Analgesic effect of topical sodium diclofenac 0.1% drops during retinal laser photocoagulation

A Comprehensive Meta-Analysis on the Role of Analgesics and Anti-Inflammatories in Pan-retinal Photocoagulation

PURPOSE

Pan-retinal photocoagulation (PRP) is the mainstay of treatment for proliferative diabetic retinopathy (PDR), reducing the risk of severe vision loss. Pain poses a potential obstacle to effective laser delivery and patient compliance. Therefore, implementing pain relief strategies can enhance both treatment efficacy and patient comfort.

DESIGN

A systematic review and meta-analysis.

METHODS

We conducted a systematic review and meta-analysis according to PRISMA guidelines. The PubMed, Embase and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials (RCTs) that enrolled patients undergoing PRP due to DR and compared analgesics or non-steroidal anti-inflammatory drugs (NSAID) to placebo. Pain was evaluated with the visual analogue scale. The version 2 of the Cochrane Collaboration's Risk of Bias in Randomized Controlled Trials tool and its version for crossover trials were used to assess the risk of bias. The Grading of Recommendations, Assessment, Development, and Evaluation tool was used to measure the certainty of evidence.

RESULTS

A total of 13 studies were included, comprising 1404 eyes from RCTs, nine of which were crossover. Patients who were administered analgesia reported a significantly lower pain sensitivity compared to those who received placebo (Standardized mean difference [SMD] -0.38; 95% confidence interval [CI] -0.58, -0.17; P<0.01; I2=69%). Subgroup analysis of systemic administration of analgesics/NSAIDs (metamizole, Entonox, acetaminophen, ibuprofen, caffeine, mefenamic acid, intramuscular ketorolac tromethamine, and potassium diclofenac) also showed a statistically significant reduction in pain when compared to placebo (SMD -0.28; 95% CI -0.50, -0.07; P<0.01; I2=43%). Exclusive eye drops administration (ketorolac tromethamine 0.5% and sodium diclofenac 0.1%) also showed a significant difference in pain sensitivity (SMD -0.46; 95% CI -0.88, -0.05; I2=83%), however with a more significant heterogeneity.

CONCLUSION

The results of this meta-analysis including over 1000 patients demonstrated that the use of analgesics significantly reduced pain sensitivity during PRP, and systemic analgesia is potentially better than topical administration when compared to placebo.

Transnasal sphenopalatine ganglion block for pain relief during panretinal photocoagulation laser for diabetic retinopathy: a pre and post interventional study

This study was performed to utilize transnasal Sphenopalatine Ganglion (SPG) block for pain reliving during panretinal photocoagulation (PRP) in diabetic patients with diabetic retinopathy. This pre and post interventional study was performed on 20 patients with proliferative diabetic retinopathy. The first PRP treatment session of all the patients is performed with no transnasal SPG block, but before holding the second session, all the patients underwent transnasal SPG block and pain levels during and after PRP were compared to each other. Before the transnasal SPG block, each nostril of all the cases was inspected for finding any obstruction in each PRP session. Transnasal SPG block was also performed in with 2% lidocaine. The mean age of the included cases was 52.84 ± 8.62 years old (from 36 to 72 years old). All the cases underwent two PRP lasers treatment sessions with the same characteristic (spot size, power and duration) for each patient. In the first and second PRP treatment sessions, the mean NRS scores were obtained immediately after the PRP laser (8.4 vs. 4.2), 15 min (8.2 vs. 4.2), 1 h (8.0 vs. 4.1), and 24 h (5.4 vs. 3.6) after the PRP respectively. The mean NRS scores significantly reduced during the second PRP treatment session compared to the first session (p < 0.001). Transnasal SPG block is a safe and effective strategy used for relieving pain caused by the PRP laser treatment in patients with diabetic retinopathy.

