Monocular accommodative facility testing reliability.

Abstract

Recently, concern has been expressed about accommodative facility testing reliability, especially for subjects rated initially as failing. Our study evaluated an extended testing period's effect on reliability. Subjects, ages 8 to 12 years, were tested for an initial 1-min period; to identify two groups; high fails (greater than 6, but less than 11 cpm, N = 30) and low fails (less than 6 cpm, N = 30), and then for an additional 2 min. Mean rate change analysis showed both high and low fail groups improved their accommodative facility over extended testing (1.29 and 0.87 cpm, respectively), although no significant difference was found between the groups. In contrast, test-retest correlations indicate a higher reliability for the baseline rates among low fail (r = 0.720) as compared to high fail (r = 0.402) subjects. The difference between groups became more evident when diagnostic classification was monitored over the 3-min testing period, with 73.3% of the low fails remaining low fails, and 43.4% of the high fails reached the pass criterion. The 1-min testing method appears more reliable if the initial rate is less than 6 cpm. For patients whose initial rate is between 6 and 11 cpm, extended testing (1 additional min) may be needed to arrive at an accurate diagnosis, especially if presenting symptoms are absent.