Comparison of long-term visual and anatomical outcomes between internal limiting membrane flap and peeling techniques for macular holes with a propensity score analysis

Abstract

Objectives: To compare visual and anatomical outcomes between internal limiting membrane (ILM) flap (IF) and peeling (IP) techniques for full-thickness macular holes (FTMHs).

Methods: A retrospective case series with propensity-score matching (PSM). Patients with a minimum 12 months follow-up were divided into IF and IP groups and matched based on FTMH size and preoperative best-corrected visual acuity (BCVA). BCVA and optical coherence tomography (OCT) findings were obtained to assess outer retinal layer integrity, foveal thickness, and foveal displacement.

Results: Twenty-six eyes were included in each group after PSM. The IF group showed significantly greater BCVA after 1 month, its corresponding change from preoperative BCVA, proportions of eyes with ellipsoid zone defects <250 μm after 1 month, and interdigitation zone restoration after 6 and 12 months (P = 0.007, 0.038, 0.048, 0.025, and 0.023, respectively), as well as less foveal gliosis after 1, 3, 6, and 12 months (P = 0.020, 0.017, 0.050, and 0.024, respectively). In the IP group, the mean outer nuclear layer thickness significantly decreased at 3 (P = 0.019) and 12 months (P = 0.016) compared to 1 month, and the foveal displacement toward the optic disc was significant after 1, 3, 6, and 12 months (P = 0.049, 0.006, 0.001, and <0.001, respectively).

Conclusions: Compared to IP, IF promoted faster recovery of BCVA and outer retinal layers and was more protective against postoperative foveal thinning and displacement; hence, it should be considered for small and large FTMHs.

Fig. 1. Preoperative and postoperative mean best-corrected visual acuity (BCVA) for internal limiting membrane flap (IF) and peeling (IP) groups.

BCVA at 1 month was significantly greater in the IF group (vertical brace). *P < 0.05; **P < 0.01; ***P < 0.001. Grey horizontal braces are for the IP group and black horizontal braces are for the IF group. LogMAR, logarithm of the minimum angle of resolution; M month.

Fig. 2. Status of outer retinal layers at postoperative follow-ups for internal limiting membrane flap (IF) and peeling (IP) groups.

A Proportion of ELM restoration. B Proportion of EZ < 250 μm. EZ < 250 μm cases include OFMD and EZR cases. C Proportion of IZ restoration. D Proportion of foveal detachment. E Proportion of foveal gliosis. *P < 0.05. ELM external limiting membrane, EZ ellipsoid zone, EZR complete ellipsoid zone restoration, IZ interdigitation zone, M month, OFMD outer foveal microdefect.

Fig. 3. Time-dependent alterations of retinal thickness at postoperative follow-ups for internal limiting membrane flap (IF) and peeling (IP) groups.

A ELM-RPE distance. B ONL thickness. *P < 0.05; **P < 0.01. ELM external limiting membrane, RPE retinal pigment epithelium, ONL outer nuclear layer, M month.

Fig. 4. Degree of foveal movement at postoperative follow-ups for internal limiting membrane flap (IF) and peeling (IP) groups.

A Change in the distance between the fovea and optic disc in eyes. B Change in the distance between the fovea and the superior retinal vessel. C Change in the distance between the fovea and the inferior retinal vessel. *P < 0.05; **P < 0.01; ***P < 0.001. M month.