The effect of cold tetracaine on the severity of burning sensation upon instillation

Pain control and subconjunctival haemorrhage after intravitreal injection using cooled anaesthetic eyedrops and antiseptics: A prospective, double-blind, randomized controlled trial

PURPOSE

To evaluate whether cooled anaesthetic eyedrops and antiseptics alleviate pain and minimise subconjunctival haemorrhage following intravitreal injection.

METHODS

A prospective, double-masked, randomised controlled trial of 100 participants receiving either cooled (n = 50) or room temperature (n = 50) topical anaesthetic eyedrops and antiseptics before receiving an injection of bevacizumab. Baseline tolerability was estimated using a self-reported pain sensitivity questionnaire.

RESULTS

Overall tolerability was comparable between the study group and the control group (0.75 ± 0.13 vs. 0.74 ± 0.14, respectively, p = 0.99). Subconjunctival haemorrhage incidence was similar in both groups (80% vs. 86%, respectively, p = 0.113), as was subconjunctival haemorrhage size (2.75 ± 5.51 mm2 vs. 5.53 ± 10.72 mm2 , respectively, p = 0.11). Sub-group analysis demonstrated that the participants taking daily ocular eyedrops who received cooled anaesthetic eyedrops and antiseptics reported less pain at 10 min and less burning sensation at 24 h compared with matched controls (0.67 ± 1.50 vs. 2.50 ± 3.03, respectively, p = 0.040 and 0.00 ± 0.00 vs. 1.44 ± 2.96, respectively, p = 0.045). Participants who received cooled eyedrops and did not use antithrombotic therapy had smaller-sized subconjunctival haemorrhages compared with matched controls (1.55 ± 1.87 mm2 vs. 8.29 ± 14.61 mm2 , respectively, p = 0.038). Participants with hypertension who received cooled eyedrops had smaller-sized subconjunctival haemorrhage compared with matched controls (2.33 ± 4.99 mm2 vs. 6.89 ± 12.41 mm2 , respectively, p = 0.045).

CONCLUSION

The benefit of using cooled anaesthetic eyedrops and antiseptics to alleviate pain and minimise subconjunctival haemorrhage following intravitreal injection was not proven in the general population. It may be beneficial in part for some patients, such as those who regularly use eyedrops, patients with hypertension or those not on antithrombotic therapy.

Efficacy of tetracaine eye drops in strabismus surgery: a systematic review and meta-analysis of randomized controlled trials

AIM

To comprehensively evaluate the efficacy and safety profile of tetracaine eye drops as a local anesthetic agent among pediatric patients undergoing for strabismus surgery.

METHODS

We systemically searched four electronic databases (PubMed, Scopus, Web of Science, and Cochrane Library) from inception until April 2023. We included randomized controlled trials (RCTs) comparing tetracaine and placebo or no intervention for intraoperative and postoperative outcomes in strabismus surgery patients. We used the Cochrane risk of bias-2 tool for the risk of bias assessment. Continuous variables were pooled as mean difference (MD) or standardized mean difference (SMD), and categorical variables were pooled as risk ratio (RR) with a 95% confidence interval (CI).

RESULTS

Six RCTs were included in the meta-analysis, with a total of 326 patients. There was no significant difference between the tetracaine and the control groups regarding the mean operative time (MD = -0.10 minutes, 95% CI [-3.79, 3.59], p = .96), the mean time to first analgesia (MD = -0.87 minutes, 95% CI [-11.15, 9.40], P = .87), the mean behavior score (SMD = -S0.48, 95% CI [-1.24, 0.28], p = .22), the rate of postoperative vomiting (RR = 1.27, 95% CI [0.62, 2.61], p = .52), or the number of additional analgesia (RR = 0.55, 95% CI [0.27, 1.13], p = .10).

CONCLUSION

Our systematic review and meta-analysis found no significant differences in the safety and efficacy of tetracaine eye drops for strabismus surgery when compared to placebo or no intervention. Further investigation is needed to establish the best local anesthetic for strabismus surgery.

