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A Deeper Look at Eye Problems

  • A showcase of glasses photographed on Friday, Sept. 29, 2017, at Fields of Vision Eye Care in Lebanon, N.H. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.

  • Cassandra Brackett, an ophthalmic assistant at Fields of Vision Eye Care, uses an Optovue machine on Karen Jameson, of Cornish, N.H., on Friday, Sept. 29. 2017, at the eye care center in Lebanon N.H. The machine uses light to make a three-dimensional image of the eye. Jameson has struggled with a variety of vision problems in recent years. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.

  • With a photo of her retina on his computer screen, patient Karen Jameson, of Cornish, N.H., talks with Dr. Chris Fields about her eyes on Friday, Sept. 29, 2017, at Fields of Vision Eye Care in Lebanon, N.H. Jameson has suffered with numerous eye issues such as a cataract, dettached retina and chronic uveitis. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.

  • Cassandra Brackett, an ophthalmic assistant at Fields of Vision Eye Care, uses an Optos machine to get a widefield image of a patient's eye on Friday, Sept. 29, 2017, at the eye care center in Lebanon, N.H. The wide image of the retina allows the doctor to look at the eye in layers. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.



Valley News Staff Writer
Tuesday, January 02, 2018

Lebanon — Diabetes is the leading cause of blindness for people of working age, but its diagnosis relies on readings of blood sugar levels high enough to cause vision problems.

In theory at least, finding changes in the eye before vision problems begin could help patients and their providers identify the disease and treat it through lifestyle changes before serious damage is done and medication is necessary.

It is the opportunity for early diagnosis that made a new technology — optical coherence tomography angiography, or OCT-A — seem exciting to Peter Mason, a former family doctor at Alice Peck Day Memorial Hospital and a patient of Dr. Chris Fields, who has recently adopted the OCT-A at his Lebanon optometry practice.

If you “pick up the problem early and you can motivate people to make some lifestyle changes (you) might mitigate the need for medication,” said Mason, whose work is now focused on addressing the opioid epidemic.

Other Upper Valley providers, however, struck a note of caution about the new technology, saying that earlier detection is not always better, that the new technology has yet to prove itself, and that primary care physicians, not optometrists, ought to be the first to detect evidence of disease.

Still, the simplicity of the eye test, which simply requires that a patient lean in, hold still and stare at a blue dot, appealed to Mason.

Many optometrists currently use optical coherence tomography to capture images of patients’ retinas. Such images help clinicians track changes in the retina, which can occur as a result of conditions such as macular degeneration or glaucoma. On their own, images captured by an OCT machine do not illustrate what is happening within the eye at a vascular level.

Adding angiography — a test used to detect blood moving through vessels in the eye — to the OCT machine’s capabilities allows clinicians such as Fields to track both changes in the structure of the retina and changes in the way blood flows.

In a patient with unmanaged diabetes, for example, the walls of blood vessels begin to break down, which causes fluid to leak out, Fields said in an interview last fall. The OCT-A machine allows him to see this change in very small capillaries, even before the patient may begin experiencing vision problems. This early detection is a step toward disease prevention, and once a problem is diagnosed, the machine can help clinicians to monitor the success of a patient’s treatment regime, he said.

In the months Fields has had the technology, which is made by California-based OptoVue and costs tens of thousands of dollars, he has not found anyone whose course of treatment for diabetes is not working.

Instead, “really what we’re doing is providing reassurance to the patient that their primary care doctor doesn’t need to change the course that they’re on,” Fields said.

If he were to identify a patient who had blood vessels beginning to break down in their eyes, but who was not yet diagnosed with diabetes, Fields would send them to their primary care doctor for further evaluation.

In addition to revealing changes that may be related to diabetes, angiograms can also highlight changes due to causes such as cancer, high blood pressure, inflammation or macular degeneration.

The new machine offers detailed images of the eye’s vasculature without the invasiveness of the current standard angiography test, which requires that a clinician dilate a patient’s eyes with drops and inject a fluorescent dye into the bloodstream that may cause nausea or an allergic reaction in some patients. With OCT-A, it takes just seconds to capture images, while the fluorescein method can take up to half an hour, according to a 2015 review of the technology published in the International Journal of Retina and Vitreous.

Another advantage to OCT-A is that it captures images in three dimensions, rather than the two dimensions captured with the fluorescein method. By combining pictures of the eye’s structure and the eye’s vasculature, a provider can see where exactly a problem is occurring.

