Photorefractive Keratectomy Involves Minimal Intraoperative Discomfort

Surveys suggest patients experience little to no pain during the corneal refractive procedure.

Pain during photorefractive keratectomy (PRK) is minimal, patients reported in a survey published in Clinical Ophthalmology. Researchers say this is the first study to specifically evaluate intraoperative pain in PRK.

The study included 268 eyes of 134 patients (110 women, 105 younger than 40 years) undergoing bilateral PRK with excimer laser at a single surgical center in Texas. The anesthesia utilized was 0.5% proparacaine hydrochloride, and topical prednisolone acetate 1% and moxifloxacin were applied to the treated eye, along with a bandage contact lens. Researchers conducted laser ablation of corneal stroma and applied child BSS to the ocular surface.

They asked participants to complete the 0-10 Numeric Rating Scale because of its established validity and simplicity. The patients ranked their pain during the procedure on each eye individually. Score choices were none (0), mild (1-3), moderate (4-6), and severe (7-10). The researchers analyzed pain scores in 2 sample z-test and analysis of variance (ANOVA).

Mean pain reported was 1.13 (95% CI=0.95-1.30). Patients most frequently reported they had no pain. Twenty-six patients reported no pain in 1 eye despite having pain in the other eye (25 mild pain, 1 moderate pain). Two patients reported severe pain, with 1 reporting 6 and 8 and 1 reporting 7 in both eyes. Mean pain was 1.01 (95% CI=0.81-1.22) in the first eye and 1.25 (95% CI=1.04-1.46 P =.09) in the second eye. 

No association was found between pain or discomfort and order of eye, right or left eye, sex, excimer platform, surgeon, or age of patient.

“The mode pain or discomfort score of zero, together with statistical analyses of pain scores reinforce that following standard of care procedures for PRK may be trusted to minimize intra-operative pain,” the researchers report. “Data gathered do not imply a benefit to modifying analgesia for the second eye treated in PRK.”

Limitations of the study related to pain scale descriptions, generalization, and small sample size.


Philbrick SM, Bennion Jl. Intra-operative discomfort in photorefractive keratectomy. Clin Ophthalmol. 2021;15:4121-4130. doi:10.2147/OPTH.S327057