Visual Acuity and Refractive Status in Congenital Macular Coloboma

Purpose: We analysed the refractive state and the factors that influence the best-corrected visual acuity (BCVA) in congenital macular coloboma (CMC) to provide new ideas for improving and predicting the vision of patients with CMC.

Methods: We reported three patients and reviewed 26 cases of CMC reported in the China National Knowledge Infrastructure (CNKI) database. We measured the BCVA, spherical equivalent refraction (SER), the macular coloboma's diameter and area, and the distance from the macular coloboma's nasal edge to the optic disc's temporal edge (DISTANCE). We analyzed the refractive status of CMC and the factors affecting BCVA.

Result: The three patients with CMC we reported all had myopia. The study also included 26 patients with CMC reported in the CNKI database (9 unilateral, 17 bilateral) and we analyzed the findings of 26 patients with 43 eyes. The mean age at diagnosis was 22.96 ± 2.32 years. All patients underwent a comprehensive eye examination; 39 eyes (91%) had myopia (44% mild myopia; 28% moderate myopia; 28% high myopia); 23 eyes (53%) had a BCVA ≤6/60 and other 20 eyes (47%)>6/60. No correlation was found between SER or BCVA and the macular coloboma's diameter or area. BCVA correlated positively with DISTANCE (r = 0.603, p < 0.001). No correlation was found between SER and DISTANCE. The study found a significant difference in SER or BCVA between the affected and fellow eyes in patients with unilateral CMC (n = 9, T=-3.259, p = 0.012; Z=-2.521, p = 0.012, respectively).

Conclusion: CMC seriously affects visual acuity. The refractive state is mostly myopia. We hypothesize that the DISTANCE is related to the integrity of the papillomacular bundle and affects BCVA.