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 deIT) 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 degrees 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.