Pain management after photorefractive keratectomy

Preservative-Free Topical Anesthetic Unit-Dose Eye Drops for the Management of Postoperative Pain Following Photorefractive Keratectomy

INTRODUCTION

Ocular pain is a common complication following photorefractive keratectomy (PRK). The level of patient satisfaction with current pain control strategies is not high. This study aims to assess the efficacy and safety of a novel regimen of preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops for post-PRK pain control.

METHODS

In a contralateral eye study, 144 eyes of 72 patients who underwent bilateral transepithelial PRK (TransPRK) were stratified into experimental and control groups. The experimental group received preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops five times daily postoperatively until complete epithelial healing, while the control group received sodium hyaluronate 0.2% instead. The main outcome measures were pain scores assessed by the verbal rating scale and visual analogue scale (VRS, VAS), the corneal epithelial defect (CED) area, epithelial healing duration evaluated by slit-lamp biomicroscopy and anterior segment optical coherence tomography (AS-OCT), and endothelial cell density (ECD) measured before and 1 month after surgery.

RESULTS

Pain scores assessed by VRS and VAS were significantly lower in the experimental group 8 h after surgery, and 1, 2, and 3 days postoperatively (P < 0.001). The mean CED area showed no significant differences between the two groups at different follow-ups (P value > 0.05). The corneal epithelial healing had a mean duration of 3.32 ± 0.47 days in both studied groups and was parallel in both eyes of each patient. In each group, 49 eyes (68%) and 72 eyes (100%) had a fully epithelialized surface on the third and fourth postoperative days, respectively. No significant changes were observed in the mean ECD 1 month following surgery in both groups (P value > 0.05).

CONCLUSION

Preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops are effective and safe in controlling early postoperative pain following TransPRK. The availability of the single-dose unit preparation can overcome the problem of topical anesthetic abuse.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05733741.

Topical analgesics for acute corneal pain: current options and emerging therapeutics

Acute corneal pain is a common complaint that causes significant distress to patients and continues to challenge therapeutic avenues for pain management. Current topical treatment options have marked limitations in terms of both efficacy and safety, thus often prompting the adjunctive use of systemic analgesics, including opioids. In general, there have not been extensive advancements in pharmacologic options for the management of corneal pain over the past several decades. Despite this, multiple promising therapeutic avenues exist which hold the potential to transform the ocular pain landscape, including druggable targets within the endocannabinoid system. This review will summarize the current evidence base for topical nonsteroidal anti-inflammatory drugs, anticholinergic agents, and anesthetics before focusing on several potential avenues in the setting of acute corneal pain management, including autologous tear serum, topical opioids and endocannabinoid system modulators.

Management of Pain after Photorefractive Keratectomy: A Report by the American Academy of Ophthalmology

OBJECTIVE

To evaluate current best practices for postoperative photorefractive keratectomy (PRK) pain control.

METHODS

Literature searches in the PubMed database were last conducted in October 2021 and were restricted to publications in English. This search identified 219 citations, of which 84 were reviewed in full text for their relevance to the scope of this assessment. Fifty-one articles met the criteria for inclusion; 16 studies were rated level I, 33 studies were rated level II, and 2 studies were rated level III.

RESULTS

Systemic opioid and nonsteroidal anti-inflammatory drugs (NSAIDs); topical NSAIDs; postoperative cold patches; bandage soft contact lenses (BCLs), notably senofilcon A contact lenses; and topical anesthetics were demonstrated to offer significantly better pain control than comparison treatments. Some other commonly reported pain mitigation interventions such as systemic gabapentinoids, chilled intraoperative balanced salt solution (BSS) irrigation, cycloplegia, and specific surface ablation technique strategies offered limited improvement in pain control over control treatments.

CONCLUSIONS

Systemic NSAIDs and opioid medications, topical NSAIDs, cold patches, BCLs, and topical anesthetics have been shown to provide improved pain control over alternative strategies and allow PRK-associated pain to be more tolerable for patients.

