Onset and duration of cycloplegic action of 1% cyclopentolate – 1%  tropicamide combination.

Samuel Kyei, Alfred Asiem Nketsiah, Kofi Asiedu, Agnes Awuah, Andrew Owusu-Ansah
1. Department of Optometry, School of Allied Health Sciences, College of Health And Allied Science,
University of Cape-Coast, Cape-Coast, PMB, Ghana
2. Refraction and Low Vision Clinic , Eye Center, Komfo Anokye Teaching Hospital, P. O Box 1934,
Kumasi, Ghana
3. Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha,
Hunan, China.

Abstract
Purpose:To study the time course (onset, time and duration of maximal cycloplegia, and the full duration) of cycloplegic action  of 1% Cyclopentolate – 1% Tropicamide.

Methods: Seventy-seven students, aged 15-24 years were purposively sampled from the University of Cape Coast and Cape   Coast Technical Institute. Subjective near addition (ADD) determination and pupil diameter measurement before and after a drop of the test agent (1% Cyclopentolate – 1% Tropicamide combination in the right eye) and the control (1% Cyclopentolate  in the left eye) were performed. Measurements of subjective near ADD and pupil diameter were made after the initial reading at  5 minutes interval for the first hour and every 30 minutes for the next 7 hours for each participant. Time of onset, time of peak  cycloplegia, duration of peak cycloplegia and duration of total cycloplegic effect was indirectly determined.

Results: 1% Cyclopentolate – 1% Tropicamide combination had rapid onset of cycloplegia (5-10 minutes), shorter time of  maximal cycloplegia (55 versus 90 minutes), and recovery (7 versus ≥ 8hours) in the majority (79.2%) of subjects.

Conclusion:Cyclopentolate –Tropicamide combination was comparable to Cyclopentolate in depth of cycloplegia produced,  and clinically superior to 1% Cyclopentolate in rapidity of cycloplegic onset, time of maximal cycloplegia and recovery from  cycloplegia.

Keywords:Cycloplegia, time course, accommodation, recovery time.