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Diabetes Management - An In-Depth Guide for the Clinical OD

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13 min read

It is important as primary eyecare providers to be aware and involved in your patient's diabetes management. Here is what you need to know.

Diabetes Management - An In-Depth Guide for the Clinical OD

How much do you know about diabetes management?

Do you know what is being prescribed?
Diabetes has become the leading cause of blindness in the United States and remains the 7th leading cause of death.1 According to the Centers for Disease Control and Prevention (CDC), in 2012, just over 29 million Americans, or 9.3% of the population had diabetes. Of those, nearly 8.1 million were undiagnosed.2
It should be noted that more people die from diabetes annually than breast cancer and AIDS combined.3
Pretty alarming numbers.
I find that many diabetics don’t fully understand the severity of the disease. It is important that we, as optometrists, the gatekeepers, understand what the normal criteria are, as well as, understand what is being prescribed so we can reinforce the importance of blood-sugar control to our patients. Helping our patients understand diabetes better will not only decrease the ocular effects of the disease but the mortality rate as well.

Diabetic Basics

First, it is important to understand the basics of diabetes.
What are the baselines for the blood-glucose and HbA1C (A1C)? When I was a student, the classifications were Insulin-Dependent Diabetes Mellitus (IDDM) and Non-Insulin Dependent Diabetes Mellitus (NIDDM) until it was changed in 2003.
Knowing the newest categories of diabetes and understanding what is being prescribed will also give you an indication of how well controlled the disease is. Are they controlling their diabetes by diet only? Are they on a single oral medication or multiple medications? Are they using just Insulin or a combination of Insulin and oral meds. All useful information.

I will include some examples of the medications and different types of insulin that are commonly prescribed for the disease and the cost associated with them. It will be very easy to see why this disease has become an epidemic and the leading cause of blindness in the U.S. in the general population. Cost of the medications may vary by region.

Fasting Blood-Glucose: A fasting blood glucose test is performed after having nothing to eat or drink (except water) for 8 hours prior to the test.
Result Fasting Plasma Glucose (FPG)
Normal less than 100 mg/dl
Prediabetes 100 mg/dl to 125 mg/dl
Diabetes >126 mg/dl
A1C: The A1C is the average Blood-Glucose level over a 2-3 month period
Result A1C
Normal less than 5.7%
Prediabetes 5.7% to 6.4%
Diabetes 6.5% or higher.
How to calculate the A1C4
A1C = (46.7 + Average Blood Glucose mg/dL) / 28.7
Some patients know their A1C, others do not. Encourage your patients to purchase a blood-glucose monitor. By recording the BG level daily, the patient can use the above formula to have an approximation of the A1C. You will find that accountability will create a better diabetic patient long term.


Type 1 diabetes is usually diagnosed in children and young adults. Only 5% of people with diabetes has this form of the disease. In Type 1, the body DOES NOT produce insulin. Insulin is needed to get glucose from the bloodstream into the cells of the body.
Since the pancreas no longer makes insulin, patients with Type 1 Diabetes need to take insulin shots to use glucose from meals (insulin breaks down glucose).
Pre-diabetes (Impaired Glucose Tolerance):
Before people develop Type 2 Diabetes, they almost always have “Pre-diabetes”—blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes.
  • A1C of 7 to 6.4%
  • Fasting blood glucose of 100-125 mg/dl
Pre-Diabetes is an interesting categorization.
Most people would understand that to mean that they will develop diabetes but pre-diabetics can lower their risk of developing Type 2 diabetes by 58% just by:
  • Losing 7% of their body weight and
  • Exercise moderately/Brisk walking 30 min/day;5 days/week5
More than half of Americans will have diabetes or be pre-diabetic by 2020 and it will cost the healthcare system $3.35 trillion if current trends go unabated.6 In today’s world, where both parents work while trying to juggle after-school activities, it is very easy to see why fast food and frozen or processed meals have become commonplace. Offering this additional information may prevent them from developing Type 2 diabetes.


