Published in Systemic Disease

Type 2 Diabetes Prevention & Remission: The Optometrist’s New Role

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9 min read

There are certain measures optometrist can take when it comes to type 2 diabetes prevention. Here are some things you should be considering.

Type 2 Diabetes Prevention & Remission: The Optometrist’s New Role

Our patients frequently ask us how they can optimize or maintain their ocular health.

Many times these patients are interested in or are already supplementing with over-the-counter eye vitamins such as AREDS formula or Ocuvite. While these antioxidant supplements are appropriate in most cases of early to moderate age-related macular degeneration, there is a lower hanging fruit known as Type 2 diabetes that needs to be addressed among our patients.
Unfortunately, if you’re obese, or smoke, or have metabolic syndrome/Type 2 diabetes, there’s really no way a supplement is going to be as effective as simply addressing the elephant in the room:

Type 2 diabetes (T2DM) is currently one of the biggest threats against optimal ocular and systemic health (and to our healthcare system) today.

T2DM (~95% of all diabetes) is the leading cause of new legal blindness in people 20-74 years of age. Roughly 90% of all diabetics will develop some form of sight-threatening retinopathy. Any and all measures that aim to prevent/reverse diabetes or metabolic syndrome will be far more effective than eye vitamins alone.
Optometrists today have a unique opportunity in healthcare to educate and counsel our patients with diabetes and pre-diabetes (now >1/3 of Americans, or over 100 million people). Most optometrists arguably spend almost twice the amount of time with each patient, when compared to the average 10 minute visit with a primary care physician (PCP) today. No longer is it solely the PCP’s role to educate patients with metabolic disease, they’re simply stretched too thin. Even at this year’s American Academy of Optometry meeting in Chicago, several lecturers emphasized the importance on optometry’s role in educating and encouraging lifestyle change, preventing retinopathy and avoiding subsequent trips to the retina specialist.
Since we are primarily optometrists and not nutrition/lifestyle coaches, we’re fortunate to have a plethora of resources to help educate our patients. Some of these evidence-based approaches may seem fringe or even completely contradictory to common advice; however, we can no longer afford to sit on the sidelines while this epidemic continues to grow. As always, when it comes to type 2 diabetes prevention, we must advocate the importance of close medical supervision prior to abrupt dietary/lifestyle change, especially when modifying oral hypoglycemic medications or insulin dosages.

Here are three strategies to discuss with your patients with diabetes or metabolic syndrome:

1) Paleolithic/Ancestral Diet [1-4]
If it comes in a bag or a box, you’re no longer interested in it.
For those with pre-diabetes, metabolic syndrome or obesity, at a minimum I will often mention the Whole-30 program and give them a copy of the program details/shopping list printed off their site. “You’re simply going to spend the next 30 days eating only foods that don’t initiate wild blood sugar/insulin excursions.”
By definition, if a patient is diabetic, or has pre-diabetes/metabolic syndrome, they’re intolerant to excessive carbohydrates and sugars. Unless someone is training for a marathon, there’s a good chance they can limit (<15g/meal) or completely remove carbohydrates from the diet altogether until optimal glucose homeostasis is achieved (fasting/post-prandial glucose levels <100mg/dL). By the time Hemoglobin A1c exceeds 6.0%, the pancreas has already thrown up the white flag, exhausted from insulin over-production (and subsequent insulin resistance).
While many patients claim they’ve tried this type of dietary approach, the towel is thrown in rather quickly after frequent hunger spells set in (failure to increase fat consumption). This is primarily due to the longstanding/outdated dogma that saturated fat and cholesterol consumption are the culprit for much of today’s chronic disease. This ideology has been disproven countless times over the past decade [5-7], yet still creates widespread confusion among patients, physicians, and dietitians alike.
2) Intermittent Fasting
For motivated patients with T2DM, I will also mention the concept of intermittent fasting (IF) and reference the workof nephrologist Dr. Jason Fung at Intensive Dietary Management, his new podcast “The Obesity Code”, or his book “The Complete Guide to Fasting.”
IF can be implemented in a variety of ways, from simply skipping breakfast (~16 hour fast) to alternate day fasting (24 hour fast) or even longer periods of several days. This approach was commonly used over 100 years ago in the pre-insulin days by many doctors, including Elliot Joslin, MD to optimize health and longevity in diabetic patients. Dr. Joslin was one of the first specialists in diabetes in the United States when he began practicing in the late nineteenth century, and the Joslin Diabetes Center in Boston is named after him.
The old dietary paradigm of “calories in — calories out,” “move more — eat less” and “portion control” may be effective for some patients in the short term. There’s a reason many of the “Biggest Losers” have difficulty maintaining their results after the season is through. Each of these approaches fails to fully address the underlying cause of metabolic disease (derangement of the endocrine system). The root cause of type 2 diabetes is excessive levels of circulating insulin (causing high blood sugar), insulin resistance (at the liver, fat and muscle cells) and an abnormal leptin response (satiety hormone).
Understanding insulin’s key role in metabolism provides clarification as to why people who restrict calories are often more hungry than people who fast or eat a higher fat diet (two ways to keep insulin nearly flat lined).
3) Ketosis and Extended Fasting
Patients with overt/uncontrolled T2DM can also consider adopting a ketogenic diet (80-90% of calories from healthy fats) in conjunction with fasting to help reduce their excessive circulating insulin levels.
Virta Health, a new company in Silicon Valley is aiming to reverse T2DM in 100 million people over the next decade. They incorporate a telemedicine approach to supervised intermittent fasting and a ketogenic diet. Their first published 10-week study proved the program to be extremely effective at reducing body mass, blood glucose/insulin, blood pressure, HbA1c, and reducing the number of medications the patients were on.
Along with retinopathy and the increased risk of retinal detachment, diabetics are also more likely to develop cataracts, cranial nerve palsies, vascular occlusion, ocular hypertension[8-9], and glaucoma[10-15]. Patients with diabetic retinopathy (any level) are twice as likely to suffer from stroke, heart failure, and cardiovascular death[16]. The level and severity of diabetic retinopathy has also been shown to accurately predict other systemic and neurological ailments such as kidney disease, cognitive decline, and dementia[17].

