An Evaluation of Methods for Determining Near Addition in Presbyopia



Purpose: To compare the tentative near add determined using four common procedures (amplitude of accommodation, NRA/PRA, age expected addition, binocular fused cross-cylinder test) with the final addition prescribed in presbyopic patients.

Methods: Two hundred healthy subjects with a mean age of 48.92 years (range 40 to 64 years) were studied. Tentative near additions were determined using four different techniques: amplitude of accommodation (AA), age-expected add, binocular fused cross-cylinder (BCC), and balance of negative and positive relative accommodation (NRA/PRA). The power of the add was then refined to arrive at the final add.

Results: The mean tentative near adds were lower than the final add for every method. These biases were small in clinical terms (less than 0.25 D) with the exception of the AA procedure (0.34 D). The intervals between the 95% limits of agreement differed substantially and were always lower than ±0.50 D.

Conclusion: Among the methods examined here, the binocular fused cross-cylinder technique produced results that correlated best with the final addition. The coefficient of agreements (COA) detected suggests that every tentative addition should be adjusted according to the particular needs of the patient.

Keywords: Accommodation, presbyopia, near addition, tentative addition, final addition



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