and is the most common motility deficit. Abduction defect due to fibrosis of the medial rectus, which may simulate sixth nerve palsy. Depression defect (Fig. 3.10B) secondary to fibrosis of the superior rectus. Adduction defect caused by fibrosis of the lateral rectus. 5) Optic neuropathy: Optic neuropathy is a fairly common (up to 6%) serious complication caused by compression of the optic nerve or its blood supply at the orbital apex by the congested and enlarged recti (Fig. 3.11) and swollen orbital tissue. Such compression, which may occur in the absence of significant proptosis, may lead to severe visual impairment if adequate and timely treatment is not instituted. Investigation Investigations other than blood tests for thyroid disease are not necessary if the diagnosis is evident clinically, but the exclusion of other conditions is sometimes indicated.  Treatment: Treatment can be classified into that of mild disease (most patients), moderate to severe active disease, and treatment of post- inflammatory complications. The first measure taken in all cases should be the cessation of smoking. Thyroid dysfunction should also be managed adequately; if radioiodine treatment is administered in patients with pre-existing TED, a short course of oral steroids should be given in concert.  Infections: Preseptal cellulitis Introduction Preseptal cellulitis is an infection of the subcutaneous tissues anterior to the orbital septum. It is considerably more common than orbital cellulitis. Organisms typically responsible are Staphylococcus aureus and Streptococcus pyogenes, with causes including skin trauma such as laceration or insect bites, spread from focal ocular or periocular infection such as an acute hordeolum, dacryocystitis, conjunctivitis or sinusitis, and hematogenous spread from remote infection such as the upper respiratory tract or middle ear. Diagnosis: The condition manifests with a swollen, often firm, tender red eyelid that may be very severe. The patient is often pyrexial. In contrast to orbital cellulitis, proptosis and chemosis are absent, and visual acuity, pupillary reactions and ocular motility are unimpaired.  Treatment: Treatment is with oral antibiotics such as co-amoxiclav 250–500 mg/125 mg 2–3 times daily or 875/125 mg twice daily, depending on severity. Severe infection may require intravenous antibiotics. The patient’s tetanus status should be ascertained in cases following trauma. 3 June 2019  44  Orbital cellulitis: Orbital cellulitis is inflammation of eye tissues behind the orbital septum. It is most commonly caused by an acute spread of infection into the eye socket from either the adjacent sinuses or through the blood. It may also occur after trauma. When it affects the back of the eye, it is known as retro-orbital cellulitis It should not be confused with periorbital cellulitis which refers to cellulitis anterior to the septum. Without proper treatment, orbital cellulitis may lead to serious consequences, including permanent loss of vision or even death.  Clinical features  Symptoms consist of the rapid onset of pain exacerbated by eye movement, swelling of the eye, malaise, and frequently visual impairment and double vision. There is commonly a recent history of nasal, sinus or respiratory symptoms.  Signs: Pyrexia often marked. VA may be reduced and colour vision impaired. Tender, firm, erythematous and warm eyelids, with periocular and conjunctival (chemosis) oedema, conjunctival injection and sometimes Subconjunctival haemorrhage; the signs are usually unilateral, though oedema may spread to the contralateral eyelids. Proptosis is common in established infection, but is often obscured by lid swelling; it may be non-axial (dystopia), particularly if an abscess is present. Painful ophthalmoplegia Choroidal folds and optic disc swelling may be present on fundus examination.  Complications: Ocular complications include optic neuropathy, exposure keratopathy, raised IOP, endophthalmitis and occlusion of the central retinal artery or vein. Subperiosteal abscess most frequently located along the medial orbital wall. Intracranial complications, which are uncommon (3–4%) but extremely serious, include meningitis, brain abscess and cavernous sinus thrombosis.  Causes:  Gram-positive stain, possibly showing staphylococcus aureus, which is one of the primary causes of orbital cellulitis.  Orbital cellulitis occurs commonly from bacterial infection spread via the paranasal sinuses usually from a previous sinus infection.  Other ways in which orbital cellulitis may occur are from blood stream infections or from eyelid skin infections.  