Long-term Evaluation of Photo Activated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL)

Purpose: The aim of this prospective study was to analyse the long-term outcome regarding corneal healing, visual rehabilitation and safety of patients treated with a crosslinking procedure due to corneal infection (PACK-CXL: Photo-Activated Chromophore for Keratitis-Collagen Crosslinking). Methods: Prospective non-randomized clinical study, that was granted approval by the Swedish ethical review authority. Screening was done for patients undergoing crosslinking with a keratitis diagnosis between 2007 and 2021 at the University Hospital Örebro. Those eligible were invited to come for a thorough follow-up visit to assess the corneal status. Results: All 13 eyes had a well-healed former infectious lesion. The final visual acuity differed corresponding to the remaining scarring, which correlated to the original expansion of the lesion. We could not see any adverse outcomes, such as general haze or corneal decompensation. All patients had an endothelial cell count better or comparable to the fellow untreated eye. None suffered of a reinfection. The procedure was effective in promoting corneal healing regardless of the cultured pathogen, which even included Acanthamoeba castellanii . Conclusion: PACK-CXL is a safe procedure with few side effects. In our patients, a heterogenous group of pathogens was identified, but all patients included in the follow-up benefited from the procedure. We saw no adverse events or cases with corneal decompensation and no reinfection despite a long follow-up of up to 13 years. PACK-CXL treatment was innocuous regarding long term safety and complications. The results support that it contributes to the healing of severe cases of keratitis and corneal melting.