A recent study compared the level of pain and discomfort as well as the epithelial healing rate of photorefractive keratectomy (PRK) and corneal collagen crosslinking (CXL), and found that the epithelial defect healing rate was faster in the CXL group, but the level of post-op pain was greater.

The prospective clinical study was comprised of 68 patients: 34 in the PRK group and 34 in the CXL group. The PRK group included patients with simple refractive errors, whereas the CXL group included patients with clinical keratoconus. Both groups had bilateral same-day surgery.

The groups were compared regarding the level of pain immediately and six hours after surgery and then one, three and seven days postoperatively. The epithelial defect size was measured at six hours after surgery and then one day and three days after surgery in both groups.

Researchers found the amount of pain was significantly higher after CXL than after PRK, although the epithelial defect size was significantly smaller in the CXL group compared with the PRK group.

The researchers concluded that although the epithelial defect was one of the main reasons for pain in these patients, the findings could potentially lead to better understanding of the other factors involved in cornea-related pain sensation.