External limiting membrane and visual outcome in macular hole repair: spectral domain OCT analysis

To investigate the relationship between postoperative visual acuity and integrity of the external limiting membrane (ELM) and inner segment-outer segment (IS-OS) junction layers, using spectral domain optical coherence tomography (SD-OCT), in eyes with macular holes (MHs) following surgical repair.

Medical charts of MH-operated cases were retrospectively identified and reviewed. The primary outcome measures were best-corrected visual acuity (BCVA) and the status of the ELM and IS-OS lines, using SD-OCT, at 6 weeks and 6 months postoperatively.

Sixty-two eyes of 62 patients were included. At 6 weeks following surgery, out of 56 (90.3%) eyes with successful MH closure: 0 eyes showed the combination of disrupted ELM and continuous IS-OS layers; 7 eyes (12.5%) demonstrated continuity of both ELM and IS-OS (ELM(c)/IS-OS(c) group); 29 eyes (51.8%) had continuous ELM with discontinuous IS-OS layers (ELM(c)/IS-OS(d) group); and 20 eyes (35.7%) had discontinuities in both the layers (ELM(d)/IS-OS(d) group). The ELM(d)/IS-OS(d) group had the lowest visual gain at 6 months (P = 0.03). At 6 months, a restoration of the integrity of IS-OS layer was observed in 51.7% eyes in the ELM(c)/IS-OS(d) group and in 5% in the ELM(d)/IS-OS(d) group (P = 0.001).

When both ELM and IS-OS layers showed disruptions 6 weeks postoperatively, a significantly worse BCVA was measured at 6 months, compared with the eyes with only IS-OS disruptions, detected 6 weeks following surgery. The integrity of the ELM layer appears to be a critical factor for the restoration of the photoreceptor layer and for predicting a successful visual outcome following MH repair.