An annual dilated comprehensive eye exam is recognized as one of the critical steps in managing diabetes, yet a large analysis comprised of over 27,000 patients age 40 or older who have diabetes shows that 23.5% of patients did not adhere to their recommended annual eye exam.¹ Survey results indicated that “no need” and “cost or lack of insurance” were the main factors driving non-adherence, while “lack of transportation,” “inability to get an appointment,” or “not having an eye doctor” were other reported factors.¹

A recent systematic review identified lack of knowledge, attitude, and motivation as other barriers to exams.² Something else to consider: A different study reveals 34% of patients who had diabetes underwent a screening during the first year, but just 16% of patients underwent a screening for two consecutive years.³ What’s more, another study shows that half of patients knew of the recommendation for annual diabetic eye examinations, while even more patients didn’t understand the rationale for the exam.⁴ (See “the Prevalence and Effect of Diabetes,” below.) It is unlikely these trends have significantly changed: The effect of the COVID-19 pandemic has, perhaps, worsened compliance with scheduled visits. We can feasibly extrapolate that by comparing it with the decrease in injections for DR during the pandemic, which ranged from 30% to nearly 100% globally, as compared to the same timepoints in 2019.⁵

Addressing these barriers requires a team-based approach by other health care providers, social workers, and eye care providers (ECPs). ECPs can take the following two steps to increase the likelihood of patients who have diabetes attending their scheduled eye care visits:

1 BUILDING AWARENESS

The lack of understanding about the importance of the diabetic eye exam is compounded by a lack of awareness about the disease: A total of 8.5 million adults ages 18 or older who met the laboratory criteria for diabetes were either unaware of this or did not report having diabetes, according to the Centers for Disease Control.⁶ Visual symptoms and the need for glasses are facilitators for the diabetic eye exam.⁷ These patients' refractions can change in both myopic as well as hyperopic shifts,⁸ which may prompt them to seek evaluation by an eye care provider.

Optometrists should educate patients on this fact during the refractive evaluation, as doing so builds awareness regarding the link between diabetes and eye conditions. Additionally, should the patient’s refractive change be suspicious for diabetes, the OD can further show their importance as a member of the patient’s health care team by contacting the patient’s primary care physician (PCP) to recommend diagnostic testing for the condition. In seeing the optometrist’s role in their care play out in front of them, patients will, no doubt, tell others about the importance of eye care, and the need to have an eye doctor.

2 PROVIDING SPECIFIC EDUCATION

Once a patient is diagnosed as having diabetes, ODs must educate patients who have the condition about the importance of regularly scheduled dilated and comprehensive eye exams, noting that adults who have type 1 diabetes must undergo an initial dilated and comprehensive eye exam within five years after the onset of diabetes, and adults who have type 2 diabetes must do so at the time of diagnosis.⁹ (Optometrists must overcome the resistance to dilated retinal examination, however, advances in retinal imaging, particularly fundus photography, can be an effective tool in capturing and diagnosing DR.¹⁰)

Patients should be educated that DR is often asymptomatic. Specifically, patients who have diabetes and early stages of DR should be reminded at each visit that their perception of their eyesight is not an indicator of a lack of disease progression and/or need for intervention and treatment. Optometrists can refer to the Early Treatment Diabetic Retinopathy Study (ETDRS), which shows that, in most cases the actual functional vision loss may not be discerned until the patient has reached the ETDRS severity levels of 43 to 47, corresponding to moderate, to moderately severe nonproliferative DR (NPDR).¹¹ ODs need to tell patients that in reaching these levels of NPDR, the probability of conversion to proliferative retinopathy (PDR), and lasting vision loss increases significantly.¹² A multidisciplinary team-based approach involving eye care providers, PCPs, community health care workers, and religious organizations should work to educate patients on the importance of complying with eye care appointments and how the absence of symptoms does not equate to the absence of vision-threatening problems.

Additionally, optometrists can play a role in educating patients on the impact of diet, exercise, smoking cessation, glucose monitoring, and close follow-up with their PCPs on their overall visual outcome. (See “Diabetes: Link it With Lifestyle,” at https://bit.ly/3uv6zyU .) In patients who have both type 1 and type 2 diabetes, the frequency of microvascular complications and the rate of progression of diabetes can be reduced by intensive glycemic control, as demonstrated by The Diabetes Control and Compliance Trial, as well as the U.K. Prospective Diabetic Study.^13,14

A recent study shows improved adherence to healthy lifestyle and glucose self-monitoring and improved re-engagement with primary care and/or endocrinology physicians in patients who had been provided structured education about diabetes by their optometrist.¹⁵

Finally, when these patients, particularly those who don’t have a perceived visual problem, are referred to a retina specialist for treatment, the importance of complying to this referral should be clearly discussed with the patient by the referring doctor and/or their designated staff. The referral loop also needs to be completed as much as possible to ensure that the patient received the proper evaluation and care.

