Li Jiang, Scott Eaves, Navpreet Dhillon, Punithawathy Ranjit

To assess and compare the long-term postoperative outcomes of trabeculectomy (TE), phacotrabeculectomy (PTE), and viscocanalostomy (VC) and to correlate postoperative intraocular pressure (IOP) with visual outcome. This retrospective cohort observational study included 520 eyes which underwent TE with mitomycin C (MMC) (n=205), PTE with MMC (n=189), and VC ± combined cataract surgery and MMC (n=126) to control IOP between June 2010 and June 2014 by a single surgeon. Complete success was defined as postoperative IOP <20 mmHg, and qualified success with IOP <20 mmHg with single topical agent. Cases requiring more than one topical agent and/or repeat surgery were considered as failure. Mixed linear regression models were constructed to determine estimated predictive values of demographic data, topical prescriptions, baseline and postoperative IOP, and optical assessment (ie, best-corrected visual acuity and mean deviation) profile. Follow-up ranged from 12 to 66 months (mean 26 months). At last follow-up, 139 (93.9%), 118 (91.5%), and 98 (94.2%) eyes achieved complete success in TE, PTE, and VC groups, respectively (p=0.0007). Failure rates were 2.7%, 3.9%, and 2.9% following TE, PTE, and VC, respectively (p=0.0052). The between-group difference of mean IOP reduction was greater in the short term (p=0.0002). Good postoperative IOP control correlates to optical outcomes reflected by best-corrected visual acuity and mean deviation following TE (β = -4.7577, p=0.0384) and PTE (β = -4.5083, p=0.02741). Significant association was observed between good postoperative IOP control and optical outcome. TE remains the more effective surgical intervention for sustained lowering of IOP. Most complications were transient and self-limiting.