Term
| AQUIRED CORNEAL DEGENERATIONS: |
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Definition
| Amyloidosis , Spheroid, ,Coat’s White Ring, Salzmann’s Degeneration, Band Keratopathy, Terrien’s Marginal Degeneration |
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Term
| SENILE CORNEAL DEGENERATIONS: |
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Definition
| White Limbal Girdle of Vogt, Anterior Crocodile Shagreen, Posterior Crocodile Shagreen, Cornea Farinata, Arcus Senilis, Descement’s Hypertrophy |
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Term
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Definition
| is a disease of unknown etiology characterized by abnormal deposition of amyloid, a translucent homogeneous glycoprotein, in various organs and tissue of the body. In the eye it may occur as a primary infection , or chronic infections, affecting any ocular structure. In the cornea the lesions consist of pink to yellow central raised fleshy masses with a nodular surface and the cornea may become vascularized. ** 6.21 |
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Term
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Definition
| it consist of yellow, oil droplets under the epithelium of the cornea, most often found at the 3 and 9 o’clock meridian, secreted by abnormal fibrocytes. Primary disease are bilateral and located in the superficial stroma, while Secondary types are unilateral and epithelial. |
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Term
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Definition
| This is small corneal opacity which is usually located in an area where there previously was a foreign body. It appears as a granular oval ring that is white and contains iron deposits. |
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Term
| Salzmann’s Nodular Degeneration |
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Definition
| This consist of a bluish, raised, non-inflammatory nodules arranged in circular fashion around the pupil area of the cornea, from previous infection, especially viral and they consist of hialine plaque replacing Bowman’s membrane by hyaline material. More common in elderly women and is associated with chronic ocular surface disease such as Trachoma or severe Blepharitis. |
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Term
| Treatment: for Salzamnn’s Nodular Degneration |
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Definition
| Excimer laser superficial keratectomy to remove the nodules or Keratoplasty. **6.42 |
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Term
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Definition
| Corneal degeneration characterized by slow development of a horizontal gray band in the central area ,caused by calcium deposition at level of Bowman’s layer, in children with low chronic iritis , idiopathic hypercalcemia, or following the use of silicone oil for retinal detachment or in phthisis bulbi. |
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Term
| Treatment of Band Keratopathy |
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Definition
| : application of ethlenediaminetetraacetic acid (EDTA) after anesthetizing the cornea and scrapping off the epithelium. EDTA chelates the calcium. **6.43-44 *6.64 |
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Term
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Definition
| ;deposition of lipid and lipoproteins leaking from new vessels in the cornea , following chronic inflammation and vascularization. |
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Term
| Terrien’s Marginal Degeneration |
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Definition
| Peripheral thinning of the cornea that progress slowly and resulting in a ring opacity similar to arcus , sparing central corneal area of unknown etiology . **6.65 |
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Term
| White Limbal Girdle of Vogt |
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Definition
| : Is an sub-epithelial opacity (hyaline degeneration) concentric with the limbus, consist of a chalky opacity in Bowman’s layer, but it is not a band keratopathy. |
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Term
| Two types of White Limbal Girdle of Vogt |
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Definition
| : 1) the opacity is discontinuous, separated from the limbus by a clear zone 2) the opacity is unbroken and continuous with the sclera with short projections extending toward the center of the cornea. ** 6.11 |
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Term
| Anterior Crocodile Shagreen: |
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Definition
| This is due to disruptions in Bowman’s membrane and it is separation from the corneal epithelium .Bilateral, polygonal, grayish opacities, separated by clear tissue. Decrease corneal sensation, usually no reduction in VA and no vascularization. Treatment is not necessary **6.12 |
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Term
| Posterior Crocodile Shagreen |
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Definition
| The same opacities and characteristics of above but placed in Descement’s membrane. May be familial and related to the central cloudy corneal dystrophy .Neither produces visuals symptoms. |
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Term
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Definition
| These opacities appear grayish and are located anterior to Descement’s membrane. Farinata might be vacuoles in the keratocytes. |
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Term
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Definition
| This is a grayish ring opacity in the periphery of the cornea, separated from the limbus by a zone of clear cornea. In younger patients is called JUVENILIS OR EMBRIOTOXON. **6.13 *6.58 |
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Term
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Definition
| (Hassall-Henle warts) (Cornea Guttata) This are rounded wart-like elevations (excrecences ) of the posterior surface of Descement’s membrane at the central or periphery of the cornea which tend to increase in olders. **6.27-28-29 * 6.40-41 |
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Term
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Definition
| (deep epithelium, basement membrane and bowman’s membrane), MEESMANN’S CORNEAL DYSTROPHY, COGAN’S MICROCYSTICCORNEQAL DYSTROPHY, FINGERPRINT DYSTROPHY, REIS-BUCKLER’S SUPERFICIAL DYSTROPHY, RECURRENT EROSIONS, VORTEX DYSTROPHY |
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Term
