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Updated: Apr 29, 2026
An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach
Published on: December 7, 2016
Comparison of Preoperative Subconjunctival Injection, Intraoperative Subconjunctival Injection, and Soaked Sponges as
Pradtana Hirunpatravong1, Nopphawan Uramphorn1, Tharnsook Kasemsup1
1Department of Ophthalmology, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok, Thailand.
Purpose:
This study evaluated the efficacy and safety of 3 mitomycin C (MMC) delivery methods in trabeculectomy for uncontrolled primary open-angle glaucoma (POAG): preoperative subconjunctival injection, intraoperative subconjunctival injection, and conventional soaked sponges.
Methods:
In this randomized controlled pilot study, 25 patients were assigned to 3 groups: Group A received a preoperative subconjunctival injection of 0.1 mL MMC 0.002% 2 weeks before surgery; Group B received an intraoperative subconjunctival injection of 0.1 mL MMC 0.01%; and Group C received MMC 0.02% via soaked sponges during surgery. Patients were followed for 6 months. Primary outcome was surgical success-complete [intraocular pressure (IOP) 5-21 mm Hg with ≥30% reduction from baseline without medications] or qualified (with medications). Secondary outcomes included IOP, medication use, best-corrected visual acuity, and complications.
Results:
At 6 months, complete success rates were 75.0% (Group A), 66.7% (Group B), and 50.0% (Group C) (P = 0.54). Mean baseline IOP was 17.40 ± 4.43 mm Hg with 3.64 ± 0.70 medications. Postoperative IOPs were 9.88 ± 2.70, 10.67 ± 4.06, and 10.38 ± 5.04 mm Hg in Groups A, B, and C, respectively (P = 0.92). Medication use postoperatively was lowest in Group A (0 ± 0), compared to Groups B (0.7 ± 1.0) and C (0.4 ± 1.1) (P = 0.30). Visual outcomes and complication rates were similar across groups.
Conclusions:
In this pilot study, all MMC delivery methods demonstrated comparable success rates, IOP reduction, and safety outcomes. Subconjunctival MMC injections show promise as a viable alternative to the conventional sponge application. However, due to the small sample size, further larger-scale studies are warranted to validate these findings.
