A multifocal electroretinography study to evaluate risk of developing macular hole in the fellow eye of patients suffering with unilateral macular hole

BACKGROUND: Visual outcome of eyes has often been found to be unsatisfactory even after successful closure of a macular hole, owing to factors like persistent metamorphopsia, scotoma, and reduced sensitivity. Therefore, it becomes critical to evaluate and study the probability and risk of developing a macular hole in the fellow eyes of the patient. This study analyzed the multifocal electroretinographic responses to help predict the risk of macular hole development in fellow eyes. METHODS: In total 26 fellow eyes, 26 eyes with macular hole, and 50 eyes of 25 controls were enrolled prospectively. The retinal responses from the different rings were compared in the three groups. Optical coherence tomography was done to rule out macular pathology or vitreomacular traction in the fellow eyes. RESULTS: All the fellow eyes under observation showed significantly reduced mean amplitudes of retinal response densities, in all rings as compared with controls (31.45 ± 10.38 versus 48.87 ± 7.55, p = 0.00). Three of the fellow eyes developed a macular hole during the 24 months observation period. The prevalence of fellow eye involvement was 11.5%. Relative risk of developing macular hole in the fellow eye ranged from 25 to 75. CONCLUSION: All the fellow eyes, including those that did not develop a macular hole, showed significantly reduced responses on multifocal electroretinogram. This indicates that macular hole may not be a focal disease. It may have widespread functional deficit which is bilateral in nature and suggestive of a degenerative or ischemic insult.