Comparing measurement techniques of accommodative amplitudes.

ABSTRACT

Aim and Background: This study was designed to compare four standard procedures, for determining the monocular accommodative amplitudes. Materials and Methods: Fifty‑two students participated in this analytical–descriptive study. Accommodative amplitudes were measured using four common clinical techniques, namely Push‑up, push‑down, minus lens, and modified push‑up. Results: The highest amplitude was obtained using the push‑up method (11.21 ± 1.85 D), while the minus lens technique gave the lowest finding (9.31 ± 1.61 D). A repeated‑measures Analysis of Variance (ANOVA) showed a significant difference between these methods (P < 0.05), further analysis showed that this difference was only between the minus lens and other the three methods (the push-up (P < 0.001), the push-down (P < 0.001) and the modified push-up (P < 0.001)). The highest and the lowest mean difference was related to the push‑up with the minus lens, and the push‑down with the modified push‑up, while the highest and the lowest 95% limits of agreement were related to the push‑up with the modified push‑up and the push‑up with the push‑down methods. There was almost a perfect agreement between the push‑up and the push‑down method, whereas, a poor agreement was present between the modified push‑up and the minus lens technique, and a fair agreement existed between the other pairs. Conclusions: The quick and easy assessment of the amplitude using the push‑up and the push‑down methods compared to other methods, and the obtained perfect agreement between these two methods can further emphasize their use as a routine procedure in the clinic, especially if a combination of the two techniques is used to offset their slight over‑ and underestimation.