Effect of trabeculectomy on retrobulbar circulation and visual field progression in patients with primary open-angle glaucoma

Abstract

BackgroundThe purpose of this study was to investigate the relationship between retrobulbar circulation and visual field change in eyes with primary open-angle glaucoma following unilateral trabeculectomy.MethodsTwenty-one patients with primary open-angle glaucoma were prospectively enrolled. Retrobulbar circulation was evaluated using color Doppler imaging. The peak systolic velocity, end-diastolic velocity, and resistive index were evaluated in the central retinal artery, temporal site of the short posterior ciliary artery (t-SPCA), and nasal site of the short posterior ciliary artery (n-SPCA). Visual field examinations were performed using a Humphrey visual field analyzer before surgery and trimonthly for 12 months postoperatively.ResultsIn the operative eyes, the end-diastolic velocity was significantly increased in the central retinal artery (P = 0.005, analysis of variance), t-SPCA (P = 0.005), and n-SPCA (P = 0.027). The resistive index was significantly decreased in the central retinal artery (P = 0.003), t-SPCA (P = 0.000), and n-SPCA (P = 0.010) postoperatively compared with preoperatively. The nonoperative contralateral eyes did not show a significant change in end-diastolic velocity or resistive index for either the SPCA or central retinal artery. The mean deviation slope in the operative eyes (−0.26 ± 0.64 dB/year) was significantly slower than that in the nonoperative eyes (−0.65 ± 0.70 dB/year; P = 0.047, Mann-Whitney U test).ConclusionThese results suggest that trabeculectomy improves the retrobulbar circulation and prevents the progression of visual field changes in patients with primary open-angle glaucoma.

Changes in choroidal thickness, axial length, and ocular perfusion pressure accompanying successful glaucoma filtration surgery

“…In our study, OPP significantly increased after trabeculectomy. These results were similar to those of the studies by Yamazaki et al 17 and Berisha et al, 5 both of whom found a significant increase after trabeculectomy. Also, many previous studies measured SFCT with EDI-OCT and they found that it was significantly associated with OPP.…”

Changes in choroidal thickness and optic nerve head morphology after filtering surgery: nonpenetrating deep sclerectomy versus trabeculectomy

“…According to Kara et al, choroidal thickening is related to an OPP increase induced by IOP reduction [24]. This corresponds to the retrobulbar blood flow rising observed after trabeculectomy [37]. Nickla and Wallman presumed that the choroidal thickness increase stemmed from two mechanisms [38]: first the synthesis of osmotically active proteoglycans, which help pull water into the choroid; second, to the increase in the size or number of the choriocapillaris vessels.…”

“…Explanation for this thickening remains uncertain. Previous studies hypothesized that the vessel size could increase due to a rise in ocular blood flow [37]. Reis et al also suggested that this modification is caused by size changes in RGC axons and astrocytes after IOP reduction [28].…”

Influence of glaucoma surgery on visual function: a clinical cohort study and meta‐analysis

“…Only a few earlier studies reported on a surgery-induced MD decline. Most studies found no influence on the MD (Tavares et al 2006;Sehi et al 2010;Yamazaki & Hayamizu 2012;Balekudaru et al 2014;Wright et al 2015;Islamaj et al 2018); one study found a deterioration of the MD after a TE (Hagiwara et al 2000). In the latter study, the postoperative MD was assessed at the end of the follow-up (mean follow-up duration was 4.75 years).…”