Real-World Validation of the VIVEX Formula for Vitreous Volume Estimation in Vitreoretinal Surgery: A First Clinical Case Series #MMPMID41361663
Borkenstein AF; Borkenstein EM; Kolesnik A; Malyugin B
Ophthalmol Ther 2025[Dec]; ? (?): ? PMID41361663show ga
BACKGROUND: Accurate, patient?specific estimation of vitreous cavity volume can support planning and safety during vitreoretinal surgery and tamponade procedures. We evaluated the performance of the vitreous volume exact (VIVEX) formula-which predicts vitreous volume from axial length (AL)-in a first clinical case series. METHODS: This retrospective observational case series included 27 eyes undergoing vitreoretinal procedures. Intraoperative volume measurements (aspirated fluid in group?1 (G1), injected silicone oil in group?2 (G2), and removed silicone oil in group?3 (G3)) were compared with VIVEX?predicted volumes computed from AL. Accuracy metrics included mean absolute error (MAE) and mean absolute percentage error (MAPE). Agreement was assessed using Pearson correlation, ordinary least-squares regression (slope, intercept, 95% confidence intervals (CIs)), and Bland-Altman analysis. RESULTS: Across all eyes (N = 27), VIVEX predictions correlated strongly with intraoperative measurements (r = 0.961, p < 0.0001). Overall, MAE and MAPE were 0.48 mL and 7.43%, respectively. Regression yielded a slope of 0.74 (95%?CI 0.65-0.83) and an intercept of 1.17 mL (95%?CI 0.60-1.74). Bland-Altman analysis showed a bias of +0.42 mL with 95% limits of agreement from -0.88 to +1.73 mL. Subgroup results were: G1 (n = 17), MAE 0.33 mL and MAPE 6.09%; G2 (n = 5), MAE 0.39 mL and MAPE 6.9%; G3 (n = 5), MAE 1.07 mL and MAPE 12.51%, with a positive bias indicating slightly higher VIVEX values than intraoperative measurements. CONCLUSIONS: The VIVEX formula demonstrates high correlation and clinically useful accuracy for individualized vitreous volume estimation across common surgical contexts. It seems that the largest error and a positive bias occur during silicone oil removal, warranting caution in oil-filled eyes. In such cases, measurement artifacts due to altered optical pathways in silicone-oil-filled eyes and the possible presence of residual oil remnants after removal may contribute to minor discrepancies between calculated and true intraoperative volumes, indicating a need for further evaluation. Overall, VIVEX may assist preoperative planning and realistic volume targeting in routine practice. As this is the first clinical case series evaluating the VIVEX formula in real surgical settings, larger prospective multicenter studies are needed to confirm and expand the findings.
Ophthalmol+Ther 2025 ; ? (?): ?
