Intra-Operative Discomfort in Photorefractive Keratectomy.

PURPOSE: Photorefractive keratectomy (PRK) remains a viable, safe, and efficacious option for patients wishing to correct refractive errors. One of its most significant drawbacks is pain. While post-operative pain has been well studied with different management options, intra-operative pain has been less well defined. The purpose of this study was to characterize intra-operative pain during PRK in regard to eye operated on, gender, excimer platform used, surgeon, and age. PATIENTS AND METHODS: A total of 134 patients (264 eyes) were prospectively randomized to undergo bilateral PRK of either the right eye first or the left eye first followed immediately by the fellow eye. In the immediate post-operative period they were surveyed using an 11-point Numeric Rating Scale regarding intra-operative pain or discomfort experienced in each eye. Resultant pain scores were then analyzed via two sample z-test and analysis of variance (ANOVA) to characterize pain overall as well as comparing first versus second eye operated on, right versus left eye, male versus female, excimer platform used, inter-surgeon variability, and age. RESULTS: Of 264 eyes surveyed the mean pain experienced on a 0-10 pain scale was 1.13 (minimal discomfort). There was no statistically significant difference in pain or discomfort when comparing first versus second eye operated on, right versus left eye, male versus female, excimer platform used, operating surgeon, or age. CONCLUSION: Intra-operative pain or discomfort experienced by patients is minimal. The absence of statistically significant differences in pain scores studied implies that standard of care procedures achieve adequate analgesia in PRK.

Dose Uniformity of Topical Corticosteroids: A Simulated Trial of Fluorometholone Acetate 0.1% and Loteprednol Etabonate Gel 0.5.

PURPOSE: The purpose of the study was to determine the concentrations of Flarex® and Lotemax® when shaken and not shaken. Many patients fail to shake or inappropriately shake suspensions of corticosteroids before instillation as directed. This study was designed to help determine what concentration of corticosteroid these patients are receiving. In addition, independent confirmation of loteprednol etabonate ophthalmic gel dose uniformity was determined and compared as a possible alternative. METHODS: Drug concentrations of shaken versus unshaken Flarex and Lotemax were determined over a 20-day simulated tapered course in our institutional laboratory. Collected samples were analyzed by reversed-phase high-performance liquid chromatography with photodiode array detection at 240 nm. RESULTS: Flarex had a mean concentration of 93.7% of the declared concentration when shaken and 7.25% when not shaken. The difference between these groups was statistically significant (P = 0.0001). Lotemax had a mean concentration of 96.74% of the declared concentration when shaken and a mean concentration of 98.97% when not shaken. The difference between these groups was not statistically significant (P = 0.194). CONCLUSIONS: Flarex maintains dose uniformity when shaken. When not shaken, it has poor dose uniformity. Lotemax was consistent whether shaken or not in our study and can be considered to eliminate the variability of poor patient compliance with shaking. The manufacturers of both drugs recommend shaking before application.