Pain Control Following Photorefractive Keratectomy: A Prospective Clinical Trial Comparing Codeine Versus Oxycodone for the Management of Postoperative Pain.

PURPOSE: To compare the efficacy of oral codeine plus acetaminophen versus oxycodone plus acetaminophen for severe pain control following photorefractive keratectomy (PRK). METHODS: This single-center trial randomized 200 patients to receive codeine 30 mg/acetaminophen 325 mg (codeine group) or oxycodone 5 mg/acetaminophen 325 mg (oxycodone group)every 4 hours as needed for severe pain for 4 days following PRK. Patients recorded postoperative pain, tablet consumption, and tetracaine use. Patients were monitored at postoperative 1 day, 1 week, and 1, 3, and 6 months for visual acuity and follow-up. Study outcomes were mean postoperative pain, treatment and tetracaine use, and visual acuity. RESULTS: Analysis of 197 patients who completed the trial (97 codeine group and 100 oxycodone group) showed mean pain scores were lower in the codeine group throughout the intervention period. Mean pain scores were higher in the oxycodone group than the codeine group on postoperative days 2 and 4 (P = .017 and P = .034, respectively). The oxycodone group consumed more tablets than the codeine group, with a difference on postoperative day 2 (P = .019), and used a greater number of tetracaine drops (P = .015). Repeated measures analysis of variance showed significant improvement in visual acuity in both groups with no difference in visual outcomes (P = .81). CONCLUSIONS: Codeine/acetaminophen is as effective and safe as oxycodone/acetaminophen for pain control following PRK, with no clinical difference in overall pain control and long-term visual outcomes. This implies that treating postoperative pain after PRK with a Schedule III opioid (codeine) is effective and potentially decreases the risk of misuse by a higher regulated Schedule II opioid (oxycodone), lowering the potential for abuse and dependence. [J Refract Surg. 2021;37(9):582-589.].

Assessment of Factors Associated With Postoperative Pain After Photorefractive Keratectomy.

PURPOSE: To define the factors that affect patient's self-assessed postoperative pain after photorefractive keratectomy (PRK). METHODS: Patients who underwent PRK in 2016 were evaluated. Anonymized data collected included patient gender, age, and season at the time of surgery, ablation depth, surgeon status (attending vs. resident), topical tetracaine use, and subjective pain scores at postoperative days (PODs) 1 and 7. Average pain scores and amount of pain medication taken were analyzed for each of the previously mentioned variables. RESULTS: Overall, 231 patients who underwent PRK were analyzed. The mean pain score and SD were 0.78 ± 1.87 on POD 1 and 0.03 ± 0.37 by POD 7. Patients who used topical tetracaine reported significantly higher pain on POD 1 and 7 compared with patients who did not use tetracaine (P < 0.001 and P = 0.038, respectively). No significant differences in pain scores were seen based on surgeon status, ablation depth, gender, and season. Patients who used topical tetracaine took a higher amount of oral pain medication (9.44 ± 6.01) compared with those who did not (7.02 ± 4.71) (P = 0.022). CONCLUSIONS: Postoperative pain was significantly elevated in patients who used tetracaine on POD 1 and POD 7. These patients were also more likely to take oral pain medication than those who did not use topical tetracaine. Surgeon status, season, gender, and ablation depth showed no significant differences in subjective pain scores. Oral pain medication should be evaluated to assess efficacy and safety in inhibiting ocular pain after 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.

Immunomodulatory therapy with anti-interleukin-1 after photorefractive keratectomy in the New Zealand white rabbit.

