One of the classic clinical pearls in refractive care is resisting the temptation to give a first-time patient the full Rx measured. A close relative of that pearl is to resist the temptation to solve more problems than the patient came in with.
Both of these pearls were in play yesterday when the 41 year-old mother who had brought her three sons in to see me “finally turned herself in”, as she put it. EP as I’ll identify her, (for Emerging Presbyopia) had no prior Rx, and presented with a chief complaint of increasing discomfort when driving. By discomfort she didn’t mean classic asthenopia, although she had a vague sense of eye strain. EP was referring more to the effort required to make visual judgments involving time and space. Or in her words, “I’m aware of having to work harder to see when driving”. She was acutely aware of this increased effort when driving at night, or in poor weather conditions.
Key refractive findings were OD +1.25 OS +0.25-0.50cx170, with both eyes at 20/20 with or without lenses in place. Fixation disparity testing at distance showed an associated phoria of ortho OD and 1^ base out OS. Stereopsis was absent on Wirt Circles without the Rx , and improved to 4/10 with the refractive values above, and to 7/10 with the added 1^ BO OS. However, when I put the full amount in a trial frame and walked EP to our front window to look out at traffic, she wasn’t comfortable. I empirically reduced the Rx to +0.50 OD and Plano OS with 0.5^ BO OS, through which she reported a greater sense of ease, comfort, and depth. That is what I prescribed, and since the Rx is primarily for driving and poor weather, AR coating and premium optics are in order.
There are two potential pitfalls with cases such as EP’s that I suspect you, like me, have succumbed to earlier in your career. One is trying to shoehorn the patient into the full measured value, and advising her when she returns with complaints that it might take a couple of weeks to adapt. The other pitfall is succumbing to the temptation to solve a problem that exists more on your part than the patient’s. In this case it would be encouraging the patient to wear the Rx for near when her only concern was distance. More problematic, which is a classic rookie mistake, is to put the patient into a progressive addition lens with more plus for near because of her age and/or better clarity on a nearpoint card. In this instance the patient will notice better vision at all distances with the Rx given without being needlessly shoehorned into a mutlifocal. In other words, often times less is more.