Analysis of the progression rate of idiopathic macular holes and the optimal cut-off for baseline minimum linear diameter and base diameter

Purpose: To determine the cut-off points of minimum linear diameter (MLD) and base diameter (BD) at which the progression rate of idiopathic full-thickness macular holes (MHs) decreases before vitrectomy. Study design: A retrospective study. Methods: We investigated the differences in MLD and BD between baseline and operation days in patients with stages 2, 3, and 4 MHs using optical coherence tomography (OCT). Each difference in OCT parameters was divided by the time interval to calculate the MH progression rates and the cut-off points of MLD and BD. Results: Overall, 269 patients (282 eyes) were included. It took an average of 36.02 ± 24.69 (7–197) days from baseline to operation. MLD and BD progressed faster in stages 2 and 3 without posterior vitreous detachment (PVD) than in stage 4 with PVD (MLD: p < 0.001 and p = 0.007; BD: p < 0.001 and p = 0.019, respectively). Simple linear regression showed the relationship between baseline MLD and BD, and the progression rate; the progression rate decreased as baseline MLD (p = 0.004) and BD increased (p < 0.001). For baseline MLD and BD, the cut-off points where the progression rate decreased were 306.0 and 470.0 μm, respectively. Conclusion: The group without PVD progressed faster than the group with PVD. Moreover, the progression rates were faster in MHs with MLD < 306.0 μm and BD < 470.0 μm. In these patients, vitrectomy without delay is expected to improve the visual prognosis.