A randomized, double-masked, clinical study of the efficacy of four nonsteroidal anti-inflammatory drugs in pain control after excimer laser photorefractive keratectomy

Topical Ocular TRPV1 Antagonist SAF312 (Libvatrep) for Postoperative Pain After Photorefractive Keratectomy

Purpose

Evaluation of safety and efficacy of topical ocular SAF312 (Libvatrep) in post-photorefractive keratectomy (PRK) pain.

Methods

In this placebo (vehicle)-controlled, participant- and investigator-masked study, 40 participants were randomized (1:1) to two treatment sequences in a bilateral PRK crossover design (SAF312 2.5% followed by vehicle [or vice versa], one eye drop, four times daily for 72 hours after PRK). Primary endpoints were visual analog scale (VAS) pain scores at 6 hours after first drop of study drug and average VAS scores over 0 to 12 hours postoperatively. Secondary endpoints included postoperative oral rescue medication (ORM) use and adverse events (AEs).

Results

All 40 participants completed the study. Both primary endpoints were met; mean difference in VAS pain scores between SAF312- and vehicle-treated eyes was -11.13 (P = 0.005, -25%) at 6 hours postoperatively and -8.56 (P = 0.017, -22%) over 0 to 12 hours. Mean VAS pain scores with SAF312 were consistently lower than with vehicle from 1 hour postoperatively up to 30 hours (P ≤ 0.10 observed in 8/11 time points). Less ORM was taken with SAF312 up to 0 to 72 hours postoperatively, with a trend of fewer participants taking ORM at 0 to 24 hours postoperatively with SAF312 versus vehicle. No serious AEs were reported. All ocular AEs were mild and transient, and none were drug related. SAF312-treated eyes showed no delay in wound healing and had a lower grade 4 conjunctival hyperemia 24 hours postoperatively versus vehicle-treated eyes.

Conclusions

SAF312 was well tolerated and effective in reducing ocular pain post-PRK.

Translational Relevance

Topical SAF312 presents a new therapeutic option for patients undergoing PRK.

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.

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.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review

SIGNIFICANCE

This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward.

PURPOSE

A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments.

METHODS

Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria.

RESULTS

One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments.

CONCLUSIONS

This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

EFFECT OF BROMFENAC ON PAIN RELATED TO INTRAVITREAL INJECTIONS: A Randomized Crossover Study

PURPOSE

To evaluate the analgesic effect of bromfenac, a topically administered nonsteroidal antiinflammatory agent, in patients undergoing intravitreal injections (IVIs) of anti-vascular endothelial growth factor agents.

METHODS

A single center, prospective, randomized, double-blind, placebo-controlled, cross over interventional study. Patients scheduled to undergo IVI of anti-vascular endothelial growth factor were randomized to receive topical bromfenac or placebo before IVI. Pain perception was assessed using the short form of the McGill Pain Questionnaire. Pain intensity was evaluated with the visual analog scale, the main component of the short form of the McGill Pain Questionnaire, and the Present Pain Intensity scores immediately and 6 hours postinjection.

RESULTS

Sixty-five patients (65 eyes) were enrolled in the study. Immediately after IVI, pain perception was statistically significant lower in patients treated with bromfenac compared with placebo as assessed by the visual analog scale pain score and the main component of the short form of the McGill Pain Questionnaire (P = 0.002 and 0.001, respectively). At 6 hours postIVI, pain was statistically significant lower in patients treated with bromfenac, according to the visual analog scale pain score, the main component of the short form of the McGill Pain Questionnaire, and the Present Pain Intensity score (P < 0.001, <0.001, and P = 0.001, respectively). Multivariable regression analysis revealed that pain perception, as evaluated with the visual analog scale pain score immediately after IVI, was significantly lower in patients of older age, female patients and those with higher number of previous injections. Immediately after IVI, bromfenac seemed to be more effective in younger patients and in those who had already undergone an amount of injections.

CONCLUSION

Topical instillation of bromfenac significantly reduced the IVI-related pain immediately after and 6 hours postinjection.

Predictors of Early Postoperative Pain After Photorefractive Keratectomy

PURPOSE

To compare the profiles of postoperative photorefractive keratectomy (PRK) pain between both eyes under the same conditions and to verify the preoperative predictors of pain such as gender, anxiety, knowledge of the procedure, and spherical equivalent refractive error (SERE).

