Selective laser trabeculoplasty induced changes in the thickness of ciliary body and iris evaluated by ultrasound biomicroscopy

Changes in peripapillary and macular vascular density after laser selective trabeculoplasty: an optical coherence tomography angiography study

OBJECTIVES

To determine the effect of laser trabeculoplasty on peripapillary retinal nerve fibre layer thickness (RNFL), fovea avascular zone (FAZ), peripapillary and macular vessel density (VD) in glaucoma using with optical coherence tomography angiography (OCT-A).

METHODS

This was a prospective observational study performed at the Glaucoma Research Centre, Montchoisi Clinic, Lausanne, Switzerland. Thirty-seven eyes with primary open-angle glaucoma from 21 patients were included. Optical coherence tomography angiography (OCT-A) scans were performed before laser trabeculoplasty and at 2 and 6 months after the procedure. AngioVue AngioAnalytic (Optovue Inc, Fremont, CA, USA) software was used to analyse the RNFL, FAZ, peripapillary and macular VD. Changes were analysed using mixed models, controlling for intraocular pressure (IOP) and signal strength index (SSI) variations.

RESULTS

Mean IOP decreased from 18.5 (±3.7) mmHg at baseline to 15.6 (±2.7) mmHg after 2 months (-15.3%; p < 0.001). No significant changes in RNFL thickness were noted following laser trabeculoplasty. Changes in peripapillary VD were mostly nonsignificant. Parafoveal (p = 0.001) and perifoveal VD (p = 0.025) significantly increased at 2 months, before reverting to near-baseline values at 6 months. No significant changes were observed in foveal parameters. Retinal nerve fibre layer thickness (RNFL) and VD changes were independent from IOP, but SSI had a significant influence on VD.

CONCLUSIONS

Following laser trabeculoplasty, peripapillary and macular VD temporarily increased before returning to near-baseline values by 6 months. No correlation was found between microvascular fluctuations and IOP, and no significant effect of laser trabeculoplasty on VD or RNFL was observed at 6 months despite persistent IOP reduction. Further research is warranted to understand its exact causes and clinical relevance.

Complications of selective laser trabeculoplasty: a review

Selective laser trabeculoplasty is a laser treatment to treat glaucoma. It was initially indicated for open-angle glaucoma but has been proven to be efficacious for various types of glaucoma. This review article summarizes the few rare complications that can be seen with selective laser trabeculoplasty. It also makes recommendations on how to avoid these problems and how to treat patients when these rare complications arise.