Light-based treatment offers new hope for a blinding eye infection

The researchers utilised the power of light and a dye named Rose Bengal to develop a unique treatment for Acanthamoeba keratitis condition.

Hyderabad: Light offers a new hope for eye specialists in treating patients with a blinding eye infection associated with contaminated water. In groundbreaking research, ophthalmologists from the city are utilising the power of light and a dye named Rose Bengal to develop a unique treatment for this severe eye condition.

When corneas, the clear protective layer of the eyes, come in contact with pathogens like bacteria, fungi, viruses, and a particularly stubborn amoeba called Acanthamoeba, they immediately lead to inflammation of the cornea, causing blurry vision, pain and blindness.

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This painful medical condition is known as Acanthamoeba keratitis (AK) and it can lead to significant vision loss and often requires complex corneal transplants. According to researchers from Hyderabad-based L V Prasad Eye Institute (LVPEI), many patients do not regain good visual acuity even after a corneal transplant, needing additional surgery.

While exploring alternative treatment modalities, the eye researchers from Hyderabad came across the promise of Photodynamic Therapy (PDAT), an innovative antimicrobial treatment that combines a special light-sensitive dye with a light source to target and destroy harmful microbes.

Their study, published in the prestigious Journal of Ophthalmic Inflammation and Infection, Springer Open, (March, 2025), demonstrated effective resolution of the eye infection when treated with early Photodynamic Therapy by using the dye Rose Bengal.

According to the researchers, the dye (called a photosensitizer) generates reactive oxygen when exposed to light, effectively killing the microbial cells. The researchers utilised Rose Bengal, a reddish dye that is already in use in several eye diagnostics.

The study involved 14 patients who received standard topical medications along with PDAT-RB treatments twice a week, using a 0.1 percent Rose Bengal solution as the photosensitizer. The results were encouraging, as patients showed a significant reduction in corneal infiltrates, which are collections of inflammatory cells that make the cornea opaque, indicating decreased inflammation.

According to the study, the infection was resolved in 85.7 percent of patients within 67 to 150 days and only two patients i.e., 14.3 percent required a corneal transplant, a significant improvement compared to the typical 30 percent to 40 percent needing surgery.

The findings pave the way for further research and clinical trials, offering a new beacon of hope for those affected by this challenging eye infection, the researchers added.