The image of the eye produced by the OCT-A gives the patient concrete evidence of the effect of the progression of their disease, Mason said in an interview last fall.

“The nice thing about this is you can show people a picture,” Mason said.

One of Fields’ patients Karen Jameson, 49, of Cornish, does not have diabetes, but she has been struggling with a variety of vision problems in recent years, including a detached retina, uveitis — swelling in the eye — and a cataract, which is a clouding of the lens in the eye. As a result of all these issues, she’s had several surgeries and continues to search for the cause of the chronic inflammation that seems to be triggering the eye issues.

As Fields’ ophthalmic assistant Cassandra Brackett took pictures of Jameson’s eyes using the new machine during a late September appointment, Jameson, a nurse and health educator, said the images have helped her to understand her eye issues.

“Until I saw this, I didn’t have a working knowledge of what the inside of the eye looked like,” she said.

Fields is an early adopter of the angiography component of the OCT machine, but others in the Upper Valley have adopted the OCT technology on its own, which allows them to see the layers of the retina clearly, but does not show blood vessels.

Dr. Nikhil Batra, a Dartmouth-Hitchcock ophthalmologist, uses OCT technology “heavily” to see abnormalities, swelling or bleeding in an eye. In an October interview, he estimated the ophthalmologists at DHMC did about 9,000 such scans last year. OCT scans are used by most, but not all optometry practices for monitoring and managing diseases of the retina, Batra said.

“The retina is basically less than a millimeter thick,” he said. “We can get clarity up to tens of millimeters — micron-level clarity.”

By measuring the retina’s thickness, the OCT test gives Batra a sense of the progression of disease, its severity and the effectiveness of treatment, he said.

D-H, however, has not yet adopted the angiography add-on for the OCT machine, said Batra.

“It’s a very early technology,” he said. “Right now, it’s not the standard of care for monitoring and managing disease of the retina.”

But, he predicted, that as OCT has become the standard, the angiography component also will become standard over time.

To get there, Batra said it will take money, but it will also require that clinicians learn how best to use the information, answering questions such as: “What are you going to do when you have the machine? Can you act upon the test? Can you interpret the test?”

Getting a clearer picture of the detail of the eye comes with advantages and disadvantages, he said. It’s a good screening tool, which would drive referrals to D-H’s specialists.

On the other hand, “not everybody needs to be referred to a specialist,” he said, noting that, in general, the more tests that are done the more abnormalities clinicians will find, some of which are not affecting people’s vision.

Before changes in the eye begin causing vision problems, patients may not need treatment, he said. Too many referrals would make it difficult for patients to get in to see specialists like him in a timely fashion.

Dr. Andrew Jones, who practices in Lebanon with his wife, Dr. Sheila Hastie, said that as an optometrist, he doesn’t have much use for angiography. If he notices retinal swelling in a regular OCT scan, he will refer a patient to a specialist.

“I don’t use the angiography because I’m not going to be doing surgery,” he said in an October interview.

Jones said he and Hastie like to have the latest technology, in part for the “wow factor.”

But, he added, “You can’t have everything.”

Dr. Samuel Giveen, an optometrist who practices in Claremont and Hanover, also said he values the OCT technology. Compared to the detail he was able to see using older technology a decade ago, Giveen said it “seems today like you were looking at it from across the room.”

But, in terms of angiography, he is waiting for the new technology to prove itself. He’s “still sort of trying to figure out the value of it,” he said in October.

Giveen said he didn’t think that insurance companies would pay for OCT-A as a screening test and early detection of changes in blood vessels resulting from diabetes is unlikely to change the way he advises patients he knows have diabetes to work with their primary care provider to get their blood sugar levels under control.

“(You’re) just telling people: ‘Look, we have a problem here; you need to take this seriously,’ ” Giveen said. “I’m not sure the message would be any different.”

Giveen also emphasized that patients should not consider an eye exam a replacement for their annual physical.

“No one should ever rely on an eye exam for diagnosis of these problems,” such as diabetes or high blood pressure, Giveen said. “Any problem like this that we found should have been found by a general practitioner five years ago.”

He is, however, hopeful it will replace the invasive procedure of injecting dye required by fluorescein angiography, eventually.

But “it takes a few years for things to kind of shake out,” he said.

Valley News Staff Writer Nora Doyle-Burr can be reached at ndoyleburr@vnews.com or 603-727-3213.