Type 2 diabetes is the most common form of diabetes. Patients with type 2 diabetes do not use insulin properly which is insulin-resistance. At first, the pancreas makes extra insulin to make up for it but, over time it isn’t able to keep up and can not make enough insulin to keep the blood glucose in check. Patients with type 2 diabetes may be prescribed both pills and insulin or just insulin by itself in their diabetes management treatment program.
Available Treatments:
Insulin: There are different types of insulin depending on the following 3 characteristics:
  • Onset is the length of time before the insulin reaches the bloodstream and begins lowering blood glucose;
  • Peak-time is the time during which insulin is at maximum strength in terms of lowering blood glucose; and
  • Duration is how long the insulin continues to lower the blood glucose.

Types of Insulin

Rapid-acting insulin: Also known as mealtime insulin. Begins to work about 15 minutes after injection, peaks in about 1 hour and continues to work for 2 to 4 hours.
Apidra ($256/10mL), Humalog and NovoLog ($210/10mL). *There is a new rapid-acting inhaled insulin called Afrezza ($322/1 box)
Regular or Short-acting insulin: usually reaches the bloodstream within 30 minutes after injection, peaks anywhere from 2 to 3 hours after injection and is effective for approximately 3 to 6 hours.
Humulin R (OTC/Rx), Novolin R ($225/10mL)
Intermediate-acting insulin: Generally reaches the bloodstream about 2 to 4 hours after injection, peaks 4 to 12 hours later and is effective for about 12 to 18 hours.
NPH (Humulin N (OTC), Novolin N ($150/10ML)
Long-acting insulin: Reaches the bloodstream several hours after injection and tends to lower glucose levels fairly evenly over a 24-hour period.
Levemir ($295/10mL), Lantus ($311/10mL), Toujeo (3x the amount of insulin in 1mL) ($406)
Your patients may be using a mixture or combination of insulins such as 70/30 (70 units of NPH and 30 units of Regular Insulin)
Some of your patients may be placed on an insulin pump. Insulin pumps deliver insulin in two ways:
  1. Basal Dose- a steady measured and continuous dose.
  2. Bolus Dose- a surge close to mealtime to control the rise in B-G after a meal.
Insulin pumps give the needed insulin consistently throughout the day but gives a surge before mealtime to allow for the breakdown of glucose.

Oral Medications:

Sulfonylureas: -stimulate the beta cells of the pancreas to release more insulin and are usually taken 1 to 2 times/day before meals.
  • Glipizide: Glucotrol 5mg $47.80 (180 ea.) and Glucotrol XL 5mg $243 (90ea): 3rd generation
  • Glyburide: Glynase 3mg PressTab $460 (30ea) and Diabeta5mg $83 (60ea.): 3rd generation
  • Glimepiride: Amaryl 1mg $78 (60ea): 3rd generation
NOTE: Diabinese and Micronase have been discontinued in the U.S.
Biguanides: -lower blood glucose levels primarily by decreasing the amount of glucose produced by the liver.
  • Metformin: also helps to lower blood glucose levels by making muscle tissue more sensitive to insulin so glucose can be absorbed. 500mg $19 (60ea.); 850mg $25 (60ea.); 1000mg $98 (60ea.)
*it is usually taken bid. A side effect of Metformin is diarrhea but improved when taken with food.
Meglitinides: -are drugs that also stimulate the beta cells to release insulin.
  • Prandin 1mg $412 (45ea.) and Starlix 120mg $316 (90ea.)7
*it is usually taken before each of three meals

New Class of Diabetes Medication

The newest groups of medications for diabetes is the DPP-4 Inhibitors. This group includes Januvia , Onglyza, CombiglyzeXR (which is the only DPP-4 inhibitor combined with Metformin), Victoza, Tradjenta (which should not be used with insulin).
Your Pre-Diabetics will usually be put on Metformin which can reduce the risk of developing diabetes by 31%.8
For Type 2 diabetics, one of the sulfonylurea drugs or Metformin used as initial therapy is reasonable because of its efficacy, low side effects and for cost as shown above. The combination of 2 oral agents will have additive effects.
Type 1 diabetics will be put on Insulin but in some cases it will be combined with Metformin to achieve an additive effect.

