Early Postoperative Pain Following Epi-LASIK and Photorefractive Keratectomy: A Prospective, Comparative, Bilateral Study

Abstract

PURPOSE: To compare postoperative pain associated with epi-LASIK versus photorefractive keratectomy (PRK). METHODS: This prospective observer-masked randomized study included 40 eyes of 20 patients with myopia and astigmatism who received epi-LASIK (Moria Epi-K) in one eye and PRK in the contralateral eye. Corneal ablation was done using the NIDEK EC-5000 excimer laser. Patients were seen at days 1, 3, and 6 to rate their pain via three measuring tools: 1) a global subjective rating, 2) a 10-cm visual analog scale, and 3) an 11-point numeric scale of pain. RESULTS: On postoperative day 1, 19 of 20 patients reported pain in both eyes. Using the global subjective rating scale, patients reported more pain for those eyes treated by PRK. Although clinically relevant, this difference was not statistically significant (P=. 56). Based on the 11-point numeric scale of pain and visual analog scale, mean pain scores were similar for both groups. On day 3, using the global subjective rating scale, 11 of 12 patients who had pain reported more in the epiLASIK treated eye (P= .0005). In addition, epi-LASIK eyes demonstrated higher mean pain scores based on the other two scales (visual analog scale, P= .045 and 11-point numeric scale of pain, P= .023). Only 6 patients reported minimal pain on day 6. It was more frequently reported and slightly more marked in epi-LASIK eyes, but did not reach statistical significance. CONCLUSIONS: Epi-LASIK and PRK have similar pain on postoperative day 1, but epi-LASIK demonstrated statistically more pain than PRK on days 3 and 6. [J Refract Surg. 2007;23:126-132.]

Wavefront-guided epithelial laser in situ keratomileusis with mitomycin-C for myopia and myopic astigmatism: Flap-on versus flap-off technique

“…16 During the first 7 days of wound healing, the retained epithelial sheet in the flap-on procedure undergoes partial apoptosis and necrosis, triggering the release of inflammatory and pain mediators such as cytokines and transforming growth factors, which induces more pain and haze formation. 4,11,13,15 This may explain our study result that pain was significantly greater in the flapon group than in the flap-off group during the first postoperative week.…”

“…6,7 Using the epikeratome spares the cornea and conjunctiva from the possible toxic effects of alcohol exposure. [4][5][6][7][8][9][10][11][12]14,15,A The thorough dissection of the epithelial sheet between the lamina lucida and lamina densa maintains an intact basement membrane and normal basal cell integrity, which are important predictors of postoperative pain and epithelial wound healing. 4,5,10,12 All keratorefractive procedures involve activation of the wound-healing cascade with epithelial-stromal and immune-cell interactions.…”

“…9,13,A Some refractive surgeons believe that when the epithelium is repositioned, it decreases pain and protects the bare anterior corneal surface from cytokines that promote scarring. 11 Other surgeons believe that replacing the epithelium hinders the formation of a new epithelial sheet, thereby prolonging surface healing. 13,A To date, the decision to keep the flap or not remains controversial and is based on the surgeon's preference.…”

“…[3][4][5][6][7][8][9][10][11][12][13][14],A It eliminates the use of alcohol to loosen the epithelium. [4][5][6][7][8][9][10][11][12]14,15,A Histologic findings of epithelial flaps removed mechanically showed a smooth surface and an intact basement membrane, with no signs of damage to surrounding tissue. 4,5,10,12 However, reports remain inconclusive about whether maintaining a viable epithelial flap contributes to less postoperative pain, faster visual rehabilitation, and better visual outcomes.…”

Pain, wound healing and refractive comparison of mechanical and transepithelial debridement in photorefractive keratectomy for myopia: Results of 1 year follow-up

“…Studies have used the VAS to quantify pain associated with strabismus and chalazion surgery [47][48][49][50]. Torres et al [51] measured global subjective rating in the study of early postoperative pain following Epi-LASIK and photorefractive keratectomy. However, Blake et al [23] used 3 of these measurement methods in the comparison of postoperative pain in patients following photorefractive keratectomy versus advanced surface ablation.…”