Central 10-degree visual field change following non-penetrating deep sclerectomy in severe and end-stage glaucoma: preliminary results.

Purpose: To report the impact of non-penetrating deep sclerectomy (NPDS) in severe and end-stage glaucoma treatment on the central 10° visual field progression (mean deviation, four central points, foveal threshold) and assess the risk of sudden visual loss.

Methods: Monocenter database study. We reviewed records of 34 eyes with severe or end-stage glaucoma that underwent NPDS between 2009 and 2015, at the National Ophthalmology Center of XV-XX (Paris, France). Severe and end-stage glaucoma were defined according to the Bascom Palmer Modified Glaucoma Staging System classification. All eyes had a constricted visual field < 10° (severe injury by the Humphrey visual field automated (HVFA) 10-2). Visual fields were recorded every 6 months after the procedure. Data from the last visit was used for the statistical analysis.

Results: The mean follow-up duration was 29 months (range 6 to 54) and 33 (97%) eyes were followed for more than 1 year. There were no cases of postoperative sudden visual loss. The intraocular pressure (IOP) decreased from 21.9 ± 8.1 to 15.0 ± 5.4 mmHg (P < .001). Twenty-eight (82%) eyes had an IOP < 21 mmHg and 19 (56%) an IOP < 16 mmHg. The MD 10-2 remained stable (- 19.8 ± 7.4 to - 19.4 ± 8.1 dB, non-significant improvement of + 0.4 dB, P = .1). The MD 10-2 slope showed an insignificant improvement of + 0.25 ± 1.8 dB per year (dB/y) (P = 0.1), but this slope was significantly better when the IOP was reduced to < 16 mmHg than when the IOP was ≥ 16 mmHg at the last visit (+ 0.84  1.2 versus - 0.48 ± 2.2 dB/y, P = .05). The mean number of the four central test points with sensitivity ≤ 5 dB and the change in mean sensitivity of the four central field points remained stable. There were no significant changes in the VFI (from 25.4% ± 13 to 25.8% ± 20) and in foveal threshold.

Conclusion: NPDS appears to provide stability of the central 10° visual field (with a trend towards improvement but non-significant) with no occurrence of "wipe-out" phenomenon and few other complications. Consideration of NPDS in end-stage and severe glaucoma is advisable given its low risk of complications and its considerable IOP decrease with a relative stability of the central visual field.