Ask Questions

Ask the patient a series of questions during the case history to see how tuned in they are to their disease.
Unfortunately… many aren't tuned in at all.
The following are some questions that I ask my diabetics in regards to their diabetes management:
  1. Do you monitor your blood sugar level?
  2. How often do you monitor your blood sugar?
  3. How do you know how much insulin to take?
  4. What medications are you taking? How often?
  5. What is your A1C?
  6. Besides medications, what else do you do to help reduce your blood sugar (exercise, diet, etc)?
  7. How often do you see your physician for the diabetes? All are important questions and will enable you to determine how serious the patient is in controlling their disease.
How well controlled the disease is may be seen during the dilated retinal exam. Don’t use scare tactics but it is imperative to discuss the necessity of annual dilated eye exams with your diabetics. A lot of what is seen can be prevented with those exams.
One thing to remember with your diabetic patients is that nearly 70% die NOT from diabetes but from heart disease and strokes.9 At the Annual National Vision Continuing Education Seminar in Chicago in June 2017, Optometrist Dr. John McGreal stated that he feels “all diabetics should be put on statins or other lipid lowering drugs.”10 And it makes sense. Unfortunately, only 50% of patients prescribed lipid lowering drugs are still taking them at 6 months and only 30% at 12 months.11
Therefore, education is important.
Education will empower your patients.
My goal as an optometrist is to empower my patients to create a better diabetic patient. Give your patients additional resources such as or I recommend a book written by Dennis Pollock, called “60 Ways to Lower Your Blood Sugar.”
It is very easy to read and is another tool to empower your patients. Also, patients can use a free app from to input their blood glucose level and it will create charts, as well as, calculate the A1C. Consider having a list of dietitians in your area to assist your patients in eating healthier.

Communicate with the Prescribing Physician

Diabetics presenting for a diabetic eye exam or being referred by their prescribing physician has been increasing recently. One reason for this is that reimbursements to the prescriber may be affected if the patient doesn't have a dilated retinal exam. In any case, more diabetics are returning for yearly dilated exams. This is also critical in diabetes management.

Send a Diabetic Eye Health Report to the patient’s prescribing physician so they are informed of the patient’s ocular health. As you continue to update the prescribing physician, you will be developing a relationship with that physician which may lead to more referrals to your office.

Diabetes is an epidemic and we need to assist our patients and their doctors at decreasing the effects of the disease.
1,2,3 “Statistics About Diabetes.” American Diabetes Association, n.d. Web. 14, April 2017.
Calazon, Jonathan. “How to Calculate Your A1C” Glucose Tracker, 1, Aug. 2014. Web. 14, April 2017
”Diabetes Basics.”. American Diabetes Association, n.d. Web. 14, April 2017
Berkrot, Bill. “Half of Americans Facing Diabetes by 2020.” Reuters, n.d. Web. 14, April 2017
7”Prescription Prices, Coupons & Pharmacy Information-GoodRx.” GoodRx, n.d. Web. 14, April 2017
8,9,10,11McGreal, John. “The Latest Trends in Contemporary Medicine.”. National Vision’s 2017. Continuing Education Seminar. Chicago. 4, June 2017. Lecture.

More about diabetes:

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Michael Hay, OD
About Michael Hay, OD

I graduated from Southern College of Optometry in Memphis, TN. Since graduating, I have worked in all modes of practice including a military setting, corporate and private practice. Currently, I work at Crystal Clear Eye Associates of Florida, PA., a large commercial group practice in Jacksonville, Florida. I enjoy writing and mentoring young doctors. I am a member of the American Optometric Association and NE Florida Optometric Society. In my free time, I enjoy spending time with my 3 sons

Michael Hay, OD
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