Pre-Emptive Topical Ketorolac Tromethamine 0.5% for Panretinal Photocoagulation

Purpose: To evaluate the efficacy of topical ketorolac tromethamine 0.5% given pre-emptively a day before, for alleviating pain in patients undergoing panretinal photocoagulation (PRP) treatment. Methods: A controlled single-blinded study was conducted on 33 patients with diabetic retinopathy (DR; severe nonproliferative DR, proliferative DR, or advanced diabetic eye disease) who required PRP treatment in both eyes simultaneously. Each eye of the patients was randomly assigned for ketorolac tromethamine 0.5% eyedrop or placebo. Both eyedrop bottles were randomly labeled. Eyedrops were self-administered by the patients, 4 times a day before the procedure (at 6 am, 12 noon, 6 pm, and 12 midnight) and every 15 min for 1 h (4 times) before the laser. Each patient was subjected to PRP using a Visulas 532s Zeiss device set to spot size 200 μm, time 0.10 s, and ∼600 burns in each eye. The pain score was evaluated immediately after treatment in each eye independently with Scott's visual analog scale (VAS) and the McGill Pain Questionnaire (MPQ). Results: VAS pain score in ketorolac-treated eyes (median 3.0, interquatile range [IQR] ±2.5) was lower than in placebo-treated eyes (median 5.0, IQR ±3.0). Total Pain Rate Index score from MPQ was lower in ketorolac-treated eyes (median 3.0, IQR ±3.0) than in placebo-treated eyes (median 3.0, IQR ±2.5). Both pain score differences are statistically significant with P ˂ 0.05. Conclusion: Topical ketorolac tromethamine 0.5% given pre-emptively a day before is effective in alleviating pain in patients undergoing PRP treatment.

Comparison of navigated laser and conventional single-spot laser system for induced pain during panretinal photocoagulation

To compare the panretinal photocoagulation (PRP)-induced pain response between novel navigated laser (Navilas) and conventional single-spot laser. The eyes were randomly assigned to Navilas or conventional laser. Contralateral eyes underwent PRP with the other system with 30 min resting interval. Pulse duration was 100 ms in conventional laser and 30 ms or 100 ms in Navilas and power setting was enough to create gray-white light burn on both devices. Pain response was evaluated by verbal scale (VS) (0-4) and visual analog scale (VAS) (0-10) after each PRP application. The mean age of 70 patients (140 eyes) was 62.52 ± 9.49 years. Mean power and spot numbers for Navilas and conventional laser were 291.9 ± 85.3 mW vs 368.4 ± 72.0 mW, and 375.4 ± 108.4 vs 374.2 ± 105.0 (p < 0.001 and p = 0.53, respectively). Pain scores for Navilas and conventional laser were 1.19 ± 0.73 and 1.99 ± 0.84 for VS and 2.41 ± 1.65 and 4.74 ± 2.17 for VAS (p < 0.001 and p < 0.001). More comfortable PRP is achieved with Navilas system in comparison with conventional single-spot laser system. However, small number of patients treated with same pulse duration and different contact lenses used for two systems should be taken into consideration. Besides, we did not report comparative clinical efficiency of either laser system.

PASCAL laser platform produces less pain responses compared to conventional laser system during the panretinal photocoagulation: a randomized clinical trial

Background

Most of patients experience pain during the panretinal photocoagulation(PRP). Laser photocoagulation delivery has advanced with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and less choroidal penetration believed to reduce pain during the laser treatment.

Objectives

To compare the severity of expressed pain scores in patients with PDR who underwent PRP either with PASCAL laser or conventional laser.

Methods

A total of 28 patients with a diagnosis of PDR who were scheduled for bilateral PRP therapy were enrolled into the prospective study. Both eyes were treated within the same session and while one eye was treated with PASCAL the other was treated with conventional laser randomly. Pulse duration was adjusted to 100-ms in conventional laser and 30 ms in PASCAL. The severity of pain was graded using a verbal scale and a visual analog scale (VAS).

