Incision Gape and Its Correlation with Surgically Induced Astigmatism in Subconjunctival Oblique Limbus Incision Cataract Surgery.

PURPOSE: To investigate the phenomenon of incision gape following subconjunctival oblique limbus incision (SCOLI) cataract surgery and to quantify its relationship with surgically induced astigmatism (SIA). METHODS: This study enrolled patients with regular corneal astigmatism ≥1.0 diopters (D) undergoing SCOLI. Anterior segment optical coherence tomography (AS-OCT) was used to measure the actual incision gape (ΔG). A theoretical model was developed to calculate the predicted incision gape (theoretical ΔG) based on preoperative keratometry and white-to-white (WTW) distance. The correlation between actual ΔG and SIA was analyzed using linear regression and a multivariate GEE model. RESULTS: Thirty-two eyes of 25 patients were analyzed. A significant positive correlation was observed between actual ΔG and SIA (R = 0.392, p = 0.026). In the multivariate GEE model, after adjusting for age (p = 0.195) and CCT (p = 0.070), actual ΔG remained a significant independent factor associated with SIA (B = 0.004; 95% CI, 0.002-0.006; p < 0.001). The theoretical ΔG showed a strong correlation with both the intraoperative ΔG (r = 0.877, p < 0.001) and the actual ΔG (r = 0.508, p = 0.003). CONCLUSION: A macroscopic incision gape is a prevalent phenomenon in SCOLI and is a significant factor associated with SIA. The developed mathematical model provides a foundation for predicting astigmatic outcomes, highlighting the potential for controlling SIA by surgically modulating the incision gape (ΔG).