Outcome of Photo Dynamic Antimicrobial therapy with Rose Bengal as an Aadjuvant Treatment
in the Management of Acanthamoeba keratitis: Prospective Interventional Trial
Bhupesh Bagga, Savitri Sharma, Gowtham Lakshminarayanan, Lalit Kishore
The Ramoji Foundation for Ocular Infection, and The Cornea Institute, LV Prasad Eye Institute, Hyderabad, India
Purpose: To assess the outcome of Photo Dynamic Antimicrobial therapy with Rose Bengal (PDAT-RB) as an adjuvant treatment in the management of Acanthamoeba keratitis.
Methods: We have recruited consecutive cases of microbiologically (smear and/ or culture proven) confirmed Acanthamoeba keratitis from August 2020 to June 2022 with informed consent of the patients. Inclusion criteria of the study was the size of infiltrate ≤ 8 mm with involvement till mid stroma while sparing of posterior stroma. Cases with corneal thinning or perforation, limbal involvement and any other ocular pathology were excluded from the study. All the patients underwent PDAT-RB along with combination of topical 0.02% PHMB and Chlorhexidine 0.02%. This was performed by applying rose bengal (0.1%) to the de-epithelialized cornea for 30 minutes, followed by irradiation with a 6 mW/cm2 custom-made green LED source for 15 minutes (5.4 J/cm2).
Results: We have performed PDAT-RB in 12 patients. Median age of the patients was 42.5 (IQR, 39.5-49.5) years and male: female ratio was 8:4. Median duration of the onset was 30 (IQR,20.75-35.25) days. There was a history of trauma in 8/12 (66.6%) cases. At presentation 10/12 cases had visual acuity equal to counting fingers <30 cm. Median vertical and horizontal size of the infiltrate was 5.75 (5-7.25) and 6.1 (4.5-7.1) mm. Other clinical signs included ring infiltrate in 9(75%), radial keratoneuritis in 2(16.6%), hypopyon in 3 (25%) patients. Median depth involvement as measured by As-OCT was 272 (252-300) microns. Median days of PDAT from the time of presentation were 10 (5-26.5) days. Follow-up duration of medical treatment was 78 (57-100) days. Seven (7/12, 58.3%) had signs of resolution (complete or partial) of infection, while remaining 5 /12 (41.6%), cases kept on worsening and needed TPK (2/12) and DALK (1/12). On comparison of clinical features between the resolved vs worsened cases, no significant difference could be found.
Conclusions: PDAT-RB application as an adjunctive role of treatment was found to be efficacious in the management of Acanthamoeba keratitis.