Hyderabad: Doctors at the LV Prasad Eye Institute in Hyderabad have discovered a new way to treat a rare but serious eye infection called acanthamoeba keratitis (AK) — a rare but serious eye infection that causes pain, redness, and can lead to vision loss.This infection is caused by amoeba found in places like water and soil. According to the study, it mostly affects people who wear contact lenses or come into contact with dirty water, such as those working on farms or using tap water to clean their lenses.Doctors tested a new light-based treatment called photodynamic therapy (PDAT-RB) and found it promising. The antimicrobial treatment uses a special dye called rose bengal, which is activated by light to produce powerful molecules that kill the infection. This, in turn, helped reduce inflammation in the eye. Rose bengal is a reddish-pink dye used in the diagnosis of eye conditions, which turned out to act as an effective photosensitising agent.Published in the United Kingdom-based Journal of Ophthalmic Inflammation and Infection, the study states that the most common cause of this disease is exposure of the eyes to contaminated water, especially in agricultural fields or washing contact lenses with tap water. An estimated 30-40% of patients suffering from AK require corneal transplantation, known as keratoplasty, on average. Despite that, many do not regain good visual acuity and require additional surgery.This study included 14 patients with AK infection. At first, they were given regular medicines to treat the infection. Then they received the new light-based PDAT treatment twice a week. The doctors used a solution with 0.1% rose bengal dye as part of the therapy.Doctors found that the treatment with the PDAT-RB reduced the need for corneal transplantation in 72% of the total patients with bacterial keratitis (inflammation of the cornea). Moreover, the infection was cleared in about 86% of patients within two to five months after the treatment.While most patients were suffering from almost complete vision loss before the treatment, only two of the total patients in the study required a corneal transplant to repair the damaged part.Although their vision improved after PDAT-RB therapy, they still had poor sight. On average, their vision went from total blindness to being able to see large objects or movement.Dr Gowtham Lakshminarayan, a research assistant scientist involved in the study, explained that the treatment works by creating powerful chemicals that destroy the harmful organisms in the eye.“The study suggests that if this treatment is used early, it can be a helpful and less-invasive (non-surgical) option to manage a severe eye infection that is usually hard to treat with regular medicines. The new treatment also shows that rose bengal is an effective photosensitiser and that early intervention with PDAT-RB treatment can yield promising results in the AK eye infection,” he added.