METHODS

This prospective study included 86 eyes of 43 patients with myopia who underwent PRK in both eyes at an interval of 14 days between the procedures. Before surgery, subjects answered the State Anxiety Inventory. After surgery, usual PRK pain treatment was given. Subjects answered the Visual Analog Scale, the Brief Pain Inventory (BPI), and the McGill Pain Questionnaire at 1, 24, 48, 72, and 96 hours after surgery. Pain scores and anxiety were compared between each eye using the Wald test and paired Student t test, respectively. The Wald test was performed for gender and SERE for each eye separately.

RESULTS

There were no statistically significant differences between both eyes for all time points regarding the Visual Analog Scale, BPI, and McGill Pain Questionnaire-Pain Rating Index pain scores. Subjects were less anxious on average before the second surgery compared with before the first surgery (P < 0.001); however, it was not related to pain ratings after surgery. Gender did not significantly affect any scale of pain, and the SERE between -3 diopters (D) and -5 D (P = 0.035) revealed effects on the BPI.

CONCLUSIONS

The profiles of postoperative pain after PRK were similar between both eyes under the same conditions. In this study, a high SERE was the only predictor for increased pain after PRK.

Analgesic effect of preoperative topical nonsteroidal antiinflammatory drugs on postoperative pain after laser-assisted subepithelial keratectomy

PURPOSE

To assess the effect of preoperative topical nonsteroidal antiinflammatory drugs (NSAIDs) on postoperative pain after laser-assisted subepithelial keratectomy (LASEK) and to investigate their mechanism.

SETTING

Severance Eye Hospital and Saeyan Eye Clinic, Seoul, South Korea.

DESIGN

Prospective randomized clinical trial.

METHODS

Participants in 2 related studies were assessed. Study 1 comprised patients scheduled for bilateral LASEK (Group 1) who were randomized to receive an NSAID in 1 eye and a placebo in the fellow eye 30, 20, and 10 minutes before LASEK. Postoperative pain, glare, tearing, and irritation were assessed using a visual analog scale. Study 2 comprised healthy subjects (Group 2) who were randomly divided into subgroups. The participants in these subgroups were randomized to receive ketorolac tromethamine 0.5% in 1 eye and placebo (ofloxacin 0.3%) in the fellow eye (Group 2A), proparacaine hydrochloride 0.5% in 1 eye and placebo in the fellow eye (Group 2B), or ketorolac tromethamine 0.5% in 1 eye and placebo in the fellow eye, followed 10 minutes later by 1 drop of proparacaine hydrochloride 0.5% in both eyes (Group 2C). In all 3 groups, corneal sensitivity was measured after 1, 2, and 6 hours.

RESULTS

The mean postoperative pain score in the NSAID-pretreated eye was statistically significantly lower than in the placebo-pretreated eye 6, 12, and 24 hours postoperatively (P < .05). The mean corneal sensitivity was statistically significantly lower in the NSAID-treated eye than in the placebo-treated eye at 1 and 2 hours in Groups 2A and 2C (P < .05).

CONCLUSION

Preoperative administration of topical NSAIDs before LASEK effectively reduces postoperative pain.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Comparison of the effect of cycloplegic versus NSAID eye drops on pain after photorefractive keratectomy

PURPOSE

To compare the effect of Homatropine and Diclofenac eye drops for reducing pain after photorefractive keratectomy (PRK).

METHODS

This randomized, double-masked, interventional study included 32 patients (64 eyes) who underwent bilateral PRK. After operation, patients received Homatropine eye drops in one eye and Diclofenac eye drops in the fellow eye for 48 h. The level of pain was evaluated using visual analogue scale (VAS), verbal rating scale (VRS), and pain rating index (PRI) at 0.5, 24, and 48 h after operation.

RESULTS

The level of pain was statistically similar between the two eyes half an hour after operation; however, Diclofenac eyes had significantly less pain 24 h after operation (1.7 ± 1.4 vs 5.8 ± 2.1, P < 0.001 for VAS, 0.6 ± 0.6 vs 2.4 ± 1.1, P < 0.001 for VRS, and 3.4 ± 3.4 vs 12.0 ± 6.9, P < 0.001 for PRI, respectively). Also, 48 h after surgery, the pain scores were less in the Diclofenac eyes (1.6 ± 1.8 vs 3.4 ± 2.8, P < 0.001 for VAS, 0.6 ± 0.6 vs 1.2 ± 0.9, P < 0.001 for VRS, and 3.3 ± 3.7 vs 6.5 ± 6.2, P < 0.001 for PRI). No case with delayed epithelial healing in both groups was observed.

