Optical Coherence Tomography Imaging vs. Fundus Photography

Imaging technology is an invaluable tool for eye care. Advances in imaging have allowed providers to capture detailed views of all eye structures, improving their ability to identify conditions such as glaucoma, macular degeneration, and diabetic retinopathy.

The value of screening for diabetic retinopathy is so well established that the Centers for Medicare and Medicaid Services (CMS) recommends annual screenings as part of standard care for all individuals with diabetes. The screenings successfully identify signs of disease before vision changes occur. Providers can then guide individuals on methods to control their blood sugar and slow their disease progression.

Traditionally, eye care specialists have been the ones to deliver screenings for diabetic retinopathy, and comprehensive eye exams from eye doctors remain the best tool for managing overall eye health and vision. However, telemedicine and mobile imaging technology have given primary care providers, home health services, and rural health clinics new opportunities to participate in diabetic eye screenings.

Optical Coherence Tomography

Optical coherence tomography (OCT) is a standard component of comprehensive eye exams. The OCT uses infrared light to create a cross-sectional image of the eye. The resulting images allow eye specialists to examine the eye in layers and identify areas of concern.

OCT imaging is a non-invasive screening that takes only minutes, which is ideal for most patients. Stored images can be used for comparison over time to track the progression of anatomical changes within the eye.

In the event of a diabetic retinopathy diagnosis, eye care specialists can coordinate with the rest of the individual’s medical team to recommend appropriate diabetes care moving forward. A dilated eye exam that includes OCT is considered by many to be the gold standard for detecting retinal disease.

One notable drawback to OCT as a routine component of diabetic care is access. OCT is offered only in optometric or ophthalmic practices, requiring individuals to make a separate appointment for that portion of their diabetic care. It isn’t always clear that Medicare, Medicaid, and other insurance plans will cover an annual diabetic retinopathy screening, making some individuals hesitant to risk incurring more medical costs.

Physical access to eye specialists is another barrier, particularly for rural residents who might need to drive a considerable distance to the nearest eye care provider. Providers may not be taking on new patients or may not accept the patient’s insurance, delaying care even further.

These barriers to access mean that many patients aren’t getting OCT exams, no matter how necessary or effective they are.

Fundus Photography

The healthcare community can overcome the barriers to access by adopting alternative technologies for retinal imaging. Fundus photography is an established diagnostic tool with a strong record of identifying eye disease. In recent years, handheld non-mydriatic portable fundus cameras have emerged as alternatives to in-office retinal imaging systems. The images can be used by an eye care provider to rule out a diagnosis of eye disease or provide an indication for a referral to an eye specialist who can perform further screening, potentially including OCT and vision tests.

Fundus photography provides high-quality retinal images that allow eye care providers to visualize the retina and evaluate it for signs of diabetic retinopathy and other eye conditions. A 2021 study found that non-mydriatic portable fundus cameras demonstrated sensitivity and specificity in glaucoma detection equal to dilated fundus examinations. The author concluded that handheld fundus photography can be a useful tool in community-based eye health programs.

Teleretinal Screening for Diabetic Retinopathy

Portable fundus photography can shift diabetic retinopathy screening out of the eye specialist’s office and into other healthcare venues, many of which are more accessible for the populations that are most at risk for diabetic retinopathy. With appropriate training, fundus photography can be performed by a range of providers, including nurses, physician assistants, para-professionals, and primary care doctors.

The resulting images from fundus cameras can be read by an off-site eye specialist via a telemedicine platform. Teleretinal screenings have been in use for a number of years, and recent reviews have found that they are an efficacious method of detecting diabetic retinopathy. An analysis noted that the telemedicine findings don’t constitute a final diagnosis. Rather, a positive finding on a teleretinal screening is a signal to refer the individual to an eye specialist.

Moving first-line diabetic retinopathy screenings into more healthcare environments is a known way to increase compliance with screening guidelines. Multiple studies have shown that introducing teleretinal screenings in primary care settings decreases the rate of vision loss. As far back as 2014, the Department of Veterans Affairs (VA) utilized a combination of teleretinal screenings and traditional eye exams, which allowed it to provide annual screenings for 90% of VA patients with diabetes.

Teleretinal screenings using fundus photography don’t constitute a replacement for OCT or in-person ophthalmological exams. Instead, they’re an important preliminary screening tool that can be used to reach more patients. Healthcare providers can incorporate retinal screenings in primary care exams that take place in community health centers, in rural health clinics, or during home health visits.

Teleretinal screening exams for diabetic retinopathy ensure more at-risk diabetic individuals get the preventive testing they need. If you want to use the IRIS platform to incorporate teleretinal screenings into your practice, connect with us to learn more.

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FAQs

What is OCT?

OCT is a type of screening used in eye exams to capture images of the eye so doctors can evaluate eye health and identify signs of eye disease.

How does Optical Coherence Tomography work?

OCT uses infrared light to create a cross-sectional image of the eye. The patient looks into the tabletop device, and infrared lights measure the distance to the back of the eyes and create an image of all the eye structures.

What Does Optical Coherence Tomography Measure?

OCT shows eye specialists changes to the eye that can indicate diseases. This helps them diagnose retinal diseases and related conditions that may affect your vision, including:

• Diabetes-related macular edema
• Diabetic retinopathy
• Cancer
• Glaucoma
• Macular degeneration
• Retinal detachment

What Is Optical Coherence Tomography Used For?

OCT is used as part of comprehensive eye exams to screen for common eye conditions. It can also be used for a follow-up screening if a prior screening, such as fundus photography, indicates a need for further examination.