Repeatability of two subjective accommodative amplitude measurements and agreement with an objective method

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Accurate measurement of accommodative amplitude (AA) is crucial for understanding visual function.
• Subjective methods like the modified push-up and minus-lens techniques are commonly used but their repeatability and agreement with objective measures vary.
• Assessing the reliability of these subjective methods is essential for clinical practice.

Purpose of the Study:

• To compare the repeatability of subjective accommodative amplitude (AA) measurements using the modified push-up and minus-lens methods.
• To determine the agreement between subjective AA measurements and objective AA measured by an autorefractor.
• To identify the optimal subjective method for assessing accommodative amplitude in adults.

Main Methods:

• Subjective accommodative amplitude (AA) was measured in 47 adults (aged 22-30 years) using the modified push-up and minus-lens methods.
• Measurements were repeated three times for each method, using both first sustained blur and unreadable criteria.
• Objective AA was measured using an open-field autorefractor, with minus-lens simulation.

Main Results:

• Accommodative amplitude (AA) values differed significantly based on the measurement method (p < 0.001).
• The minus-lens method with the first sustained blur criterion yielded AA values closest to the objective autorefractor measurements (10.10 ± 1.71 D vs. 9.01 ± 1.49 D).
• The minus-lens method demonstrated better agreement with objective AA than the modified push-up method, with the first sustained blur criterion showing the highest agreement.

Conclusions:

• The subjective minus-lens method is more accurate for assessing accommodative amplitude (AA) in adults compared to the modified push-up method.
• The minus-lens method employing the first sustained blur criterion is the optimal technique for subjective AA assessment.
• The minus-lens method with the unreadable criterion is also clinically applicable, though it yields slightly higher AA values.