Changes in Flow Density Measured Using Optical Coherence Tomography Angiography after iStent Insertion in Combination with Phacoemulsification in Patients with Open-Angle Glaucoma.

Maged Alnawaiseh,Larissa Lahme,Viktoria Müller,Nicole Eter,Ralph Laurent Merté

doi:10.1155/2018/2890357

Abstract

Purpose To evaluate changes in flow density after the implantation of a trabecular microbypass stent (iStent) in combination with cataract surgery. Methods A total of 48 eyes of 48 patients, who underwent either cataract surgery alone (cataract group) or cataract surgery with implantation of two iStent inject devices (iStent group), were prospectively included in this study. Intraocular pressure (IOP) and flow density data before and after surgery were extracted and analyzed. Results In the iStent group, the mean IOP was 18.2 ± 3.3 mmHg prior to surgery and 13.2 ± 2.3 at follow-up, and this difference was statistically significant (p < 0.001). The mean IOP in the cataract group also improved significantly after surgery (before: 17.1 ± 2.4; after: 15.1 ± 2.7 p = 0.003). The flow density (whole en face) in the superficial and deep retinal OCT angiogram of the macula (superficial: p = 0.002; deep: p = 0.034) and in the ONH (p = 0.011) improved significantly after surgery in the iStent group. The differences in the cataract group were not significant. Conclusions Flow density of the macula and ONH, as measured by OCTA, improved significantly after cataract surgery with iStent. Noninvasive quantitative analyses of flow density provide a new parameter, which can help for the monitoring of therapy success after glaucoma surgery.

Highlights

Glaucoma is a leading cause of irreversible blindness worldwide, and its prevalence is projected to rise in the future
The aim of this study is to evaluate the impact of implantation of a trabecular microbypass stent (iStent) insertion in combination with phacoemulsification on the flow density of the macula and optic nerve head (ONH) as measured using Optical coherence tomography angiography (OCTA)
The iStent has become an important player among microinvasive glaucoma surgeries

Summary

Introduction

Glaucoma is a leading cause of irreversible blindness worldwide, and its prevalence is projected to rise in the future. The treatment of glaucoma is based on a lowering of intraocular pressure to minimize the risk of visual loss [1, 2]. The microbypass stent or iStent is a small intraocular implant, which is inserted ab interno, sits within Schlemm canal, and reduces the IOP in mild to moderate glaucoma combined with a favorable safety profile [3,4,5,6]. It is possible to quantify the blood flow in the retina and ONH using OCTA, and a number of studies have demonstrated a reduced disc perfusion in patients suffering from glaucoma with this imaging procedure [9, 13, 14]

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