The Effect of Pupil Dilation on Ocular Biometry Measurements in the Senile Cataractous Eyes

Objective: The study aimed to evaluate the effect of cycloplegia on the ocular biometric parameters and intraocular lens (IOL) power calculated by Sanders–Retzlaff–Kraff/theoretical (SRK/T) formula in the cataractous eyes. Materials and Methods: This cross-sectional study included 68 senile cataractous eyes of 68 patients scheduled to undergo cataract surgery. Measurements of anterior chamber depth (ACD), axial length (AL), white to white (WtW) diameter, keratometry (K1, K2, Kmean), central corneal thickness (CCT), and pupil size (PS) were obtained with AL-Scan (Nidek Co., Ltd, Gamagori, Japan) before and after cycloplegia. The SRK/T formula was used to calculate IOL power with target refraction of 0 D. Cycloplegia induced by cyclopentolate hydrochloride %1. Results: The mean age of the patients was 70.60±4.07 years (range 65 to 80). A significant increase was observed in ACD after cycloplegia (p< 0.001). There was no statistically significant difference between pre-dilation and post-dilation AL, WtW, CCT, K1, K2, Kmean, and IOL power readings (p> 0.05). Two cases observed a decrease above 0.5 D of IOL power after cycloplegia. Conclusion: Cycloplegia induced by cyclopentolate hydrochloride %1 does not affect the measurement of the AL, WtW, CCT, keratometry, and SRK/T calculated IOL power except ACD in senile cataractous eyes.