Anatomic Changes Induced By Brimonidine Measured By Swept-Source Optical Coherence Tomography Of Anterior Segment

Published 2024 - 42nd Congress of the ESCRS

Reference: PP18.06 | Type: Free paper | DOI: 10.82333/y4ma-8n96

Authors: Lucia Del Carmen Gabian Fortes* ¹ , Pablo Alexis Limón Zurita ²

¹Anterior Segment,Fundación Hospital Nuestra Señora de la Luz IAP,Mexico City,Mexico;Uveitis,Fundación Hospital Nuestra Señora de la Luz IAP,Mexico City,Mexico, ²Anterior Segment,Fundación Hospital Nuestra Señora de la Luz IAP,Mexico City,Mexico

Purpose

To quantitatively determine the decrease in pupillary diameter induced by brimonidine using SS-OCT, as well as to evaluate the induction of other anatomical changes not previously described.

Setting

Brimonidine has slight miotic properties without inducing refractive changes, making it an adjunct therapy to reduce halos and glare in patients undergoing phacorefractive surgery. However, there is limited literature on the magnitude of miosis and other anterior segment anatomical changes that could be induced by this medication.

Methods

Cross-sectional, experimental, or quasi-experimental (interventional) study. Sample: n=64. To achieve a power of 95% and a significance level of 5%, to detect a mean difference of 0.12 between pairs, assuming the standard deviation of differences is 0.18. Outcome Measures: Pupillary diameter in millimeters, Angle opening distance, Iris thickness, Lens thickness, Anterior chamber depth, and Lens vault.

Swept-source optical coherence tomography will be performed using the ANTERION® system to generate the depth profile and cross-sectional image, with a resolution of 10um and 65 B-scans per second. 0.2% brimonidine will be instilled (Nor-tenz ophthalmic solution 2 mg/mL, Grin Laboratories). After 60 minutes, SS-OCT scanning will be repeated.

Results

More females (60%) than males (40%) participated, mean age of 63.90 (SD: 11.47) years. Differences in paired variables pre and post brimonidine were analyzed; significant differences were found in pupil diameter, angular opening distance, iris thickness, and anterior chamber depth. Pupil diameter and iris thickness decreased post-brimonidine (4.17 vs 3.19, p= .000) and (351.7 vs 341.06, p=.014) respectively. Angular opening distance increased post-brimonidine (.412 vs .455, p=.000). Anterior chamber depth increased post-brimonidine (3.274 vs 3.284, p= .000). Significant differences were observed in pupil diameter, angular opening distance, anterior chamber depth, and lens vault with and without brimonidine.

Conclusions

The Instillation of 0.2% brimonidine induces a decrease in pupillary diameter and angle opening, but decreasing the depth of the anterior chamber. Lens vault increases with the instillation of 0.2% brimonidine. While lens or iris thickness don´t have any significant changes with the instillation of 0.2% brimonidine.