Risk assessment of sudden visual loss following non-penetrating deep sclerectomy in severe and end-stage glaucoma

To assess the risk of immediate sudden visual loss ("wipe-out" phenomenon) following non-penetrating deep sclerectomy (NPDS) for end-stages glaucoma within the first 6-months postoperative period.

Monocenter database study. We reviewed the results for 73 eyes with severe or end-stage glaucoma that underwent NPDS. End-stage glaucoma (stage 5) was defined by the inability of patients to perform the Humphrey visual field test or by a visual acuity <20/200 due to glaucoma, according to the Glaucoma Staging System classification. Severe glaucoma (stage 4) was defined by a mean deviation (MD) <-20 dB by the preoperative 24-2 Humphrey visual field assessment. All eyes had a severe defect on the central 10° visual field: only a central island of vision remained. "Wipe-out" was defined as the permanent postoperative reduction of visual acuity to <20/200 or to "counting fingers" or less if preoperative visual acuity was <20/200.

The mean age was 60 years (range 22-86). Before surgery, the average MD (Humphrey 24-2) was -25.6 ± 3.8 dB, the MD (Humphrey 10-2) -19.9 ± 7.0 dB, and the VFI 24.6 ± 13%. There were no cases of postoperative flat anterior chamber. No patients experienced "wipe-out" within the first 6 months following surgery. At the six-month visit, intraocular pressure (IOP) had decreased significantly from 22.0 ± 8.8 to 13.5 ± 4.5 mmHg (P<0.001). There were no significant changes in mean visual acuity after 6 months (P = 6).

In our study, NPDS provided considerable IOP decrease with no occurrences of "wipe-out" and few other complications. Consideration of NPDS in end-stage and severe glaucoma is advisable given its low risk of intraoperative and postoperative complications and the low risk of wipe out. This surgery should probably be offered with less apprehension about the risk of "wipe-out" in end-stages glaucoma.