Abstract
Purpose: To assess the effects of 0.5% and 1% cyclopentolate on the main parameters of the anterior segment (central corneal thickness (CCT), anterior chamber angle (ACA), depth (ACD) and volume (ACV)) in low/moderate myopia and hyperopia along with the effect on IOP.
Patients and Methods: Both eyes of 30 subjects (15 myopic and 15 hyperopic) with mean age +/- standard deviation of 21.4 +/- 3.6 years were enrolled. Each participant was administered two drops of cyclopentolate 1% in the right eye and two drops of cyclopentolate 0.5% in the left eye, 15 minutes apart. All participants underwent intraocular pressure (IOP) measurement using noncontact tonometry, and anterior chamber parameter measurement using Pentacam.
Results: Following the use of 0.5% and 1% cyclopentolate among the hyperopic group, there was a statistically significant increase in ACD for 1% (pre 2.762 +/- 0.28 mm and post 2.89 +/- 0.25 mm) and 0.5% (pre 2.71 +/- 0.28 and post 2.86 +/- 0.27 mm) and ACV for 1% (pre 141.40 +/- 20.59 mm3 and post 154.35 +/- 19.69 mm3) and 0.5% (pre 137.40 +/- 20.48 mm3 and post 152.93 +/- 20.50 mm3). In contrast, ACA decreased with both doses 1% and 0.5%, but was not statistically significant (p for both >0.05%). With 0.5% and 1% cyclopentolate among the myopia group, there was a significant increase in ACD following cyclopentolate 1% (pre 3.18 +/- 0.22 mm and post 3.25 +/- 0.21 mm) and 0.5% (pre 3.200 +/- 0.22 mm and post 3.26 +/- 0.05 mm), p.0.05. The ACV was significantly increased following 1% cyclopentolate, p.0.001. The ACA showed a statistically significant decrease following cyclopentolate 1%, P=0.01, but not a significant decrease after cyclopentolate 0.5%, P=0.170. There was a significant increase in the IOP after 1%, p.0.001, while a decrease with 0.5%, p=0.008.
Conclusion: A topical dosage of cyclopentolate 1% showed significant changes in ACA and ACV among the hyperopia and myopic groups compared to 0.5%. Therefore, it is important to consider the use of a 0.5% cyclopentolate dosage to minimize changes to anterior chamber parameters.