While optometrists did not go to school to be endocrinologists, we’re still being called from the sidelines to promote healthy lifestyle change in these patients with metabolic disease.

We already know that intensive pharmacologic reduction in blood sugar level does not solve the underlying issue of excessive insulin levels, and in fact increases the risk of all-cause mortality[18-20] (ACCORD/Advance Trials).
Not everyone is receptive or ready for drastic lifestyle modification, and that is OK. We still have a unique opportunity to educate and encourage our patients to take back their health. As long as we continue to see patients come in with irreversible end-organ damage (tractional retinal detachment or neovascular glaucoma), we’re no longer able to say it’s solely the PCP’s role to discuss lifestyle change and metabolic control.
As integral players in the healthcare system, we can help to drastically reduce the number of patients that develop permanent vision loss from this largely preventable disease process.
  1. Jönsson, Tommy et al. “Beneficial Effects of a Paleolithic Diet on Cardiovascular Risk Factors in Type 2 Diabetes: A Randomized Cross-over Pilot Study.” Cardiovascular Diabetology 8 (2009): 35. PMC. Web. 4 Dec. 2017.
  2. Ryberg, M, et al. “A Palaeolithic-Type diet causes strong tissue-Specific effects on ectopic fat deposition in obese postmenopausal women.” Journal of internal medicine., U.S. National Library of Medicine, July 2013,
  3. Saslow, Laura R., et al. “A Randomized Pilot Trial of a Moderate Carbohydrate Diet Compared to a Very Low Carbohydrate Diet in Overweight or Obese Individuals with Type 2 Diabetes Mellitus or Prediabetes.” PLOS ONE, Public Library of Science, 9 Apr. 2014,
  4. Esposito, Katherine. "Effects of a Mediterranean-Style Diet on the Need for Antihyperglycemic Drug Therapy in Patients With Newly Diagnosed Type 2 Diabetes." Annals of Internal Medicine Ann Intern Med 151.5 (2009): 306. Web.
  5. Dehghan, M, et al. “Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study.” Lancet (London, England)., U.S. National Library of Medicine, 4 Nov. 2017,
  6. Siri-Tarino, Patty W et al. “Meta-Analysis of Prospective Cohort Studies Evaluating the Association of Saturated Fat with Cardiovascular Disease.” The American Journal of Clinical Nutrition 91.3 (2010): 535–546. PMC. Web. 4 Dec. 2017.
  7. Nettleton, Joyce A., et al. “Saturated Fat Consumption and Risk of Coronary Heart Disease and Ischemic Stroke: A Science Update.” Annals of Nutrition and Metabolism, Karger Publishers, 27 Jan. 2017,
  8. Chang, Y. C., Lin, J., Wang, L. C., Chen, H. M., Hwang, J. J., & Chuang, L. M. (2009). Association of intraocular pressure with the metabolic syndrome and novel cardiometabolic risk factors. Eye, 24(6), 1037-1043. doi:10.1038/eye.2009.247
  9. Sato, Tsuyoshi, and Sayon Roy. "IOVS | Effect of High Glucose on Fibronectin Expression and Cell Proliferation in Trabecular Meshwork Cells." IOVS | Effect of High Glucose on Fibronectin Expression and Cell Proliferation in Trabecular Meshwork Cells. Investigative Ophthalmology and Vision Science, 5 May 2001. Web. 02 Mar. 2016.
  10. Lin I-C, Wang Y-H, Wang T-J, et al. Correction: Glaucoma, Alzheimer’s Disease, and Parkinson’s Disease: An 8-Year Population-Based Follow-Up Study. PLoS ONE. 2016;11(3):e0150789. doi:10.1371/journal.pone.0150789.