CONCLUSION

The effect of Homatropine seems to be lower compared to Diclofenac for reducing pain after photorefractive keratectomy.

Efficacy and safety of pain relief medications after photorefractive keratectomy: review of prospective randomized trials

The objective of this review was to provide a comprehensive overview and comparison of results from all prospective randomized trials published to date of medications used to treat pain after photorefrative keratectomy (PRK). A PubMed database search revealed 23 prospective and randomized studies. They included the following classes of medications: nonsteroidal antiimflammatory drugs (NSAIDs), anesthetics, opiates, acetaminophen, gabapentin, and pregabalin. The studies found that although the efficacy of drugs tended to be similar, tetracaine 1% and nepafenac 0.1% tended to have the most analgesic effect. Delayed corneal reepithelialization was a common side effect of both topical anesthetics and topical NSAIDs. Tetracaine 1% resulted in the most significant delay in reepithelialization when tested against placebo control compared with other topical medications tested against placebo. Concomitant use of topical NSAIDs and topical anesthetics, especially tetracaine, may have to be avoided to minimize the risk for delayed corneal healing.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

Time-resolved spectroscopic characterization of a novel photodecarboxylation reaction mediated by homolysis of a carbon α-bond in flurbiprofen

Flurbiprofen (Fp), a nonsteroidal anti-inflammatory drug (NSAID) currently in use for arthritis pain relief and in clinical trials for metastatic prostate cancer, can induce photosensitization and phototoxicity upon exposure to sunlight. The mechanisms responsible for Fp phototoxicity are poorly understood and deserve investigation. In this study, the photodecarboxylation reaction of Fp, which has been assumed to underpin its photoinduced side effects, was explored by femtosecond transient absorption (fs-TA), nanosecond transient absorption (ns-TA), and nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopic techniques in pure acetonitrile (MeCN) solvent. Density functional theory (DFT) calculations were also performed to facilitate the assignments of transient species. The resonance Raman and DFT calculation results reveal that the neutral form of Fp was the predominant species present in MeCN. Analysis of the ultraviolet/visible absorption spectrum and results from TD-DFT calculations indicate that the second excited singlet (S2) can be excited by 266 nm light. Due to its intrinsic instability, S2 rapidly underwent internal conversion (IC) to decay to the lowest lying excited singlet (S1), which was observed in the fs-TA spectra at very early delay times. Intriguingly, three distinct pathways for S1 decay seem to coexist. Specifically, other than fluorescence emission back to the ground state and transformation to the lowest triplet state T1 through intersystem crossing (ISC), the homolysis of the carbon α-bond decarboxylation reaction proceeded simultaneously to give rise to two radical species, one being carboxyl and another being the residual, denoted as FpR. The coexistence of the triplet Fp (T1) and FpR species was verified by means of TR(3) spectra along with ns-TA spectra. As a consequence of its apparent high reactivity, the FpR intermediate was observed to undergo oxidation under oxygen-saturated conditions to yield another radical species, denoted as FOR, which subsequently underwent intramolecular hydrogen transfer (IHT) and dehydroxylation (DHO) to form a final product, which could react with the carboxyl from the decarboxylation reaction to generate a minor final product. TD-DFT and transient state (TS) calculations for predicting the absorption bands and activation energies of the transient species produced in the photodecarboxylation reaction have provided valuable mechanistic insights for the assignment of the intermediate species observed in the time-resolved spectroscopy experiments reported here. The results of the time-resolved spectroscopy experiments and DFT calculations were used to elucidate the reaction mechanisms and intermediates involved in the photochemistry of Fp.

Effect of Homatropine eye drops on pain after photorefractive keratectomy: A pilot study

PURPOSE

To assess the effect of homatropine eye drops on pain after photorefractive keratectomy (PRK).

