Corneal Dystrophy, Congenital Stromal

Clinical Characteristics
Ocular Features: 

This rare congenital form of stromal dystrophy is sometimes considered a disorder of collagen fibrils with abnormally small diameters.  These may appear disorganized in areas.  Corneal opacities are often evident at birth or during the neonatal period.  Numerous small spots of fluffy, flaky deposits are found throughout the stroma creating a diffuse cloudy appearance and these may become more numerous with age indicating some progression.  The epithelium, Descemet membrane and the endothelium are not affected and the stroma is of normal or slightly increased thickness.  In some areas abnormal fibrillar layers are seen.  Although corneal erosions and photophobia are usually not clinically significant, acuity may be as low as hand motions and penetrating keratoplasty may be indicated.  In one series this was necessary at an average age of 20 years.  In the same series of 11 patients, 4 had strabismus, 3 eyes developed open angle glaucoma and band keratopathy was present in one patient.  Nystagmus has not been reported.

Deposition of abnormal decorin contributes to the stromal opacities. 

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

This is a rare autosomal dominant stromal dystrophy that results from a mutation in the DCN gene on chromosome 12 (12q21.3).  Several frameshift mutations have been reported    in the decorin (DCN) gene causing premature truncation of the protein product.

Treatment
Treatment Options: 

Penetrating keratoplasty can be successful in restoring vision.  Grafts have been reported to remain clear for up to 36 years in more than half of the patients in one series but opacities recurred in others.

References
Article Title: 

References

Bredrup C, Stang E, Bruland O, Palka BP, Young RD, Haavik J, Knappskog PM, Rodahl E. Decorin accumulation contributes to the stromal opacities found in congenital stromal corneal dystrophy. Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5578-82.

PubMedID: 20484579

R??dahl E, Van Ginderdeuren R, Knappskog PM, Bredrup C, Boman H. A second decorin frame shift mutation in a family with congenital stromal corneal dystrophy. Am J Ophthalmol. 2006 Sep;142(3):520-1.

PubMedID: 16935612

Bredrup C, Knappskog PM, Majewski J, R??dahl E, Boman H. Congenital stromal dystrophy of the cornea caused by a mutation in the decorin gene. Invest Ophthalmol Vis Sci. 2005 Feb;46(2):420-6.

PubMedID: 15671264