OUR RESPONSIBILITY

While there are still many barriers that patients who have diabetes face, optometrists can make an impact in changing the perception of “no need” to “need” by educating on the importance of screening exams and regular follow-up visits. The result: early diagnosis and better visual outcomes. OM

References
1. Chou CF, Sherrod CE, Zhang X, et al. Barriers to eye care among people aged 40 years and older with diagnosed diabetes, 2006-2010. Diabetes Care. 2014;37(1):180-8. doi:10.2337/dc13-1507
2. Mukamel DB, Bresnick GH, Wang Q, Dickey CF. Barriers to compliance with screening guidelines for diabetic retinopathy. Ophthalmic Epidemiol. 1999;(1):61-72. doi: 10.1076/opep.6.1.61.1563.
3. Hartnett ME, Key IJ, Loyacano NM, Horswell RL, Desalvo KB. Perceived barriers to diabetic eye care: qualitative study of patients and physicians. Arch Ophthalmol. 2005;123(3):387-91. doi:10.1001/archopht.123.3.387
4. Centers for Disease Control and Prevention. Prevalence of Both Diagnosed and Undiagnosed Diabetes.https://www.cdc.gov/diabetes/data/statistics-report/diagnosed-undiagnosed-diabetes.html. (Accessed March 29, 2022.)
5. Tai MC, Lin SY, Chen JT, Liang CM, Chou PI, Lu DW. Sweet hyperopia: refractive changes in acute hyperglycemia. Eur J Ophthalmol. 2006 Sep-Oct 2006;16(5):663-6. doi: 10.1177/112067210601600501.
6. Solomon SD, Chew E, Duh EJ, et al. Diabetic Retinopathy: A Position Statement by the American Diabetes Association. Diabetes Care. 2017;40(3):412-418. doi: 10.2337/dc16-2641.
7. Salz DA, Witkin AJ. Imaging in diabetic retinopathy. Middle East Afr J Ophthalmol. 2015;22(2):145-50. doi:10.4103/0974-9233.151887.
8. Mazhar K, Varma R, Choudhury F, et al. Severity of diabetic retinopathy and health-related quality of life: the Los Angeles Latino Eye Study. Ophthalmology. 2011;118(4):649-55. doi:10.1016/j.ophtha.2010.08.003
9. Fundus photographic risk factors for progression of diabetic retinopathy. ETDRS report number 12. Early Treatment Diabetic Retinopathy Study Research Group. Ophthalmology. May 1991;98(5 Suppl):823-33.
10. Nathan DM, Group DER. The diabetes control and complications trial/epidemiology of diabetes interventions and complications study at 30 years: overview. Diabetes Care. 2014;37(1):9-16 doi: 10.2337/dc13-2112.
11. King P, Peacock I, Donnelly R. The UK prospective diabetes study (UKPDS): clinical and therapeutic implications for type 2 diabetes. Br J Clin Pharmacol. 1999;48(5);643-8.doi: 10.1046/j1365-2125.1999.00092.x
12. American Optometric Association. Study: Collaboration and bigger roles by doctors of optometry buttress care for diabetes patients. https://www.aoa.org/news/clinical-eye-care/diseases-and-conditions/diabetes-and-prediabetes?sso=y. (Accessed March 29, 2022)
13. World Health Organization. Global Report on Diabetes. https://apps.who.int/iris/bitstream/handle/10665/204871/9789241565257_eng.pdf. (Accessed March 29, 2022). 
14. World Health Organization. Diabetes.https://www.who.int/news-room/fact-sheets/detail/diabetes. (Accessed March 29, 2022.)
15. U.S. Department of Health and Human Services. Centers for Disease Control and Prevention. National Diabetes Statistics Report 2020. Estimates of Diabetes and Its Burden in the United States. https://www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf. (Accessed March 29, 2022).

DR. M. RAFIEETARY is a consultative optometric physician at the Charles Retina Institute, in Germantown, Tenn. He is on the advisory board of a number of professional organizations, and lectures and writes on posterior segment disease. Email him at mrafieetary@charlesretina.com.

DR. S. RAFIEETARY received his Doctor of Medicine degree from the University of Tennessee Health Science Center. He subsequently completed his residency in ophthalmology at the University of Tennessee/Hamilton Eye Institute. He is currently completing his vitreoretinal surgery fellowship at the Charles Retina Institute.