Effects of intracameral tissue plasminogen activator injection on posterior capsular opacification, fibrin formation, and intraocular pressure in dogs after phacoemulsification

Objective: To evaluate whether intracameral tissue plasminogen activator (tPA) injection is effective in regulating posterior capsular opacification (PCO), fibrin formation and intraocular pressure (IOP) after cataract surgery. Animal Studied: Prospective study involving 30 eyes of 21 dogs that underwent phacoemulsification. Procedures: Thirty eyes were randomly divided into two groups of 15 eyes (control and tPA groups). Intracameral tPA (25 mu g/0.1 mL) was injected into tPA group eyes before corneal incision closure but not into the eyes of the control group. The grades of anterior fibrin formation and PCO were compared based on slit lamp biomicroscope examination at 1 and 2 weeks, 1 month, and 2-3 months postoperatively. IOP was measured using applanation tonometry every 30 min for 4 h immediately after operation and on the following morning. The IOP of the two groups at each time was compared. Results: The grade of anterior fibrin formation and that of PCO were not significantly different between the two groups at any time point (p > .05). However, the IOP of the tPA group was significantly lower than that of the control group at each point on the day of surgery (p < .05). No complications were observed with tPA injection, except for temporary hyphema (for 3 days) in one eye. Conclusions: Although the intracameral tPA injection did not affect anterior fibrin formation and PCO, it effectively maintained normal IOP immediately after phacoemulsification. Thus, our findings provide valuable insights into the potential benefits of intracameral tPA injection in achieving immediate IOP control after phacoemulsification.