Evaluating the Safety of Rose Bengal Photodynamic Therapy

Abstract

Purpose : To evaluate the corneal changes in healthy rabbits after treatment with varying concentrations of rose bengal (RB) diluted strips and photodynamic antimicrobial therapy (PDAT).

Methods : Eighteen rabbits were divided into five groups: groups 1 to 4 had three rabbits and group 5 had six rabbits. Each group received the following treatment: Group 1 - corneal de-epithelization (CDE), Group 2 - CDE and Rose Bengal drops (8 strips of 1.3mg in 5cc of balanced salt solution [BSS] every 3 minutes for 30 minutes), Group 3 - CDE and green light exposure (5.4J/cm² for 15 minutes), Group 4 - RB (four strips of 1.3mg in 5cc of BSS) and PDAT, and Group 5 - RB (eight strips of 1.3mg in 5cc of BSS) and PDAT. All rabbits were followed clinically. RB solution analysis was performed by diluting four sterile RB strips and eight sterile RB strips at different time points in 5cc of BSS.

Results : In groups 1 to 4, 3 out of 3 rabbits (100%) had an epithelial defect that was completely healed on day 3. In group 5, 3 out of 6 rabbits (50%) had a persistent epithelial defect. The RB concentration of four RB strips in 5cc of BSS at 1 minute was 0.0965 ± 0.001%, 2.5 minutes was 0.134 ± 0.001%, 5 minutes was 0.154 ± 0.002% and 10 minutes was 0.176 ± 0.004%. The RB concentration of eight RB strips in 5cc of BSS at 10 minutes was 0.310± 0.008%, 70 minutes was 0.340 ± 0.015%, and 130 minutes was 0.36 ± 0.01%.

Conclusions : RB-PDAT with four RB strips is a safe procedure and there was no difference in corneal epithelial healing time compared to the control group.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.