Evaluation of the efficacy of high-fluence corneal collagen cross-linking in fusarium corneal ulcer in rabbits

Background Accelerated photoactivated chromophore for keratitis–corneal collagen cross-linking (PACK-CXL) was investigated to be effective in the treatment of fungal keratitis in many studies. High-fluence CXL was used effectively in the treatment of progressive keratoconus but not tested in PACK-CXL for fungal infection. Aim To evaluate the antifungal efficacy of high-fluence CXL in the treatment of induced fusarium corneal ulcer in rabbits. Design This is an experimental interventional study. Patients and methods This is an experimental interventional study conducted on 16 eyes of eight rabbits for which fusarium corneal infection was induced by intrastromal corneal injection. The rabbits were divided into two groups: group A received no treatment and was left as a control group. Group B received a single high-fluence PACK-CXL session. All rabbits were followed up for 6 days and then the eyes were enucleated. Culture was performed for seven corneas and histopathology for the remaining cornea. Results There was statistically significant deterioration in group A (P=0.003), while a statistically significant clinical improvement was seen in group B (P<0.001). The median colony-forming units was more in group A (4×104) than in group B (2×102). Histopathological examination also revealed less inflammatory signs in high-fluence PACK-CXL-treated group. Conclusions High-fluence PACK-CXL total ultraviolet A fluence of 7.2 J/cm2 is effective in the treatment of mycotic keratitis.