Abstract
Purpose :
Foveal anatomy is abnormal in albinism patients, but correlation with function is incompletely understood. This study correlates multifocal (mfERG) and full field (ffERG) electroretinograms, optical coherence tomography (OCT) and visual acuity (VA) in albinism patients and compares with age-matched controls.
Methods :
Prospective ERGs and retrospective chart review. Diagnosys ffERG and VERIS mfERG were obtained using standard ISCEV protocols. Macula OCT and VA data were obtained by chart review. Nonparametric permutation testing was utilized to determine significance.
Results :
13 albinism patients (7 males, 6 females, mean age 14.8 years, range 6-46) and 16 controls (5 males, 11 females, mean age 23 years, range 9-47) were included. mfERG: 9 of 13 albinism patients had Ring 1 amplitudes within 1 standard deviation (SD) of controls (75+/-25 nV/deg2), even in the absence of a visible fovea on OCT. Patients averaged lower amplitudes and shorter latencies in Ring 1 than controls (p=0.0197; p=0.034). However, patients averaged higher amplitudes than controls in Rings 5 and 6 ((p=0.035). There was no significant correlation between VA and mfERG amplitudes in any Ring (highest r=-0.19, p=0.27, Ring 1). ffERG: Patients averaged higher amplitudes on 30 Hz flicker (p≤0.05), a-waves in all conditions (p≤0.02), and b-waves in light adapted 3.0 (p=0.022) than controls. There was no correlation between ffERG amplitudes and VA (highest r=0.16; p=0.33, 30 Hz flicker). OCT and VA: In patients, thicker central macula on OCT correlated with lower mfERG amplitudes in Rings 1 and 2 (r=-0.54; r=-0.61, p<0.05) and lower a-wave amplitudes on ffERG (r=-0.634, p=0.024). There was no correlation between OCT macular thickness and VA (r=-0.179, p=0.28).
Conclusions :
Conclusions:
Neither ERG amplitudes nor foveal thickness on OCT correlate with VA in albinism, although they negatively correlate with each other. This suggests that foveal hypoplasia is not the only cause of decreased vision in albinism. ERG is not helpful for diagnosis or prognosis in albinism.
References: Ophthalmology. 1989 Dec;96(12):1778-85; Am J Ophthalmol 2006;14(6):1156-8; Invest Ophthalmol Vis Sci. 2014 May 20;55(7):4186-98. doi: 10.1167/iovs.13-13217.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.