Clinical and genetic spectrum of genetic eye diseases seen in two newly developed ophthalmic genetics clinics: two-year experience.

Abstract

Background: Genetic eye diseases (GED) are among the top ten leading causes of global blindness. Ophthalmic genetics has emerged as a dedicated subspecialty, integrating clinical and genetic diagnosis with genetic counseling.

Methods: We conducted an electronic and physical medical records search for the patients attending the clinics. Clinical data included patient demographics, presenting complaint, physical exam findings, best-corrected visual acuity (BCVA), available ophthalmic and diagnostic radiology imaging, and genetic testing results.

Results: Electronic medical records of 499 patients were examined; 472 patients were diagnosed with GED. The mean age was 22.7 years. Males represented 57.1% of the patients. The most common diagnosis was isolated retinitis pigmentosa (32.2%), followed by Stargardt disease (11.0%), early-onset severe retinal dystrophy (10.3%), cone dystrophy (7.1%), cone-rod dystrophy (4.7%), autosomal recessive bestrophinopathy (3.6%), and enhanced S-cone syndrome (3.1%). The mean BCVA was 6/48, where 42% exhibited moderate to severe visual impairment, and 24% were classified as blind. Genetic tests were done for 28.8% of the GED patients with a molecular solving rate of 87.5%. Positive cases encompassed 47 genes; the most common were ABCA4 (11.8%), CRB1 (10.1%), BEST1 (8.4%), and NR2E3 (5.9%). Systemic associations were reported by 12.7%. Within this group hearing loss was the most common association encountered (45%), followed by intellectual disability (16.7%), and polydactyly (15%).

Conclusion: This study provides a comprehensive overview of the encountered GEDs spectrum. The data are valuable for refining clinical diagnoses, establishing accurate inheritance patterns, informing family planning, and assessing patient eligibility for emerging gene-targeted therapies.