Results

Mean age was 61.36±9.10 years. Mean verbal and VAS scores were 1.32±0.47 and 2.86±1.21 in the PASCAL laser and 2.39±0.49 and 5.75±1.35 in the conventional laser group, respectively. Differences between expressed pain scores obtained by both two scales were statistically significant (p<0.001).

Conclusion

PASCAL laser significantly alleviates pain levels possibly due to the shorter laser pulse duration and lower intensity.

Analgesic Effect of Topical Sodium Diclofenac before Retinal Photocoagulation for Diabetic Retinopathy: A Randomized Double-masked Placebo-controlled Intraindividual Crossover Clinical Trial

PURPOSE

To evaluate the analgesic effect of topical sodium diclofenac 0.1% before retinal laser photocoagulation for diabetic retinopathy.

METHODS

Diabetic patients who were candidates for peripheral laser photocoagulation were included in a randomized, placebo-controlled, intraindividual, two-period, and crossover clinical trial. At the first session and based on randomization, one eye received topical sodium diclofenac 0.1% and the other eye received an artificial tear drop (as placebo) three times before laser treatment. At the second session, eyes were given the alternate drug. Patients scored their pain using visual analogue scale (max, 10 cm) at both sessions. Patients and the surgeon were blinded to the drops given. Difference of pain level was the main outcome measure.

RESULTS

A total of 200 eyes of 100 patients were enrolled. Both treatments were matched regarding the applied laser. Pain sensation based on visual analogue scale was 5.6 ± 3.0 in the treated group and 5.5 ± 3.0 in the control group. The calculated treatment effect was 0.15 (95% confidence interval, -0.27 to 0.58; p = 0.486). The estimated period effect was 0.24 (p = 0.530) and the carryover effect was not significant (p = 0.283).

CONCLUSIONS

Pretreatment with topical sodium diclofenac 0.1% does not have any analgesic effect during peripheral retinal laser photocoagulation in diabetic patients.

Metamizole versus placebo for panretinal photocoagulation pain control: a prospective double-masked randomized controlled study

BACKGROUND

Diabetic retinopathy is one of most common and threatening ocular diseases. Many of these patients need to be submitted to panretinal photocoagulation (PRP), experiencing a significant level of pain. The purpose of this study is to evaluate the effectiveness of oral metamizole in reducing pain during PRP in patients with proliferative diabetic retinopathy (PDR) and very severe non-proliferative diabetic retinopathy (VSNDR).

METHODS

Patients from a single center with PDR or VSNDR and indication of bilateral PRP were recruited for a double-masked, controlled, prospective study. The treated eyes were randomly assigned in two groups, and each patient had one eye assigned per group. Group A received 1000 mg of metamizole and group B received a placebo pill 40 min before the laser treatment. The groups were switched for the treatment of the fellow eye. Each patient scored the pain sensation immediately after each PRP section using Scott's visual analogue scale (VAS). The paired Student t test was used to measure the significance between the two groups VAS scores, with significance level adopted of p < 0.05.

RESULTS

Twenty-one patients were recruited. The level of pain was significantly lower when submitted to PRP after oral metamizole treatment compared to placebo (p = 0.002). The mean pain scores for groups A and B were 4.72 ± 1.708 and 5.89 ± 1.967, respectively. The minimum/maximum scores within groups A and B were 1/8 and 1/10, respectively.

CONCLUSIONS

The use of 1000 mg of metamizole 40 min before PRP significantly reduces the pain associated with the procedure in patients with PDR or VSNDR.

Manual acupuncture for relieving pain associated with panretinal photocoagulation

OBJECTIVE

The feasibility of manual acupuncture for reducing pain associated with panretinal photocoagulation (PRP) was investigated.

