Infracyanine Green-Based Photodynamic Therapy for Immune-Mediated Keratitis in Horses

Area of Science:

• Veterinary Ophthalmology
• Photodynamic Therapy
• Equine Health

Background:

• Immune-mediated keratitis (IMMK) is a significant cause of corneal disease in horses.
• Current treatment options for IMMK can have limitations.
• Infracyanine green-based photodynamic therapy (InfraCG-PDT) offers a novel therapeutic approach.

Purpose of the Study:

• To describe the protocol for InfraCG-PDT in horses with IMMK.
• To evaluate the clinical outcomes and complications associated with InfraCG-PDT in horses.

Main Methods:

• Retrospective study of horses diagnosed with IMMK from 2014-2020.
• Treatment involved intrastromal injections of EmunDo (InfraCG) followed by diode laser irradiation.
• Dosage varied based on whether quadrants or the entire cornea were treated.

Main Results:

• Fifty-one eyes from 47 horses were included in the study.
• Common complications included prolonged dye retention and superficial ulceration; severe complications were rare.
• IMMK remained inactive in 77.5% of horses during the follow-up period.

Conclusions:

• InfraCG-PDT appears to be an effective treatment for equine immune-mediated keratitis.
• Further research is recommended to optimize the InfraCG-PDT protocol.
• This therapy presents a viable option for managing challenging cases of IMMK.