Photodynamic therapy with infracyanine green induces keratocyte depopulation in the normal equine cornea

The purpose of this study was to investigate the morphologic effects and safety of in vivo photodynamic therapy (PDT) on the healthy equine cornea. Six university-owned horses underwent unilateral corneal PDT with intrastromal infracyanine green and photoactivation with an 810nm diode laser (500mW for 2.5 min = 75 Joules). Complete ophthalmic examinations, clinical scoring, digital and infrared photography, ocular thermography, in vivo confocal microscopy (IVCM), and ultrasound biomicroscopy (UBM) were performed pre-treatment and post-treatment on study days 1, 5, 15, 33, and 103.