Sequential versus concurrent KERARINGS insertion and corneal collagen cross-linking for keratoconus

Purpose To evaluate the safety and efficacy of combined intracorneal ring segments (KERARINGS) insertion and corneal collagen cross-linking (CXL) performed in one session or two sessions and to present the refractive outcomes.

Setting Magrabi Eye Hospital, Cairo, Egypt.

Methods This prospective comparative study included 16 eyes of 10 patients with progressive mild to moderate keratoconus that were randomly divided into two groups. Group 1 included nine eyes that underwent KERARINGS insertion followed by CXL 6 montsh later; group 2 included seven eyes that underwent the two procedures at the same day. In both groups channel creation was performed using the femtosecond laser (Intralase FS 60).

Results There was statistically significant improvement in both groups' uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), with significant reduction in refractive error and keratometric values (p<0.05). There was no statistically significant difference between both groups regarding the changes in UDVA, CDVA and refractive error (p>0.05). However, group 2 revealed more statistically significant reduction of keratometric values on topographical examination (p=0.046). The stromal haze that developed in both groups was more marked and persistent in group 2 than in group 1.

Conclusion Combined KERARINGS insertion and CXL can be performed safely in one or two sessions. However, the same-session procedure appears to be more effective regarding the improvement in the corneal shape.