Corneal Dystrophy, Fleck

Clinical Characteristics
Ocular Features: 

This stromal dystrophy may be congenital as it can be seen in the first years of life.  It is nonprogressive and generally has little clinical significance as it does not impair vision or require treatment in most cases.  It is usually diagnosed on routine examination from the presence of multiple, minute, whitish or grayish discrete opacities throughout the stroma.  The largest numbers are located centrally and posteriorly.  These may be flat, round or oval, and sometimes resemble snowflakes.  Keratocyte cell bodies contain cytoplasmic inclusions or vacuoles likely as the result of defective intracellular organelle trafficking.  Other layers such as the epithelium, Bowman layer, Descemet and endothelium are normal.  Expressivity is highly variable with considerable asymmetry of opacities in the two eyes and even unilateral involvement.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

This is an autosomal dominant stromal dystrophy resulting from mutations in the PIKFYVE (PIP5K3) gene on chromosome 2 (2q35).  A variety of missense, frameshift, and protein-truncating mutations have been found.  The gene product is a member of the phosphoinositide 3-kinase family that regulates the synthesis, sorting, and transportation of intracellular multivesicular bodies.

Treatment
Treatment Options: 

No treatment is required in most cases.

References
Article Title: 

References

Li S, Tiab L, Jiao X, Munier FL, Zografos L, Frueh BE, Sergeev Y, Smith J, Rubin B, Meallet MA, Forster RK, Hejtmancik JF, Schorderet DF. Mutations in PIP5K3 are associated with Francois-Neetens mouchetee fleck corneal dystrophy. Am J Hum Genet. 2005 Jul;77(1):54-63.

PubMedID: 15902656

Nicholson DH, Green WR, Cross HE, Kenyon KR, Massof D. A clinical and histopathological study of Francois-Neetens speckled corneal dystrophy. Am J Ophthalmol. 1977 Apr;83(4):554-60.

PubMedID: 141212

Goldberg MF, Krimmer B, Sugar J, Sewell J, Wong P. Variable expression in flecked (speckled) dystrophy of the cornea. Ann Ophthalmol. 1977 Jul;9(7):889-96.

PubMedID: 302662