Adjusting to a new prescription represents a milestone for many patients in their eye care journey. But what’s the best balance between ease of adaptation and optimal visual acuity?
A new Clinical and Experimental Optometry research paper retrospectively analyzed a dataset of 196 patients from a 1996 randomized clinical trial (RCT) in which patients were required to wear two different prescriptions – one taken from an autorefractor (modified by an algorithm for ease of adaptation) and one subjective refraction obtained from optometrists, who were simply told to prescribe as they would in practice. Each pair of spectacles – with prescription order randomized among the cohort – were worn for three weeks, with participants filling in a questionnaire as to which glasses they preferred – as well as their quality of distance vision and ease of adaptation – rated 1 to 10.
The nature of the initial experiment allowed the current researchers to tailor the existing data to their own analysis. They found that, generally speaking, spectacle wearers tended to prefer prescriptions that had been modified for ease of adaptation rather than for best visual acuity or better subjective quality-of-distance vision.
But is this preference something optometrists take into account when making their prescriptions? “There is evidence that [less experienced] optometrists don’t partial-prescribe as much,” explains the study’s lead author, David Elliot of the School of Optometry and Vision Science at the University of Bradford. “But with every decade of experience [optometrists] are 34 percent more likely to use partial prescribing. Essentially, as you work in practice and see more patients return with complaints, you learn for yourself what the ‘prescribing rules’ are.”
Elliot is hopeful that these study findings will go some way to influencing how optometrists “think about modifying the amount of change in prescriptions to help adaptation.” He believes that this consideration applies especially to older patients, citing a 2007 RCT that examined whether optometric intervention might help reduce fall rates in the elderly. Contrary to their initial hypothesis, the 2007 trial’s researchers discovered that 74 percent of the patients who received “relatively large changes in refractive error of 0.75D or more” were more at risk of falling than those who received minor refractive changes.
With increased patient satisfaction with prescriptions and potentially fewer falls for the elderly, is it time you prioritized ease of adaptation over optimal visual acuity for your patients? Or do you already modify prescriptions with ease of use in mind?