Upper respiratory infection,  sinus infection,  trauma to the eye, ocular or periocular infection, and  systemic infection all increases one's risk of orbital cellulitis. Following organisms are the most common causes:  Staphylococcus aureus  Haemophilus influenza B, 3 June 2019  45  Moraxella catarrhalis,  Streptococcus pneumoniae  and beta-hemolytic streptococci are bacteria that can be responsible for orbital cellulitis.  Investigation: Investigations may include:  Complete blood count (CBC)  Blood cultures.  Culture of nasal discharge.  High-resolution CT of the orbit, sinuses and brain is vital to subperiosteal or intracranial abscess.  MRI is also sometimes performed.  Lumbar puncture if meningeal or cerebral signs develop.  Treatment  Hospital admission is mandatory, with urgent otolaryngological assessment and frequent ophthalmic review. Paediatric specialist advice should be sought in the management of a child.  Antibiotics are given intravenously, with the specific drug depending on local sensitivities; ceftazidime is a typical choice, supplemented by oral metronidazole to cover anaerobes. Intravenous antibiotics should be continued until the patient has been apyrexial for 4 days, followed by 1–3 weeks of oral treatment.  Surgery. Drainage of an orbital abscess should be considered at an early stage; drainage of infected sinuses should be considered if there is a lack of response to antibiotics, or if there is very severe sinus disease. Biopsy of inflammatory tissue may be performed for an atypical clinical picture. Severe optic nerve compression may warrant an emergency canthotomy / cantholysis  Thrombosis of cavernous sinus: It is due to the extension of thrombosis from various sources which communicate with the cavernous sinus.  Anatomy of Communication of Cavernous Sinus: It is of great clinical importance as infection may travel from face, lips orbit, mouth, pharynx, ear, nose, accessory sinuses or as a metastasis in infectious diseases or septicaemia. 3 June 2019  46 Fig: 4.3. Communications of cavernous sinus—lateral view  The superior and inferior ophthalmic veins enter the sinus anteriorly.  The superior and inferior petrosal sinus leave the sinus posteriorly.  It communicates directly and indirectly with the pterygoid plexus, cerebrum and middle ear. Therefore the swelling behind the ear is diagnostic of cavernous sinus thrombosis.  The sinus of one side communicates with the other by two or three transverse sinuses which surround the pituitary body.  Symptoms:  They are same as for orbital cellulitis.  There is severe supraorbital pain due to involvement of ophthalmic division of the 5th nerve which is situated on the lateral side of cavernous sinus.  High-grade fever, rigor and vomiting are present usually.  Signs:  Oedema over the mastoid process of the temporal bone of the affected side, i.e. behind the ear is the most important early diagnostic sign.  Transference of symptoms to opposite eye in 50% cases is seen. Paralysis of opposite lateral rectus muscle is suspicious of bilateral involvement.  Paralysis of extraocular muscles may be present.  Corneal anesthesia and dilated pupil are seen in later stages due to involvement of 5th nerve.  Proptosis occurs in almost all cases but is of late onset.  Fundus examination  Retinal veins are dilated and engorged  There may be pronounced papillitis  Papilloedema may be present.  Complication Meningitis and cerebral abscess may occur which may lead to death.  Treatment  Modern potent third generation broad-spectrum antibiotic should be started immediately by intravenous route in massive doses.  Anticoagulant therapy may be helpful in dissolving the clot. 3 June 2019  47 SCA: 1 a) Name the bones which take parts in the formation of bony orbit 1.5 b) Which structures pass the superior orbital fissure 2.0 SCA: 2 a) What is proptosis? 1.0 b) What are causes of unilateral and bilateral proptosis in adult? 2.5 SCA: 3 a) What is orbital cellulitis? 0.5 b) What are the clinical features? 1.5 c) Treatment of orbital cellulitis 1.5 SCA: 4 A lady of 50-year came to you with bilateral proptosis. She is smoker also. a) What may be the diagnosis? 1.0 b) What are the risk factors of this disease? 1.0 c) What are the ocular features you may get? 1.5 SCA: 5 a) What is preseptal cellulitis? 0.5 b) What are the organisms responsible for preseptal cellulitis? 1.0 c) How will you manage it? 2.0 SCA: 6 a) What is orbital cellulitis? 0.5 b) What are the clinical features? 1.5 c) What may be the complications? 