  11. Zhou M, Wang W, Huang W, Zhang X. Diabetes Mellitus as a Risk Factor for Open-Angle Glaucoma: A Systematic Review and Meta-Analysis. Vavvas D, ed. PLoS ONE. 2014;9(8):e102972. doi:10.1371/journal.pone.0102972.
  12. Zhao, Di, Juhee Cho, Myung Kim, and David Friedman. "Diabetes, Glucose Metabolism, and Glaucoma: The 2005-2008 National Health and Nutrition Examination Survey." PLoS One Open Access Journal. PLoS One, 13 Nov. 2014. Web. 28 Feb. 2016
  13. Lonneville, Yıldız H., şengül C. özdek, Merih önol, &idot;lhan Yetkin, Gökhan Gürelik, and Berati Hasanreisoğlu. "The Effect of Blood Glucose Regulation on Retinal Nerve Fiber Layer Thickness in Diabetic Patients." Ophthalmologica 217.5 (2003): 347-50. Web. 2 Mar. 2016.
  14. Lopes de Faria JM, Russ H, Costa VP. Retinal nerve fibre layer loss in patients with type 1 diabetes mellitus without retinopathy. The British Journal of Ophthalmology. 2002;86(7):725-728.
  15. Barber, A. J., E. Lieth, S. A. Khin, D. A. Antonetti, A. G. Buchanan, and T. W. Gardner. "Neural Apoptosis in the Retina during Experimental and Human Diabetes. Early Onset and Effect of Insulin." Journal of Clinical Investigation J. Clin. Invest. 102.4 (1998): 783-91. Web. 2 Mar. 2016.
  16. Mottl, Amy K. et al. “The Degree of Retinopathy Is Equally Predictive for Renal and Macrovascular Outcomes in the ACCORD Trial.” Journal of diabetes and its complications 28.6 (2014): 874–879. PMC. Web. 4 Dec. 2017.
  17. Exalto, Lieza G. et al. “Severe Diabetic Retinal Disease and Dementia Risk in Type 2 Diabetes.” Journal of Alzheimer’s disease : JAD 42.0 3 (2014): S109–S117. PMC. Web. 4 Dec. 2017.
  18. Dluhy, robert G., and Graham T. McMahon. “Intensive Glycemic Control in the ACCORD and ADVANCE Trials — NEJM.” New England Journal of Medicine, 12 June 2008,
  19. “Effects of Intensive Glucose Lowering in Type 2 Diabetes — NEJM.” New England Journal of Medicine, The Action to Control Cardiovascular Risk in Diabetes Study Group, 12 June 2008,
  20. Zoe Arvanitakis, Robert S. Wilson, Julia L. Bienias, Denis A. Evans, David A. Bennett. Diabetes Mellitus and Risk of Alzheimer Disease and Decline in Cognitive Function. Arch Neurol. 2004;61(5):661–666. doi:10.1001/archneur.61.5.661
Kevin Cornwell, OD
About Kevin Cornwell, OD

Dr. Kevin Cornwell graduated from The New England College of Optometry in 2015. He went on to complete a residency in ocular and systemic disease with Indian Health Services in Zuni, New Mexico. He now works with MACT Health Board, Inc in Northern California, a nonprofit organization that provides healthcare for Native Americans. He is enthusiastic about bringing eye care to populations in need, both domestically and abroad. He has been involved with several humanitarian outreach projects, in various parts of California, New Mexico, Nicaragua and Mexico. He is passionate about managing the ocular manifestations of systemic disease, and monitoring ocular pathology through retinal imaging with spectral domain optical coherence tomography. He’s also an avid health crusader and enjoys educating and encouraging patients to better manage metabolic disease. Dr. Cornwell enjoys hiking in the Sierras and recording music as a guitarist for Cornwell Studios' youtube channel.

Kevin Cornwell, OD
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