Resveratrol increases tear production and ocular pain after corneal abrasion in male, but not female, rats using a photorefractive keratectomy model

Photorefractive keratectomy (PRK) is an alternative to LASIK and can cause intense acute pain that is often not relieved by standard treatments. To assess potential therapeutics for this type of acute pain, appropriate preclinical models are needed. We describe a preclinical corneal abrasion rat model that simulates the initial stages of PRK surgery and demonstrates similar pain and tear dysfunction as seen clinically. We used both behavioral and homeostatic assays to determine the therapeutic potential of resveratrol on pain and tear production. Studies were conducted in male and female Sprague-Dawley rats. Heptanol was applied to one eye and the superficial corneal epithelium was removed, mimicking the abrasion used in PRK. Spontaneous pain was assessed with orbital tightening (OT) scores for 7 days. Topical resveratrol increased OT scores sex-specifically in abraded males, but not females, at 72 h and 1 week after abrasion. Resveratrol increased tear production in abraded males, with no effect in abraded females. There was no correlation between OT score at 1 week and tear production measurements, demonstrating no relationship between spontaneous ocular pain and tear dysfunction in this model. These findings demonstrate the usefulness of our corneal abrasion preclinical PRK model for the assessment of ocular pain therapeutics and indicate that topical resveratrol may not be useful for managing PRK-induced pain.

Thygeson Superficial Punctate Keratitis: A Clinical and Immunologic Review

ABSTRACT

Thygeson superficial punctate keratitis (TSPK) is clinically characterized by exacerbations and remissions of gray-white opacities within the corneal epithelium, most often bilateral but may be asymmetric. Symptoms typically include photophobia, tearing, blurring, and eye irritation. Although disease progression and prognosis are well described, the exact cause is unknown. Hypotheses exist implicating virus-mediated immunity as the cause of TSPK following cases of viral keratitis; however, several polymerase chain reaction studies refute the infectious process concurrently with symptomatic TSPK. This is further supported by the consistent lack of response to antiviral and antibacterial treatment. A subset of dendritic cells known as Langerhans cells (LC) found within the corneal epithelium has been positively correlated with exacerbations of TSPK. Langerhans cells proliferate to protect and mitigate the cornea's inflammatory response, but the inflammatory triggers and relapses associated with TSPK are not well understood. Several topical drugs exist to treat inflammation related to TSPK; however, drug delivery is a major barrier to treatment because of the tear film and epithelial barrier. Drug-eluting contact lenses that target intermediates of inflammation could serve as a more effective treatment modality because of the increased bioavailability of the drugs. This review is an in-depth survey of the literature regarding the relationship between the origin and pathophysiology of LC and TSPK at the immunologic level. We also discuss potential pharmacotherapeutic interventions for TSPK prevention and treatment.

Preoperative Predictors for Acute Pain After Photorefractive Keratectomy

PURPOSE

The aim of this study was to identify preoperative predictors for the occurrence of early severe postoperative pain in patients undergoing photorefractive keratectomy (PRK). The implementation of preoperative screening methods may facilitate more specific or aggressive pain therapies specifically targeted to individuals at a high risk of experiencing severe postoperative pain.

METHODS

This was exploratory research that included patients who underwent PRK. Before PRK, patients were administered a sociodemographic questionnaire, the Pain Catastrophizing Scale, and the State-Trait Anxiety Inventory and underwent corneal sensitivity and conditioned pain modulation (CPM) tests. Post-PRK pain was assessed using a pain intensity visual analog scale (VAS), and the short-form McGill Pain Questionnaire (SF-MPQ) was completed 21 days before PRK and 1, 24, 48, and 72 hours after PRK. Spearman correlations were calculated for pain scores and preoperative predictors.

RESULTS

This research included 34 eyes of 34 patients. Preoperative corneal sensitivity was positively correlated with post-PRK pain scores as assessed by VAS and SF-MPQ (rho = 0.39 and rho = 0.41, respectively, P < 0.05). No correlations were found between Pain Catastrophizing Scale, State-Trait Anxiety Inventory, and CPM scores and post-PRK pain scores (P > 0.05).

CONCLUSIONS

Abnormal presurgical corneal sensitivity was a protective marker for severe pain after PRK, while scores as assessed by VAS and SF-MPQ and CPM were not related to postoperative pain.

Efficacy of Diclofenac in Pain Reduction after Topography-Guided Transepithelial Surface Ablation

PURPOSE

To report the efficacy of postoperative diclofenac eye drops for pain reduction in patients undergoing topography-guided transepithelial surface ablation.

METHODS

Retrospective consecutive case series of patients undergoing topography-guided transepithelial surface ablation for refractive myopia treatment using a 1 KHz excimer laser. Patients were divided into three groups. Group 1 did not receive any diclofenac drops, group 2 received one diclofenac drop postoperatively (day 1), and group 3 received one drop of diclofenac postoperatively (day 1) and on the day after treatment (day 2). Postoperative pain was self-assessed by patients per eye daily for the first 4 consecutive days (days 1 to 4) after the treatment using the visual analogue scale (VAS). We compared VAS with respect to the use of additional oral or topical treatment as well as VAS with regards to the total amount of ablated tissue (< 50 µm, 50 - 100 µm, ≥ 100 µm) among the groups.

