Short-term effects of deep sclerectomy on retinal vessel density and visual field function in primary open-angle glaucoma

Purpose

To explore the short-term effects of Mitomycin C-augmented non-penetrating deep sclerectomy (NPDS) procedure on the retinal microvasculature and visual field function of eyes with primary open-angle glaucoma (POAG).

Design

Single-arm, non-randomized, interventional prospective study

Methods

22 POAG eyes of 22 patients without previous surgical interventions for glaucoma, whose disease was progressing and/or the intraocular pressure was not at the target level with full topical medications, were allocated to this prospective interventional study. All the patients underwent the NPDS procedure and were followed up for a month. The IOP, Humphrey visual field (HVF) 30–2 (as mean deviation (MD) and pattern standard deviation (PSD)), retinal nerve fiber layer (RNFL), and the vessel density (VD) of the optic nerve head (ONH) and macula (by RTVue XR Avanti OCTA) were evaluated one day before the surgery and one month after the NPDS procedure.

Results

At the one-month post-op follow-up, the IOP was significantly lower than the pre-op visit (8 mmHg vs. 23.5 mmHg, p: <0.001). The visual field MD was significantly better one month after the NPDS procedure (-13.06 dB vs. -15.44 dB, p:0.038), although the PSD did not indicate any significant change. Neither the peripapillary nor the macular VD significantly changed in our follow-up. However, the post-op MD was significantly and positively correlated to the ONH whole image, peripapillary, perifoveal, and parafoveal VD.

Conclusion

The deep sclerectomy procedure is a compelling choice of POAG treatment, which could significantly decrease the IOP. However, this procedure may not alter the retinal microvasculature in a short period. Nevertheless, the positive correlation between retinal VD and the visual field MD proposes a possible vascular mechanism for the visual field defect in glaucomatous eyes.