Ultrasound biomicroscopy insights: Ciliary body changes during accommodation in young adults

Abstract

Purpose: The purpose of the study was to evaluate changes in the ciliary body area (CBA) at rest and during accommodation in young patients, as measured by ultrabiomicroscopy (UBM). Materials and Methods: A prospective, cross-sectional, observational study was conducted. Healthy young patients aged 18–30 years, with a refractive error of no more than 2 diopters were included. UBM was performed by 2 independent experienced ocular echographists. A longitudinal temporal projection and an axial projection were taken during accommodation and at rest. Anterior chamber depth (ACD), lens thickness (LT), pupil diameter (PD), and CBA were measured independently by two observers. Results: Thirty right eyes were included in the analysis. The mean age of the participants was 27.2 years, with 63.3% women and 36.7% men. The mean CBA at rest was 1.64 ± 0.27 mm², whereas during accommodation, it decreased to 1.55 ± 0.29 mm². The mean central LT increased from 3.39 ± 0.17 mm at rest to 3.66 ± 0.18 mm during accommodation. The mean pupil diameter (PD) was 4.48 ± 0.82 mm at rest and decreased to 2.78 ± 0.74 mm during accommodation. The ACD decreased from 3.07 ± 0.23 mm at rest to 2.83 ± 0.23 mm during accommodation. All differences in measurements were statistically significant. An agreement analysis was performed, showing statistically significant results with good strength of agreement in every variable. Conclusions: Ultrasound biomicroscopy (UBM) is a valuable tool for quantifying changes in anterior segment structures during accommodation. Observed modifications in the CBA in young patients encourage further investigation to determine whether the CB maintains its function despite age-related changes in the anterior segment.

Keywords

• accommodation
• ciliary body
• ultrabiomicroscopy