RESULTS

We enrolled 163 eyes of 163 patients (55.0% female), with a mean age of 31.3 years (SD ± 6.6; range 21 - 68). We excluded 16 patients who applied other additional analgesics. Group 1 comprised 35 eyes (21%), group 2 had 21 eyes (13%), and group 3 consisted of 107 eyes (66%). Median pain score (VAS) was 5 (range 0, 10) in group 1, which was higher than in groups 2 (median 1, range 0 to 7) and 3 (median 1.5, range 0 to 7) on the day of surgery (p < 0.0001). Percentage of patients using an additional oral NSAID on days 1 and 2 was significantly higher in group 1 (69/83%) when compared to groups 2 (24/43%) or 3 (31/49%) (p < 0.001 day 1, p = 0.001 day 2). No correlation was found between pain sensation and maximum ablation depth (Spearman correlation p > 0.05).

CONCLUSION

The instillation of one drop of diclofenac after topography-guided transepithelial surface ablation reduced subjective pain sensation according to VAS and decreased the need for additional topical anesthetic drops or oral NSAID.

Bandage contact lens soaked in 0.1% diclofenac to relieve early postoperative pain and foreign body sensation after transepithelial photorefractive keratectomy

PURPOSE

To study the effects of a bandage contact lens immersed in 0.1% diclofenac on pain management for patients undergoing transepithelial photorefractive keratectomy (TPRK).

METHODS

In a prospective, comparative, contralateral, randomized, double-masked study, we assessed a total of 51 patients. The eyes of each patient were randomly divided into two groups. After TPRK, a normal soft bandage contact lens was placed on one eye as the control group, and a bandage contact lens soaked in diclofenac was placed on the other eye as the experimental group. When the bandage contact lens was not removed, postoperative pain and other ocular discomforts were compared at 2, 18, and 24 h and 2, 3, 4, and 5 postoperative days. Patients were then examined after 1 month. Visual acuity and subepithelial haze were also evaluated.

RESULTS

The mean pain score was 2.69 ± 1.96 in the control group, which was significantly higher than that in the experimental group, which received the diclofenac-soaked bandage contact lens at 2 postoperative hours. The statistical difference between the two groups' mean foreign body sensation at 2 postoperative hours was detected (p = 0.035). No differences were detected between the two groups' subepithelial haze scores or visual acuity.

CONCLUSION

A bandage contact lens soaked in 0.1% diclofenac solution can be used as a potential drug-delivery system to relieve early postoperative pain and foreign body sensation after TPRK.

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.

Single-Step Transepithelial Photorefractive Keratectomy in Low to Moderate Myopia: A One-Year Follow-Up Study

Aim

To evaluate predictability, safety, efficacy, and visual outcome of StreamLight. ™ (SL.), the newly released single-step transepithelial photorefractive keratectomy platform by Alcon WaveLight™ (WL).

Methods

In this prospective cohort study, photorefractive keratectomy (PRK) was conducted on 500 eyes of 250 patients seeking myopic refractive vision correction. The new single-step transepithelial PRK method was applied, using the SL. platform installed in the WL. Ex 500 excimer laser machine. Patients were followed up to monitor intensity and duration of postoperative pain, as well as speed of epithelial healing in the early post-operative period and visual acuity, postoperative refraction and development of postoperative haze for one year post-operatively.

Results

Average pain duration was 1.5 days, and the mean pain intensity score on a scale of 0–10 was 3.74 + 1.51. Mean postoperative spherical equivalence was 0.01 ± 0.38 D, and the final postoperative uncorrected distance visual acuity (UCDVA) was 20/20 in 98% of eyes included in this study. None of the eyes lost more than one Snellen chart line or developed visually significant postoperative haze during the follow-up period.

Conclusion

The new SL. platform for transepithelial PRK is a safe, accurate platform, offering an easier early post-operative recovery, with no compromise in final visual outcome.

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Preferred practice patterns for photorefractive keratectomy surgery

Over the past two decades, excimer laser-based refractive surgery procedures have been successfully established for their safety and satisfactory visual outcomes. Surface ablation procedures or photorefractive keratectomy (PRK) are practised commonly for the correction of refractive errors including myopia, astigmatism and hyperopia. Satisfactory visual outcomes are achieved in majority of cases, although a very small percentage have issues related to corneal haze, regression, and its associated visual disturbances. To ensure optimal outcomes and to minimize complications, certain keys to success have been designed on the basis of the current review of literature on surface ablation procedures.

CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

Photorefractive keratectomy (PRK) Prediction, Examination, tReatment, Follow-up, Evaluation, Chronic Treatment (PERFECT) protocol - A new algorithmic approach for managing post PRK haze

Purpose

The aim of this study was to discuss the possible risk factors predisposing to post photorefractive keratectomy (PRK) haze formation and develop and validate a risk scoring system, so that this could be applied to our clinical practice as an algorithmic approach.

Methods

Study was divided into 2 arms, in the retrospective arm we looked at 238 eyes of patients undergoing PRK where certain presumed risk factors from literature and clinical experience were identified and statistical significance of association was studied in the development of corneal haze. The risk scoring system was applied to the 450 eyes in the prospective arm for validation. This was then used to formulate an algorithmic approach to manage post-PRK haze.

Results

22 out of 238 eyes in the retrospective arm developed haze where risk factors such as contact lens intolerance, altered tear film break up time, meibomian gland drop out and vitamin d levels were significantly associated with post-PRK haze (p < 0.05) and these factors were identified in the prospective arm. Treatment of these modifiable factors led to a significant reduction in post-PRK haze.

Conclusion

Thus identifying and treating risk factors of haze in patients undergoing PRK could improve surgical outcomes and patient satisfaction.

Early Corneal and Epithelial Remodeling Differences Identified by OCT Imaging and Artificial Intelligence Between Two Transepithelial PRK Platforms

PURPOSE

To analyze corneal and epithelial remodeling differences between SmartSurfACE reverse transepithelial PRK (SCHWIND eye-tech-solutions) and Streamlight (Alcon Laboratories, Inc) transepithelial PRK procedure using optical coherence tomography (OCT) and artificial intelligence (AI).

METHODS

This was a prospective, interventional, and longitudinal study. A contralateral eye study was conducted in which one eye was assigned to the SmartSurfACE group and the fellow eye was assigned to the Streamlight group. OCT was performed preoperatively and 1, 3, and 6 months after surgery. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and residual refractive error was measured only preoperatively and at 3 and 6 months. From OCT, curvature and aberrations of the air-epithelium (A-E) interface, epithelium-Bowman's layer (E-B) interface, and epithelium Zernike indices (EZI) were derived. Pain was evaluated at 1 day postoperatively using the Wong-Baker scale.

RESULTS

Both groups had similar UDVA, CDVA, residual refractive error, and changes in A-E and E-B curvatures at 3 and 6 months postoperatively (P > .05). However, many parameters indicated that the Streamlight group underwent a greater change in A-E aberrations, E-B aberrations, and EZI than the SmartSurfACE group postoperatively (P < .05). The EZI indicated a greater level of epithelial thickness distortion in the Streamlight group than in the SmartSurfACE group (P < .05). Using AI, the EZI were most indicative of remodeling differences between the two groups. Further, the pain was significantly greater at 1 day in the Streamlight group (P < .05).

CONCLUSIONS

Early remodeling differences existed because the Streamlight procedure removed a greater amount of epithelium than the SmartSurfACE procedure. However, the visual and refractive outcomes were comparable. [J Refract Surg. 2020;36(10):678-686.].

Survey of Postoperative Pain in Photorefractive Keratectomy Using Topical versus Oral Nonsteroidal Anti-Inflammatory Drugs

Purpose

To evaluate and compare postoperative pain following photorefractive keratectomy (PRK) in patients using a preventive regimen of oral versus topical nonsteroidal anti-inflammatory drugs (NSAIDs).

Patients and Methods

A prospective, randomized, longitudinal survey of postoperative PRK pain was performed on 157 subjects in a tertiary academic medical center setting. Patients were randomized to either topical ketorolac 0.4% every 12 hours or oral naproxen sodium 220 mg every 12 hours for 72 hours following PRK, beginning at the time of surgery. The primary outcome measure was the daily peak pain score from the validated numerical rating scale (NRS) for five days after surgery.

Results

The peak pain scores were significantly higher in the oral NSAID group (mean 5.82, SD 1.94) compared to the topical NSAID group (mean 4.2, SD 2.19) (p<0.0001) after PRK. When comparing each postoperative day after PRK, the pain scores from 24 to 48 hours (day 2) were significantly higher in the oral NSAID group (mean 5.17, SD 2.25) as compared to the topical NSAID group (mean 3.21, SD 2.09) (p<0.0001). Pain scores 24–72 hours after surgery (days 2 and 3) were higher than pain scores on days 1, 4, and 5 for both groups.

Conclusion

Twice daily oral naproxen sodium 220 mg is inferior to twice daily topical ketorolac 0.4% in the treatment of early postoperative pain after PRK. This study also identified a consistent trend in which pain scores were highest 24–72 hours after the procedure. This additional observation may be useful in understanding, preventing, and treating post-PRK pain.