Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul 14:2021:8661098.
doi: 10.1155/2021/8661098. eCollection 2021.

Age and Sex Variation in the Duration of Action and Corneal Touch Threshold (CTT) following Instillation of 0.5% Topical Ophthalmic Proparacaine and Tetracaine Hydrochlorides

Samuel Kyei  1 , Nana Yaw Abaka Dadzie  2 , Ebenezer Zaabaar  1 , Kwasi Antwi Asamoah Dwomoh  1 , Kofi Asiedu  3
Affiliations

Age and Sex Variation in the Duration of Action and Corneal Touch Threshold (CTT) following Instillation of 0.5% Topical Ophthalmic Proparacaine and Tetracaine Hydrochlorides

Samuel Kyei et al. J Ophthalmol. .

Abstract

Purpose: We investigated the effect of age and sex on corneal touch threshold (CTT) and duration of action following administration of 0.5% topical ophthalmic proparacaine and tetracaine hydrochlorides.

Methods: A prospective, randomized, subject-masked, crossover study design was used. Two hundred and forty human volunteers were enrolled in the study. Corneal touch threshold (CTT) was determined using a Cochet-Bonnet esthesiometer. CTT was measured every 15 seconds for the first 1-minute and at 5-minute intervals subsequently for a period of 40 minutes after the application of each anesthetic. CTT and duration of action of the ophthalmic solutions were tested for statistical significance using repeated measures ANOVA.

Results: The total duration of effect was 20 minutes for females and 25 minutes for males for both anesthetics. The total duration of the effect of both solutions decreased with increasing age; however, elderly participants had the longest duration (5 minutes) of the maximal effect (minimum CTT) of the two ophthalmic preparations. There was a significant influence of sex, F (2.39, 569.65) = 2.86, p=0.04; F (3.48, 828.19) = 4.41, p=0.003, and age, F (4.78, 566.18) = 8.97, p < 0.001; F (7.19, 852.56) = 20.55, p < 0.001 on CTT following application of proparacaine hydrochloride and tetracaine hydrochloride, respectively.

Conclusion: CTT and duration of anesthetic effect after instillation of 1 drop of 0.5% proparacaine hydrochloride and 0.5% tetracaine hydrochloride vary based on sex and age.

PubMed Disclaimer

Conflict of interest statement

The authors declare that there are no conflicts of interest.

Figures

Figure 1
Figure 1
Time course curve showing the effect of age on the onset and duration of actions of (a) proparacaine and (b) tetracaine. Values plotted are mean corneal touch threshold ± standard error of mean (n = 80). Repeated measures ANOVA followed by post hoc Tukey HSD.
Figure 2
Figure 2
Time course curve showing the effect of sex on the onset and duration of actions of (a) proparacaine and (b) tetracaine. Values plotted are mean corneal touch threshold ± standard error of mean (n = 120). Repeated measures ANOVA followed by post hoc Tukey HSD.
See this image and copyright information in PMC

References

    1. Meduri A., Grenga P. L., Scorolli L., Ceruti P., Ferreri G. Role of cysteine in corneal wound healing after photorefractive keratectomy. Ophthalmic Research. 2009;41(2):76–82. doi: 10.1159/000187623. - DOI - PubMed
    1. Meduri A., Urso M., Signorino G. A., Rechichi M., Mazzotta C., Kaufman S. Cataract surgery on post radial keratotomy patients. International Journal of Ophthalmology. 2017;10(7):1168–1170. doi: 10.18240/ijo.2017.07.23. - DOI - PMC - PubMed
    1. Duvall B., Kershner R. M. Ophthalmic Medications and Pharmacology. 2nd. Philadelphia, PA, USA: Elsevier; 2007. - PubMed
    1. Kumar M., Chawla R., Goyal M. Topical anesthesia. Journal of Anaesthesiology Clinical Pharmacology. 2015;31(4):p. 450. doi: 10.4103/0970-9185.169049. - DOI - PMC - PubMed
    1. Lemke K. A., Dawson S. D. Local and regional anesthesia. Veterinary Clinics of North America: Small Animal Practice. 2000;30(4):839–857. doi: 10.1016/s0195-5616(08)70010-x. - DOI - PubMed

LinkOut - more resources