Treatment of Non-Infectious Corneal Injury: Review of Diagnostic Agents, Therapeutic Medications, and Future Targets

Corneal injuries can occur secondary to traumatic, chemical, inflammatory, metabolic, autoimmune, and iatrogenic causes. Ocular infection may frequently occur concurrent to corneal injury; however, antimicrobial agents are excluded from this present review. While practitioners may primarily rely on clinical examination techniques to assess these injuries, several pharmacological agents, such as fluorescein, lissamine green, and rose bengal, can be used to formulate a diagnosis and develop effective treatment strategies. Practitioners may choose from several analgesic medications to help with patient comfort without risking further injury or delaying ocular healing. Atropine, cyclopentolate, scopolamine, and homatropine are among the most frequently used medications for this purpose. Additional topical analgesic agents may be used judiciously to augment patient comfort to facilitate diagnosis. Steroidal anti-inflammatory agents are frequently used as part of the therapeutic regimen. A variety of commonly used agents, including prednisolone acetate, loteprednol, difluprednate, dexamethasone, fluorometholone, and methylprednisolone are discussed. While these medications are effective for controlling ocular inflammation, side effects, such as elevated intraocular pressure and cataract formation, must be monitored by clinicians. Non-steroidal medications, such as ketorolac, bromfenac, nepafenac, and diclofenac, are additionally used for their efficacy in controlling ocular inflammation without incurring side effects seen with steroids. However, these agents have their own respective side effects, warranting close monitoring by clinicians. Additionally, ophthalmologists routinely employ several agents in an off-label manner for supplementary control of inflammation and treatment of corneal injuries. Patients with corneal injuries not infrequently have significant ocular surface disease, either as a concurrent pathology or as an exacerbation of previously existing disease. Several agents used in the management of ocular surface disease have also been found to be useful as part of the therapeutic armamentarium for treatment of corneal injuries. For example, several antibiotics, such as doxycycline and macrolides, have been used for their anti-inflammatory effects on specific cytokines that are upregulated during acute injuries. There has been a recent wave of interest in amniotic membrane therapies (AMTs), including topical, cryopreserved and dehydrated variants. AMT is particularly effective in ocular injuries with violation of corneal surface integrity due to its ability to promote re-epithelialization of the corneal epithelium. Blood-based therapies, including autologous serum tears, plasma-enriched growth factor eyedrops and autologous blood drops, have additionally been explored in small case series for effectiveness in challenging and recalcitrant cases. Protection of the ocular surface is also a vital component in the treatment of corneal injuries. Temporary protective methods, such as bandage contact lenses and mechanical closure of the eyelids (tarsorrhaphy) can be particularly helpful in selective cases. Glue therapies, including biologic and non-biologic variants, can also be used in cases of severe injury and risk of corneal perforation. Finally, there are a variety of recently introduced and in-development agents that may be used as adjuvant therapies in challenging patient populations. Neurotrophic corneal disease may occur as a result of severe or chronic injury. In such cases, recombinant human nerve growth factor (cenegermin), topical insulin, and several other novel agents may be an alternate and effective option for clinicians to consider.

A double-blinded randomized clinical trial for pain perception: The efficacy and safety of topical cold saline solution anesthesia in phacoemulsification

Purpose:

To compare the efficacy and safety of cold saline solution (0.9% NaCl) with topical ophthalmic proparacaine for maintaining topical anesthesia of patients undergoing phacoemulsification surgery.

Methods:

The prospective, double-blinded, and randomized clinical study was randomly assigned to two groups that underwent phacoemulsification surgery due to cataracts. The cold saline group included 86 eyes of 86 patients with topical anesthesia of cold saline solution alone. The proparacaine group included 84 eyes of 84 patients with topical ophthalmic proparacaine (room temperature) anesthesia alone. The patients were scored according to a pain survey questionnaire of Visual Analog Scale (VAS) ranked between 0 and 10. The surgeon scored surgical experience by a Surgeon Questionnaire Scale (SQS) in three parameters, each of which was ranked from 1 to 3 based on questions regarding ease and comfort during the surgery.

Results:

The mean VAS scores were 1.29 ± 0.65 and 1.22 ± 0.66 for the cold saline and proparacaine groups, respectively (P = 0.182). The mean scores of SQS (lower values represented favorable results) were 4.11 ± 0.76 and 3.97 ± 0.74 in the cold saline and proparacaine groups, respectively (P = 0.163). Ten patients in the proparacaine group experienced corneal epitheliopathy in the postoperative period.

Conclusion:

As an easily accessible and cost-effective method, cold saline solution alone might be an alternative to topical ophthalmic proparacaine alone with comparable safe and effective results. The absence of allergic or toxic effects also provided a significant advantage in the cold saline application.