Abstract
Purpose: :
To determine the prevalence, hereditary pattern, age of onset of symptoms, time of diagnosis and classification of chorioretinal dystrophies in an ophthalmologic referral center in Mexico City.
Methods: :
The clinical records from July 2004 to July 2007 of patients seen by the retina and genetic clinics at our institution were reviewed retrospectively. We evaluated sex, age at the beginning of the symptoms, age at diagnosis, hereditary pattern and classification of the retinal dystrophies.
Results: :
We identified 256 cases of chorioretinal dystrophies in 3 years. The most common dysthropy in our series was retinitis pigmentosa with 42% of all the cases, followed by Stargardt disease with 15 % of all cases. There was a higher prevalence in the female gender (54% vs. 45%) in our patients affected by retinitis pigmentosa, Leber congenital amaurosis and Bardet-Biedl syndrome. The inheritance pattern of retinitis pigmentosa was: 45% were sporadic, 38.5% were autosomic recessive, 11% autosomic dominant and 5.5% X-linked recessive. Syndromic retinitis pigmentosa presented an autosomic recessive pattern in 100% of the cases. Cone rod-dysthropies were sporadic in 62.5% and autosomic recessive in 29.2%. 61% of all dystrophies were rod-cone dystrophies, 12% cone dystrophies, 15% retinal pigmented epithelium, 11% cone-rod dystrophies and only 1% choroidal dystrophies. We obtained the standard error by founding the difference between the age of beginning of the symptoms and the age of diagnosis. We found that cone-rod dystrophies were the first ones to be detected, followed by the choroidal ones. Both had the least time span between beginning of the symptoms and diagnosis.
Conclusions: :
Chorioretinal dystrophies are rare disorders in our population. We found that our series shows almost the same pattern as in other countries. We found that our patients seek help only when visual acuity diminishes and the rest of the symptoms are frequently ignored. It is important to know the epidemiology of chorioretinal dysthropies so we can give accurate genetic counseling and maybe in the future detect them at an early stage could improve the visual prognosis.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • degenerations/dystrophies • retinal degenerations: hereditary