Long‐term result of combined ab externo Schlemm’s canal surgery and phacoemulsification in management of open angle glaucoma in cataract patients

Abstract

AbstractPurposeTo evaluate the effectiveness of segmental Schlemm’s canal (SC) distension using Kumar’s Schlemm’s canal expander (SCE) in decreasing intraocular pressure (IOP) in cataract patients suffering from open angle glaucoma (OAG).MethodsBetween October, 2012 and March, 2020 in a prospective interventional case series study. SCE device, made from 0.04 mm thick medical grade stainless steel wire, having inner lumen diameter of 0.12 mm and outer – 0.2 mm, 4–5 mm long was implanted into SC ab externo after completion of cataract surgery of 59 patients (38 male and 21 female; average age – 75.47 ± 6.2 years) suffering from OAG. Outcome measures were IOP change, number of glaucoma medications pre‐ and postoperatively and complications. Success rates were evaluated using World Glaucoma Association guidelines. A paired t‐test was used for analysis. Results were significant when p less than 0.05.ResultsMean preoperative IOP was 28+/–4.7mmHg and mean number of medications – 2.4 ± 0.8. At 4 years mean IOP reduced by 27%+/–15.5% and was 20,4+/–4,9 (n=59; p=.0000006) use of medications reduced to 1 ± 1.2 (p = 0.0000001). Complete success was achieved in 24% (14/59) cases and partial – in 49% (29/59) respectively. Intraoperatively, microperforation occurred in 5 cases (8.5%). Postoperatively, 6 cases (10%) required YAG laser trabeculopuncture to control IOP. In these cases, one end of SCE was lying in anterior chamber angle without contact with intraocular structures. Postoperatively, specific complications related to SCE were rare. In one case the body of SCE ruptured TM because of extra pressure put on eye ball while inserting goniolens. Both ends of the expander were embedded in SC. Patient’s IOP was under control with one medication.ConclusionsCombined surgery phacoemulsification with intraocular lens implantation and SCE implantation in surgical management of OAG in cataract patients show significant reduction in IOP from the baseline and in hypotensive medication(s) use in long‐term period.