The following variables were analyzed: sex, age, preoperative best corrected visual acuity (pre-BCVA), BCVA 6 months after the surgery (6M-BCVA), the axial length of eye (EL), the minimum diameter of FTMH, the diameter of basal side of FTMH, the continuity of subfoveal ellipsoid zone (EZ) and external limiting membrane (ELM) 6 months after the surgery, and the preoperative presence or absence of LHEP. We did not include the presence or absence of ERM as a variable for the statistical analysis because ERM did not exist in all cases of FTMH without LHEP and exists in all cases of FTMH with LHEP in this study.
Canonical correlation analysis was used to evaluate the relationships between preoperative parameters (e.g., sex, age, pre-BCVA, EL, the minimum diameter of FTMH, the diameter of basal side of FTMH, and the presence of LHEP) and postoperative parameters (e.g., 6M-BCVA, the continuity of subfoveal EZ and ELM 6 months after the surgery).
If present, LHEP was gently peeled together with ERM with a special care to avoid tearing it from the FTMH edge.
Twenty-eight eyes had FTMH with LHEP (group A) and 130 without LHEP (group B).
The minimum MH diameter, the diameter of basal side of FTMH, and the presence of LHEP were inversely correlated with the postoperative continuity of EZ and ELM.
Previous reports stated that FTMH with LHEP accounts for 8-9.6% of all FTMH cases [6, 7].
In this study, there was no difference in the smallest FTMH diameter between FTMH with and without LHEP. This result is at odd with previous reports [10, 11].
The result of canonical correlation analysis demonstrated strong positive association of preoperative BCVA with postoperative BCVA and inverse relationship of the FTMH diameter and the presence of LHEP with the postoperative photoreceptor integrity.
In conclusions, we performed a comparative study of surgical outcomes for FTMH with and without LHEP. The preoperative presence of LHEP was inversely associated with the postoperative functional and morphological outcome.
Caption: Figure 2: Typical OCT finding of FTMH with LHEP, which have a fluid cuff (white arrowheads).