The Ophthalmology Examinations Review - part 4 potx

118 The Ophthalmology Examinations Review I I’ll like to Ask patient for a histoly of 0 Arthritis (indomethacin) Breast CA (tamoxifen) 0 Cardiac diseases (amiodarone) Connective tissue diseases (chloroquine) 0 Dementia, psychiatric diseases (chlorpromazine) I Tell me about the mucopolysaccharidoses “Mucopolysaccharidoses are a group of systemic storage diseases due to deficiency of lysosomal enzymes.” “There are numerous specific types, each with own systemic and ocular features.” “The systemic features include mental retardation, coarse facies, skeletal abnormalities and cardiac diseases.” “In general, the ocular features include corneal deposit, retinal degeneration and optic atrophy.” Type Name Cornea Retinal Optic Notes deposition degeneration atrophy 1 H Hurler tt+ + + All are AR except Hunter’s (SLR) 1 S Scheie +++ + + Hurler and Scheie have the most severe corneal lesions 2 Hunter - tt +++ “Hunter” are males and have clear corneas - 3 Sanfilippo +t+ + 4 Morqio + - t 4 and 6 have no retinal degeneration 5 None 5 became “Scheie 6 Maroteaux + - Lamy - + Te//me about Wilson’s disease “Wilson’s disease is a metabolic systemic disease.” “Characterised by deficiency in alpha 2 globulin (ceruloplasmin).” “Resulting in deposition of copper throughout the body.” LAMP EXAM (page 121) Wilson’s disease 1. Systemic features Liver (40%) CNS (40%) No mental retardation Basal ganglia (flapping tremors) Spasticity, dysarthria, dysphagia Psychiatric problems Normal total serum copper Low serum ceruloplasmin High urine copper Laboratory results Section 3: Corneal and External Eye Diseases 2. Ocular features Deposition in Descemet’s membrane Kayser Fleisher ring (KF ring) 90% of all patients, almost 100% if CNS involved Green “sunflower” cataract Decrease copper intake Accommodation difficulty (deposition in ciliary muscles) 3. Treatment Penicillamine (KF ring will resolve with treatment) 119 TOPIC I2 SCLERITIS What is scleritis? "Scleritis is an inflammatory disease of the sclera." "It can be classified into " Scleritis 1. Classification Anterior scleritis Noninflammatory (40%) Diffuse (benign disease) Nonnecrotizinghleromalacia perforans (benign) Nodular (visual loss in 25%) Necrotizing (visual loss in 75%, mortality in 25%) Inflammatory (40%) Posterior scleritis (20%) 2. Systemic associations (50%) Noninfective Rheumatoid arthritis (RA) (40%) Surgically-induced necrotizing scleritis (SINS) Herpes zoster TB, syphilis Systemic lupus erythematosis Wegener's granulomatosis, polyarteritis nodosa, relapsing poly- chondritis Infective 3. Investigations CBC, ESR VDRL, FTA Collagen disease markers CXR Treat associated systemic diseases 4. Treatment Treat associated ocular complications (glaucoma, cataract) Treatment of scleritis depends on type and severity Anterior scleritis, nonnecrotizing (NSAIDs, topical steroids) Posterior scleritis (oral systemic steroids) Anterior scleritis, necrotizing with inflammation (IV steroids and immunosuppressive agents) What are the clinical features of posterior scleritis? "Posterior scleritis is an inflammatory disease of the sclera posterior to the equator." "It represents about 20% of all scleritis " Posterior scleritis 1. 20% of all scleritis 120 Section 3: Corneal and External Eye Diseases 121 2. 3. 4. 5. Clinical presentations vary 20% associated with systemic diseases 80% associated with concomitant anterior scleritis Visual prognosis is poor (80% develop visual loss) Other presentations 80% present as either disc swelling or exudative RD Subretinal mass (more common in females) Ring choroidal detachment (more common in males) Macular edema, subretinal exudation, choroidal folds Vitritis I*’ Clinical aDDrOaCh to scleritis “There is a yellowish necrotic nodule seen in the superior sclera.” “There is associated inflammation of the surrounding sclera and injection of scleral vessels. ” Or “There is marked thinning of the superior sclera with little inflammation seen.” Look for Corneal peripheral thinning (important sign for RA, systemic lupus, Wegener’s, polyartertitis nodusa) AC activity and keratitic precipitates Previous cataract or pterygium surgey (SINS) Differential diagnoses for a NORMAL SLIT LAMP EXAM 1 Cornea Keratoconus L/d scarring (herpes zoster) Bilateral disease (RA, systemic lupus, Wegener’s, polyartert/tis nodusa) Systemic features (RA, systemc lupus, Wegener’s, polyartentis nodusa) 1’11 like to Check IOP (glaucoma in scleritis) Check the fundus for optic disc swelling, choroidal folds, RD Examine patient systemically (RA, sys- temic lupus, Wegener’s, polyartertitis nodusa) Vortex keratopathy Microcystic epithelial corneal dystrophy Kayser Fleisher ring Fuch’s endothelial dystrophy Rubeosis Atrophy Peripheral anterior synechiae Phacodonesis Glankomflecken Scleritis 2. Iris 3. Lens 4. Sclera TOPIC 13 CORNEAL GRAFTS Opening question NO. 1 : Tell me about corneal grafts “Corneal graft is a surgical procedure in which diseased host cornea is replaced by healthy donor cornea.” “Broadly, corneal grafts can be either partial thickness4amellar or full thickness/ penetrating ” “The indications for full thickness corneal graft are ” ”Prior to the operation, the patient must be evaluated for ” Opening question No. 2: What are the indications for penetrating keratoplasty (PKP)? “The indications for corneal grafts can be ’I Indications for PKP 1. Optical . 