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.

Retinal Blood Velocity and Flow in Early Diabetes and Diabetic Retinopathy Using Adaptive Optics Scanning Laser Ophthalmoscopy.

Using adaptive optics scanning laser ophthalmoscopy (AOSLO), we measured retinal blood velocity and flow in healthy control eyes and eyes of diabetic patients with or without retinopathy. This cross-sectional study included 39 eyes of 30 patients with diabetes (DM) with mild non-proliferative diabetic retinopathy (NPDR) or without retinopathy (DM no DR) and 21 eyes of 17 healthy age-matched controls. Participants were imaged with a commercial optical coherence tomography angiography (OCTA) device (RTVue-XR Avanti) and AOSLO device (Apaeros Retinal Imaging System, Boston Micromachines). We analyzed AOSLO-based retinal blood velocity and flow, and OCTA-based vessel density of the superficial (SCP), deep retinal capillary plexus (DCP), and full retina. Retinal blood velocity was significantly higher in eyes with DM no DR and lower in NPDR across all vessel diameters compared to controls. Retinal blood flow was significantly higher in DM no DR and lower in NPDR in vessel diameters up to 60 µm compared to controls. When comparing flow outliers (low-flow DM no DR eyes and high-flow NPDR eyes), we found they had a significantly different retinal vessel density compared to the remaining eyes in the respective groups. Retinal blood velocity and flow is increased in eyes with DM no DR, while these parameters are decreased in eyes with mild NPDR compared to healthy age-matched controls. The similarity of OCTA vessel density among outliers in the two diabetic groups suggests an initial increase followed by progressive decline in blood flow and OCTA vessel density with progression to clinical retinopathy, which warrants further investigation.