Pseudophakia Is Associated With an Increased Risk of Post-Operative Fibrin Formation in Dogs Undergoing Phacoemulsification Compared to Elective Aphakia.

Objective: To evaluate the occurrence and effect of fibrin formation following phacoemulsification in dogs with pseudophakia and elective aphakia.

Animal studied: A total of 193 eyes (116 dogs) undergoing phacoemulsification with or without intraocular lens implantation.

Procedures: Retrospective evaluation of medical records (2016-2020) from a private referral clinic in the United Kingdom. Signalment, pre-operative ophthalmic findings, surgical parameters, postoperative complications, and duration of follow-up were evaluated. All surgeries were performed by one surgeon using one hydrophobic acrylic lens (LOKI; Cristalens). Cross-tabulations and Fisher's exact tests were used to evaluate associations between lens implantation, fibrin formation, and visual outcome at 6 months postoperatively.

Results: Records of 193 eyes from 116 dogs were reviewed. Postoperative fibrin formation was recorded in 31/72 (43%) pseudophakic eyes and 18/121 (15%) aphakic eyes. Pseudophakic eyes were three times more likely to experience fibrin formation compared to aphakic eyes (p < 0.001). Signalment, diabetic status, presence of concurrent ocular or systemic disease, cataract stage, or development of postoperative ocular hypertension were not associated with fibrin formation (p > 0.1). At 6 months postoperatively fibrin formation was significantly associated with vision loss in pseudophakic eyes (p = 0.003), but there was no association between fibrin formation and vision loss in aphakic eyes (p = 0.6). There was no direct association between the presence of an intraocular lens and vision loss (p > 0.4).

Conclusion: In this study, pseudophakia was associated with increased occurrence of postoperative fibrin formation. Although pseudophakia was not directly associated with vision loss, fibrin formation in pseudophakic eyes was associated with a poorer visual outcome.