Dentistry Ophthalmology Lecture 2022 Final PDF

 Link to the lecture https://drive.google.com/file/d/10SOKpz80R6XClQFtHjoLGfC1fpcd7zRE/ view?usp=drivesdk ANATOMY OF THE EYE BALL IHAB OSMAN PROF. OF OPHTHALMOLOGY ALEXANDRIA UNIVERSITY  COATINGS OF THE EYE BALL  Outer coat( cornea- sclera)  Middle coat( iris- ciliary...

 Link to the lecture https://drive.google.com/file/d/10SOKpz80R6XClQFtHjoLGfC1fpcd7zRE/ view?usp=drivesdk ANATOMY OF THE EYE BALL IHAB OSMAN PROF. OF OPHTHALMOLOGY ALEXANDRIA UNIVERSITY  COATINGS OF THE EYE BALL  Outer coat( cornea- sclera)  Middle coat( iris- ciliary body- choroid)  Inner coat (retina) Outer coat Cornea  Transparent  Avascular  11mm  0.5-0.6 mms  Highly sensitive  Ant. 1/6 of the eye  Main refractive medium Sclera  Post5/6 of the eye  1mm thick  Opaque white Middle coat  Iris  Colored part (what is the normal color)  Contains: 1. Pigment 2. Muscles( sphincter –dilator pupillae) 3. Vascular stroma  Function :Diaphragm (how?)  Nerve supply(sympath.- parasympath.)  Ciliary body  Two parts: 1. Smooth post. part 2. Ciliated ant. Part  Contains: 1. Muscles 2. Pigment 3. Vascular stroma  Function: 1. Formation of aqueous 2. Accomodation  Nerve supply (parasympath.)  Choroid  Contains: 1. Pigment 2. Vascular stroma  Function : 1. absorb light 2. nutrition Inner layer  Retina  Receptors: 1. Cones (fewer in number- color and details) 2. Rods( more in numb.- motion and light perception )  Layers (10) outer most receptors inner most nerve fiber  Important areas: 1. Optic disc( no receptors- blind spot) 2. macula Optic nerve  2nd cranial nerve  Leaves orbit via optic foramen  Formed of nerve fiber layer  Protective coatings(D-P-A)  Pathway of visual impulse: Retina-optic nerve- optic chiasma-optic tract- visual centers Contents of the eye ball 1. Aquous humor 2. Lens 3. Vitreous body 4. Angle of anterior chamber 5. Optic nerve Aqueous humor  Formation  Circulation  Function ( nutrition- IOP) Hypopyon Hyphyma Lens  Transparent biconvex structure  Formed of (capsule- cortex- nucleus)  Suspended by zonules  Function: 1. refractive media 2. accomodation Vitreous body  Jelly like- clear –avascular  Fills the globe Refractive media of the eye  Cornea  Aqueous humor  Lens  Vitreous Protective mechanisms of the eyeball  Conjunctiva  Eye lids  Lacrimal apparatus  Orbit Examination of the eye  Clinical examination:  v/a  Lids- conjunctiva-cornea( fl. Stain)-sclera- ac-iris- lens-pupil- tension( 12-20)- muscles- lacrimal  Instrumental examination:  Slit lamp  Ophthalmoscope( direct and indirect)  Errors of refraction( retinoscopy- autorefractometer)  Field of vision( perimeter)  Colour vision testing  IOP ( tonometer)  Bacteriological swab  Retina ex. ( fl. Angio and OCT)  Cornea exam ( topography and pachymetry) Lids Muscles : action AND nerve supply Blood supply : 1. Artery: ophthalmic 2. Vein: ophthalmic to cavernous sinus Pterygoid plexus part to ant facial vein Lymphatic drainage: upper and lateral to….. lower and medial to…….. Lacrimal system Secretory part Excretory part: p, c, s, n Epiphora : excess watering of the eye Orbit Openings in the orbit: Sup. Orbital fissure ( contents III,IV,V,VI and ophth. vein) Inf. Orbital fissure ( contents maxillary nerve and venules) Optic foramen( content)( OPTIC N. AND OPHTH. ART) Opening of the nasolacrimal canal Walls Roof : lacrimal gland and relation to ant cranial fossa , sloping Lateral wall: longest , related to temp fossa ant and to the middle cranial fossa post Medial wall: shortest , related to ethmoid air cells ant and sphenoid sinus post, fossa for lacrimal sac Inferior wall : horizontal and related to maxillary sinus Contents of the orbit Eyeball Extraocular muscles Nerves and vessels Fat and fascia Extraocular muscles 1. 