13 Anterior Corneal Dystrophies

Corneal dystrophy

Broad term for diseases where corneal transparency is reduced due to the presence of abnormal material

Epithelial Basement Membrane Dystrophy (EBMD)

• anterior basement membrane dystrophy, map-dot-fingerprint dystrophy, or cogan’s microcystic dystrophy

• Condition characterized by structural changes & abnormal thickening of epithelial basement membrane w/ resultant folds

• Most common anterior corneal dystrophy

Symptoms of EBMD

• pain (severe)

• Redness

• Blepharospasm

• Watering

• RCEs common in these individuals

Signs of EBMD

• best seen on retroillumination

• Can be isolated or in combination

• Include dots, fingerprint, or maps

Tx/management of EBMD

• dependent on severity of condition

  • Signs but no symptoms > PFATS QID and sodium chloride 5% ung

  • Signs w/ symptoms > consider mild adjustment dependent on symptomatology > PFATs QID OR sodium chloride 5% QID & sodium chloride 5% ung

Anterior stromal puncture

Minor surgical procedure that utilizes a needle to induce microscopic scars that anchor epithelium to underlying stroma

Meesmann Corneal Dystrophy (juvenile hereditary epithelial dystrophy)

Condition characterized by microcysts in corneal epithelium (autosomal dominant)

Electron microscopy appearance of meesmann corneal dystrophy

Accumulation of tiny vesicles in epithelium; contain PAS (periodic acid-Schiff)

Meesmann Corneal Dystrophy is a genetic defect in

KRT3 and KRT12 genes

Pathogenesis of meesmann corneal dystrophy

• autosomal dominant genetic mutation in KRT3 or KRT12

• Resultant weakening of corneal epithelium

• Development of small, transparent epithelial cysts filled w/ cellular debris & abnormal keratin protein clumps

• Possibility of cysts rupture > corneal erosions

Symptoms of meesmann corneal dystrophy

• pain (severe(

• Redness

• Blepharospasm

• Watering

• RCEs may present

Lisch Corneal Dystrophy

Superficial corneal dystrophy characterized by densely crowded microcysts localized to epithelium (X-linked dominant condition)

Electron microscopy appearance of lisch corneal dystrophy

Accumulation of diffusely vacuolated cytoplasm of epithelial cells (most evident in wing cells)

Signs of Lisch Corneal Dystrophy

Cornea epithelial opacifications

• gray white

• Comprised of numerous vacuoles

• Pattern described as whorl, flame, feather-shaped

• No associated staining