To determine which are the most sensitive tests, together with accommodative amplitude, to classify accommodative insufficiency (AI), we analyzed the relation between monocular estimated method (MEM) dynamic retinoscopy, monocular and binocular accommodative facility (MAF, BAF), and positive relative accommodation (PRA) with or without the presence of reduced amplitude of accommodation.
We studied 328 symptomatic patients who presented consecutively to an optometric clinic. From this sample, we selected the 41 patients who presented amplitude of accommodation at least 2 D below the minimum age-appropriate amplitude according to Hofstetter’s formula: 15 − 0.25 × age. We also selected data from 40 consecutive subjects (control group) with no general binocular disorders and normal accommodative amplitudes. We studied the specificity and sensitivity of the four signs related with the accommodative insufficiency: high MEM dynamic retinoscopy, failing MAF and BAF with minus lenses of ±2 D flipper lenses, and low PRA.
Using the standard deviation as the cutoff, the specificity values were MEM = 0.88, MAF = 1, BAF = 0.93, and PRA = 1. When using the mean value as the cutoff, the specificity diminished, fundamentally for MEM. The sensitivity for the 41 patients using standard deviation as the cutoff was MEM = 0.44, MAF = 0.34, BAF = 0.27, and PRA = 0.27, and when using the mean value as the cutoff the four, sensitivity values increased.
According to the sensitivity results, with both cutoffs used, failing the ±2 D MAF test seems to be the sign that is most associated with the accommodative insufficiency.