Purpose:
To determine if topically formulated LN, DP, and TG are as effective as VN in the treatment (TX) of CU caused by SP.
Methods:
Forty RB were randomized to either 5% LN drops, 2.5% VN drops, 5% DP drops, 0.1% TG drops, or normal saline (control). After the RB were anesthetized, 100µL (1x106 CFU/mL) of SP suspension was injected into the stroma of the right eye and the overlying epithelium was then abraded. The 12 hour incubation started immediately after the eyes were injected. Clinical eye exams (CEE) were conducted pre- and post-TX; a scale of 0-3 (with 3 being the worse possible score) was used to rate blepharitis, conjunctivitis, and corneal edema. The antibiotic (ABX) or saline drops were instilled in the infected eye every 15 minutes for the next 5 hours (21 doses). After TX, the RB were sacrificed and 5mm corneal buttons were trephined, emulsified, and plated. Colony counts (CC) were performed at 24 and 48 hours.
Results:
A total of 39 RB were included in analysis. A total CEE score was calculated for each eye pre- and post-TX; by adding the three rating categories together for a single number for each study eye (maximum possible score of 9). Scores were analyzed using Kruskal-Wallis ANOVA. No significant difference was detected when comparing LN, DP, or TG total CEE scores pre- or post-TX, to either control or VN. CC were analyzed using ANOVA. Each ABX was compared to control and LN, DP, and TG were also compared to VN. All topically formulated ABX were significantly better than control (p=0.0008), see table.
Conclusions:
No significant difference was noted between any of the ABX tested as rated by post-TX CEE scores although a trend was noted for LN, DP, and TG as being less toxic in this model than VN. LN, DP and TG were shown to be as effective as VN at treating SP CU. To our knowledge these are the first data to be presented for topically formulated DP and TG in a RB model.
Keywords: antibiotics/antifungals/antiparasitics • bacterial disease • cornea: epithelium