METHODS

This randomized, double masked, interventional study included 15 patients (30 eyes) who underwent bilateral PRK. After operation, patients received homatropine eye drops, 4 times daily in only one eye (homatropine eye). The level of pain was evaluated using visual analogue scale (VAS), verbal rating scale (VRS) and pain rating index (PRI) at 0.5, 24 and 48 h after operation.

RESULTS

The level of pain was statistically similar between the two eyes half an hour after operation, however, homatropine eyes had significantly less pain 24 h after operation compared to fellow eyes (2.5 ± 1.9 vs 5.3 ± 2.5, P = 0.004 for VAS, 2.0 ± 1.2 vs 3.2 ± 0.9, P = 0.023 for VRS, and 9.4 ± 5.7 vs 16.0 ± 9.0, P = 0.031 for PRI). Also, 48 h after surgery, the pain scales were less in the homatropine eyes (2.3 ± 1.7 vs 4.0 ± 2.1, P = 0.014 for VAS, 1.6 ± 1.0 vs 2.5 ± 1.0, P = 0.038 for VRS, and 6.8 ± 5.7 vs 12.0 ± 8.9, P = 0.005 for PRI). No delayed epithelial healing was observed.

CONCLUSION

Homatropine eye drops may be useful for reducing pain after Photorefractive keratectomy.

Effect of nepafenac sodium 0.1% on delayed corneal epithelial healing and haze after photorefractive keratectomy: retrospective comparative study

PURPOSE

To assess delayed epithelialization and corneal haze related to nepafenac ophthalmic suspension 0.1% (Nevanac) use after photorefractive keratectomy (PRK).

SETTING

Private practice, Beverly Hills, California, USA.

METHODS

This retrospective comparative chart review comprised 69 eyes (44 patients) that were divided into 2 treatment groups that were not statistically significantly different in age or preoperative spherical equivalent. The nepafenac group consisted of 34 eyes (22 patients) that received nepafenac 0.1%, moxifloxacin, and fluorometholone postoperatively. The non-nepafenac group included 35 eyes (22 patients) that received moxifloxacin and fluorometholone only. Patients were seen between 1 day and 5 days postoperatively for evaluation of epithelial healing and haze formation. Delayed epithelialization was defined as healing after day 5. All patients were followed for haze formation for a minimum of 3 months.

RESULTS

Statistical analysis showed no difference between the nepafenac and non-nepafenac groups in delayed epithelialization (P = .61, chi-square test). Neither group had significant corneal haze.

CONCLUSION

Nepafenac did not appear to delay corneal epithelial healing or contribute to haze formation after PRK.

Effects of nonsteroidal ophthalmic drops on epithelial healing and pain in patients undergoing bilateral photorefractive keratectomy (PRK)

The present study, which was designed as a prospective, double-masked, randomized, controlled, single-site study, was conducted to compare the effects of 3 approved ophthalmic nonsteroidal anti-inflammatory drugs-nepafenac ophthalmic suspension 0.1% (Nevanac; Alcon Laboratories, Inc., Fort Worth, Tex), ketorolac tromethamine ophthalmic solution 0.4% (Acular LS; Allergan, Irvine, Calif), and bromfenac 0.09% (Xibromtrade mark; ISTA Pharmaceuticals, Irvine, Calif)-on corneal reepithelialization and postoperative pain control in patients undergoing photorefractive keratectomy. In addition to nonsteroidal anti-inflammatory drugs, each patient received an antibiotic-moxifloxacin hydrochloride ophthalmic solution 0.5% (nepafenac group) or gatifloxacin ophthalmic solution 0.3% (ketorolac and bromfenac groups). All treatments were administered 3 times daily beginning 1 d preoperatively and continuing for 1 wk postoperatively; prednisolone acetate 1.0% was administered concurrently 4 times daily. Bandage contact lenses were replaced at each postoperative visit for corneal staining and epithelial defect grading. Self-evaluation of pain relief was recorded on postoperative days 1 and 3 with the use of a visual analog scale. A total of 29 patients (58 eyes) were enrolled and underwent bilateral custom photorefractive keratectomy. Mean time to reepithelialization was 5.50+/-1.59 d for the nepafenac 0.1% group, 5.62+/-1.23 d for the ketorolac 0.4% group, and 7.25+/-2.53 d for the bromfenac 0.09% group. A significant difference was detected between nepafenac 0.1% and bromfenac 0.09% and between ketorolac 0.4% and bromfenac 0.09% (P<.05). Significant reductions in pain scores were observed with nepafenac 0.1% on day 1 (-1.13) and day 3 (-1.32), ketorolac 0.4% on day 3 (-0.88), and bromfenac 0.09% on day 3 (-0.83). No adverse events were reported. Eyes treated with nepafenac 0.1% or ketorolac 0.4% achieved complete reepithelialization significantly faster than those treated with bromfenac 0.09%. Daily contact lens removal and application of fluorescein may have delayed reepithelialization in the overall population; however, the effect would have been the same in all 3 groups. Pain relief with nepafenac 0.1% was achieved sooner than with ketorolac 0.4% or bromfenac 0.09%.

