SURGICAL OUTCOMES AND PROGNOSTIC FACTORS OF PARS PLANA VITRECTOMY FOR PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT WITH EXTENSIVE RETINAL INVOLVEMENT

Purpose: To evaluate anatomical and visual outcomes after pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD) involving at least two retinal quadrants and to identify factors associated with surgical prognosis. Methods: This prospective, single-center, single-arm interventional study included 66 eyes of 66 patients with primary RRD involving at least two quadrants who underwent PPV at Hanoi Eye Hospital between February and December 2024. Assessments were performed preoperatively and at postoperative day 1, week 1, month 1, and month 3. Outcomes included retinal reattachment, best-corrected visual acuity (BCVA), intraocular pressure, complications, and prognostic factors. Multivariable logistic regression was used to identify factors independently associated with final anatomical success and BCVA better than 20/200. Results: The mean age was 56.03 ± 16.3 years, 63.6% of patients were male, and all eyes had macula-off RRD. The mean detachment extent was 2.9 ± 0.9 quadrants. Final anatomical success was achieved in 54 eyes (81.8%). Mean BCVA improved from 2.16 ± 0.81 logMAR preoperatively to 1.11 logMAR at 3 months, and 34.8% of eyes achieved BCVA better than 20/60. Greater detachment extent independently reduced the odds of anatomical success (adjusted OR = 0.304, 95% CI: 0.107–0.863; p = 0.025) and BCVA better than 20/200 (adjusted OR = 0.301, 95% CI: 0.145–0.626; p = 0.001). Combined phacoemulsification was independently associated with BCVA better than 20/200 (adjusted OR = 3.785, 95% CI: 1.007–14.223; p = 0.049), but not with anatomical success. Conclusions: PPV achieved favorable anatomical outcomes and meaningful visual improvement in eyes with extensive primary RRD. Detachment extent was the principal independent predictor of both anatomical and visual outcomes. Careful assessment of detachment extent may improve surgical planning and prognostic counseling, while the observed visual association with combined phacoemulsification should be interpreted cautiously.