Superficial degeneration is in most cases detected before the age of 20 years. It is not associated with other eye disorders or with systemic diseases.
Posterior dystrophy is quite common. The patients are often older than 40.
Symptoms and findings
Depending on the form of disease, the following may be seen:
map- or fingerprint-like or, sometimes, blister-like lesions of the superficial cornea
reduced visual acuity, increased astigmatism
painful corneal erosions
recurrent epithelial erosions, particularly in the morning when opening the eyes
accumulations of some material in various corneal layers.
In some forms of the disease, visual acuity can remain good for a long time and the eye can be asymptomatic.
Workup
Visual acuity
Corneal tomography and biomicroscopy
Gene tests are recommended for the differential diagnosis of certain types of degeneration.
In stromal degeneration, they are recommended for testing the TGFBI gene defects.
If the Meretoja syndrome (Finnish-type familial amyloidosis http://www.orpha.net/en/disease/detail/85448) is suspected, the gelsolin gene c.640G>A gene defect should be tested for.
Treatment
An ophthalmologist will perform a more detailed diagnosis and classification of corneal degeneration.
Treatment varies depending on the type of disease.
In superficial degeneration, phototherapeutic keratectomy (PTK, laser treatment of the superficial corneal tissue) may be considered.
In stromal degeneration, moisturising drops are useful.
Partial thickness or penetrating corneal transplantation is considered in advanced disease.
References
Seppänen M, Kaarniranta K, Setälä N, Uusitalo H (eds.). [Handbook of Ophthalmology]. 3rd revised edition. Duodecim Publishing Company 2022. Available in Finnish.