Front Med (Lausanne). 2022 Mar 7;9:830678. doi: 10.3389/fmed.2022.830678. eCollection 2022.

ABSTRACT

OBJECTIVE: To assess anterior segment optical coherence tomography angiography (AS-OCTA) imaging of the episcleral vessels before and after trabecular bypass minimally invasive glaucoma surgery (MIGS).

DESIGN: A prospective, clinical, single-centre, single-arm pilot feasibility study conducted at National University Hospital, Singapore.

SUBJECTS: Patients with primary glaucomatous optic neuropathy undergoing Hydrus Microstent (Ivantis Inc., Irvine, CA, USA) implantation, who require at least one intra-ocular pressure-lowering medication. One or two eyes per patient may be enrolled.

METHODS: We performed AS-OCTA (Nidek RS-3000 Advance 2, Gamagori, Japan) pre- and up to 6 months post-MIGS implantation using a standard protocol in all cornealimbal quadrants, to derive episcleral vessel densities (VD) using a previously described technique.

MAIN OUTCOME MEASURES: Episcleral VD pre- and post-surgery, in sectors with and without the implant.

RESULTS: We obtained serial AS-OCTA images in 25 eyes undergoing MIGS implantation (23 subjects, mean age 70.3 ± 1.5, 61% female) with mean preoperative intraocular pressure (IOP) of 15.5 mmHg ± 4.0. We observed reductions in postoperative episcleral VD compared to preoperative VD at month 1 (mean difference -3.2, p = 0.001), month 3 (mean difference -2.94, p = 0.004) and month 6 (mean difference -2.19, p = 0.039) in sectors with implants (overall 6 month follow-up, p = 0.011). No significant changes were detected in episcleral VD in the sectors without implants (p = 0.910).

CONCLUSION: In our pilot study, AS-OCTA was able to detect changes in the episcleral VD following trabecular bypass MIGS, which may be a useful modality to evaluate surgical outcomes if validated in future studies.

PMID:35321475 | PMC:PMC8936187 | DOI:10.3389/fmed.2022.830678