Due to its ability to inhibit pathogen growth riboflavin/UVA cross-linking is seen as a promising treatment option for the management of cases of infectious keratitis which are unresponsive to antibiotic therapy, and the clinical studies support this [1-2]. In a study involving 40 patients with infectious keratitis, the use of riboflavin/UVA cross-linking and continued antibiotic treatment resulted in 85% of the cases being resolved without the need for emergency penetrating keratoplasty [2].  It was noted however that the success rate was higher for bacterial infections than fungal infections and that the treatment should be avoided in eyes with prior herpes simplex. The encouraging results of another study involving 16 patients, in which riboflavin/UVA cross-linking was used as a primary treatment for bacterial keratitis [3] indicate that larger randomized trials are warranted to compare the benefits of cross-linking treatment with customary antibiotic therapy in terms of the healing time and complication frequency.  

The term photoactivated chromophore for infectious keratitis -corneal collagen cross-linking (PACK-CXL) was proposed at the 9th CXL congress in Dublin to distinguish the use of cross-linking for infectious keratitis treatment from its use for corneal ectatic disorders.

[1] Iseli H. et al. Ultraviolet A/riboflavin corneal cross-linking for infectious keratitis associated with corneal melts. Cornea 2008; 27: 590–594.

[2] Price M. et al. Photoactivated riboflavin treatment of infectious keratitis using collagen cross-linking technology. J Refract Surg 2012; 28: 706–713.

[3] Makdoumi K. et al. UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study. Graefe’s Archive for Clinical and Experimental Ophthalmology 2012; 250: 95–102.