Objective: To determine whether mitomycin C suppresses aqueous humor formation in cynomolgus monkeys.
Methods: Three monkeys received subconjunctival injections (50 microL) in four quadrants bilaterally, one eye receiving mitomycin C (0.5 mg/mL) and the other receiving distilled water. Seven monkeys underwent 360 degrees conjunctival peritomy bilaterally and episcleral application of mitomycin C-soaked (0.5 mg/mL) cellulose sponges for 5 minutes in all four quadrants unilaterally. Aqueous humor flow was measured fluorophotometrically 1 and 3 days, and 1, 2, and 4 weeks after subconjunctival injection; and 3 days and 1, 2, 3, and 4 weeks after episcleral application.
Results: There was no change in aqueous flow in either eye and no difference between eyes following subconjunctival injection. Aqueous flow was reduced by 8% +/- 7% (mean +/- SEM), 20% +/- 3% (P < .01), 9% +/- 10%, and 0% +/- 4% compared with contralateral controls 1, 2, 3, and 4 weeks, respectively, after episcleral application of mitomycin C.
Conclusions: Episcleral application of mitomycin C can produce at least a modest short-term reduction of aqueous humor flow in primates. Reduced aqueous flow might contribute to early postoperative hypotony following trabeculectomy with mitomycin C.