4 recti ( sup. , inf., med., lat.) 2. Two oblique( sup., inf.) Origin and insertion Nerve supply  Squint Def: Is the condition in which the 2 visual axes are not parallel when looking ahead or in any direction of gaze  Types 1. Paralytic squint: Direction of deviation Loss of Movement Complaining of nausea and vomiting and diplopia 2. Concomitant squint:  Angle is fixed, children with refractive error  Amblyopia Treatment of squint  Surgical strengthening of the weak muscle by resection  Surgical weakening of the strong muscle by recession  Muscle transposition  Conjunctiva Parts: palpebral and bulbar ,canthi, fornices   Diseases of cornea Fungal keratitis usually of plant trauma Acanthamoebic Keratitis usually contact lens wearer or swimming pool infection Infective Keratitis Topical Anti-infective: Antibiotic , antifungal , antiviral and antiacanthameobic Tumors Retinoblastoma : Malignant T. of retina Age 2-3 y Presentation : leucocoria Treatment : enucleation or radiotherapy, laser therapy, cryo therapy Tumors Malignant melanoma: Malignant T. of the choroid Age 40 y Dissemination mainly blood to liver Treatment excision Cataract Definition : development of opacity in the lens Etiology: Congenital ( rubella) Complicated ( secondary to RD or inflammation) Traumatic Senile ( most common) Clinical picture: diminution of vision Treatment : Surgical removal Sutureless surgery( phaco and IOL implantation) ( femto cataract) Glaucoma Definition : increase of intraocular pressure more than normal( 10-21mm hg) with visual field and optic nerve affection. Types of Glaucoma 1. Primary glaucoma : A)Congenital B)Adult: -Acute ( ACG) -Chronic(OAG) 2. Secondary glaucoma ( inflammation – lens )  Clinical picture : Congenital glaucoma : eye is big and bluish tinge sclera , cornea hazy ACAG: acute pain , n, v, headache, coloured halos , drop of vision, eye is tender , red hazy cornea OAG: fairly painless with drop in field of vision Treatment : Medical : miotics ( pilocarpine ED) beta blockers carbonic anhydrase inhibitors Intravenous manitol prostaglandin analouges Surgical : trabeculectomy – shunt surgical devices Laser trabeculoplasty Emergency treatment of an attack of CAG by hospitalization and sedation followed by YAG LASER iridotomy Retinal detachment Definition : separation of retina from choroid More in myopes Blunt trauma may predispose Clinical picture: Flashes- floaters- diminution of vision- field loss treatment: Surgery to reposit the retina.( buckle or vitrectomy) Laser around retinal tears  Errors of refraction myopia( short Definitionsightedness) : parallel rays from a distant object focus infront of retina. Corrected by concave lenses  Errors of refraction hypermetropia( far sightedness) Definition : parallel rays from a distant object focus behind the retina. Corrected by convex lenses  Errors of refraction Astigmatism Images are not distinctly focused on retina due to different refractive power of the corneal planes eg horizontal and vertical planes. Corrected by cylindrical lenses  presbyopia Is not a refractive error It is physiological decrease of the power of the human lens to accommodate for near with age above 40 years. corrected by convex lens Treatment of errors of refraction Glasses Contact lenses LASIK FEMTO CORNEAL SURGERIES PHAKIC IOLs Corneal implants  Ocular injuries A) Burns and chemical injuries B)Foreign bodies C) Penetrating injuries D) Orbital fractures Clinical picture History of injury Pain – lacrimation- photophobia- blepharospasm Diminution of vision Redness of conjunctiva Foreign bodies on or in the eye Corneal ulceration Fracture of orbital walls may cause enophthalmos Treatment Removal of foreign bodies Copious irrigation with saline 2 liters for about 30 minutes Neutralize chemical agents: 1. Wash with saline or tap water 2. 3% sodium bicarbonate soln. in case of acids 3. EDTA in case of lime 4. 3% boric aid soln. in case of alkalies 5. Starch soln. in case of iodine Local antibiotics and topical steroids Surgical repair of ocular wounds and fractures Enucleation of the eye in severe injuries Inflammation Orbital cellulitis Keratoconjunctivitis episcleritis Uveitis Optic neuritis Corneal ulcers Iridiocyclitis: Definition Causes: Systemic diseases: syphilis , TB, Leprosy Septic focus e.g.. Teeth Local eye diseases e.g.. Corneal ulcers , old RD, surgeries DD of ciliary and cojunctiaval injection