Effectiveness Of Intrastromal Injection Of Fourth-Generation Quinolones For Pseudomonas Aeruginosa Keratitis.

Determine the therapeutic efficacy of intrastromal injection vs. topical fourth-generation quinolones in the treatment of Pseudomonas aeruginosa (P. aeriginosa) keratitis.

1. Department of anterior segment. Ophthalmology Institute, Ioannina, Greece.
2. Department of anterior segment. Hospital Dr. Luis Sánchez Bulnes - Association to Prevent Blindness in Mexico, APEC, Mexico City, Mexico. 
3. Unit for Biomedical Research in Cancer, National Cancer Institute - Institute for Biomedical Research,National Autonomous University of Mexico, Mexico City, Mexico. 

We develop an experimental, comparative in vivo study using rabbits (N=20) to determine the effect of intrastromal injection vs. topic treatment. One drop of P. aeruginosa culture was instilled. The rabbits were randomized to 5 groups. Groups A and E received intrastromal treatment:2 doses of moxifloxacin 0.5 µg/0.02 cc every 3 days. Groups B and D received topical moxifloxacin every 4 hours. Treatment began 48-72 hours after induction of infection. Corneoscleral dissection, histopathological study and alpha-smooth muscle actin (α-SMA) immunofluorescence were performed.Z-scores to integrate macroscopic and microscopic findings and comparison between topic and Intrastromal was done using Mann-Whitney test. Significance was set at p<0.05. 

The digital photographs showed varying improvements in corneal ulcers. The statistical analysis showed a risk ratio of 0.88 between groups, suggesting a 22% improvement with intrastromal treatment; however, no statistical significance was observed.

Intrastromal injection is associated with less corneal damage on histopathological and macroscopic study. However, the infection/healing process by α-SMA was evident in groups that received topical and intrastromal treatment, suggesting that this marker may be used at later stages in order to determine differences in therapeutic response in animal models.