1.0  Write short notes on: a) Orbit b) Medial wall of the orbit c) Floor of the orbit d) Proptosis e) Exophthalmos f) Superior orbital fissure g) Inferior orbital fissure h) Preseptal cellulitis i) Orbital cellulitis j) Thyroid eye disease (TED) MCQ: 1  The orbit is formed by the following bones: a) palatine b) ethmoid and c) lacrimal bone d) nasal bone e) occipital bone MCQ: 2  Followings ate the characteristic of bony orbit: a) it is a pear-shaped cavity, 3 June 2019  48 b) the stalk of which is the optic canal c) it has 3 walls d) the bony orbit is formed by 9 bones e) orbit communicates with middle cranial fossa through optic canal MCQ: 3  Superior orbital fissure – transmits the following structures: a) lacrimal nerve b) frontal nerve c) optic nerve d) inferior ophthalmic vein e) infratrochlear nerve MCQ: 4  Roof of orbit is formed by a. orbital plate of frontal bone b. greater wing of sphenoid bone c. palatine bone d. lesser wing of sphenoid bone e. zygomatic bone MCQ: 5  Causes of hyphaema are a. ametropia b. trauma c. hypertension d. allergic conjunctivitis e. blood dyscrasias. MCQ: 6  Following are the avascular tissue of the eye a) lens b) trabecular Meshwork c) iris d) ciliary body e) vitreous MCQ: 7  The floor consists of following bones: a) the zygomatic, b) lacrimal bone c) maxillary and d) ethmoid bone e) palatine. MCQ: 8 Clinical features of orbital cellulitis are: a) dimness of vision b) normal pupillary light reaction c) proptosis d) painful ophthalmoplegia 3 June 2019  49 e) deep anterior chamber  Answer of MCQ 1) T. T. T. F. F 2) T. T. F. F. T. 3) T, T, F, F, F. 4) T. F. F. T. F 5) F. T. F. F. T 6) T, T, F, F, T. 7) T. F. T. F. T. 8) T. F. T. T. F. Chapter: 5. Dry Eye  Introduction  Definitions  Physiology  Precorneal tear film:  Lipid layer  Aqueous layer  Mucin layer  Classification of dry eye:  Aqueous-deficient Sjögren syndrome dry eye (primary or secondary). Non-Sjögren syndrome dry eye.  Evaporative  Clinical features of the dry eye  Investigation of dry eye  Treatment of dry eye  Introduction  Definitions 3 June 2019  50 Dry eye occurs when there is inadequate tear volume or function, resulting in an unstable tear film and ocular surface disease. It is an extremely common condition, particularly in postmenopausal women and the elderly.  Keratoconjunctivitis sicca (KCS) refers to any eye with some degree of dryness.  Xerophthalmia describes a dry eye associated with vitamin A deficiency.  Xerosis refers to the extreme ocular dryness and keratinization that occurs in eyes with severe conjunctival cicatrization.  Sjögren syndrome is an autoimmune inflammatory disease of which dry eyes is a feature.  Physiology Function of tear film in general 1) It maintains the health of the ocular surface by providing the moist environment essential for the corneal and conjunctival epithelial cells. 2) It preserves clear vision by filling in irregularities in the corneal surface, assuring a smooth surface for light refraction. 3) It is the primary source of nutrition, waste removal and antibacterial action. It supplies oxygen and nutrients to the avascular cornea and provides a pathway for the removal of metabolic products of corneal and conjunctival cells. 4) It keeps cell membranes moist, preventing breakdown of epithelial cells by lubricating the eyelids during blinking. 5) It is the first line of defense against microbial infection, containing antibacterial substances and antibodies that protect the corneal surface. 6) It ensures comfort. The constituents are complex, with as many as a hundred distinct proteins identified.  Spread of the tear film The tear film is mechanically distributed over the ocular surface through a neuronal controlled blinking mechanism. Three factors are required for effective resurfacing of the tear film: Normal blink reflex. Contact between the external ocular surface and the eyelids. Normal corneal epithelium. The precorneal tear film has three layers. From outer to inner they are: a) Lipid layer b) Aqueous layer c) Mucin layer 3 June 2019  51 Fig: 5.1. The precorneal tear film  Lipid layer Secretion; This layer is secreted by glands of eyelids, meibomian gland, gland of Zeis and gland of moll. Functions To prevent evaporation of the aqueous layer and maintain tear film thickness. To act as a surfactant allowing spread of the tear film. Deficiency results in evaporative dry eye.  Aqueous layer Secretion The main lacrimal glands produce about 95% of the aqueous component of tears and the accessory lacrimal glands of Krause and Wolfring produce the remainder. Functions To provide atmospheric oxygen to the corneal epithelium. Antibacterial activity due to proteins such as IgA, lysozyme and lactoferrin. To wash away debris and noxious stimuli and facilitate the transport of leukocytes after injury. To optically enhance the corneal surface by abolishing minute irregularities.  Mucous layer Secretion They are produced mainly by conjunctival goblet cells but also by the lacrimal glands. Functions To permit wetting by converting the corneal epithelium from a hydrophobic to a hydrophilic surface. Lubrication.  