Corneal dystrophies: 9/10/2011 Zana Hameed 1 Corneal dystrophies Dr.Zana Gh. Hameed Corneal dystrophies:: 9/10/2011 Zana Hameed 2 Corneal dystrophies: Are a group of progressive disorders usually bilateral, mostly genetically determined , non-inflammatory opacifying disorders. Based on biomicroscopical and histopathological features. Classification: 9/10/2011 Zana Hameed 3 Classification 1.Epithelial 2.Bowman`s 3.Stromal 4.Endothelial Slide 4: 9/10/2011 Zana Hameed 4 Slide 5: 9/10/2011 Zana Hameed 5 Cogan Meesman Lisch Slide 6: 9/10/2011 Zana Hameed 6 Lisch Meesman Cogan Type AD,X-linked AD Sporadic,AD Inheritance Ocular irritation Ocular irritation Recurrent corneal erosion Symptom Whorled configeration, micro cyst. Myriad cyst,thin cornea,reduced sensation Dot-like,map-like,microcyst,finger print. Sign ThickBM. ThickBM. ThickBM,pr.dep.,abscent hemidesmosom Histology Lubricant Lubricant Lubricant Treatment Slide 7: 9/10/2011 Zana Hameed 7 Schnyder: 9/10/2011 Zana Hameed 8 Schnyder Slide 9: 9/10/2011 Zana Hameed 9 Schnyder CDB2 CDB1 Type AD AD AD Inheretance VA, Glare. Recurrent corneal erosion. Recurrent corneal erosion. Symptoms Central crystaline opacity. Subepithelial opacities(honeycomb) configeration. Fine,round,polygonal subepithelial opacities. Signs Phospholipid & cholesterol deposition. B.L replaced by curly fibers. B.L & B.M replaced by fibrous tissue. Histology E.L keratectomy Not necessary Lubricant, E.L keratectomy Treatment CDB1 CDB2 Schnyder: 9/10/2011 Zana Hameed 10 CDB1 CDB2 Schnyder Stromal corneal dystrophies: 9/10/2011 Zana Hameed 11 Stromal corneal dystrophies Lattice work: 9/10/2011 Zana Hameed 12 Lattice work Lattice dystrophy: 9/10/2011 Zana Hameed 13 Lattice dystrophy Slide 14: 9/10/2011 Zana Hameed 14 Lattice III Lattice II Lattice I Type AD AD AD Inheritance Photophobia,↓VA , Watering. Recurrent corneal erosion Recurrent corneal erosion Symptoms Thick rope-like band lattice. Radial periphery lotcated short,fine lattice, ↓corn.sensation. Glassy dots,fine lattice,outward spread,stromal haze,↓corn.sensation Signs Amyloid deposition Amyloid deposition Amyloid deposition Histology Keratoplasty if affect the vision. Keratoplasty if affect the vision. Keratoplasty if affect the vision. Treatment Amyloid deposit in multiple organs cause neuropathy,thick itchy skin ,protruded lips,cardiac arrhythmias …etc. : 9/10/2011 Zana Hameed 15 Amyloid deposit in multiple organs cause neuropathy,thick itchy skin ,protruded lips,cardiac arrhythmias …etc. Mask face in amyloidosis: 9/10/2011 Zana Hameed 16 Mask face in amyloidosis Gelatinous drop-like dystrophy: 9/10/2011 Zana Hameed 17 Gelatinous drop-like dystrophy AR inheritance. Rare mainly affecting Japanese people so called Japanese type amyloid corneal dystrophy. Usually presented at 1 st or 2 nd decade with sever photophobia , watering and visual impairment. JAPANESE: 9/10/2011 Zana Hameed 18 JAPANESE Gelatinous drop-like dystrophy: 9/10/2011 Zana Hameed 19 Gelatinous drop-like dystrophy Biomicroscopical examination shows: Gray subepithelial nodules which increase in size and confluence then giving rise to Mulburry-like appearance. Gelatinous drop-like dystrophy Histology: 9/10/2011 Zana Hameed 20 Gelatinous drop-like dystrophy Histology Histologicaly there is sub epithelial and anterior stromal deposition of amyloid. This condition should be treated with repeated superficial keratectomy as recurrence in graft is very high. Granular corneal dystrophy: 9/10/2011 Zana Hameed 21 Granular corneal dystrophy GCDI GCDII(Avellino) AD AD 1 st decade 2 nd decade Recurrent erosion uncommon. Rec. eros. Uncommon GCD I(Groenouw type I): 9/10/2011 Zana Hameed 22 GCD I(Groenouw type I) Avellino-Italy: 9/10/2011 Zana Hameed 23 Avellino-Italy Slide 24:
9/10/2011 Zana Hameed 24 GCDI Centrally located corneal opacities (ring,snowflake,crubms,sugar granules)not reaching limbus. Overall appearance gives the shape of
tree. Corneal sensation decrease. VA impared at advanced stage. GCDII(granular-lattice dys.) Centrally dens opacities (ring,disc,star,snowflake) like GCDI Overall pattern radially spread like Lattice dystrophy .
