Objective amplitude of accommodation using different accommodative stimuli.

Abstract

Clinical relevance: While the amplitude of accommodation is commonly measured using subjective procedures in the clinic, objective techniques are more repeatable and can be adopted using any technique to stimulate accommodation.

Background: The aim of this work is to evaluate the differences, concordance and reliability of objective methods for measuring the amplitude of accommodation using different procedures to stimulate accommodation.

Methods: A descriptive, cross-sectional study. Objective (dynamic retinoscopy push up, push down and push away) and subjective (push up, push down and push away) procedures were used to measure the monocular amplitude of accommodation in 80 subjects between 18 and 27 years of age by two independent evaluators over two sessions.

Results: Neither the objective nor subjective methods showed significant differences between the two sessions (p > 0.05). Post-hoc comparisons showed significant differences between the push up method of stimulating accommodation and the other procedures (all p < 0.001). However, the objective push up method showed poor concordance with the other objective procedures. Poor to moderate concordance was found for the subjective methods with moderate precision and accuracy.

Conclusions: While the objective push up procedure provided significantly higher findings than the push down and pull away techniques, the differences were small (mean ≤ 0.25D) and so any of the techniques adopted here can be used to stimulate accommodation in an objective assessment of the accommodative amplitude.