Why the Retinal Periphery Matters

Peripheral changes often precede vision-threatening central disease

Dr. Gerson: One of the strengths of the optomap ultrawidefield digital retinal imaging is that it allows us to view the peripheral retina. Does the periphery matter when it comes to vision-threatening diseases?

Dr. Schaeffer: Optometry is very different than it was 10 years ago. Today, we do not refer patients to the retinal specialist unless they need surgery. Take retinal holes for instance. A week doesn't go by that I am not monitoring two or three patients with retinal holes. Now that I have the optomap, the patient no longer has to sit dabbing his tearing eye with tissues while I examine him for an extended period. I can use the optomap to direct myself right to the area of interest. I can compare images from different visits to check for changes. I am very comfortable following these patients, seeing them every 2 to 3 months if needed, with the optomap.

Anybody can see an optic nerve. Anybody can see a macula. It is the periphery that is hard to see in these difficult cases.

Field of View and Diabetes

Dr. Nelson: Increasingly, research shows that not only does the periphery matter, it may very well be the place where disease starts. In many cases, we see drusen forming in the periphery before we see it in the central macula. We see hemorrhages in the periphery before we see hemorrhages in the central macula. We see peripheral nonperfusion as well, particularly in diabetic patients. Nearly a third of macular edema is thought to be caused by peripheral nonperfusion. Optos technology, particularly ultra-widefield fluorescein angiography, has played a major role in what is being learned.

Dr. Schaeffer: The optomap facilitates precise monitoring and documentation of small peripheral hemorrhages in diabetic patients.

Figure 3. Retinoschisis

Figure 4. Peripheral reticular degeneration

Dr. Gerson: In addition, it can help us to diagnose diabetes in patients who are not aware they have it. Studies indicate that up to 20% of people with Type 2 diabetes already have retinopathy at the time of diagnosis.

Dr. Nelson: Diabetes is an imminent epidemic in the United States. Eye doctors are going to be on the front line working with primary care physicians to make sure people with diabetes are diagnosed early and receive proper treatment.

Figure 5. Diabetic retinopathy.

Dr. Schaeffer: I require optomap images for every diabetic patient, which is especially important for children.

Dr. Gerson: Does everyone on the panel scan young diabetic patients to obtain a baseline image?

Dr. Nelson: Yes, without question. The ability to view the different wavelength scans separately makes a big difference for detecting small hemorrhages. When I switch to the green laser separation, the hemorrhages light up in black, and it is much easier to see them. With just a quick scan, I can see whether diabetic retinopathy is present throughout the retina.

Dr. Rothschild: I scan all diabetic patients, too. I have seen some beautiful, healthy-looking posterior poles with hemorrhages all around the periphery in diabetic patients.

Dr. Gerson: What if you see a single peripheral hemorrhage? I think some people would make the argument, so what?

Dr. Schaeffer: Every time I see a hemorrhage in the eye, I think the patient deserves a physical. Even if a primary care workup finds the cause to be insignificant, it is important to follow through. Furthermore, it makes optometry part of the medical model, part of the entire team of physicians caring for that patient.

Dr. Rothschild: The Optos technology gives us the opportunity to reach out to other doctors in the community and let them know we are willing to make it available to their patients, especially young patients with diabetes.

Field of View and AMD

Dr. Gerson: Seddon and colleagues published a paper in 2009 about the association between peripheral drusen and reticular pigmentary changes and the development of macular degeneration.¹ Their results opened my eyes to the importance of peripheral pathology and how it might change how we manage and educate patients with AMD and patients at risk for the disease.

Another good example of what we find in the peripheral retina really matters in relation to central vision-threatening disease is a study done in Reykjavik.² That group of investigators reported on peripheral changes being predictive of macular changes. They also noted widefield images revealed considerable pathological changes at the periphery in AMD patients. OM

References

1. Seddon JM, Reynolds R, Rosner B. Peripheral retinal drusen and reticular pigment: association with CFHY402H and CFHrs1410996 genotypes in family and twin studies. Invest Ophthalmol Vis Sci 2009;50:586-591.
2. Geirsdottir A, Jonasson F, Cairns D, et al. Twelve-year incidence of age-related macular degeneration (AMD) in the Reykjavik Eye Study and initial characterization of wide field images. Presented during the 2009 meeting of the Association for Research in Vision and Ophthalmology (ARVO). Presentation 269/A369; May 3, 2009.