The incidence of ulceration and perforation in the cornea of alkali-injured eyes is significantly reduced by treatment with trisodium citrate or sodium ascorbate. Topical citrate reduces the inflammatory response in the cornea by inhibiting polymorphonuclear leukocytes. Topical ascorbate elevates the depressed level of this vitamin in the alkali-injured cornea, reversing a scorbutic condition. The purpose of the current study was to determine whether combined treatment with topical citrate and ascorbate has an additional therapeutic value when compared with citrate alone. Adsorbotear without EDTA was used as the vehicle for both medications. Rabbit eyes were injured with 1N NaOH for 35 s using a 12-mm well and were rinsed. Group I (47 eyes) received two drops of 10% citrate every hour on the hour and Adsorbotear on the half-hour for 14 h/day. Group II (48 eyes) received two drops of 10% citrate every hour on the hour and 10% ascorbate every hour on the half-hour for 14 h/day. The citrate/ascorbate group had significantly fewer ulcerations during the experiment than did the group receiving citrate alone (2 of 48 versus 10 of 47, 0.01 less than p less than 0.02). Both anterior ulcers in the citrate/ascorbate group and five ulcers in the citrate group healed to no ulcer by the end of the experiment (0 of 48 versus 5 of 47, 0.02 less than p less than 0.05). The average depth of ulceration was significantly less for the citrate/ascorbate group (p less than 0.001). No descemetoceles or perforations were observed in either group.(ABSTRACT TRUNCATED AT 250 WORDS)