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Definition
| GRANULAR DYSTROPHY, LATTICE DYSTROPHY, MACULAR DYSTROPHY, FLECK DYSTROPHY, SCHNYDER’S CRISTALINE DYSTROPHY, FUCH’S EPITHELIAL/ENDOTHELIAL DYSTROPHY, POSTERIOR POLIMORPHUS DYSTROPHY |
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Term
| Meesmann’s Corneal dystrophy |
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Definition
| A dominant , hereditary, bilateral dystrophy involving only the corneal epithelium. It commences at 18 months of age with gradual progression, finally discovered in the older patient. It characterized by numerous small punctate opacities regularly distributed throughout the epithelium intra-palpebrally. **6.18 |
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Term
| Treatment for Meesmannn’s Corneal Dystrophy |
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Definition
| : Lamellar Keratoplasty, if the condition causes a disturbance in vision. |
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Term
| Cogan’s Microcystic corneal dystrophy |
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Definition
| This consists of gray cyst that affect the eyes bilaterally in pupillary zone. The lesions can be round, comma-shaped, or oblong and granular and occur in intraepithelial spaces. Vision normal but recurrent erosions can occur.* *6,16 |
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Term
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Definition
| This consists of fine, wavy lines, anterior to Bowman’s membrane. Epithelial basement membrane dystrophy. Asymptomatic and can present recurrent erosions. Bilateral ,more frequent in woman**6.16 |
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Term
| Reis-Buckler’s Superficial Dystrophy |
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Definition
| Hereditary, present recurrent erosions and opacification of Bowman’s. There is decreased visual acuity ,ciliary injection ,irregular astigmatism and distortion of the cornea. Begins with fragmentation of the collagen fibrils of Bowman’s with epithelial involvement secondary. Treatment : Penetrant and Lamellar keratoplasty.**6.19 * 6.33 |
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Term
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Definition
| this can be familial, spontaneous, or associated with another problems or traumas. |
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Term
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Definition
| Rare dominantly inherited, corneal dystrophy involving superficial layers of the cornea and characterized by small brownish opacities on Bowman’s arranged in a whirlpool-shape line formation radiating out from the center of the cornea. It is also called cornea Verticillata. **6.66 *6.65 |
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Term
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Definition
| Irregular, discrete nodules of hyaline degeneration beginning in the superficial stroma. NOTE: Good prognosis until middle age.**6.22 |
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Term
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Definition
| interlacing lines and nodules of amyloid deposits in collagen fibers and under epithelium. Present in first decade of life with recurrent erosions. VA Deteriorates slowly, and corneal grafting is often necessary in third or fourth decade. **6.20 |
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Term
| Macular Stromal Dystrophy |
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Definition
| : characterized by a lot of spots forming an apparent opacity due to accumulation of MPS or glycoprotein in stroma and degeneration of Bowman’s membrane. **6.24 *6.38 |
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Term
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Definition
| Autosomal Dominant, in origen. Lesions are bilateral, round, gray, and distributed through all layers of the cornea. Patients are usually unaware of the problem and no treatment is necessary. |
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Term
| Schnyder’s Cristalline Dystrophy |
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Definition
| autosomal dominant. Polychromatic crystals are distributed within a a ring shaped yellow corneal opacity in the anterior stroma. If VA affected Treatment with corneal graft , might be necessary.**6.69 *6.66 |
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Term
| Fuch’s Epithelial/Endothelial Dystrophy : |
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Definition
| Dominant in origen. The endothelium fails as an effective pump with resulting edema consisting of vesicles which later become opacities, and after an extremely slow course, the cornea becomes opaque and insensitive. Ttt Penetrating keratoplasty must be performed. ** 6.27 |
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Term
| Posterior Polymorphous Dystrophy: |
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Definition
| Dominant transmission. Plaque of calcium crystals accumulate in the deep stromal layers and vesicle-like opacities are noted on Descement’s membrane. Edema occurs, but vision is usually not affected except in sever cases and the condition is no progressive.**6.30-31 *6.42-43 |
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Term
| Corneal Changes in Inborn Errors in Metabolism |
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Definition
| Protein and amino acid metabolism, Porphyria , Amyloidosis, Cystinosis, Alkaptonuria, Wilson’s Disease Etc. |
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Term
| Disorders in Carbohydrate Metabolism |
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Definition
| Hurler’s Synd. Scheie’s Synd, Morquio’s Synd. Sanfilippo’s Synd. Hunter’s Synd. Etc. |
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Term
| Changes in Chromosomal Abnormalities |
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Definition
| Trisomy 21(Down’s Synd, mongolism) Trisomy 13-15 (Patau’s Synd) Turner’s Synd. Etc. |
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Term
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Definition
| Lupus Erythematosus , Sjogren’s Synd., Marfan’s Synd. Etc. |
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Term
| Endocrine System Disorders |
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Definition
| Diabetes Mellitus , Thyroid Disorders , Parathyroid Disoders ,Hyphosphatemia Etc. |
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Term
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Definition
| Acne Rosacea, Atopic Dermatitis, Ichtiosis, Psoriasis Etc. |
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