Conjunctiva PDF

Conjunctiva General - May be unilateral or bilateral. - Highly contagious, ask in Hx about recent URTI or contact - Conjunctiva is a thin, transparent mu...

Conjunctiva General - May be unilateral or bilateral. - Highly contagious, ask in Hx about recent URTI or contact - Conjunctiva is a thin, transparent mucous membrane. with people with red eyes. - Lines the inside of the eyelids and covers the sclera. - Characterized commonly by an acute follicular conjunctival - Composed of rare stratified columnar epithelium. reaction and preauricular adenopathy. ➔ Follicles are raised, gelatinous, oval lesions about 1mm - Divided into 3 parts: in diameter. ➔ Palpebral/tarsal: lines the eyelids. ➔ Found usually in the lower tarsal conjunctiva and upper ➔ Bulbar: covers the eyeball, over the sclera. tarsal border and occasionally at the limbus. ➔ Fornix: forms the junction between the ➔ Each follicle represents a lymphoid collection with its bulbar and palpebral conjunctivas. own germinal center. ➔ Unlike papillae, the causes of follicles are more specific - Layers: (e.g. viral and chlamydial infections). ➔ Epithelium: non-keratinizing, five cell layers deep. - Usually benign and self-limited but tends to follow a longer ➔ Stroma (substantia propria): consists of course than bacterial lasting for approximately 2-4 weeks. richly vascularized loose connective tissue. - Steroids can be used to reduce inflammation. ➔ Conjunctiva-associated lymphoid tissue (CALT): is critical in the initiation and regulation of ocular surface immune - Signs & symptoms: responses. ➔ Ocular itching & foreign body sensation. ➔ Tearing, redness, discharge. - Function: ➔ Lid oedema, photophobia. ➔ Helps lubricate the eye by producing mucous and tears. ➔ No loss of vision. ➔ Contributes to immune surveillance. ➔ Bilateral involvement with the second eye is less severely affected. ➔ Prevents the entrance of microbes into the eye. - Distinguished from bacterial conjunctivitis by: Viral Conjunctivitis ➔ A watery and limited purulent discharge. - Viruses are a common cause of conjunctivitis ➔ Presence of follicles. in patients of all ages. ➔ Enlarged preauricular lymph nodes. - Adenovirus is the MC. - HSV is the most problematic.  Conjunctiva Bacterial Conjunctivitis ➔ Encouraged by poor hygiene and overcrowding in a dry, hot climate. ➔ The housefly acts as a vector. - Acute bacterial conjunctivitis: ➔ The hallmark of the disease is subconjunctival fibrosis ➔ Commonly caused by: caused by frequent re-infection associated with the  Staphylococci, streptococci. unhygienic conditions.  Chlamydia organism. ➔ Blindness may occur due to corneal scarring from  Gonocci: most severe. recurrent keratitis and trichiasis. ▪ Causes corneal ulcer and blindness. ➔ Can cause eyelid deformities. ▪ Can cause lymphadenopathy ➔ Rx: oral or topical tetracycline or erythromycin. (more with viral). ➔ Entropion and trichiasis require surgical correction. ➔ Signs & symptoms: - Neonatal conjunctivitis (Ophthalmia Neonatorum):  Redness of the eyes. ➔ Refers to any conjunctivitis that occurs in the first 28  Discharge (purulent white yellow). days of neonatal life.  Ocular irritation. ➔ Commonly occurs due to maternal vaginal infection. ➔ Infants may acquire these infective agents as they pass ➔ Treatment: through the birth canal during the birth process.  Usually self-limiting 10-14 days, although a broad ➔ Chlamydia is the MC infectious agent. spectrum antibiotic eye drops (tobramycin) 1-3 days ➔ Others: gonococci. will resolve the condition.  Severe purulent discharge and eyelid edema.  Mild conjunctivitis is usually benign, self-limited and  Confirmed with Gram stain and culture. can be easily treated with antibiotics. ➔ Prevented by prophylactic erythromycin drop. ➔ Severe conjunctivitis such as that caused by gonococci, - Inclusion keratoconjunctivitis: can cause blindness and can signify a severe underlying ➔ Caused by Chlamydia trachomatis. systemic disease. ➔ An STD. ➔ Conjunctival swabs for culture are indicated if the ➔ Presents with mucopurulent follicular conjunctivitis and condition fails to resolve. develop micropannus with subepithelium scarring. ➔ Diagnosis is confirmed by: - Trachoma:  Detection of chlamydial antigens by immunofluorescence. ➔ Caused by Chlamydia trachomatis.  