PURPOSE: To examine the safety and efficacy of topical anti-interleukin-1 (anti-IL-1) following photorefractive keratectomy (PRK) in rabbit eyes. SETTING: Joint Warfighter Refractive Surgery Center, Lackland Air Force Base, Texas, USA. DESIGN: Experimental study. METHODS: After standard PRK, 48 eyes of 24 New Zealand white rabbits were divided into 4 treatment arms and 1 control arm. Eyes in the treatment arms were randomized to receive fluorometholone 0.1% or an anti-IL-1 suspension (2.50 mg, 1.25 mg, or 0.25 mg doses) plus standard moxifloxacin, balanced salt solution (BSS), and an ocular lubricant (Systane) 4 times a day. Control eyes received only moxifloxacin, balanced salt solution, and ocular lubricant. RESULTS: No adverse events were observed with anti-IL-1. The safety of anti-IL-1 was affirmed because there was no statistically significant difference in time to epithelial closure, foam-layer histology and thickness, or final stromal thickness measurements between the anti-IL-1 and the steroid or control groups. No increase in haze was observed with anti-IL-1. There was a trend toward decreased haze with anti-IL-1 at several data points compared with the control and steroid groups. Finally, there was a trend toward less haze in all metrics at almost every timepoint for the 2.50 mg anti-IL-1 group compared with lesser concentrations. CONCLUSIONS: Anti-IL-1 therapy might be a safe, effective alternative to steroids for haze prevention after PRK. Of the doses studied, 2.50 mg of anti-IL-1 4 times a day appeared to be most effective. Further studies in human eyes are needed. FINANCIAL DISCLOSURE: Dr. Reilly has been a consultant to Alcon Laboratories, Inc., and Abbott Medical Optics, Inc. None of the authors has a financial or proprietary interest in any material or method mentioned.

Comparison of pachymetry measurements between the Alcon Wavelight EX500 and Sonogage Corneo-Gage plus platforms.

PURPOSE: To compare the agreement of intraoperative central corneal thickness (CCT) measurements of the Wavelight EX500 (Alcon Laboratories, Fort Worth, TX) that uses optical low coherence reflectometry to the Corneo-Gage Plus ultrasound pachymetry device (Sonogage, Cleveland, OH). METHODS: In this retrospective study, 50 eyes of 26 patients undergoing LASIK were evaluated. Following LASIK flap creation, each eye was measured by both optical low coherence reflectometry and ultrasound pachymetry immediately prior to flap lifting and then again after flap lifting. RESULTS: The mean CCT value before lifting the flap was 556.9 and 557.78 µm as measured by ultrasound pachymetry and optical low coherence reflectometry, respectively. After lifting the flap, the mean ultrasound pachymetry value was 440.96 µm and the mean optical low coherence reflectometry value was 441.7 µm. A two-sample Kolmogorov-Smirnov test demonstrated that the ultrasound pachymetry and the optical low coherence reflectometry distribution of measurements were the same. A Shapiro-Wilk test of normality could not be rejected. Bland-Altman plots showed strong agreement. The correlation between the two tests was 0.98 before flap lifting and 0.97 after flap lifting, both with a 95% confidence interval. CONCLUSIONS: The pachymetry measurements by the optical low coherence reflectometry correlated with those of the ultrasound pachymetry device. The Wavelight EX500 optical low coherence reflectometry may be used in place of the ultrasound pachymetry device for measuring CCT.

Comparison of 3 silicone hydrogel bandage soft contact lenses for pain control after photorefractive keratectomy.

PURPOSE: To evaluate the relative pain with 3 U.S. Food and Drug Administration-approved bandage soft contact lenses (SCLs) applied after photorefractive keratectomy (PRK). SETTING: Joint Warfighter Refractive Surgery Center, Lackland Air Force Base, Texas, USA. DESIGN: Prospective comparative case series. METHODS: Patients having PRK were randomized to a senofilcon A (Acuvue Oasys), balafilcon A (Purevision), or lotrafilcon A (Air Optix) bandage SCL in each eye postoperatively. Patients were evaluated 1 and 4 days postoperatively and completed a survey rating absolute pain in each eye on a visual analog scale. RESULTS: The study enrolled 54 patients. At 1 and 4 days, eyes with the senofilcon A lens had the lowest pain scores followed by eyes with the lotrafilcon A lens and then eyes with the balafilcon A lens. Averaging qualitative results from 1 and 4 days showed that eyes with the senofilcon A lens were reported as having more pain by 4% of patients, eyes with the lotrafilcon A lens by 27%, and eyes with the balafilcon A lens by 53%; 16% reported no difference (P<.001). Quantitatively, the senofilcon A lens was 40% more comfortable than the lotrafilcon A lens and 65% more comfortable than the balafilcon A lens on average. The lotrafilcon A lens was 38% more comfortable than the balafilcon A lens on average (P<.01). CONCLUSIONS: There was a statistically and clinically significant difference in post-PRK pain between the 3 bandage SCLs. The senofilcon A lens caused the least pain. FINANCIAL DISCLOSURE: Dr. Reilly is a consultant to Alcon Laboratories, Inc. and Abbott Medical Optics, Inc. but was not at the time of the study. No other author has a financial or proprietary interest in any material or method mentioned.