ESCRS - POCAT596 - Impact Of Age On Anterior Segment Biometric Changes Induced By Mydriasis And Cycloplegia Assessed By Anterior Segment Oct

Impact Of Age On Anterior Segment Biometric Changes Induced By Mydriasis And Cycloplegia Assessed By Anterior Segment Oct

Published 2026 - 44th Congress of the ESCRS

Reference: POCAT596 | Type: Free paper | DOI: 10.82333/55ba-g871

Authors: Ms Marina Ramos Gonçalves* 1 , A/Prof. André Messias 1

1Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery (ROO) of the Medical School of Ribeirão Preto (FMRP) at the University of São Paulo,Medical School of Ribeirão Preto (FMRP) at the University of São Paulo,Ribeirão Preto,Brazil

Purpose

To investigate the influence of age on changes in anterior chamber depth (ACD) and lens thickness (LT) induced by mydriasis and cycloplegia, evaluating the progressive reduction in the biomechanical response of the lens–zonule–ciliary body complex with aging and its implications for the stability of measurements used in intraocular lens planning.

Setting

Academic ophthalmology department.

Methods

Individuals aged 20 to 80 years underwent anterior segment biometry using OCT. Measurements of ACD and LT were obtained under physiological miosis, after isolated pharmacological mydriasis, and after mydriasis associated with cycloplegia. Variations between conditions (mydriasis − miosis; cycloplegia − mydriasis) were calculated. Participants were stratified into <50 and ≥50 year groups, with intergroup comparisons performed using t-tests (α=5%).

Results

Cycloplegia induced an increase in ACD and a reduction in LT in both groups, with greater magnitude in individuals <50 years (ACD: +0.030 mm; LT: −0.027 mm) compared to those ≥50 years (ACD: +0.012 mm; LT: −0.004 mm). Effect sizes ranged from moderate to large (ACD: d≈0.61; LT: d≈0.82). Isolated mydriasis produced no measurable changes in ACD or LT across age groups (p>0.05).

Conclusions

Isolated mydriasis did not significantly alter ACD or LT, whereas cycloplegia induced measurable biometric changes. Although small in absolute magnitude, the cycloplegia-induced alterations were systematic and statistically robust, demonstrating the influence of baseline accommodative tone on anterior segment geometry in normal young eyes. These findings suggest that biometry in younger eyes may not reflect a completely stable structural state, unlike what is observed in senile cataract eyes. Therefore, the applicability of biometric models derived from older populations may need to be reassessed in young patients undergoing surgery with high refractive demands.