Changes in anterior chamber depth during accommodation: a pilot study

PURPOSE: To study anterior chamber depth (ACD) behaviour in different positions, with different degrees of accommodation. SETTING: Academic department associated to a regional hospital. METHODS: ACD data were acquired from 20 young, healthy subjects under 8 different vergences, from +2 dioptres (D) to –5 D using a Pentacam HR device. Measurements were taken for the central zone of the ACD and for 4 more positions, each in a different direction (superior, inferior, nasal and temporal), 2 mm from the centre. RESULTS: Changes in each position of the ACD resulting from accommodation were small and generally insignificant (P > 0.05). The statistically deepest ACD value for all vergences was found at the central position. The superior-nasal and temporal-inferior pairs did not show statistically significant differences (P > 0.05) for all vergences. In addition, temporal and inferior chamber depths were statistically significantly deeper (P < 0.05) than superior and nasal chamber depths. CONCLUSIONS: While the central position presents the deepest ACD, the superiornasal pair presents the narrowest ACD. No significant changes in ACD occur after 5 D of accommodation.