Anterior Capsule Contrast and Capsulorhexis Geometry Across Visualization Systems in Cataract Surgery: An Exploratory Image-Based Comparison

Introduction: Objective, image-based comparisons of anterior capsule visualization across conventional microscopy and digital heads-up visualization systems remain limited. This exploratory retrospective study quantitatively compared capsule contrast and capsulorhexis geometry among conventional microscopy and two successive generations of a digital heads-up system, both of which apply yellow digital filtering. Methods: This retrospective, non-randomized observational study included 67 eyes of 60 patients undergoing phacoemulsification using a conventional microscope (21 eyes) or NGENUITY with yellow filtering [version 1.4 (N1.4; 25 eyes) or 1.5 (N1.5; 21 eyes)], with visualization modality determined by clinical availability at the time of surgery. Color contrast ratio (CCR), ovality index, and concentricity were quantified from masked video analysis using linear mixed-effects models (patient as random intercept) with Holm–Bonferroni-adjusted comparisons. Results: Mean CCR was significantly higher in both NGENUITY groups than the Microscope group (N1.4: 1.55 ± 0.55; N1.5: 1.70 ± 0.29; Microscope: 1.14 ± 0.09; both p ≤ 0.008), with no difference between versions. The ovality index was significantly lower in the N1.5 group than the Microscope group (2.90 ± 1.78% vs. 5.08 ± 3.38%; p = 0.022), though this difference did not reach significance in the per-patient sensitivity analysis (p = 0.071); no significant difference was observed between the Microscope and N1.4 groups. Concentricity did not differ significantly among groups. Conclusions: Anterior capsule contrast, as captured in recorded surgical video, was objectively higher with NGENUITY than with conventional microscopy, whereas a modest improvement in capsulorhexis circularity was observed only with version 1.5. These exploratory, hypothesis-generating findings are intended to motivate, rather than substitute for, a prospective, randomized, within-system study; they provide a standardized measurement framework showing that contrast parameters differ across visualization modalities, while geometric advantages across system generations warrant confirmation in such future studies.