METHODS

This was a prospective, comparative nonrandomized study on patients with proliferative diabetic retinopathy who were receiving PRP treatment. The protocol of PRP included three sequential sessions of treatment at 2-week intervals. Both the acupuncture (acuPRP) and control groups had no acupuncture in the first session. In the second session, acupuncture was given to the acuPRP group only. The third session of PRP completed the laser treatment course. Acupuncture performed only at GB 37 (Guāngmíng) just before PRP, and the needle was removed after the treatment. An 11-point Likert-type verbal pain score test was given to all patients after each PRP treatment.

RESULTS

Of 34 patients with proliferative diabetic retinopathy, 18 patients were allocated to the acuPRP group and 16 patients were allocated to the control group. After the first PRP treatment, there was no statistical difference in mean pain scores between the acuPRP and control groups (6.8±1.2 versus 6.3±2.1, respectively, p=0.383). After the second PRP treatment, the mean pain score in the acuPRP group was significantly lower, compared with the control group (3.9±1.8 versus 7.4±1.9, respectively, p<0.0001). Within the group, the mean pain scores were significantly higher during the second PRP treatment, compared with the first PRP treatment, in the control group (p=0.0003). In contrast, the mean pain scores were significantly lower during the second PRP treatment, compared with the first PRP treatment in the acuPRP group (p<0.0001). No adverse reactions or complications were noted.

CONCLUSIONS

Acupuncture might help reduce pain during PRP treatment. However, further randomized studies are necessary to verify these preliminary results.

Analgesic effect of etoricoxib (Arcoxia®) 120 mg during retinal laser photocoagulation

Purpose

Panphotocoagulation reduces the risk of vision loss in proliferative diabetic retinopathy. However, not many patients tolerate this treatment well due to pain. Therefore, we evaluated the analgesic effect of etoricoxib during photocoagulation in patients with proliferative diabetic retinopathy.

Methods

A prospective, randomized, double-blind study was conducted on 44 consecutive patients eligible for panphotocoagulation due to proliferative diabetic retinopathy. During the first panphotocoagulation session, both groups were treated without medication. During the following session, the control group received a placebo pill while the other group received etoricoxib 120 mg. Both groups took the medicines 1 hour before the treatment. After each session, the patients quantified the level of pain on a subjective visual scale.

Results

A total of 52 patients were selected for the study and the data of 44 patients were analyzed. In the control group, the average level of pain in the first session was 7.68 (standard deviation 1.70), dropping to an average of 7.32 (standard deviation 1.39) after ingestion of placebo. Therefore, there was no statistical difference (p=0.1187). In contrast, the average level of pain without the drug in the group taking etoricoxib 120 mg was 7.95 (standard deviation 1.46) vs 5.18 (standard deviation 1.65) with the drug, a significant statistical difference (p<0.001).

Conclusions

Etoricoxib 120 mg reduces pain and can be used before panphotocoagulation. Data show that the medication is more effective against pain during photocoagulation than placebo.

Pain perception at laser treatment of peripheral retinal degenerations with green and infrared wavelengths

PURPOSE

To compare the pain perception at laser treatment of peripheral retinal degenerations with green (532-nm) and infrared (810-nm) wavelengths.

DESIGN

Prospective randomized clinical trial.

METHODS

Sequential patients with indications for photocoagulation of bilateral peripheral retinal degenerations were invited to participate in the study. Thirty patients (60 eyes) were enrolled in the study. Each patient had 1 eye treated with infrared laser (diode, 810-nm wavelength) and the other eye treated with green laser (frequency-doubled solid-state laser, diode-pumped, with 532-nm wavelength). The eyes were randomized to infrared or green wavelengths. The right eye was the first treated in all cases regardless of the wavelength arrangement. Immediately after photocoagulation of each eye, the patient was asked to grade pain perception according to an 11-point (ie, 0-10) numerical rating scale (NRS), with 0 meaning "No pain" and 10 meaning "Pain as bad as you can imagine." The primary outcome was the assessment of pain.

RESULTS

The mean grading of pain perception was 2.80 (SD 1.27; mode and median = 2) to green wavelengths and 5.07 (SD 1.36; mode = 4 and median = 5) to infrared wavelengths (P < .001).

