Epithelial basement membrane dystrophy

Epithelial basement membrane dystrophy (EBMD), also known as Map-dot-fingerprint dystrophy and Cogans's microcystic dystrophy, is a disorder of the eye, sometimes included in the group of corneal dystrophies. It diverges from the formal definition of corneal dystrophy in being in most cases non-familial. It also has a fluctuating course, while for a typical corneal dystrophy the course is progressive.

Pathophysiology

In some families autosomal dominant inheritance and point mutations in the TGFBI gene encoding keratoepithelin have been identified,[1] but according to the International Committee for Classification of Corneal Diseases (IC3D)[2] the available data still does not merit a confident inclusion of EBMD in the group of corneal dystrophies. In view of this, the more accurate designation of the disease is possibly not dystrophy but corneal degeneration.[3]

The main pathological feature of the disease is thickened, multilaminar and disfigured basement membrane of corneal epithelium. The change in the structure affects the epithelium, some cells of which may become entrapped in the rugged membrane and fail to migrate to the surface where they should undergo desquamation.

Clinical presentation

EBMD is a bilateral anterior corneal dystrophy characterized by grayish epithelial fingerprint lines, geographic map-like lines, and dots (or microcysts) on slit-lamp examination. Findings are variable and can change with time. While the disorder is usually asymptomatic, up to 10% of patients may have recurrent corneal erosions, usually beginning after age 30; conversely, 50% of patients presenting with idiopathic recurrent erosions have evidence of this dystrophy.[4]

Treatment

Phototherapeutic keratectomy (PTK) done by an ophthalmologist can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies including EMBD.[4]

See also

References

  1. ↑ Boutboul S, Black GC, Moore JE, Sinton J, Menasche M, Munier FL, Laroche L, Abitbol M, Schorderet DF (June 2006). "A subset of patients with epithelial basement membrane corneal dystrophy have mutations in TGFBI/BIGH3". Hum. Mutat. 27 (6): 553–7. doi:10.1002/humu.20331. PMID 16652336.
  2. ↑ Weiss JS, Møller HU, Lisch W, Kinoshita S, Aldave AJ, Belin MW, Kivelä T, Busin M, Munier FL, Seitz B, Sutphin J, Bredrup C, Mannis MJ, Rapuano CJ, Van Rij G, Kim EK, Klintworth GK (December 2008). "The IC3D classification of the corneal dystrophies". Cornea 27 (Suppl 2): S1–83. doi:10.1097/ICO.0b013e31817780fb. PMC 2866169. PMID 19337156.
  3. ↑ David Verdier. Dystrophy "Map-dot-fingerprint". eMedicine.
  4. ↑ 4.0 4.1 Online 'Mendelian Inheritance in Man' (OMIM) 121820