Abstract
Purpose: :
To determine what factors significantly contribute to post-op pain after PRK.
Methods: :
Retrospective review of consecutive medical records of patients undergoing PRK. Records were reviewed for pain scores, patient age, sex, epithelial removal technique (Amoils brush v. ETOH), intra-operative use mitomycin-C (MMC), post-op use of either oral gabapentin 300 mg, topical ketorolac 0.4%, or topical bromfenac 0.09%. Pain was self-assessed, graded on a 1 to 10 scale, and was recorded on post-op days (POD) 1 and 4. For statistical analysis, age was converted into 4 age groups (under 25, 25 to 35, 36 to 45, and over 45). A paired sample t-test was used to determine if reported pain on POD1 differed significantly from POD4. Two-way ANOVAs (alpha = 0.05) were used to determine the effects of patient demographic (gender and age), epithelial removal technique (Amoils brush v. ETOH), use of MMC, and non-narcotic analgesia (use of gabapentin and topical NSAIDs) on post-op pain scores. An alpha of 0.05 was used.
Results: :
A total of 898 records (84.6% male, 15.4% female; mean age 32.4 +/- 8.05) were reviewed. Paired sample t-test demonstrated significantly more pain on POD1 (2.17 +/- 2.98) than on POD4 (0.36 +/- 1.33; t(896)=17.23, p<0.0001). Neither demographic profile [gender (p=0.089), age group (p=0.089) or gender*age group (p=0.23)] nor non-narcotic pain management [gabapentin (p=0.22), NSAID (p=0.24), or gabapentin*NSAID (p=0.43)] had a significant effect on POD1 pain scores. The main effect of epithelial removal technique on post-op pain (Brush M=1.9; ETOH M=2.7) significantly impacted POD1 pain scores (F(1,894)=8.2, p=0.004). However, the main effect of MMC (p=0.37) or the interaction of epithelial removal technique and use of MMC was not significant (p=0.20).
Keywords: refractive surgery: PRK