Outcome of photodynamic therapy with Rose Bengal in conjunction with topical PHMB and chlorhexidine combination in Acanthamoeba keratitis.

Purpose: To report the outcome of Acanthamoeba keratitis, with early addition of Photo-dynamic antimicrobial therapy with Rose Bengal (PDAT-RB) to the medical treatment (combination of 0.02% Polyhexamethylene Biguanide (PH)and 0.02% chlorhexidine(CH)).

Methods: Patients were recruited based on the infiltrate size being < 8 mm and limited to the mid stroma, < 300µ, and confirmed microbiological diagnosis. Along with the continuation of PHMB + CH, patients were also treated with PDAT-RB twice with a gap of one week using 0.1% w/v RB and green LED (525 nm) array immediately after the confirmation of diagnosis.

Results: A total of 14 patients were enrolled. All the enrolled patients received adjuvant PDAT-RB within 5 (2.5 to 11) days of diagnosis. The average diameter and median depth of the infiltrate were 5.7 ± 1.56(V), 5.9 ± 1.38(H) mm, and 250 (250 to 300)µ, respectively. The mean LogMAR visual acuity at the time of presentation was 2.52 ± 0.95. Out of 14 enrolled patients, infection was resolved in 12 (85.7%) patients, whereas 2 (14.3%) patients needed TPK. The median days to resolve were 110 (67 to 150) days. The final mean LogMAR Visual acuity at the end of the follow-up was 1.60 ± 1.3.

Conclusion: The study demonstrates the effective resolution of Acanthamoeba keratitis when treated with early adjuvant photodynamic antimicrobial therapy using Rose Bengal (PDAT-RB).