0 0 0 0 Bullous keratopathy (pseudophakic and aphakic) Keratoconus Corneal dystrophy Corneal inflammatory diseases - interstitial keratitis, HSV Corneal traumatic scars Failed grafts 2. Tectonic Corneal perforation Peripheral corneal thinning Infective keratitis 3. Therapeutic What are preoperative factors to look out for prior to PKP? Preoperative factors 1. Evaluate patient’s ocular condition and manage poor prognostic factors prior to PKP Factors 0 0 0 0 factors well (Big 4 poor prognostic factors) Ocular inflammation Glaucoma Corneal vascularization Ocular surface abnormalities 1 Associated lid abnormality (entropian, ectropian) Tear film dysfunction and dry eyes 122 Section 3: Corneal and External Eye Diseases 123 Other factors to consider Corneal hyposthesia Cornea irregularity Pre-existing cataract (consider triple procedure) Structural changes of AC (peripheral anterior synechiae, rubeosis) 2. Assess visual potential Amblyopia Optic atrophy Retinal and macular conditions (e.g. cystoid rnacular edema) 3. Topical antibiotics/steroids/cyclosporin A if necessary Steps in PKP Preoperative preparation GA Maumanee speculum Superior and inferior rectus bridle suture with 410 silk Flieringa ring if necessary (indications: post vitrectorny, aphakia, trauma, children) Overlay suture if necessary (7/0 silk at limbus) Check recipient bed size with Weck trephine (usually 7.5mm) Donor button Check corneoscleral disc Harvest donor cornea button with Weck Approach from posterior endothelial side Use trephine size 0.25-0.5mm larger than recipient bed Keep button moist with viscoelastic 3-point fixation (2 from bridle suture, one with forceps) Weck trephine imprint to check size and centration trephine on Troutman punch Recipient bed Other types of trephine Baron Hessberg trephine and Hannah trephine (suc- tion mechanism) Fill AC with viscoelastic Set trephine to 0.4rnm depth Enter into AC with blade Complete incision with corneal scissors Fixation of graft Place donor button on recipient bed “How do you check the corneoscleral disc?” Container (name, date of harvest etc.) Media (clarity and colour) Corneal button (clarity, thickness, irregularity, surface damage) “Why IS the donor button made larger than recipient bed?” Because donor button is punched from posterior endothelial surface Tighter wound seal for graft Increases convexity of button (less penpheral anterior synechiae More endothelial cells with larger button POStOP) 16 interrupted sutures 4 cardinal sutures with lO/O nylon (at 12 o’clock first, followed by 6, 3 and then 9) Advantages of interrupted sutures Easier for beginners Better for inflamed eyes and eyes with vascularization 124 The Ophthalmology Examinations Review Other suture techniques Continuous suture Faster Better astigmatism control Combined continuous and interrupted sutures 5. End of operation Subconjunctival steroids/antibiotics Check water tightness and astigmatism with keratometer HOW is the donor corneal button stored? “Storage media can be divided into ” Storage media 1. Short term (days) Moist chamber Humidity 100% Temp 4 degrees C Storage duration: 48 hours Temp 4 degrees C Storage duration: 2-4 days McCarey-Kaufman medium Standard tissue culture medium (TCI 99, 5% dextran, antibiotics) 2. Intermediate term (weeks) DexsoVOptisoVKsoVProcell Temp 4 degrees C Storage duration: 1-2 weeks Organ culture Disadvantage: Increase infection rate? Temp 37 degrees C Storage duration: 4 weeks Standard tissue culture medium (TC199) plus chondroitin sulphate, HC03 buffer, amino acid, gentamicin Advantage: Decrease rejection rate? (culture kills off antigen-presenting cells) 3. Long term (months) Cryopresetvation Liquid nitrogen Temp -196 degrees C Storage duration: 1 year Disadvantages: Expensive and unpredictable results What are the contraindications for donation of corneas? “The contraindications included patients with ” Contraindications for cornea donation 1, Systemic diseases Death from unknown cause Infections CNS diseases of unknown