Purpose
Macular hole pathogenesis is believed to involve tractional forces that are not fully understood. In this study, we characterized retinal vascular remodeling after surgical relief of these forces.
Methods
Preoperative and one to 15-month postoperative fundus images of 9 patients who had macular hole surgery were retrospectively examined. Surgery consisted of vitrectomy and internal limiting membrane peeling from arcade to arcade with adjuvant use of indocyanine green. Postoperative images were registered and scaled to preoperative images by using custom software. Vessel landmarks were identified in both images by using a point-and-click method to create coordinate point-pairs, and the displacement of each landmark was illustrated upon fundus images as vector plots (e.g. Figure 1). Total displacement was the largest movement in any direction and radial displacement was movement relative to the center of the macular hole. Relationships between displacement magnitudes and hole size and eccentricity (distance from center) were examined by using Pearson correlations. Differences in mean regional displacements (superior vs. inferior hemispheres) were examined by using Mann-Whitney tests.
Results
In each photo, we identified 20 point-pairs with mean eccentricity of 2175 ± 885 µm (± SD; range: 644 to 4898 µm). Vector plots depicted a general post-surgical movement nasally and toward the horizontal raphe (Figure 1). On average, displacement was nasal in all 9 patients (mean 91 ± 56 μm) and was also directed toward the center of the hole in 7 of 9 (78%) patients (mean 27 ± 108 μm). Displacement magnitudes were not correlated with hole size (total displacement, r=0.04, p=0.90) and were not correlated with eccentricity (radial r=0.07, p =0.99; total r=0.04, p=0.92). Regionally, mean radial and total displacements were not different between superior and inferior hemispheres (radial, p=0.29; total, p=0.82). Statistically, the minimum detectable difference in radial and total displacement was 117 μm (α=0.05, β=0.20, n=9).
Conclusions
After macular hole surgery, retinal vessels shift inward toward the hole, but also shift more nasally. This magnitude of shift is not correlated with hole size or eccentricity based on points sampled. This suggests that surgery relieves tractional forces directed away from the hole and also temporally.
Keywords: 586 macular holes •
762 vitreoretinal surgery •
763 vitreous