Abstract:  Objective To analyze the impact of primary posterior capsulotomy (PC) in phaco-vitrectomy on postoperative refractive outcomes and anterior chamber depth (ACD). Design Prospective non-randomized controlled study. Parcitipants Between September 1, 2021 and September 30, 2022, 50 patients (50 eyes) in the triple group who underwent Phaco-vitrectomy combined with PC surgery due to full-thickness macular hole, epiretinal membrane, or vitreoretinal traction syndrome, and 50 patients (50 eyes) in the control group who needed cataract extraction combined with IOL implantation due to cataracts were prospectively recruited. Methods The Barrett UII formula was used to calculate the IOL power for all the patients. The best corrected visual acuity, refractive error (PE), anterior chamber depth (ACD), standard deviation, mean absolute error, median absolute error, and percentage of eyes with PE within ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D for all patients before and 1 month after surgery were checked and recorded. Main Outcome Measures Postoperative PE and ACD. Results The postoperative PE of the control group was 0.054 ± 0.397 D, and that of the triple group was -0.091±0.668 D. Both groups showed no systematic error compared to 0 (t=0.962, P=0.341, and t=-0.963, P=0.340, respectively). The postoperative ACD in both groups deepened compared to preoperative levels, with a control group of 4.407±0.324 mm and a triple group of 4.259±0.254 mm. However, the ACD in the triple group was shallower than that in the control group, with a significant difference (t=2.537, P=0.013). The accuracy of refractive prediction in the triple group patients was poor, manifested as higher standard deviation, mean absolute error, and median absolute error compared to the control group, while the percentage of eyes in all given PE ranges was lower than that in the cataract group. Conclusions Compared with the cataract group, simultaneous use of PC during phaco-vitrectomy resulted in a significant shallowness in ACD at 1 month post-surgery. Although the triple group did not show significant myopic or hyperopic errors, its accuracy in predicting refractive error was significantly lower than that of the cataract group. (Ophthalmol CHN, 2024, 33: 200-204)

Key words: cataract, pars plana vitrectomy, posterior capsulotomy, refractive error, anterior chamber depth