Changes in the anterior chamber during accommodation assessed with a Scheimpflug system

Abstract

Purpose: To study changes in the anterior chamber depth (ACD), anterior chamber angle, and pupil diameter with accommodation.

Setting: University of Valencia, Valencia, Spain.

Design: Evaluation of diagnostic technology.

Methods: A rotating Scheimpflug camera (Pentacam HR) was used to measure changes in the ACD, anterior chamber angle, and pupil diameter with accommodation. Peripheral ACD was measured at the corneal center and 2.0 mm away from it in the nasal, superior, temporal, and inferior directions. The anterior chamber angle was computed as the mean anterior chamber angle of the entire eye. All measurements were obtained with accommodation stimuli ranging from +1.0 to -4.0 diopters (D) in 1.0 D steps.

Results: Eighty subjects (80 eyes) aged 22 to 30 years were evaluated. The ACD did not vary significantly with accommodation in any location. The relative change was 3.67%, 3.65%, 3.67%, 5.66%, and 6.22% in the central, nasal, temporal, superior, and inferior locations, respectively. The central ACD values were significantly higher than the nasal, temporal, superior, and inferior values. The nasal ACD was significantly less than the central, temporal, and inferior ACD. Temporal versus inferior ACD and nasal versus superior ACD yielded similar values. No significant accommodation-related changes occurred in the anterior chamber angle or pupil diameter.

Conclusions: Although the ACD and anterior chamber angle remained stable with accommodation, the pupil diameter varied. Regarding location-dependent ACD variability, the nasal-superior areas were significantly shallower than the temporal-inferior areas.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.