Prospective evaluation of penetrating deep sclerectomy in advanced open-angle glaucoma: Filtration surgery adapted to resource scarcity in developing countries.

PURPOSE

Two of the hurdles that are facing ophthalmologists in developing countries are scarcity of resources and patient follow-up. Deep sclerectomy (DS) has proven less costly and more effective than topical therapies and has a more favorable safety profile than trabeculectomy. The main factors preventing its use in developing countries are the need to perform laser goniopuncture in 40-80% of cases to maintain filtration and the risk of postoperative iris incarceration. The purpose of this study is to assess the efficacy and safety profile in advanced open-angle glaucoma of a relatively new surgical technique designed to overcome this limitation: penetrating DS.

SETTING

This was an investigator-initiated, prospective, interventional study, conducted at a single ophthalmology center in Kinshasa, Congo. The study was conducted in full compliance with the Declaration of Helsinki.

METHODS

Fifty-one eyes (34 patients) with uncontrolled advanced primary open-angle glaucoma (visual field mean deviation<-10 dBs) were enrolled between October 2012 and June 2016. Age, gender, comorbidities (hypertension/diabetes), best-corrected visual acuity, topical medications, medicated and unmedicated intraocular pressure (IOP) were recorded. All patients underwent penetrating DS, during which, following standard dissection of the scleral flaps, the anterior chamber was penetrated through the trabeculo-Descemet membrane and an iridectomy was performed. Patients attended postoperative appointments at months 1, 3, 6 and 12. Surgical success was defined as a 20% reduction of IOP from baseline in conjunction with a 12-month unmedicated IOP≤12mmHg.

RESULTS

The mean age was 64.5±14.0 years (44.1% female, 100% African). Mean IOP decreased from 20.2±6.1 (medicated) and 30.7±9.8mmHg (unmedicated) preoperatively to 12.1±4.1 at 12 months. Concomitantly, the number of topical medications decreased from 1.5±0.7 to 0.0. Complete surgical success was achieved in 64.7%. Four eyes (7.8%) were considered surgical failures due to uncontrolled IOP. None of the eyes lost light perception or required additional surgery. A significant association between surgical failure and hypertension was observed (HR=1.49; P=0.008). There were no intraoperative complications. Postoperatively, 4 bleb encapsulations (7.8%) and 1 iris incarceration (2%) were observed.

CONCLUSIONS

The present study demonstrates that penetrating DS achieved similar efficacy and safety results to traditional non-penetrating DS. In addition, it showed a lower potential for intraoperative complications, which might be associated with a more benign surgical learning curve. Finally, the rates of serious postoperative complications (iris incarceration, choroidal effusion and hypotony) were significantly lower than in DS and trabeculectomy, and this technique does not require subsequent Nd: YAG laser goniopuncture to maintain filtration, making frequent follow-up visits less critical. In view of these findings, perforating deep sclerectomy could offer a viable option for glaucoma management in developing countries as well as worldwide.