Pre- and Post-Phacoemulsification Morphologic Iridocorneal Angle Analysis by Anterior Segment Gonioscopic Imaging as a Predictor of Postoperative Glaucoma in Dogs.

OBJECTIVE

To serially assess iridocorneal angle (ICA) gonioscopic morphology following phacoemulsification in dogs and to determine whether postoperative changes are associated with the development aphakic/pseudophakic glaucoma.

ANIMALS STUDIED: Client-owned dogs presented for cataract removal by phacoemulsification.

PROCEDURES: All enrolled eyes underwent preoperative and serial postoperative gonioscopic ICA imaging using a retinal imaging camera (RetCam), with images acquired from all four quadrants at baseline and at scheduled postoperative timepoints up to 1 year. Images were evaluated for angle width and pectinate ligament dysplasia (PLD) severity, which were integrated into a ZibWest Angle Index score for each eye at each timepoint. Clinical outcomes, including the development of glaucoma, were recorded throughout the study period.

RESULTS

Thirty-nine dogs (74 eyes) were included, and 29 dogs (74.3%) completed the study through the final 1-year follow-up. Iridocorneal angle morphology changed significantly over time, including angle width, PLD, and Zibwest Angle Index score. Despite these changes, no statistically significant associations were found between pre- or postoperative ICA morphology and the subsequent development of aphakic/pseudophakic glaucoma.

CONCLUSION

Gonioscopically visible aspects of the canine ICA undergo significant morphologic change following phacoemulsification. However, within this study population and study period, no association was identified between preoperative ICA morphology and postoperative glaucoma. Larger longitudinal studies and imaging modalities that assess deeper angle structures may help refine postoperative glaucoma risk prediction.