cause Septicemia Leukemias, lymphomas, disseminated cancer Creutzfeld-Jacob disease, CMV encephalitis, slow virus diseases Congenital rubella, rabies, hepatitis, AIDS Malignancies Section 3: Corneal and External Eye Diseases 125 2. Ocular diseases lntraocular surgery lntraocular tumors < 1 year old History of glaucoma and intis 3. Age Small diameter and friable Low endothelial cell count Corneas are difficult to handle Very steep cornea (average keratometry = 50D) >65 years 4. Duration of death >6 hours What are the complications of corneal grafts? ‘The complications can be divided into complications specific to wmeal grafts or general complications of intraocular surgery.” “They can occur in the early or late postoperative period ” Complication of corneal grafts 1. Early postoperative Glaucoma or hypotony Persistent epithelial defect Endophthalmitis Wound leak Recurrence of primary disease 2. Late postoperative Rejection Infective keratitis Recurrence of disease Astigmatism Persistent iritis Late endothelial failure Cataract RD Expulsive hemorrhage Retrocorneal membrane CME 3. Others complications of intraocular surgery Whaf are causes of graft failure? “Graft failure can be divided into early failure or late failure.” Graft failure 1. Early failure (< 72 hours) Primary donor cornea failure Unrecognized ocular disease Low endothelial cell count Storage problems Surgical and postoperative trauma Handing Trephination lntraoperative damage Recurrence of disease process (e.g. infective keratitis) 126 The Ophthalmology Examinations Review Others Glaucoma Infective keratitis 2. Late failure (> 72 hours) Glaucoma Persistent epithelial defect Infective keratitis Recurrence of disease process Late endothelial failure Rejection (30% of late graft failures) What are factors which affect graft survival? “The factor which affect graft survival can be divided into ” Graft survival 1. Factors associated with higher risk of graft rejection Young age Repeat grafts Exposed sutures Deep stromal vascularization Other factors associated with graft failure Preexisting glaucoma and high IOP Ocular surface (lids, tears) lntraocular inflammation (iritis) Size of graft (large graft) Position of graft (eccentric graft) Presence of peripheral anterior synechiae 2. I prognostic factors! I HO Wdo you grade corneal graft prognosis according to disease categories? Brightbill’s classification GRADE I (Excellent) Keratoconus Lattice and granular dystrophy Traumatic leukoma Superficial stromal scars Bullous keratopathy Fuch’s dystrophy Macular dystrophy rn Small vascularized scars Interstitial keratitis Failed Grade I PKP Active bacterial keratitis Vascularized cornea Active HSV keratitits 0 Congenital hereditary endothelial dystrophy Failed Grade II PKP Active fungal keratitis Congenital glaucoma GRADE II (Good) Combined PKP and cataract op GRADE 111 (Fair) GRADE IV (Guarded) Section 3: Corneal and External Eye Diseases 127 Pediatric grafts Mild keratoconjunctivitis sicca Mild chemical burns Corneal blood staining Corneal staphylomas Failed Grade 111 PKP GRADE V (Poor) Severe keratoconjunctivitis sicca (Stevens Johnson’s syndrome, ocular cicatrical pemphigoid, chemical and thermal burns) Ti// me about graft rejection “Graft rejection is a type 4 immune reaction.” “It can be divided into epithelial, subepithelial, stromal and endothelial rejection.” Graft rejection 1. Pathophysiological basis of rejection Type 4 immunological reaction Divided into: epithelial, subepithelial, stromal and endothelial rejection Immunological phenomenon Age (young age) Repeat grafts Size of graft (large grafts) Position of graft (eccentric graft) Peripheral anterior synechiae Exposed sutures Deep stromal vascularization 3. Clinical features EDithelial rejection 2. Risk factors 2 weeks onwards (if less than 2 weeks, consider other diagnosis) Epithelial rejection line (advancing lymphocytes, replaced by epithelial cells from recipient) Usually low grade, asymptomatic, eye is quiet Subepithelial rejection Nummular white infiltrates (Krachmer’s Mild AC activity Stromal rejection Symptoms spots) Most important of the 4 types Decreased VA Redness Pain Limbal injection AC activity Keratic precipitates Signs NOTES “What is the evidence that rejection IS an immune phenomenon?” Rejection of 2nd graft from same donor begins after shorter interval and progresses more rapidly Brief period of latency (2 weeks) before rejection Rejection correlates with amount of antigen introduced in graft Neonatally thymectomized animals reject grafts with difficulty NOTES “What are the problems of large grafts?” Increased risk of rejection Increase IOP (more peripheral Large epithelial defect (Iimbal (nearer vessels) anterior synechiae) stem cell failure) Stromal edema Endothelial rejection line (Khodadoust‘s line) Endothelial rejection Combination of stromal and endothelial rejection [...]