Double-masked study of the effects of nepafenac 0.1% and ketorolac 0.4% on corneal epithelial wound healing and pain after photorefractive keratectomy

Two NSAIDs--nepafenac 0.1% and ketorolac tromethamine 0.4%-were compared in terms of their effects on corneal reepithelialization and pain after photorefractive keratectomy (PRK) in a randomized, double-masked, contralateral eye, multicenter study. A total of 40 healthy adult patients who were undergoing sequential bilateral PRK received nepafenac 0.1% and ketorolac 0.4% in contralateral eyes, 1 drop 3 times daily for 3 d after bandage contact lens insertion. Patients were assessed on postoperative days 1, 3, 4, 5, and 7. At each visit, patients provided a general rating of pain. Each patient also assessed the sensation of each eyedrop following instillation (after-drop pain, irritation, burning/stinging, and overall comfort). Starting on day 3, epithelial defect size was assessed. Mean epithelial defect size was similar between treatments at each postoperative visit (P>.05). The average time-to-healing was 4.18 d for nepafenac 0.1% and 4.00 d for ketorolac 0.4% (P=.3134). No statistical difference was observed between nepafenac 0.1% and ketorolac 0.4% in mean postoperative pain scores (P>.05). On day 3, the nepafenac 0.1% group had significantly lower mean sensation scores than did the ketorolac 0.4% group for after-drop pain (P=.0090), irritation (P=.0007), and burning/ stinging (P=.0003). Mean overall comfort score was also significantly better for nepafenac 0.1% on day 3 (7.43 vs 6.41; P<.0001). Nepafenac 0.1% and ketorolac 0.4% provide postoperative pain relief after PRK surgery without associated adverse effects on corneal epithelial healing. Nepafenac 0.1% treatment may offer greater comfort upon instillation in patients who have undergone PRK.

Corneal ulceration and perforation with ketorolac tromethamine (Acular) use after PRK

PURPOSE

To report a case of corneal ulceration and perforation after PRK connected with high doses of ketorolac tromethamine (Acula).

METHODS

A 31-year-old man presented 5 days after PRK in the left eye with corneal ulceration and perforation requiring penetrating keratoplasty. The patient admitted to using Acular every hour, ciprofloxocin every hour, and prednisolone acetate 1% QID postoperatively.

RESULTS

Laboratory tests, including corneal cultures, were normal. A diagnosis of corneal ulceration secondary to incorrect use of high-dose ketorolac tromethamine was made.

CONCLUSION

Judicious patient counseling is recommended when using topical NSAIDs in the setting of PRK.

Relationships Between the Concentrations of Prostaglandins and the Nonsteroidal Antiinflammatory Drugs Indomethacin, Diclofenac, and Ibuprofen

STUDY OBJECTIVES

To study the concentration-effect relationships of the nonsteroidal antiinflammatory drugs (NSAIDs) indomethacin, diclofenac, and ibuprofen; to investigate whether standard doses of these drugs inhibit prostaglandin concentrations to a similar extent, determined by measuring the concentration of a surrogate marker of prostaglandin E 2 (PGE 2 ); and to determine the extent to which dose increases produce analogous increases in prostaglandin inhibition.

DESIGN

Single-dose, randomized, crossover trial with a 1-week washout period.

SETTING

University biopharmaceutics and pharmacokinetics laboratory.

SUBJECTS

Eight healthy adult volunteers younger than 35 years old.

INTERVENTION

Subjects were administered two different standard doses of regular formulations (not enteric coated) of each NSAID on separate occasions.

