Comparison Of Early Ocular Pain And Visual Outcomes In Alcohol-Assisted Photorefractive Keratectomy And Transepithelial Photorefractive Keratectomy

To describe and compare early ocular pain and associated symptoms, visual acuity and objective quality of vision after corneal refractive surgery using either alcohol-assisted photorefractive keratectomy (aPRK) or transepithelial photorefractive keratectomy (tPRK).

Refractive Surgery Unit of the Ophthalmology Department, Centro Hospitalar Universitário de Santo António, ULS Santo António, Porto, Portugal.

In this prospective observational study, 60 eyes of 30 candidates to PRK were enrolled. In each patient, one eye underwent aPRK and the fellow tPRK, with random selection of the eyes and 2 weeks between surgeries. The WaveLight EX500 excimer laser (Alcon Laboratories, Inc.) was used. Besides best corrected visual acuity (bcVA) and non-corrected visual acuity (ncVA), objective quality of vision was assessed using HD Analyzer, preoperatively and on the fourth day after surgery. Ocular pain and associated symptoms were evaluated through the Ocular Pain Assessment Survey 2 days after the procedure. The eyes were divided into aPRK and tPRK groups and the ocular pain and visual results were compared between groups, using non-parametric tests.

The pain survey showed no statistically significant differences between eyes that underwent tPRK and aPRK. There were no statistically significant differences in ncVA [logMAR 0,27±0,19(aPRK), 0,27±0,16(tPRK), p=0,73] or objective quality of vision [OSI 4,4±4,4(aPRK), 3,4±2,4(tPRK), p=0,74] on D4. A secondary analysis was conducted to compare the 1st and 2nd operated eyes. There was a statistically significant difference in questions related to eye pain intensity, with patients complaining of greater pain in the 2nd eye [Q1: median(IQR) 2(1-3) (1st), 4(3-4) (2nd), p=0,005; Q6: 4(0-5,25) (1st), 6,5(3,5-8,25) (2nd), p=0,027]. There was a tendency for greater impact on quality of life in the 2nd intervention, without statistical significance. 

The literature has established that both aPRK and tPRK are effective in long-term visual outcomes. However, evidence regarding early postoperative pain and visual recovery time is inconclusive, with a possible tendency favoring tPRK. In this cohort, no significant differences were observed in early visual outcomes or ocular pain between eyes that underwent aPRK or tPRK. Notably, we found that patients reported greater postoperative pain in the second eye that underwent surgery, independently of the technique. Further studies with larger samples and extended follow-up periods are needed to comprehend the impact of each surgical technique in the postoperative period.