Purpose: To evaluate the natural history of Familial Exudative Vitreoretinopathy (FEVR) with emphasis on the effect of the age of onset on its severity and on the development of late complications such as cataract and retinal detachment. Also, to evaluate affected patients for DNA abnormalities.
Methods: The records of thirty-nine patients with FEVR were studied. All were asked to come in for a final follow-up examination. The referring physician was asked to provide the latest findings for those who could not. On 10 patients, karyotypes were prepared.
Results: Only 2 of 28 patients whose onset of symptoms was prior to their third birthday had a final visual acuity of 20/200 or better. Older patients had a better prognosis, because they were more likely to have asymmetrical retinal deterioration with only one eye deteriorating. Preservation of good visual acuity into the teens and later was no guarantee that deterioration would not occur. In 3 eyes of 4 patients who were asymptomatic until 15 years of age, the final visual acuity was counting fingers or worse. In 5 patients, retinal detachment developed 6 to 17 years after apparent stabilization. The karyotype of 10 patients showed no evidence for rearrangement, altered size, translocations or deletions of chromosome 11 or any other chromosome. Of the 31 eyes in patients older than 15 years, 10 (32%) had a significant cataract. Three eyes underwent cataract surgery.
Conclusions: The prognosis for infants with FEVR is extremely poor and the long-term prognosis for patients with a later onset of the condition is guarded. Retinal detachment, macular dragging, and cataract are common late complications which can develop even in patients whose eye findings appear to be stable. Karyotype studies ruled out involvement of chromosome 11 or others at a gross level, but did not exclude them at the location for some genetic defect related to FEVR because single base changes and small deletions or insertions may be undetectable by the methods utilized.