CONCLUSIONS

The results showed a statistically and clinically significant difference of pain perception between the 2 groups, with advantage to the green laser group.

Reduction of fluence to decrease pain during panretinal photocoagulation in diabetic patients

BACKGROUND AND OBJECTIVE

To assess the effect of laser fluence reduction to reduce pain during panretinal photocoagulation.

PATIENTS AND METHODS

Twenty-five patients (50 eyes) with diabetic retinopathy who had indication for panretinal photocoagulation were included in this prospective, interventional, and comparative study. The right eyes were treated using low fluence parameters (LFP), whereas the left eyes were treated with standard fluence parameters (SFP). At the end of each session, the patient was asked to rate pain from 0 (no pain) to 10 (maximum pain) for each eye (NRS-11 scale). Fluence per burn and total fluence were determined for each eye. Statistical analysis was performed using the Mann-Whitney U test and the Pearson correlation coefficient.

RESULTS

Pain perception (P < .01) and fluence per burn (P < .01) were significantly less using LFP compared with SFP. Pain was proportional to fluence per burn (R(2) = 0.4), but not to number of burns (R(2) = -0.2).

CONCLUSION

The use of LFP seems to be a good option to diminish the pain during panretinal photocoagulation.

Nonsteroidal anti-inflammatory drugs in ophthalmology

Nonsteroidal anti-inflammatory drugs (NSAIDs) are increasingly employed in ophthalmology to reduce miosis and inflammation, manage scleritis, and prevent and treat cystoid macular edema associated with cataract surgery. In addition, they may decrease postoperative pain and photophobia associated with refractive surgery and may reduce the itching associated with allergic conjunctivitis. In recent years, the U.S. Food and Drug Administration has approved new topical NSAIDs, and previously approved NSAIDs have been reformulated. These additions and changes result in different pharmacokinetics and dosing intervals, which may offer therapeutic advantages. For example, therapeutic effects on diabetic retinopathy and age-related macular degeneration may now be achievable. We provide an updated review on NSAIDs and a summary of their current uses in ophthalmology with attention to potential future applications.

Analgesic effects of tramadol during panretinal photocoagulation

Purpose

To evaluate the effectiveness of tramadol for the reduction of pain in panretinal photocoagulation (PRP).

Methods

A double-masked randomized controlled study was performed. Fifty-eight eyes in 29 patients with proliferative diabetic retinopathy were enrolled. The eyes of the patients were randomized into two groups. Group A received an empty capsule. Group B received an oral intake of 100 mg tramadol. The capsule used in Group A had the same appearance as that used in Group B. Pain during PRP was assessed using a visual analog scale. Vital signs, including blood pressure and heart rate, were measured.

Results

The mean pain scores for groups A and B were 4.80±2.10 and 3.83±1.82 (p=0.09). There were no significant differences in the mean pain scores between the two groups. More patients in group A complained of greater pain than moderate intensity (visual analogue scale=4). Systemic blood pressure increased significantly in group A after laser treatment. However, there were no significant differences in the diastolic blood pressure changes between the two groups. We found no statistical correlation in the heart rate changes.

Conclusions

We failed to prove that tramadol is effective for pain relief because of the small sample size. However, tramadol was effective for the relief of more severe pain. It was also found to stabilize vital sign changes, such as systolic blood pressure during PRP.

Oral versus topical diclofenac for pain prevention during panretinal photocoagulation

PURPOSE

To investigate the effect of pretreatment oral and topical diclofenac on pain reduction during panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR).

DESIGN

Prospective, randomized, double-masked, placebo-controlled clinical trial.

PARTICIPANTS AND CONTROLS

A total of 90 patients with PDR requiring PRP for the first time were assigned randomly to 1 of 3 study groups: oral diclofenac (n = 30), topical diclofenac (n = 31), or placebo (n = 29).

