I tried something new this week. I saw a multifocal patient this past week and diagnostically fit the lenses exactly like the fitting guide wanted me to. I have to say, I was a bit surprised when the patient came back happy. Mind you, the vision wasn’t perfect, but the patient was nothing less than ebullient about the outcome.
This brings me to review what the definition of success in multifocal contact lenses. You probably hear from continuing education lecturers or “experts” in multifocals how to gauge success and how to promote success in patients. I doubted it. I even heard a consultant advise against any visual acuity testing with the new multifocal lenses. If the patient can navigate across the office and write their name on a check, then that was functioning vision and was as good as recording a visual acuity rating.
Then I wondered. Does functional vision performance better or equal to visual acuity as a reflection of outcome? I think I have hear a lot of LASIK surgery lectures where a 20/20 in one person may not be a “20/20 happy” in another. It’s quite possible, therefore, that functional performance may be a proxy for visual acuity. It sure seems like it in this case. It’s hard to tell a patient who was as happy as the one I saw that she may not see as well as I think she should. Still I mentioned that her daytime visual performance should be better than her night time performance.
I guess what this means is that visual acuity may not be as good an indicator of actual task performance as it was designed to be. If a happy patient can function easily in all of their activities, then it might not matter that the distance acuity is 20/30 in each eye or that the best reading is J4.
Alas, maybe the lighting in our examination rooms has a lot to do with our misreading of a satisfactory patient. If multifocals don’t do as well at low light levels, then what sense is it to test with the lights down on a project light against a screen. Or even a LCD panel in a dim light. I decided on something new and had the patients read a Bailey Lovie Wall Chart at 13 feet. And I checked stereo acuities at near with the multifocals. I don’t have enough data points yet, so I haven’t come to any conclusion whether there is a difference in acuities in the exam room vs. a well lighted room.
In summary, I think doctors may find that the patient has a different standard of success than we do. It’s probably not a good generalization, but it is enough for me to take a bit more time about watching the patient and looking for the signs of happiness. It’s better to send a patient home happy than one that isn’t.