Sponge-Applied vs Subconjunctival Injection of Mitomycin-C during Phaco-Trabeculectomy in Asian Eyes

Abstract

Purpose : To compare the outcomes of phaco-trabeculectomy with intra-operative sponge-applied versus subconjunctival injection of mitomycin-C (MMC) in Asian eyes.

Methods : A single-centre, retrospective review of consecutive eyes which underwent phaco-trabeculectomy performed by 4 surgeons, from January 2013 to June 2014. Data was collected from pre and post-operative clinical charts. Outcome measures included intraocular pressure (IOP), number of glaucoma medications, best corrected visual acuity (BCVA) and post-operative complications. Outcomes were compared at 1, 6, and 12 months post-operatively.

Results : Data from 108 eyes of 101 subjects were collected. The mean age was 70.0 ± 9.6 (25 to 89) years. 57 (52.8%) eyes and 51 (47.2%) eyes were from male and female subjects respectively. 65 (60.2%) had primary open-angle glaucoma, 25 (23.2%) had primary angle-closure glaucoma and 18 (16.7%) had normal tension and secondary glaucoma. 24 (22.3%) eyes received 0.02% subconjunctival MMC injection (‘Group 1’) and 84 (77.8%) received 0.04% sponge-applied MMC (‘Group 2’). There was no difference between both groups in demographics, baseline IOP and number of glaucoma medications. In both groups, there was a reduction in IOP at both 6 and 12 months post-operatively (12 months: Group 1, -2.8 ± 5.36 mmHg, p=0.052; Group 2, -5.7 ± 6.39 mmHg, p=0.004). Group 2 showed a trend toward greater IOP reduction (-5.86 ± 8.14mmHg) compared to Group 1 (-1.55 ± 7.10 mmHg) at 1 month (p=0.066). However, there was no difference in IOP reduction between both groups at 6 and 12 months. Mean number of glaucoma medications for Group 1 was reduced from 2.84 ± 0.96 pre-operatively to 0.37 ± 0.50 (p=0.002) at 12 months. Mean number of medications for Group 2 were reduced from 2.74 ± 0.73 to 0.18 ± 0.56 (p<0.001). There was no difference in reduction of medications and BCVA between both groups. Post-operative bleb manipulation procedures (bIeb needling, flap lift, bleb revision) were required in 2 (4.17%) eyes in Group 1 and 9 (10.71%) eyes in Group 2. 2 (4.17%) eyes in Group 1 and 3 (3.57%) eyes in Group 2 experienced hypotony post-operatively.

Conclusions : Phaco-trabeculectomy with either sponge-applied or subconjunctival MMC injection is effective in lowering the IOP and the number of glaucoma medications up to 12 months post-operatively. There was no significant difference in outcomes between both groups.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.