Proparacaine Hydrochloride

This study compared the efficacy of cyclopentolate hydrochloride at 10‐, 20‐ and 30‐min post‐instillation in White 6‐ to 7‐year‐olds, with and without prior instillation of proxymetacaine hydrochloride. The primary aim was to determine if accurate autorefraction values can be obtained sooner than the current standard of 30‐min post‐cycloplegia. The secondary aim was to investigate whether proxymetacaine hydrochloride enhances the efficiency of cyclopentolate.

Participants were 112 White 6‐ to 7‐year‐olds from the Child Eye Health Study. The right eye received 0.5% proxymetacaine hydrochloride and 1.0% cyclopentolate hydrochloride, and the left eye received only 1.0% cyclopentolate hydrochloride. Non‐cycloplegic and cycloplegic refractive error (at 0, 10, 20 and 30 min) was measured using a binocular, open‐field autorefractometer. Data were analysed through paired t‐tests, concordance analysis, linear regression, equivalence testing and Bland–Altman analysis, using the 95% limits of agreement.

Mean spherical equivalent refraction (SER) (SD) in the right eye at 0‐, 10‐, 20‐ and 30‐min post‐instillation was 0.62 (1.45) D, 1.52 (1.80) D, 1.64 (1.81) D and 1.72 (1.80) D, respectively. Mean left eye SER (SD) were 0.68 (1.24) D, 1.42 (1.66) D, 1.56 (1.66) D and 1.68 (1.72) D, respectively. Bland–Altman analysis showed a high level of agreement, and equivalence testing confirmed that there was no clinically significant difference in SER at 20 and 30 min in both eyes (within ±0.50 D), with mean differences of 0.08 (0.23) D in the right eye and 0.13 (0.30) D in the left eye (p = 0.21). However, SER at 10 and 30 min were equivalent in the right eye only.

Accurate autorefraction values can be obtained 20‐min post‐instillation of 1.0% cyclopentolate in white children aged 6–7 years, potentially reducing clinical testing times. Proxymetacaine pre‐instillation allows for reliable measurements as early as 10‐min post‐instillation of cyclopentolate. Further research is needed to validate these findings in non‐White populations and to determine the safe discharge time post‐proxymetacaine instillation.

To compare the effectiveness of 0.5% and 0.25% proparacaine eye drops in providing topical anesthesia for routine ocular procedures.

137 patients (274 eyes) were included in this study. They were categorized into two groups. Group A patients received 0.5% and Group B received 0.25% proparacaine drops. A single surgeon performed all the procedures. Intraprocedural and postprocedural pain scores, surgeon comfort, supplemental anesthesia, and vital parameters, were noted.

The mean age of the participants was 69.42 years (±12.05). An equal number of procedures were performed (n = 30) for applanation tonometry, lacrimal sac syringing, and A-scan biometry. The other procedures performed were removal of the conjunctiva (n = 5) and corneal foreign bodies (n = 16 per group), corneal scraping (n = 8 per group), and corneal suture removal (n = 18 per group).The mean visual analog pain score during the procedure was 6.9663 in Group A and 8.0803 in Group B (P = 0.66). The mean postprocedural pain score was not significant (P = 0.21). None of the patients required any additional anesthesia during or after the procedure. The average surgeon's experience was 0.152±0.507 in Group A and 0.111±0.402 in Group B (P = 0.07).In Group A, 133 of 137 patients (97.08%), and in Group B, 132 out of 137 patients (96.35%) preferred to use the same anesthetic for future procedures. None of the patients experienced a vasovagal attack or any change in vital parameters.

The present study aimed to establish equivalence between two concentrations of proparacaine hydrochloride in which false positive and false negative errors were expected. This is the inherent challenge in the equivalence and inferiority trials. To mitigate these risks, the present study was carefully designed with specific statistical methods, sample size calculation, and rigorous methodology. Nevertheless, it is crucial to recognize that the risk of false positive errors remains, and the results should be interpreted with this in mind.

These findings indicated that 0.25% proparacaine is a viable alternative to the standard 0.5% concentration in routine ophthalmic procedures, with the potential for improved patient comfort.