METHODS

Study medications were administrated before the first PRP treatment, and pain levels experienced during and 15 minutes after PRP were recorded on a visual analog scale (VAS). Pain levels during a second PRP session, performed on a later date with no pretreatment medications, also were recorded on a VAS.

MAIN OUTCOME MEASURES

The primary outcome measures were the mean VAS pain scores during the first PRP treatment. Secondary outcome measures were the mean VAS pain scores 15 minutes after the first PRP and during the second PRP, and reported side effects after the first PRP.

RESULTS

Mean VAS pain scores during the first PRP were: oral diclofenac, 25.7+/-19.9; topical diclofenac, 33.8+/-27.9; and placebo, 41.3+/-31.0. The pain score difference between oral diclofenac and placebo was both clinically significant (>or=13) and statistically significant (P = 0.02), whereas differences between oral and topical diclofenac (P = 0.20) and topical diclofenac and placebo (P = 0.33) were not. Multivariate regression analysis for age, gender, and total laser energy demonstrated lower pain levels for both oral diclofenac (P = 0.015) and topical diclofenac (P<0.0001) versus placebo, but no difference between oral and topical diclofenac (P = 0.67). For the first PRP, all 3 groups had lower mean pain scores at 15 minutes after treatment compared with during treatment (P<or=0.0003). Mean pain scores were higher during the second compared with the first PRP for the oral diclofenac (P = 0.02) and placebo (P = 0.05) groups. No significant rate difference for any side effect was found between groups.

CONCLUSIONS

When given in a single dose, oral diclofenac is an effective pretreatment analgesic agent for reducing the pain experienced during PRP for PDR.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Topical Ketorolac 0.5% for Ocular Pain Relief During Scatter Laser Photocoagulation with 532 nm Green Laser

PURPOSE

The aim of this study was to evaluate the analgesic effect of topical ketorolac tromethamine 0.5% during scatter laser photocoagulation procedure in proliferative diabetic retinopathy patients.

METHODS

60 eyes of 30 consecutive proliferative diabetic retinopathy patients were included to this prospective, randomized, double-masked, controlled study. One (1) h before laser treatment session, ketorolac tromethamine 0.5% was instilled to 1 eye and artificial tear drop to the fellow eye. Just after treatment, the patients were asked for the severity of pain in both eyes. Visual analog scale was used to assess the level of pain.

RESULTS

Mean pain level for placebo-instilled eyes was 4.88+/-2.56 and ketorolac instilled eyes were 4.45+/-2.25. There was no significant difference for pain levels between placebo and ketorolac-instilled eyes (P=0.29).

CONCLUSIONS

Topical ketorolac tromethamine usage is no more effective than artificial tears for pain relief during posterior segment laser procedures in proliferative diabetic retinopathy patients.

Double masked randomised controlled trial to assess the effectiveness of paracetamol in reducing pain in panretinal photocoagulation

AIM

To assess the effectiveness of pre-emptive analgesia with paracetamol in reducing pain associated with panretinal photocoagulation (PRP) in a prospective, double masked, randomised controlled trial.

METHOD

60 patients undergoing PRP for the first time were enrolled and randomised to paracetamol or placebo, taken for 2 days starting 24 hours before the laser treatment. The laser treatment was performed following a standardised protocol. Pain during and after treatment was assessed using the McGill pain questionnaire (MPQ) and visual analogue scales (VAS).

RESULTS

The statistical analysis looked for differences between the two study groups immediately after the laser surgery and 24 hours later. There was no statistically significant difference in the primary outcome measure of perception of pain during and 24 hours after PRP, between the paracetamol and placebo group. However, none of the patients in the paracetamol group reported increased total pain at 24 hours, whereas six patients in the placebo group reported increased pain; this difference (21%) was significant to p = 0.01.

