Optical coherence tomography in patients with cone-rod dystrophy

Purpose: To analyze morphologic characteristic features in patients with cone-rod dystrophy (CORD) and examine correlation between visual function and morphometric parameters. Methods: 8 patients (aged 16-33, mean 22 yrs) with the clinical diagnosis of CORD underwent OCT (Stratus OCT 3, Zeiss) examination. Foveal thickness (FT) and total macular volume (TMV) were evaluated. Disturbance of central visual acuity was detected at the age of 6-7 yrs. Photoaversion is a common clinical symptom. Results: FT of patients ranged 96-182 micrometers (mean 139.75 +/- 26,1 ), TMV ranged 4,6-7,5 mm³ (mean 5.63 +/- 0,94 ). FT and TMV of the normal cohort in our Institute range between 130-180 micrometers and 6.2-7.2 mm³. Both parameters of the patients showed a decrease of the lower limit compared to the normal values. Alterations observed in the foveal architecture were retinal thinnig and blunting of the foveal pit. There was only a weak positive correlation (r=0,443) between visual acuity and foveal thickness, and it was moderately stronger (r=0,527) between visual acuity and total macular volume Conclusions: OCT is a useful non-invasive additional method in the differential diagnosis of cone-rod dystrophy.