VERTICAL AND HORIZONTAL METAMORPHOPSIA ONE YEAR AFTER SURGERY FOR MACULAR HOLES ≤ 500 µ m WITH AND WITHOUT INVERTED INTERNAL LIMITING MEMBRANE FLAP.

PURPOSE: To investigate the effect of an inverted internal limiting membrane flap (IF) and other factors on metamorphopsia after macular hole surgery. METHODS: Prospective case series of patients undergoing pars plana vitrectomy with gas tamponade, with either conventional internal limiting membrane peeling (CP) or an IF, for primary idiopathic macular holes ≤ 500 µ m. Vertical and horizontal metamorphopsia were measured as M-scores (degrees) using M-charts preoperatively and at 2, 6, and 12 months postoperatively. RESULTS: Fifty-three eyes of 53 patients were included of whom 27 underwent CP and 26 were treated with an IF. After macular hole surgery, all patients were pseudophakic. Vertical and horizontal metamorphopsia improved from 1.08 (±0.51) and 0.98 (±0.70) preoperatively to 0.58 (±0.37) and 0.45 (±0.36) at 2 months ( P < 0.01), with no further significant improvement at 6 months (0.39 [±0.31], P = 0.07 and 0.31 [±0.28], P = 0.18) or at 12 months (0.37 [±0.30], P = 0.72 and 0.28 [±0.28], P = 0.99). There was no significant difference in the mean vertical and horizontal metamorphopsia between patients with CP and with an IF at 2 months ( P = 0.063, P = 0.10), 6 months ( P = 0.25, P = 0.16), or 12 months ( P = 0.62, P = 0.22). Preoperative vertical M-score improved at 12 months after macular hole surgery by 61% and 64% in the CP and IF groups, respectively ( P = 0.84), and the horizontal M-score by 65% and 71%, respectively ( P = 0.98). CONCLUSION: The use of an IF has no evident bearing on the degree of postoperative metamorphopsia 12 months after surgical repair of macular holes ≤ 500 µ m.

Repeatability and Reproducibility of Macular Hole Size Measurements Using Optical Coherence Tomography.

The purpose of this study was to assess the repeatability and reproducibility of measuring the minimum linear diameter (MLD) of macular holes (MHs) using horizontal linear and radial scan modes in optical coherence tomography (OCT). Patients with concurrent sets of radial and horizontal linear OCT volume scans were included. The MLD was measured twice in both scan modes by six raters of three different experience levels (groups). Outcome measures were the reliability and repeatability of MLD measurements. Fifty patients were included. Mean MLD was 317.21(±170.63) µm in horizontal linear and 364.52 (±161.71) µm in radial mode, a difference of 47.31 (±26.48) µm (p < 0.001). In the radial scan mode, MLD was identified within 15° of the horizontal meridian in 27% and within 15° of the vertical meridian in 26.7%, with the remainder (46.3%) in oblique meridians. The intra-group coefficients of repeatability (CR) for horizontal linear mode were 23 µm, 33 µm and 45 µm, and for radial mode 25 µm, 44 µm and 57 µm for groups 1, 2 and 3, respectively. The inter-group CR, taking group 1 as reference standard for groups 2 and 3, were 74 µm and 71 µm for the linear mode, and 62 µm and 78 µm for radial mode. The radial mode provides good repeatability and reliability for measurement of MLD. In a majority of cases the MLD does not lie in the horizontal meridian and would be underestimated using a horizontal OCT mode.