MEASUREMENTS AND MAIN RESULTS

Plasma samples were collected for determination of drug and 13,14-dihydro-15-keto-PGE 2 (PGEM; the surrogate marker of PGE 2 ) concentrations at regular intervals after administration of each NSAID dose. Statistically significant linear correlations were found between the percent reduction in PGEM concentration and the concentrations of diclofenac, indomethacin, and ibuprofen in plasma (R 2 = 0.992-0.999). The PGEM plasma concentrations correlated inversely with NSAID plasma concentrations, indicating maximum inhibition when the highest NSAID plasma concentrations were achieved. Statistically significant differences in the percent inhibition of PGEM concentrations were observed between the two doses for each NSAID (p<0.05), but not between subjects for each NSAID. Doubling the dose (100% increase) of diclofenac and indomethacin produced a 60-65% increase in maximum inhibition of PGEM concentrations, whereas a 50% increase in dose produced a 44% increase in the maximum effect of ibuprofen.

CONCLUSION

Prostaglandin inhibition, as measured by changes in PGEM concentrations, correlated significantly with NSAID concentrations in plasma and differed significantly between high and low NSAID doses. Measurement of PGEM plasma concentrations appears to be a promising marker for estimation of relative potency of NSAIDs.

Characterisation of the lowest singlet and triplet excited states of S-flurbiprofen

The photophysical properties of S-flurbiprofen [S-2-fluoro-alpha-methyl-4-biphenylacetic acid], a nonsteroidal anti-inflammatory drug, have been examined using steady-state and time-resolved spectroscopic techniques. The energy of its first singlet excited state is 99 kcal mol(-1). The fluorescence quantum yields and lifetimes (at 300 nm) have been determined in acetonitrile, methanol, hexane and PBS; they are in the range 0.15<phi(F)< 0.33 and 0.7<tau(F)<2.0 ns. The intersystem crossing quantum yields are between 0.45 and 0.71; the lambda(max) of the T-T absorption is 360 nm, and the triplets live from 15 to 106 micros. Steady state photolysis in aqueous medium leads to S-2-hydroxy-alpha-methyl-4-biphenylacetic acid via photonucleophilic aromatic substitution, in addition to the photodecarboxylation products observed in organic solvents.

A new index to measure the accuracy of refractive operations

PURPOSE

To create a new index to help evaluate the accuracy of the outcome of refractive surgery.

METHODS

By combining information given by the cross-cylinder form of surgically induced refractive change (SIRC) and basic methods of vector analysis, we constructed a new index which serves as a tool to evaluate postoperatively the changes achieved by refractive surgery. This new index gives easily understandable numerical values and takes into account changes in both spherical refraction and astigmatism. We demonstrated the use of this index in two study populations consisting of 20 consecutive eyes operated on using two different lasers, Meditec MEL60 and MEL70, respectively.

RESULTS

Although postoperative uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were better in the MEL70 group, the difference of photoefractive keratectomy (PRK) for combined astigmatism and myopia was not statistically significant. Comparison of the changes in refraction achieved by the two lasers indicated that the MEL60 was more accurate; this was also seen when comparing the total index of error between the two groups.

CONCLUSIONS

We suggest the use of this total index of error (TIE) in clinical praxis because it provides an easy and accurate method of evaluating the accuracy of refractive operations. These inaccuracies might otherwise go unnoticed if the basic values only (e.g. UCVA, BCVA and haze) were used in postoperative evaluation.

Intractable eye pain: indication for triptans

Management of pain is difficult in many eye diseases. Particularly in patients undergoing surgical procedures, postoperative intractable pain is a major concern and severely influences the patient's comfort. We present 13 patients (eight male, five female, mean age 36 years) in whom sumatriptan, a highly selective 5-HT1B/1D agonist that is normally used as a specific anti-migraine drug, was used for the treatment of pain following photorefractive keratectomy (PRK). In two patients both eyes were operated on different days, resulting in a total of 15 operated eyes. A positive clinical response was achieved in all patients. In particular, in four patients, who received a second dose prophylactically 4 h following the first dose and before the recurrence of pain, we achieved excellent efficacy and stable control of pain. Further controlled studies are needed to investigate the usefulness of 5-HT1B/1D agonists in painful eye conditions.