Granular corneal dystrophy: 9/10/2011 Zana Hameed 25 Granular corneal dystrophy GCDI histology shows amorphous hyaline deposits which stain bright red with Masson trichrome. GCDII histology shows both hyaline and amyloid in the stroma that stains with Masson trichrome and Congo red. Granular corneal dystrophy: 9/10/2011 Zana Hameed 26 Granular corneal dystrophy GCDI has to be treated by keratoplasty usually at 5 th decade when there is visual impairment while GCDII most of the time not require treatment. Gene defects: 9/10/2011 Zana Hameed 27 Gene defects (Groenouw type II)Macular dystrophy : 9/10/2011 Zana Hameed 28 ( Groenouw type II ) Macular dystrophy Macular dystrophy is the least common stromal dystrophy, in which a systemic inborn error of keratan sulphate metabolism seems to have only corneal manifestations. It has been divided into clinically indistinguishable types I, IA and II depending on the presence or absence of antigenic keratan sulphate in the serum and cornea; these have been shown to be due to mutations in the same sulfotransferase gene ( CHST6 ). Macular dystrophy: 9/10/2011 Zana Hameed 29 Macular dystrophy Histology shows abnormally close packing of collagen in the corneal lamellae and abnormal aggregations of glycosaminoglycans which stain with Prussian blue and colloidal iron Macular dystrophy: 9/10/2011 Zana Hameed 30 Macular dystrophy The onset is towards the end of the 1st decade with visual deterioration . Biomicroscopy shows: : • Anterior stromal haze, initially involving the central cornea . • Greyish-white, dense, focal, poorly delineated spots in the anterior stroma centrally and posterior stroma in the periphery. • Superficial deposits may produce an irregularity of the corneal surface, although recurrent erosions are unusual . • Increase in size and stromal haze . • Increasing opacification with eventual involvement of full-thickness stroma up to the limbus, associated with corneal thinning. Treated by keratoplasty but recurrence may occure. François central cloudy dystrophy : 9/10/2011 Zana Hameed 31 François central cloudy dystrophy 1 . AD Inheritance. 2 . Polygonal, cloudy grey opacities separated by relatively clear spaces, in the posterior stroma most prominent centrally, creating a leather-like appearance 3 .The signs are similar to posterior crocodile shagreen but it is differentiated by its central, posterior location and mode of inheritance . 4 . Treatment is not required. Slide 32: 9/10/2011 Zana Hameed 32 Fuchs end. dystrophy: 9/10/2011 Zana Hameed 33 Fuchs end. dystrophy Fuchs endothelial dystrophy ) FED) is characterized by bilateral accelerated endothelial cell loss. It is more common in women and is associated with a slightly increased prevalence of open-angle glaucoma . Fuchs end. dystrophy: 9/10/2011 Zana Hameed 34 Fuchs end. dystrophy 1 Inheritance may occasionally be AD although the majority are sporadic . 2 Onset of this slowly progressive disease is commonly in old age, although earlier onset can occur . Slide 35: 9/10/2011 Zana Hameed 35 • Cornea guttata refers to irregular warts or ‘excrescences’ of Descemet membrane secreted by abnormal endothelial cells. • Specular reflection shows tiny dark spots caused by disruption of the regular endothelial mosaic • Progression occurs to a ‘beaten metal’ appearance which may be associated with melanin deposition. Slide 36: 9/10/2011 Zana Hameed 36 Endothelial decompensation gradually leads to central