Advancing Primary Eyecare
By: Paul M. Karpecki, OD, FAAO
Clinical Director – PECAA
Advanced Diagnostics are allowing optometry to manage ocular diseases at a primary care level. This is how medical eyecare should be managed.
I once thought that primary eye care meant doing the basics of vision care but I was completely wrong. Primary Eyecare means managing EVERYTHING related to the eyes and vision that isn’t secondary care (think retina or cornea specialist) or tertiary (surgical like cataract, refractive, retinal surgery and transplants). That’s a lot to oversee and essentially quarterback as it can range from deciding if the choroidal lesion is a malignant melanoma or simply a nevi. It also means differentiating eye misalignment from a neurological condition that can be verified with pupil and color vision and evoked potential. Truly the only way to get that level of accuracy, in most cases, is with advanced diagnostics. Let’s look at a few of those technologies:
Ultrasound to advance your ability to manage anterior and posterior segment disease
More than a decade ago when an A-scan/B-scan/UBM ultrasound combination was six figures, it didn’t seem to fit with primary eye care. Today, because of advances in technology such as the DGH Technology Scanmate Flex, the price is now about 1/10th of that and shows relatively high resolution. Now it definitely fits into primary eye care and may be one of the most essential pieces of diagnostic equipment for practicing at a high level. Just a few years prior to this technology, a retina specialist was the one taking the measurements to determine if this indeed was a choroidal melanoma. Now, with advanced but reasonably priced diagnostics, that role can reside in optometry. Two of the most important determinants for differentiating a malignant melanoma from a nevi are the basal diameter and the elevation. The only way to accurately obtain this information is from B-scan ultrasonography. A basal (base) diameter that increases over time and/or elevation over 2mm are significant signs of a likely malignant melanoma. Other signs include the presence of lipofuscin (orange pigment) on the surface of the lesion, the presence of sub-retinal fluid and if the lesion is touching the optic nerve. Ultrasound can also confirm a retinal detachment or see the retina when there is no clear view (e.g. vitreous heme). It can assess axial length for cataract surgery (A-scan) and UBM can determine angle closure and narrow angles, iris cysts or tumors etc. We routinely have every patient diagnosed with a moderate or large nevi undergo ultrasound measurements and monitor for progression. These patients can then be referred for a retina specialist or ocular oncologist at the more appropriate time.
Technologies for Ocular Neuro:
Visually evoked potential testing plays a key role in determining neuropathy as it measures the signal passing through the optic nerve to the brain. One of the most common causes of neuropathy is glaucoma. Two technologies available in this space – Diopsys and EvokeDx (Konan Medical) are worth looking at as new advances include being smaller and portable, less noise, easier to apply etc. The EvokeDx in particular uses a digital interface, has easy electrode attachments all in a band, reduces noise and is easier for the patient and doctor to utilize. A very recent new diagnostic is that of RetEval, which is a hand-held, portable but powerful ERG device to measure retinal function. Numerous causes ranging from early retinitis pigmentosa to diabetic retinopathy non-perfusion can be assessed without the need for dilation.
One of the key “vitals” of the eye is the pupil so we know it is critically important. But the traditional swinging flashlight test is a rather difficult test especially in patients with dark iridis. It’s also very difficult for a clinician to determine a small RAPD. Unfortunately a small RAPD is significant and can help in an early diagnosis of pathologies including glaucoma. A new electrodiagnostic device known as EyeKinetix (Konan Medical) recently became available. This test, which takes about 30 seconds, can determine the presence of a 0.5 RAPD between eyes, helping with an over-all neuro assessment screening to potential diagnosis of glaucoma (often being an asymmetric neuropathy), concussion, syphillis (Ades tonic pupil) or other neurological abnormalities.
This new diagnostic tool can detect and measure eye alignment in less than 2 minutes. The technology utilizes peripheral focusing and is objective and accurate for measuring vertical and horizontal phorias. It also has the ability to transfer those measurements into a spectacle lens called a neuroLens that is essentially a progressive prism design to correct the problem. It’s similar to a progressive addition lens but the proprietary prism changes are what progress. In the pivotal study, 93% of patients using this technology had a reduction in symptoms and 74% stated the symptoms were decreased substantially or basically gone.1 So this 2 minute test can not only accurately diagnose eye alignment issues that often result in chronic or frequent headaches, asnthenopia, dry eye sensation, but also prescribe the appropriate treatment.
This new test was developed by US Air Force and is known as Cone-Isolation. The US Air Force, School of Aerospace Medicine OBVA (Operational Based Vision Assessment) Team initiated a research project and engaged Konan Medical in the development of this new cone-isolation test, which has been shown to greatly enhance accuracy. In fact it has been shown the Ishihara plates miss 100% of all protanopes. We have to advance in our technology utilization to accurately assess key vital findings such as Color Vision. The test has easy usability, because it display’s various color and various contrast Landolt C images and the patient simply determines in which direction the opening of the C is pointing. This is a very new test as ColorDx CCT-HD was only just commercialized late in 2017. Although as many as 8% of all males have color deficiency and require diagnosis, accurate vision testing such as ColorDx has been shown to aid in the diagnosis of numerous pathologies including glaucoma, MS, early AMD, even Alzheimers and leukemia.
It’s time for the primary care optometrist to own primary eye care which now more than ever means retinal disease management involving ultrasound technology (which also greatly benefits anterior segment pathology), advanced color vision testing (which is reimbursable by the way). Eye alignment detection and treatment, pupil testing with advanced diagnostics such as Eyekinetix and proper pathway testing via VEP and ERG. It’s an exciting time to be a primary care optometrist and those that differentiate themselves in medical eye care and through better technology will be well positioned now and in the future.