Classification of dry eye: 3 June 2019  52  Aqueous-deficient Sjögren syndrome dry eye (primary or secondary). Non-Sjögren syndrome dry eye.  Evaporative Intrinsic Meibomian gland deficiency, e.g. posterior blepharitis, rosacea. Drug action, e.g. antihistamines, beta-blockers, antispasmodics, diuretics. Extrinsic Vitamin A deficiency.  Keratoconjunctivitis Sicca (Sjögren’s Syndrome)  It is an autoimmune disease which results in the fibrosis of the lacrimal glands.  It occurs in women after menopause usually female to male ratio of 9:1.  It is often associated with rheumatoid arthritis and presence of antinuclear antibody.  Clinical features of the dry eye: Symptoms i.Feeling of dryness ii.Irritation iii. Foreign body sensation iv. Burning v. Thread-like mucus discharge vi. Itching vii. Photophobia viii. Pain if keratitis is there Signs Mucus stands and debris: Normally these mucus and debris are washed away by the lacrimal fluids but in dry eye they accumulate in tear film and moves away with the blinking of the eye. Marginal tear meniscus: Normally the meniscus is about 0.1 to 0.5 mm broad and forms a convex band along the lid margin. In dry eye, this meniscus is thin, concave and irregular. Keratopathy is characterized by: Punctate epithelium erosion of the cornea which is best seen with slit lamp biomicroscopy.  Investigation: The aim of investigation is to confirm and quantify a clinical diagnosis of dry eye. The reliability of tests improves as the severity of dry eye increases. The tests measure the following parameters: Stability of the tear film as related to its break-up time (BUT). Tear production (Schirmer, fluorescein clearance and tear osmolarity). Ocular surface disease (corneal stains and impression cytology). There is no clinical test to confirm the diagnosis of evaporative dry eye. It is therefore a presumptive diagnosis based on the presence of associated clinical findings. It is suggested the tests are performed in the following order because the Schirmer strip paper can damage the ocular surface and cause staining. 3 June 2019  53  Tear film break-up time The tear film BUT is abnormal in aqueous tear deficiency and meibomian gland disorders. It is measured as follows: Fluorescein 2% or an impregnated fluorescein strip moistened with non-preserved saline is instilled into the lower fornix. The patient is asked to blink several times. The tear film is examined at the slit lamp with a broad beam using the cobalt blue filter. After an interval, black spots or lines appear in the fluorescein-stained film (Fig. 4.8A), indicating the formation of dry areas. The BUT is the interval between the last blink and the appearance of the first randomly distributed dry spot. A BUT of less than 10 seconds is suspicious. The development of dry spots always in the same location may indicate a local corneal surface abnormality (e.g. epithelial basement membrane disease) rather than an intrinsic instability of the tear film.  Schirmer test The Schirmer test is a useful assessment of aqueous tear production. The test involves measuring the amount of wetting of a special (no. 41 Whatman) filter paper, 5 mm wide and 35 mm long. The test can be performed with or without topical anaesthesia. In theory, when performed with an anaesthetic (Schirmer 2) basic secretion is measured and without anaesthetic (Schirmer 1) it measures maximum basic plus reflex secretion. In practice, however, topical anaesthesia cannot abolish all sensory and psychological stimuli for reflex secretion. The test is performed as follows: Excess tears are delicately dried. If topical anaesthesia is applied the excess should be removed from the inferior fornix with filter paper. The filter paper is folded 5 mm from one end and inserted at the junction of the middle and outer third of the lower lid, taking care not to touch the cornea or lashes. The patient is asked to keep the eyes gently closed. After 5 minutes the filter paper is removed and the amount of wetting from the fold measured. Less than 10 mm of wetting after 5 minutes without anaesthesia or less than 6 mm with anaesthesia is considered abnormal. Results can be variable and a single Schirmer test should not be used as the sole criterion for diagnosing dry eye, but repeatedly abnormal tests are highly supportive.  Treatment Treatment of dry eye can be divided by 3 groups a) Life style modification and adjustment with environment b) Medical therapy c) Surgery: Reserve for severe condition  Life style modification and adjustment with environment  Establishment of realistic expectations and emphasis on the importance of compliance. 