stromal oedema and blurred vision, worse in the morning and clearing later in the day . Epithelial oedema develops when stromal thickness has increased by about 30%. . Persistent epithelial oedema results in the formation of microcysts and bullae (bullous keratopathy) which causes pain and discomfort on rupture, thought to be due to exposure of naked nerve endings. Fuchs end. Dystrophy Treatment: 9/10/2011 Zana Hameed 37 Fuchs end. Dystrophy Treatment a Conservative options include topical sodium chloride 5% drops or ointment, reduction of intraocular pressure and using a hair dryer to speed corneal dehydration in the morning b Bandage contact lenses provide comfort by protecting exposed nerve endings and flattening bullae . c Penetrating or deep lamellar endothelial keratoplasty has a high success rate and should not be delayed. d Other options in eyes with poor visual potential include conjunctival flaps and amniotic membrane transplants . Fuchs end. dystrophy: 9/10/2011 Zana Hameed 38 Fuchs end. dystrophy Cataract surgery may accelerate endothelial cell loss and result in decompensation. A ‘ triple procedure ’ (cataract surgery, lens implantation and keratoplasty) should be considered in eyes with corneal epithelial oedema or when preoperative pachymetry measurement is greater than 640 µm. If corneal thickness is less than 640 µm, a good visual outcome is to be expected . Posterior polymorphous dystrophy : 9/10/2011 Zana Hameed 39 Posterior polymorphous dystrophy Posterior polymorphous corneal dystroph ) PPCD) is a rare, innocuous and asymptomatic condition in which corneal end. cells display characteristics similar to epithelium. There are three forms, PPCD1-3, each caused by mutations in different genes . PPCD: 9/10/2011 Zana Hameed 40 PPCD AD Inheritance. Symptoms start at birth or soon thereafter, although it is most frequently identified by chance in later life. Signs consist of subtle vesicular endothelial lesions that may become confluent band-like lesions or diffuse opacities which may be asymmetrical . Ocular associations include iris abnormalities, glaucoma and Alport syndrome . Treatment is not required . Congenital hereditary endothelial dystrophy: 9/10/2011 Zana Hameed 41 Congenital hereditary endothelial dystrophy Congenital hereditary endothelial dystrophy ) CHED) is a rare dystrophy in which there is focal or generalized absence of corneal endothelium. There are two main forms, CHED1 and CHED2, the latter being more severe . CHED: 9/10/2011 Zana Hameed 42 CHED Inheritance of CHED1 is AD with the gene locus on 20p11.2-q11.2. CHED2 is AR with the gene locus on 20p13 It starts perinatally. Microscopically there is bilateral, symmetrical, diffuse corneal oedema resulting in a blue-grey, ground-glass appearance to total opacification • Visual impairment is variable and visual acuity may surpass that expected from the corneal appearance . CHED: 9/10/2011 Zana Hameed 43 CHED Treated by penetrating keratoplasty which has a reasonable chance of success when performed early but is risky and technically more difficult than in adults. Undue delay in surgical intervention carries the risk of dense amblyopia . Put in your mind not to confuse CHED with other causes of neonatal corneal opacification such as congenital glaucoma, rubella , keratitis mucopolysaccharidoses, birth trauma and sclerocornea . Thanks for attentive listening: 9/10/2011 Zana Hameed 44 Thanks for attentive listening