METHODS: It is a prospective, randomized, comparative, interventional study. Ninety-five patients with nonclearing VH were randomized to receive PPV with normalized IOPs of 15 mmHg (Group I: 32 eyes), 25 mmHg (Group II: 32 eyes) and 35 mmHg (Group III: 31 eyes) at the end of surgery. The grade of vitreous opacity and best-corrected visual acuity (BCVA) on postoperative day 1, week 1, month 1 and month 3 were compared with a mixed model for repeated measures analysis.
RESULTS: All 3 groups achieved significant improvement on postoperatively in BCVA (p < 0.01) and vitreous opacity (p < 0.01) compared with the baseline. The group difference was significant at the end of week 1 and showed a trend of higher IOP set at the end of PPV with better anatomical (p < 0.01) and visual recovery (p < 0.01). However, at postoperative month 1 and month 3, equivalent anatomical (month 1: p = 0.56; month 3: p = 0.36) and visual outcomes (month 1: p = 0.16; month 3: p = 0.88) were obtained in the 3 groups. The average effect of IOP on BCVA (group II versus group III: effect size (ES): 0.41, p < 0.01; group I versus group III: ES: 0.66, p < 0.01) and vitreous opacity (group II versus group III: ES: 0.70, p < 0.01; group I versus group III: ES:1.09, p < 0.01) over the course of the study period was statistically significant. The only postoperative complication was recurrent VH in two patients allocating in group I and II, respectively.
CONCLUSIONS: A relatively higher IOP set at the end of vitrectomy resulted in a more stable and rapid recovery with fewer complications in patients with non-complex VH.