3 June 2019  54  Lifestyle review including the importance of blinking whilst reading, watching television or using a computer screen (which should be orientated below eye level to minimize palpebral aperture size), and the management of contact lens wear.  Environmental review, e.g. increasing humidity may be possible for some environments.  Omega fatty acid supplements (e.g. omega-3 fish oil, flax seed oil) can have a dramatic effect on symptoms and may facilitate the reduction of topical medication.  Medical therapy  Artificial tear drop: Doses of the eye drop depends upon the severity of the dryness. It is better to use preservative free eye drop (but the availability and price of preservative free eye drop is a concern)  Artificial tear substitutes including gels and ointments at night or even at day time in case of severe dry eye.  Topical steroids, generally low-intensity preparations such as fluromethalone, are effective supplementary treatment for acute exacerbations. The risks of longer-term treatment must be balanced against the potential benefits in each case.  Topical cyclosporine (usually 0.05%) reduces T-cell mediated inflammation of lacrimal tissue, resulting in an increase in the number of goblet cells and reversal of squamous metaplasia of the conjunctiva.  Oral Tetracyclines for an extended course, often 3 months at a relatively low dose, may control associated blepharitis, especially meibomianitis, and reduce tear levels of inflammatory mediators. Doxycycline may be preferred to minocycline on the grounds of adverse effect profile.  Systemic medication review to exclude contributory effects and eliminate offending agents. Discontinuation of toxic/ preserved topical medication if possible.  Surgical therapy:  Punctal occlusion: Temporary and permanent  Computer Ergonomics for healthy vision: It seems nearly everyone in this digital world is spending a lot of time in front of a computer, which can strain the eyes as well as other parts of the body. And anyone who uses a computer for prolonged periods —whether on the job, at school or at home for enjoyment — is at risk for headaches, burning eyes, a stiff neck and other symptoms that comprise computer vision syndrome (CVS). Prolonged computer work also can cause physical stress that eventually could lead to a disability. Here's the good news: You can reduce computer-related discomfort by becoming more aware of your body during computer work and adjusting your work station and viewing habits to avoid these problems. The key is something called computer ergonomics.  What Is "Computer Ergonomics"? Ergonomics is the science of designing a job, equipment and/or workplace to fit the worker. The goal is to optimize the "fit" between each worker and his or her work environment to optimize performance and reduce the risk of repetitive strain injuries. 3 June 2019  55 Computer ergonomics addresses ways to optimize your computer workstation to reduce the specific risks of computer vision syndrome (CVS), neck and back pain, carpal tunnel syndrome and other disorders affecting the muscles, spine and joints. Some experts in this field also use the term "visual ergonomics" when talking about designing a computer workstation with the goal of preventing CVS.  Computer and Visual Ergonomics: Tips  You don't need an expensive consultant to create a computer workstation that reduces your risk of stress, discomfort and potential injury.  With better posture, this computer worker might avoid neck and back strain. Here are some of the top computer ergonomics tips recommended by the U.S. Department of Labor's Occupational Safety & Health Administration (OSHA). These tips are designed to reduce the risk of stress, physical injury and computer eye strain from prolonged computer use.  Sit so your head and neck are upright and in-line with your torso, not bent down or tilted back.  Face your computer screen directly. Avoid viewing your screen with your head turned or back twisted.  Keep your elbows comfortably close to your body.  Use a chair that provides support for your lower back and has a cushioned seat with a contoured front edge.  Keep your mouse close to your keyboard so you don't have to reach for it.  Position your computer display so the top of the screen is at or slightly below eye level. This will allow you to view the screen without bending your neck.  Adjust the position of your display to prevent reflections of overhead and outdoor lighting appearing on your screen.  Put your monitor close enough to your eyes so you can comfortably read text on the screen without leaning forward.  When working with print documents, use a document holder that positions them at the same height and distance as your co