Defining a Cutoff for Progression of Macular Holes.

Purpose The purpose of this study was to determine a cutoff for progression of idiopathic full-thickness macular hole (MH) size. Methods Retrospective analysis of consecutive patients waiting 4 weeks for MH surgery. Two observers performed 3 repeat sets of MH size measurements on optical coherence tomography (OCT) high-density radial scans taken at first presentation and 4 weeks later before surgery. Primary outcome was the definition of a cutoff for true enlargement of MH size versus measurement error. Secondary outcomes were risk factors for change in minimum linear diameter (MLD) size and best-corrected visual acuity (BCVA). Results Fifty-one patients were included with a mean MH size of 334 µm (±179 µm; range 39 to 793 µm). The cutoff for an increase in MLD size calculated as the outer confidence limit for the 99.73% limits of agreement was 31 µm. This was independent of MH size. Using this cutoff, MLD size increased in 9/34 (26.5%) of patients without and in 14 of 17 (82.4%) of patients with vitreomacular traction (VMT; P 400 µm) changed over the 4-week period. Conclusions Using a cutoff discriminates change from measurement error. A significant proportion of MHs progressed by 4 weeks, particularly in the presence of VMT. Translational Relevance The established cutoff enables clinicians to differentiate true MH enlargement from measurement error.