J Korean Ophthalmol Soc.  2021 Feb;62(2):253-260. 10.3341/jkos.2021.62.2.253.

Effect of Reducing Intraocular Pressure on Vessel Density after Trabeculectomy Using Optical Coherence Tomography Angiography

• Kang MS
• Kwon JM
• Shin J

• KMID: 2512946
• DOI: http://doi.org/10.3341/jkos.2021.62.2.253

Abstract

Purpose
To evaluate peripapillary and macular vessel density changes in glaucoma patients after lowering intraocular pressure (IOP) by trabeculectomy, using optical coherence tomography (OCT) angiography.
Methods
A retrospective study was conducted on 20 glaucomatous eyes that underwent trabeculectomy. Preoperative and postoperative IOP, peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell-inner plexiform layer thickness, peripapillary and macular vessel density measured by OCT, and OCT angiography were analyzed by the Wilcoxon signed-rank test. A regression analysis was performed to identify the factors influencing the change in vessel density.
Results
The mean IOP was 31.0 ± 11.80 mmHg prior to surgery, 11.47 ± 4.52 mmHg at 1 month (p < 0.001), and 11.52 ± 3.34 mmHg at 6 months (p < 0.001). Peripapillary RNFL thickness (p = 0.002) increased significantly 6 months postoperatively. Peripapillary vessel density increased significantly 6 months after surgery (p = 0.007) and the magnitude of the reversal of peripapillary vessel density was significantly associated with a greater reduction in IOP (p < 0.001), and the lower preoperative peripapillary vessel density value (p = 0.003) and change in peripapillary vessel density increased significantly. The improvement in peripapillary RNFL thickness was associated with a greater reduction in the IOP (p = 0.011).
Conclusions
Measuring peripapillary vessel density using OCT angiography was useful to identify the reversible changes in optic nerve damage caused by reducing IOP after trabeculectomy.

Keyword

Glaucoma, Optical coherence tomography angiography, Vessel density