Consensual Ophthalmotonic Reaction in Fellow Eyes in the Early Postoperative Period Following Unilateral Glaucoma...

Consensual ophthalmotonic reaction (COR) refers to consensual intraocular pressure (IOP) change in the fellow eye following alteration of IOP in one eye. The study aimed to investigate COR and the magnitude of consensual IOP change after unilateral glaucoma surgery.

We analyzed 356 eyes from 293 patients who underwent unilateral trabeculectomy, bleb needling, trabectome, or microcatheter-assisted trabeculectomy (MAT) between 2016 and 2022. In the fellow eye, baseline IOP was compared with IOP at 1 day, 1 week, 1 months, 3 months, and 6 months postoperatively. Fellow eyes with IOP change exceeding 4 mmHg or 20% increase from baseline were defined as fellow eyes with COR. Univariate and multivariate analysis were performed to identify influencing factors associated with COR and IOP change in the fellow eye.

In fellow eyes, IOP was 18.3 ± 7.3 mmHg at baseline, significantly increasing to 19.3 ± 7.5 mmHg at postoperative day 1 (POD1) and remaining stable at other time points, with a COR incidence of 40.7% (145 eyes) at POD1. Univariate and multivariate analysis identified preoperative use of α₂-receptor agonists in the fellow eye as a significant protective factor against COR after trabeculectomy and bleb needling. We also identified that key influencing factors for COR varied by surgery type: pseudophakia in the fellow eye was protective in trabeculectomy, history of diabetes was a risk factor for bleb needling, and prior glaucoma surgery predicted COR after trabectome. Greater IOP reduction in the operated eye correlated with a larger consensual IOP rise following minimally invasive glaucoma surgery (MIGS) procedures.

Collectively, our findings suggest that COR is a common early postoperative phenomenon regardless of glaucoma surgery type, and the preoperative use of α₂-receptor agonists is associated with a lower incidence of COR. Therefore, it is essential to monitor IOP in the fellow eye perioperatively.