The Growing Prevalence of Diabetic Retinopathy: Why Patients with Diabetes Should Receive Eye Exams Early and Often

Introduction

People living with diabetes are more likely than not to develop diabetic retinopathy (DR) – according to the American Diabetes Association (ADA), nearly all patients with type 1 diabetes and more than 60% of patients with type 2 diabetes develop DR during their first two decades of disease1. With the global number of patients with diabetes estimated to reach 300 million by 2025 and 366 million by 20302, and DR cases predicted to reach 130 million by 20303, the needs for effective diagnosis and treatment are now more critical than ever.

DR is the most common diabetic eye disease and the leading cause of vision loss and blindness in American working age adults4. Damage caused by DR is often irreversible and, if left untreated, can lead to permanent blindness. Early diagnosis and intervention of DR is of paramount importance to suppress severe damage to the retina and vision loss.

Early and accurate diagnosis prevents irreversible blindness from DR

The most recent data from the U.S. government show that only 58.3% of patients with diabetes received a yearly eye exam in 2020, well short of the government’s goal for at least 70.3% of patients to be screened5. In a more recent study of DR screening in the emergency department, digital fundus photography, which captures an image of the retina, in the ED detected a high rate of undiagnosed DR and half of participants reported barriers to routine care6. Regular eye exams are beneficial even to those who are not diagnosed with diabetes – the American Optometric Association reports that 20% of patients learn they’re diabetic through the results of an eye exam7.

At present, DR can be diagnosed by an optometrist or ophthalmologist with a simple dilated eye examination, and in many cases, diagnosis can occur before any overt symptoms are noticed by the patient. If severe DR or diabetic macular edema (DME) is suspected, a fluorescein angiography or optical coherence tomography (OCT) test may be performed to assess broken or leaky blood vessels.

As highlighted in last month’s OcuTerra Insights, artificial intelligence has emerged with tremendous potential to transform the diagnosis of DR and make it more accessible. Research presented at the 2023 ADA Scientific Sessions in San Diego in June discussed the use of machine learning to identify the risk of early progression by assessing retinal images. Out of nearly 10,000 images, the algorithm was able to accurately assign disease progression risk in 91% of cases, demonstrating that the use of machine learning algorithms may further refine the risk of disease progression and personalize screening intervals for patients, possibly reducing costs and improving vision-related outcomes8.

Enabling earlier interventions to follow earlier diagnosis

When doctors diagnose a case of DR in its earliest stages, interventions have the greatest likelihood of success. Early detection, timely treatment and appropriate follow-up care can reduce a person’s risk for severe vision loss from diabetic eye disease by 95%9. Therefore, it is critical that people with diabetes receive regular eye exams to prevent long-term damage of DR. The ADA recommends that adults with type 2 diabetes have their first eye exam when they are diagnosed and people with type 1 diabetes have their first eye exam within five years of diagnosis10.

People might also be more inclined to undergo regular screening for DR if there were active interventions available for the earliest stages of disease. Despite the high prevalence of DR, the current standard of care for patients newly diagnosed with DR is “watch and wait” until symptoms advance to the point where a sight-threatening complication arises – at which point the most common treatments are laser photocoagulation or intravitreal injections. While both of these treatments can be effective, they are invasive and associated with significant side effects and complications which may further impact vision.

OcuTerra is advancing OTT166, a novel selective integrin inhibitor designed to be delivered by eye drop, with the hope that patients receiving early DR diagnosis could have a therapeutic option to delay or even prevent the progression of this devastating condition. OTT166 is currently under evaluation in the Phase 2 DR:EAM clinical trial, which has reached full enrollment and is scheduled to conclude at the end of 2023. As a non-invasive therapeutic that has been purpose-engineered to reach the retina through topical application, OTT166 could create a significant shift to the next steps for people newly diagnosed with DR.

Conclusion

Even if your vision is normal and you haven’t experienced any unusual ocular symptoms, regular eye exams can play an incredibly valuable role in managing overall health. Cases of diabetes are rapidly rising in the U.S. and worldwide – eye exams could even inform patients of their diabetes status before symptoms arise or primary care doctors take notice. As we push for the rate of people receiving regular eye exams to increase the next step is to develop therapeutics that can actively address DR as soon as it is diagnosed. As OcuTerra prepares to share data from the DR:EAM trial in 2024, we hope that OTT166 can eventually help a critically underserved population of patients with DR.

Learn more about OTT166: https://www.ocuterratx.com/pipeline.

References

  1. Fong, D. S., Aiello, L., Gardner, T. W., King, G. L., Blankenship, G., Cavallerano, J. D., Ferris, F. L., & Klein, R. (2004). Retinopathy in diabetes. Diabetes Care, 27(suppl_1), 84–87. https://doi.org/10.2337/diacare.27.2007.s84

  2. Zhao, M., & Jiang, Y. (2019). Great Expectations and challenges of artificial intelligence in the screening of diabetic retinopathy. Eye, 34(3), 418–419. https://doi.org/10.1038/s41433-019-0629-2

  3. Tan, T.-E., & Wong, T. Y. (2023). Diabetic retinopathy: Looking forward to 2030. Frontiers in Endocrinology, 13. https://doi.org/10.3389/fendo.2022.1077669

  4. Centers for Disease Control and Prevention. (2022, December 19). Diabetes and Vision Loss. Centers for Disease Control and Prevention. https://www.cdc.gov/diabetes/managing/diabetes-vision-loss.html#:~:text=This%20common%20eye%20disease%20is,vision%20or%20stopping%20blood%20flow

  5. U.S. Department of Health and Human Services. (n.d.). Increase the proportion of adults with diabetes who have a yearly eye exam - D‑04. Increase the proportion of adults with diabetes who have a yearly eye exam - D‑04 - Healthy People 2030. https://health.gov/healthypeople/objectives-and-data/browse-objectives/diabetes/increase-proportion-adults-diabetes-who-have-yearly-eye-exam-d-04

  6. Williams, A. M., Weed, J. M., Commiskey, P. W., Kalra, G., & Waxman, E. L. (2022). Prevalence of diabetic retinopathy and self-reported barriers to eye care among patients with diabetes in the emergency department: The Diabetic Retinopathy Screening in the Emergency Department (DRS-ED) study. BMC Ophthalmology, 22(1). https://doi.org/10.1186/s12886-022-02459-y

  7. American Diabetes Association to Highlight Innovations in Diabetes Technology for Glucose Management and Diabetic Eye Condition. (2023, June 23). American Diabetes Association | Newsroom. Retrieved August 15, 2023, from https://diabetes.org/newsroom/press-releases/2023/american-diabetes-association-highlight-innovations-diabetes-technology-glucose-management-diabetic-eye-condition

  8. American Diabetes Association to Highlight Innovations in Diabetes Technology for Glucose Management and Diabetic Eye Condition. (2023, June 23). American Diabetes Association | Newsroom. Retrieved August 15, 2023, from https://diabetes.org/newsroom/press-releases/2023/american-diabetes-association-highlight-innovations-diabetes-technology-glucose-management-diabetic-eye-condition

  9. People with diabetes can prevent vision loss. National Eye Institute. (n.d.). https://www.nei.nih.gov/sites/default/files/2019-06/diabetes-prevent-vision-loss.pdf

  10. American Diabetes Association. (n.d.). What can you do to protect your eyes?. What Can You Do to Protect Your Eyes? https://diabetes.org/diabetes/eye-health/take-charge/what-can-you-do-protect-your-eyes#:~:text=The%20American%20Diabetes%20Association%20recommends,within%20five%20years%20of%20diagnosis

Brad Good