Macular sensitivity and fixation patterns in patients with autosomal dominant optic atrophy

INTRODUCTION: The objective of this study was to test macular sensitivity, fixation stability and fixation location using microperimetry in patients with autosomal dominant optic atrophy (ADOA) and mutation-free relatives.

MATERIAL AND METHODS: This was a cross-sectional study of 43 patients with exon 28 (2826 delT) mutation in OPA1 (age 11.7-71.5 years, best-corrected visual acuity (BCVA) 20/24-20/13). The patients and 49 mutation-free first-degree relatives (BCVA 20/25-20/10) underwent ophthalmic examination including macular microperimetry out to 12° eccentricity with registration of fixation stability and fixation location.

RESULTS: The average (± standard deviation) sensitivity was significantly reduced in ADOA patients compared with controls, 14.9 (± 4.4) dB versus 19.7 (± 0.4) dB (p < 0.0001). In a retinotopic projection, the largest relative sensitivity deficits in ADOA were seen in the nasal macula (13.6 (± 5.7) dB versus 19.7 (± 0.7) dB) and in the central macula (14.2 (± 5.1) dB versus 19.9 (± 0.3) dB). The average sensitivity decreased with decreasing BCVA in ADOA (p < 0.0001). Stable fixation was found in 58% of ADOA patients versus 86% of controls, and relatively unstable fixation was observed in 35% of ADOA patients versus 14% of controls. Unstable fixation was found only in ADOA, where its prevalence was 7%.

CONCLUSION: ADOA was associated with unstable fixation and subnormal microperimetric sensitivity, especially in the central and nasal macula where the ganglion cell deficit is most pronounced.

FUNDING: The study was supported by Øjenfonden, Øjenforeningen, and Synoptikfonden.

TRIAL REGISTRATION: NCT01522638.