Can postoperative dexamethasone nanoparticle eye drops replace mitomycin C in trabeculectomy?

Gauti Jóhannesson,María Soffía Gottfredsdóttir,Einar Stefánsson,Guðrún Marta Ásgrimsdóttir,Thorsteinn Loftsson

doi:10.1111/aos.14370

Gauti Jóhannesson, María Soffía Gottfredsdóttir + Show 3 more

Open Access

https://doi.org/10.1111/aos.14370

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Abstract

Compare (a) nonmitomycin C (MMC) trabeculectomy and 1.5% dexamethasone nanoparticle (DexNP) eye drops postoperatively with (b) trabeculectomy with MMC and Maxidex® eye drops postoperatively. Randomized prospective single masked clinical trial with 20 patients with primary open-angle glaucoma undergoing primary trabeculectomy. The study group consisted of 10 patients without MMC intraoperatively and postoperative DexNP eye drops, and the control group consisted of 10 patients treated with MMC intraoperatively and postoperative Maxidex® . The drops were tapered out over 8weeks. The main outcome measures were as follows: rates of complete success, that is intraocular pressure (IOP) within target pressures at different time-points without IOP-lowering medication, or reoperation. Secondary outcome measures included the following: relative success rate (with IOP-lowering medications), number of glaucoma medications and reoperations. Patients were followed for 36months. Both groups showed similar postoperative course and IOP reduction. Intraocular pressures (IOPs) in the DexNP group and in the control group were 25.6 and 24.4mmHg, respectively, at baseline. Intraocular pressures (IOPs) were reduced to 13.2 and 14.5mmHg at 12months, 11.7 and 12.6mmHg at 24months and 11.7 and 12.1mmHg at 36months, respectively. There were no statistically significant differences between the groups in absolute (p=0.36) or relative (p=1.0) success rates, number of medications (p=0.71) or reoperations (p=1.0) between the groups at any time-point. DexNP eye drops are effective postoperative treatment following trabeculectomy. The potent anti-inflammatory and antifibrotic effect of DexNP may offer an alternative to mitomycin C in glaucoma surgery.

Highlights

Trabeculectomy is the most commonly used method of filtration surgery performed to lower intraocular pressure (IOP) in glaucoma (EGS 2014), and it is still considered by many to be the gold standard in glaucoma surgery (Conlon et al 2017)
The study included a total of 20 patients with primary open-angle glaucoma (POAG) undergoing primary trabeculectomy because of poorly controlled IOP and/or intolerance to topical eye drops
The study group included 10 subjects treated with dexamethasone nanoparticle (DexNP) without mitomycin C (MMC), and the control group included 10 subjects treated with MMC and MaxidexÒ (Fig. 1)

Summary

Introduction

Trabeculectomy is the most commonly used method of filtration surgery performed to lower IOP in glaucoma (EGS 2014), and it is still considered by many to be the gold standard in glaucoma surgery (Conlon et al 2017). The procedure, in which an alternative outflow pathway for aqueous humour is created, sparks a healing reaction in which the body tries to close the pathway through inflammation and scarring, potentially causing the surgery to fail. To counteract this reaction, mitomycin C (MMC) is frequently used intraoperatively. Mitomycin C is a naturally occurring compound with an antiproliferative activity. It acts as an alkylating agent after enzyme activation, resulting in DNA cross-linking (Seibold et al 2012). MMC is a potent antifibrotic agent that reduces scar tissue formation and its use in trabeculectomy results in higher success rates (Wilkins et al 2005; Cabourne et al 2015)

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