Comparison of surgical outcomes of sponge application versus subconjunctival injection of Mitomycin-C during combined phacoemulsification and trabeculectomy surgery in Asian eyes

Abstract

Purpose: To compare the outcomes of combined phacoemulsification–trabeculectomy surgery with intraoperative sponge-applied versus subconjunctival injection of mitomycin-C (MMC) in Asian eyes. Methods: This was a retrospective review of 95 eyes that consecutively underwent combined phacoemulsification–trabeculectomy surgery in a tertiary eye center in Singapore from January 2013 to June 2014. Data collected included intraocular pressure (IOP), best corrected visual acuity, and number of glaucoma medications. Outcome measures included postoperative IOP and complications at various timepoints up to 12 months after surgery. Results: Twenty eyes (21.1%) received 0.2 mg/ml subconjunctival MMC injection (“Group 1”) and 75 (78.9%) received 0.4 mg/ml sponge-applied MMC (“Group 2”). There was no difference between groups in demographics, IOP, and number of glaucoma medications preoperatively. There was a reduction in IOP at postoperative month (POM) 1, 6, and 12 in both the groups (POM12: Group 1, −2.8 ± 5.36 mmHg, P < 0.001; Group 2, −5.8 ± 6.29 mmHg, P = 0.054). At POM1, Group 2 showed a trend toward greater IOP reduction (−5.89 ± 7.67 mmHg vs. −1.55 ± 5.68 mmHg, P = 0.061). However, at both POM6 and POM12, there was no statistically significant difference in IOP reduction between the two groups. At POM12, complete success, defined as achieving an IOP of between 6 and 15 mmHg without the use of antiglaucoma medications, was achieved in 11 (55%) eyes in Group 1 and 48 (64%) in Group 2 ( P = 0.9). There was a lower rate of postoperative hypotony in the Group 1 (0%) compared to Group 2 (8%) ( P = 0.34). Conclusion: Combined phacoemulsification–trabeculectomy with subconjunctival MMC injection has comparable outcomes to that with sponge-applied MMC, with a similar reduction in IOP at 1, 6, and 12 months postoperatively and a lower postoperative complication rate.

Surgical outcomes of trabeculectomy augmented with sub-Tenon injected mitomycin C

“…One of the major risk factors for decreasing CECD after trabeculectomy is MMC (57). Very few clinical studies investigated the effect of intra-Tenon injection of MMC on endothelial cell count (18)(19)(20)38). Overall, no differences in endothelial cell count between MMC-soaked sponge group and intra-Tenon injection of MMC group were found.…”

“…Overall, the sub-Tenon injection of MMC is considered to be a safe and effective alternative to the conventional soaked sponge method. This method may produce more favourable bleb morphology after trabeculectomy (20,38). On the other hand, little information is available regarding the concentration and dosage of MMC applied using intra-Tenon injection.…”

“…Similarly, a few studies reported the use of MMC at a fi xed concentration and volume. In a very recent study, patients received a sub-Tenon injection of 0.15 ml of MMC at a concentration of 0.1 mg/ml (20). The same concentration of MMC but applied in a volume of 0.1 ml was used in the study by Esfandiari et al (18).…”

“…Various methods o f applying MMC during trabeculectomy surgery such as the traditional sponge method and intra-Tenon injection have been studied (18)(19)(20)(21)(22). However, there are some concerns with the use of sponges, including loss and retention of MMC-soaked sponges, damage to the conjunctiva during sponge manipulation and the limited effi cacy to treat a large area of sclera with sponges (23).…”

Novel Therapies for the Prevention of Fibrosis in Glaucoma Filtration Surgery

“…Although the method of application may affect the rate of surgical failure and complications, multiple studies have found that it does not result in significant differences. In a study looking at Asian eyes, phacoemulsification-trabeculectomy combined with subconjunctival MMC injection had comparable outcomes to that of sponge-applied MMC, with a similar reduction in IOP at 1, 6, and 12 months postoperatively and a lower postoperative complication rate [ 43 ]. However, MMC injection may lower the need for clinic visits within the first 3 postoperative months and reduce the need for 5-FU intervention when compared to MMC sponge application [ 117 ].…”