... = - l D of myopia 3 types of ablation * Wide area ablation Scanning slit “Flying spot” Indications and limitations PRK works well for low and moderate myopia and astigmatism 135 The Ophthalmology Examinations Review 136 3 For myopia -6 D 5 0-7 5% see 20 /40 or better 3 0-7 0% predictability 5-1 5%... bundles Orbiculo-anterocapsularbundle Orbiculo-posterocapsularbundle Between the 2 is the canal of Hannover Between the orbiculo-posterocapsular bundle and the anterior vitreous cortex is the canal of Petit What is the embrvoloav of the vitreous? “There are classically 3 overlapping phases of vitreous development.” Embryology of vitreous 1 2 3 4 Primary vitreous (vascular vitreous) 4Ih week of gestation:... HA removed + gel shrinks The large domains of HA spread apart the collagen fibers to minimize light scattering What are t h e functions o f t h e vitreous? The vitreous has several functions .” Functions of t h e vitreous 1 Mechanical function Prevents globe from collapsing Viscoelastic property of HA-collagen interaction 147 The Ophthalmology Examinations Review 140 2 3 4 Shock absorbing function... keratoconus Degeneration - pellucid marginal degeneration, Terrien’s degeneration Infection- scar formation Inflammation- peripheral ulcerative keratitis (RA, Mooren’s ulcer) Traumatic scar formation - I38 3 The Ophthalmology Examinations Review Iatrogenic Large incision cataract surgery Penetrating keratoplasty Whaf are the options in the management of corneal astigmatism? 1 2 3 4 Glasses Contact lens... and elderly Lack of manual dexterity Therapeutic indications 131 The Ophthalmology Examinations Review 132 What are the pathophysiological changes to the eye with contact lens wear? The pathophysiologicalchanges included ” Pathophysiological changes to the eye I 2 3 4 Dessication Microtrauma Hypoxia Hypersensitivityhoxicity Whatare the complications of contact lens wear? “Contact lens wear complications... epithelial cyst, retraction of flap, bleeding, ptosis) Section 4 SURGICAL RETINA TOPIC I THE RETINA Openingquestion NO I: What is the anatomy of the retina? "The retina is the innermost layer of the globe " "It is divided into the inner neurosensoty layer and the outer retinal pigment epithelium." Gross anatomy of the retina 1 2 3 Neurosensory retina and RPE Classic 10 layers RPE Outer segment o photoreceptor... rehabilitation Lower risk of rejection and therefore less use of topical steroids Disadvantages 0 Ooes not replace damaged endothelium Interface scarring Technically more difficult 129 TOPIC I 4 BASICS IN CONTACT LENS Whatare the indications for contact lens in ophthalmology? "The indications can be divided into " Indications for contact lens 1 2 3 4 Refractive (most common) Therapeutic (see below) Cosmetic... Separates retina from sclera Classic 3 layers Choriocapillaries Middle vascular layer Outer vascular layer Openingquestion NO 2: Tell me about the rods and cones Rods and cones 1 Rods 120 million; 50pm long Nucleus 143 The Ophthalmology Examinations Review 144 Inner segment Inner (myoid) contains Golgi apparatus Outer (ellipsoid) contains mitochondria Outer segment Composed of 1000 stacked discs Discs... bed Cornea cap is then reapplied to cornea bed Laser procedures PRK (photorefractive keratectomy) Up to -6 D LASIK (laser in-situ keratomileusis) Modification of ALK, using laser for the second pass Up to-150 lntraocular surgery ICSR (intracorneal stromal ring) PMMA half rings are threaded into peripheral mid stroma to effect a flattening of the cornea Up to-6D High myopia procedures (> -1 2D) Clear lens... Chronic epithelial/stromal ulcer after resolution of active infective disease Neurotrophic ulcer Chemical injury Bullous keratopathy Descematocoele 139 140 2 The Ophthalmology Examinations Review Problems with conjunctival flap Temporary treatment No view of cornea Low drug penetration Postoperative complication (button hole, epithelial cyst, retraction of flap, bleeding, ptosis) Section 4 SURGICAL . Examinations Review For myopia < ;-6 D 7 0-8 0% predictability 1% significant corneal haze 8 0-9 0% see 20 /40 or better 1-5 % IOSS Of BCVA High myopia > ;-6 D 3 0-7 0% predictability 5-1 5%. DWSCL 4. Indications for EWSCL 132 The Ophthalmology Examinations Review What are the pathophysiological changes to the eye with contact lens wear? The pathophysiological changes included. Stromal edema Endothelial rejection line (Khodadoust‘s line) Endothelial rejection Combination of stromal and endothelial rejection 128 The Ophthalmology Examinations Review 8 Clinical