Identification of typical inclusion bodies by Giemsa ➔ The MC preventable infective cause of blindness in the staining conjunctival swab or scrape specimens. world although it’s uncommon in developed countries. ➔ Treated by topical and systemic tetracycline.  Conjunctiva Allergic Conjunctivitis ▪ Infiltrate, giant papillae, found in allergic eye disease, are formed by the coalescence of papillae. - Acute (hay fever conjunctivitis): ➔ Acute IgE-mediated reaction to airborne ➔ Treatment: allergen usually pollens.  Initial therapy is with antihistamines and mast cell stabilizers. ➔ Signs & symptoms:  Topical steroids are required in severe cases, but long-  Itching, lacrimation. term use is avoided if possible because of the  Conjunctival injection and swelling (chemosis). possibility of steroid induced glaucoma or cataract.  No pain. ➔ Giant papillary conjunctivitis:  Contact lens wearer may develop an allergic - Chronic (vernal conjunctivitis/spring catarrh): reaction to the lens or to lens cleaning material. ➔ IgE mediated.  Present with mucoid discharge on the upper tarsal ➔ Affects boys with atopy Hx. plate. ➔ Not triggered by a specific antigen.  Treatment: stop lens use permanently, topical mast cell stabilizers. ➔ Signs & symptoms:  Some patients are unable to continue contact lens  Itching, lacrimation, photophobia. wear due to recurrence of the symptoms.  Papillary conjunctivitis on the upper tarsal plate, papilla may coalesce to form Giant (cobblestone). ➔ Keratoconus, shield like corneal ulcer can develop as a complication.  Limbal follicles and white spots. ➔ Can be associated with progressive myopia and astigmatism.  Punctate lesions on the corneal epithelium.  An opaque, oval plaque which in severe disease Palpebral Vernal Limbal Vernal Conjunctivitis Conjunctivitis replaces an upper zone of the corneal epithelium.  Papilla: ▪ Raised lesions on the upper tarsal conjunctiva. ▪ 1 mm in diameter with a central vascular core. ▪ Cobblestone appearance. ▪ Non-specific signs of chronic inflammation. ▪ Result from fibrous septa between the conjunctiva and sub conjunctiva which allow only the intervening papillae tissue to swell with inflammatory.  Conjunctiva Conjunctival Degeneration Band Keratopathy - RFs: excessive exposure to UV light, ageing. - Subepithelial deposition of calcium phosphate in the exposed part of the cornea. - Pinguecula: - Seen in chronic uveitis and glaucoma. ➔ Common benign asymmptomatic degeneration of the - May cause visual loss or discomfort if epithelial collagen fibers of conjunctival stroma. erosion form over the band. ➔ Small yellow white nodule usually near the limbus - If symptomatic: nasally. ➔ Scraped off surgically. ➔ No treatment required, only if inflamed use mild topical ➔ Aided by chelating agent (sodium adetate) & excimer steroids. laser (ablating affected surface). ➔ Can become pterygium if reaches the cornea. - Can also be a sign of systemic hypercalcemia. - Pterygium: Foreign Body ➔ A triangular wing shaped continuous growth of the - MC cause is spark metal. degenerative conjunctival tissue over the limbus toward - Treatment: the cornea. ➔ Must be removed + evert eyelids. ➔ Apex is toward from limbus. ➔ Antibiotics. ➔ Causes astigmatism. ➔ Treat as corneal abrasion. ➔ Treatment: by surgery if threatens visual axis, usually for ➔ CT scan if hx suggests a foreign body in posterior segment of the eye. cosmetic reasons. ➔ Recurrence:  Common. Tumors  To prevent it: myocytin C, amniotic membrane, graft. - Rare. - Squamous cell CA: ➔ Irregular raised area of conjunctiva. ➔ May invade deeper tissue. - Melanoma: ➔ The differential diagnosis from benign pigmented lesions (for example a naevus) may be difficult. ➔ Review is necessary to assess whether the lesion is increasing in size. - Biopsy, to achieve a definitive diagnosis, may be required.