CONCLUSIONS

Pre-emptive analgesia with paracetamol did not significantly reduce pain associated with PRP. This study has described for the first time the type of pain associated with PRP, which is perceived mainly as a discomfort. The main attributes of the pain that patients described, were sharp, flashing, tiring, intense, piercing, intermittent, and brief.

Interventions for relieving pain associated with panretinal photocoagulation: a prospective randomized trial

PURPOSE

To evaluate the efficacy of pain relief by oral diazepam, acetaminophen, mefenamic acid, intramuscular ketorolac tromethamine, and peribulbar anaesthesia in panretinal photocoagulation (PRP).

METHODS

A total of 220 patients with proliferative diabetic retinopathy requiring PRP treatment were enrolled in this study. Before laser treatment, the patients were allocated randomly to one of eight groups: group 1: diazepam (n=22), group 2: acetaminophen (n=21), group 3: mefenamic acid (n=21), group 4: diazepam and acetaminophen (n=22), group 5: diazepam and mefenamic acid (n=22), group 6: peribulbar anaesthesia with lidocaine (n=23), group 7: intramuscular injection of ketorolac tromethamine (n=22), group 8: placebo (n=67). Pain after the laser treatment was assessed by a verbal descriptive scale. Blood pressure and heart rate were measured before and after laser treatment.

RESULTS

Patients receiving peribulbar anaesthesia had a significantly lower pain score than the control group (P<0.0001). Additionally, the peribulbar anaesthesia-treated group had the significantly least PRP-associated rise in either systolic (P=0.043) or diastolic blood pressure rates (P=0.030). There were no significant differences in pain score using other anesthetic agents when compared with the control group. There were no significant changes in heart rate after PRP treatment.

CONCLUSION

Peribulbar anaesthesia is effective in reducing pain and blood pressure increase after PRP treatment. Oral diazepam, mefenamic acid, and acetaminophen (either alone or in combination with each other) are not effective in preventing PRP treatment-associated pain. Intramuscular injection of ketorolac tromethamine is also not effective in reducing PRP-associated pain.

Entonox as an analgesic agent during panretinal photocoagulation

BACKGROUND/AIMS

Panretinal photocoagulation (PRP) reduces the risk of visual loss in proliferative diabetic retinopathy but some patients cannot tolerate PRP because of pain. Inhaled Entonox was evaluated as an analgesic during PRP.

METHODS

A randomised, crossover, double masked pilot study was performed. Patients inhaled either air or Entonox and half the PRP was applied. The treatment was completed with the alternate inhaled gas. Patients graded pain experienced during both stages of the treatment using a visual analogue scale. Pain scores were compared using a paired t test.

RESULTS

20 patients participated. Mean pain scores from the Entonox and air treatments were 2.94 (SD 2.73) versus 3.73 (SD 3.20) respectively (p<0.03).

CONCLUSION

Entonox can be used as a safe and effective analgesic agent during PRP treatment.

Efficacy of lignocaine gel for outpatient laser treatment in inflamed eyes

PURPOSE

To evaluate the efficacy and safety of topical 2% lignocaine gel in providing analgesia during outpatient transpupillary or trans-scleral laser treatment of inflamed eyes.

METHODS

A prospective study was carried out of consecutive eligible eyes undergoing laser treatment using 2% lignocaine gel as a topical anaesthetic and a coupling medium. At the conclusion of each procedure, patients were asked to grade a pain score (0 = no discomfort, 1 = mild discomfort, 2 = mild pain, 3 = moderate pain, 4 = severe pain).

RESULTS

Twenty eyes in 19 patients received laser treatment. No pain was reported in 95% of cases treated (no discomfort in 75%, mild discomfort in 20%) and only mild pain in 5% (one patient). No adverse reactions were encountered in any of the patients. There were no complications associated with the procedures.

CONCLUSIONS

Lignocaine 2% gel is safe and effective for outpatient transpupillary and trans-scleral laser treatment in inflamed eyes, providing adequate analgesia and serving as a coupling medium at the same time.