Asymmetric elongation of foveal tissue after macular hole surgery and its impact on metamorphopsia

Purpose: To evaluate the elongation profile of foveal tissue after macular hole (MH) surgery and to investigate its impact on visual function. Design: Prospective, interventional case series. Participants: Thirty-one eyes from 31 patients who underwent surgery for an MH less than 400 μm in diameter. Methods: The distance between the parafoveal edge of the outer plexiform layer (OPL) was defined as the inter-OPL distance and measured on the basis of optical coherence tomography images at the first postoperative visit and the 2- and 6-month postoperative visits. Further elongation of the foveal tissue in certain directions was defined as asymmetric elongation. The association of the mean degree of asymmetric elongation with visual acuity and metamorphopsia score (M-score) outcome was evaluated. Main Outcome Measures: Inter-OPL distance and M-score. Results: Macular hole sealing was noted in all eyes after surgery. The horizontal inter-OPL distances measured at the defined time points were 361.6±99.6 μm, 558.8±93.3 μm, and 575.4±94.8 μm, respectively. The vertical inter-OPL distances were 324.2±93.8 μm, 481.2±104.6 μm, and 494.6±85.0 μm, respectively. Both the horizontal and vertical inter-OPL distances were increased during the follow-up period (P<0.001). Horizontal inter-OPL distances were significantly longer than vertical distances at 1, 2, and 6 months (P<0.001, P<0.001, and P<0.001, respectively). Further nasal and superior elongation was noted on the horizontal and vertical planes in 90.3% and 61.3% of eyes, respectively. The mean degree of asymmetric spreading was significantly associated with an M-score at 6 months postoperatively (P = 0.044) and a difference in M-score between preoperative and 6-month postoperative examinations (P = 0.027). Conclusions: Elongation of the foveal tissue was noted after MH surgery. This elongation was usually asymmetric, and the degree of asymmetry was associated with postoperative metamorphopsia. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.