Comparison of Two Scleral Incision Techniques in 23-Gauge Transconjunctival Vitrectomy

BACKGROUND AND OBJECTIVE: To compare two 23-gauge transconjunctival vitrectomy incision techniques, parallel and perpendicular to the alignment of scleral fibers, in terms of hypotony and postoperative intraocular pressure (IOP). PATIENTS AND METHODS: Fifty-three eyes of 53 patients who underwent 23-gauge one-step trocar pars plana vitrectomy were randomly assigned to undergo scleral incision parallel (group 1, 26 eyes) or perpendicular (group 2, 27 eyes) to the limbus. Patients were observed postoperatively for wound healing, leakage, endophthalmitis, IOP, and hypotony at 1 day, 1 week, and 1, 3, 6, and 9 months. RESULTS: No difference in preoperative IOP was observed (P = .229). Postoperative IOP was significantly lower in group 2 (P = .009). Hypotony rates did not differ between the groups. Intraocular gas or silicone tamponade was used intraoperatively in 26 cases. In cases in which no gas or silicone was given (n = 27), IOP measurements were significantly lower in group 2 (P = .021). There was no difference in hypotony ratios for gas/silicone injection versus no injection (P = 1.00) or in postoperative visual acuity (P = .350). Visual acuity improved significantly in both groups at follow-up examinations. CONCLUSION: Parallel and perpendicular incisions resulted in similar postoperative hypotony rates, but perpendicular incisions were associated with lower IOP.