Anterior dystrophies · Pure epithelial dystrophies
Lisch epithelial dystrophy
Cues: AD/AR inheritance · graft recurrence +++ high ++ intermediate + low · bold = key terms · Differential diagnosis (blue) and Treatment (amber) boxes.
- Genetics
- X-linked X-linked
- Mutation
- Xp22.3 (pseudo-autosomal lesion)
- Laterality
- Bilateral but sometimes unilateral
- Symmetry
- Yes
- Systemic factors
- No
- Age of onset
- First years of life
- Location
- epithelial cells only
Appearance:
- Direct illumination: diffuse grey opacities in bands, spirals or feather-like patterns extending from the limbus to the pupillary area (as if abnormal limbal cells were migrating toward the center).
- Retroillumination: microcystic dystrophy producing an appearance of multiple clustered/confluent clear cysts.
The microcysts, containing a dense homogeneous or lamellar substance, are present throughout the full thickness of the epithelium.
Note that the dystrophy begins at the limbus.
- Recurrent pain or erosion
- no
- Visual acuity
- often preserved unless the cysts cover the pupil.
- Ancillary investigations:
- OCT: epithelial hyperreflectivity in the affected area. The lesions are more extensive in the superficial layers than in the basal layers, giving the typical inverted-pyramid appearance.
- Confocal microscopy: shows numerous round hyporeflective structures well delineated by hyperreflective tissue
Treatment
Treatment: Not necessary, except in the case of central opacities:
- Debridement, with a risk of recurrence
- Contact lens
Recurrence: yes
Differential diagnosis
The 4 differential diagnoses of epithelial cysts are
- The dots in Cogan dystrophy or in recurrent erosion syndrome: not seen on direct illumination
- Meesmann: multiple clear solitary cysts sparing the limbus, seen on retroillumination
- Lisch: multiple clustered/confluent clear cysts extending to the limbus, seen on retroillumination (typically whiter than the two preceding ones)
- Cornea verticillata: ultrafine clustered cysts seen on retroillumination. Direct examination shows brown arcuate or spiral lines, comet-shaped and centered on a point located in the inferior part of the cornea.
- Iatrogenic intraepithelial cysts from "ADC"-type chemotherapies, antibodies conjugated to a cytotoxic molecule.
- Rare early Acanthamoeba keratitis (pain+++)