Catching up on some of my reading, the February 2013 issue of Optometric Management caught my eye. Here is a link to a fascinating page titled Profession Pulse. We’ve noted previously in this blog that as much as we value evidence based medicine, the evidence considered to support our day-to-day clinical judgement is valued as much by the source as it is by the science. It’s therefore nice to see OM address Binocular Vision as a Hot Topic in Optometry discussed by their experts. And the experts cited are not the typical sources such as our vision help.com, COVD, OEP, NORA, or CSO colleagues. They are Drs. Milton Hom and Ben Gadie, two primary care ODs who write and lecture widely on topics related to eye disease, hence the inclusion of this piece in an issue dedicated to “The Medical Model”. How revealing to read what Dr. Hom writes:
“Sometimes, we encounter cases of unsolvable dry eye. One theory is that binocular imbalances can cause dry eye symptoms. I have heard of many cases in which the dry eye remains symptomatic despite conventional treatments. Often, as a last-ditch effort, we finally look at binocular dysfunction, and it is found to be the cause of the symptoms.”
I say it’s revealing because Dr. Hom is essentially saying that despite the fact that dry eye business is booming — there are increasing numbers of articles written about it, CE lectures addressing it, research funding to support it, and practices dedicated almost exclusively to it — many patients do not experience satisfactory resolution. Evaluation of binocular vision disorders has taken such a back seat in the medical model of practice, that binocular dysfunction is only considered if the doctor has exhausted all other possible explanations for a patient’s symptoms or performance problems. Finally, in desperation, the doctor thinks of probing binocular vision further and voila! There it is. A screaming convergence insufficiency. Don’t misinterpret what I’m saying – this isn’t sour grapes that our profession has abandoned its collective responsibility toward its roots in shifting the scope of practice toward the medical model. Rather it is sweet grapes that a primary care guru like Dr. Hom is reminding readers that binocular vision concerns need to be on the map. Dr. Hom cites a study that he did with Dr. Lynn Lowell, a colleague from SCCO, presented as a poster at last year’s Academy meeting, that patients with ABI and Binocular Dysfunction suffer from severe dry eye symptoms measured with a validated questionnaire (the Ocular Surface Disease Index, or OSDI).
The second expert that the OM profession pulse page cites is Dr. Ben Gaddie. Dr. Gaddie writes: “The conundrum of the lack of correlation between signs and symptoms of dry eye continues. Binocular vision problems can can certainly mimic dry eye symptoms. I have been enjoying some new technology called Opt-Align to assist me in identifying patients suffering from dry eye symptoms. I typically see horizontal disparities causing dry eye and vertical disparities resulting in chronic, debilitating headaches. Simple optometric therapy of prism (vertical or base out) has yielded phenomenal results for my patients.” Dr. Gaddie continues by lauding the Opt-Align device made by Stereo Optical. As I blogged earlier last year in a three part series, this device is an impressive fixation disparity tester (based on modified Turville Infinity Balance) with a hefty price tag designed to help primary care docs detect patients who may benefit from prism, even when they’re not complaining about double vision.
So here’s the bottom line: symptoms and signs of visual discomfort and performance problems from dry eye and symptoms and signs of visual discomfort and performance problems from BV problems such as convergence insufficiency overlap. That is because they are both disorders that rely heavily on similar patient symptom surveys for management decisions: The CISS for CI, and the OSDI for Dry Eye. While Optometry has embraced drops, gels, ointments, plugs, nutrition, and lifestyle changes for OSD, it has overlooked VT/Lenses/Prisms for masquerading problems. Kudos to Drs. Hom & Gaddie.