Diabetic eye disease generally has no symptoms in the early stages, so prevention is critical to protect patients’ vision. Retinopathy is an eye condition that can lead to serious complications (figure).1 High blood glucose levels can cause eye tissue to swell and lead to blood vessel damage.



Early detection and treatment can delay or prevent blindness caused by diabetic retinopathy in 90% of individuals with diabetes, according to the CDC.2 However, at least 50% of patients do not have their eyes examined or the condition is diagnosed too late for successful treatment.2 Pharmacists can play an important role as part of an interdisciplinary team to manage patients with diabetes and prevent eye complications.

SCREENING AND TREATMENT RECOMMENDATIONS
The American Diabetes Association guidelines recommend that adults with type 1 diabetes (T1D) have an initial dilated and comprehensive eye examination by an ophthalmologist or optometrist within 5 years after the onset of diabetes.3 Patients with type 2 diabetes (T2D) should receive an initial dilated and comprehensive eye examination once the disease is diagnosed.3 If their blood glucose is well controlled and there is no sign of retinopathy, then eye exams can be done every 1 to 2 years.3

Telemedicine programs that use validated retinal photography, which is evaluated remotely by an eye specialist, can be an appropriate screening strategy.3 Women with T1D or T2D who are planning to become pregnant should receive an eye examination before pregnancy, if possible, and pregnant patients should have one in the first trimester, with follow-up monitoring up to 1 year postpartum, depending on retinopathy severity.3 A recent study published in Ophthalmology analyzed data from the National Health and Nutrition Examination Survey to examine adherence of patients to annual diabetic eye exams within the preceding 12 or 24 months. The investigators found that 63.4% and 78.7%, respectively, adhered to treatment recommendations.4 Additionally, the study results found that adherence with eye exams did not improve over the past 10 years.4 More education is necessary to encourage patients to receive retinopathy screenings.

Prompt treatment of diabetic retinopathy is extremely important to prevent vision loss. Standard treatment options include intravitreous injections of the antivascular endothelial growth factor ranibizumab and panretinal laser photocoagulation therapy, which destroys abnormal blood vessels in the retina.3 Lowering blood pressure using angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers also can decrease retinopathy progression.

Pharmacists can play an important role in preventing diabetic retinopathy, according to the results of a study published in Pharmacy Practice.5 Pharmacists worked in a collaborative drug therapy management service and provided comprehensive cardiovascular risk reduction consultations to patients with diabetes. As part of the protocol, the pharmacists had the authority to initiate, adjust, and stop medications for diabetes, hypertension, and smoking cessation. Additionally, they provided disease-state, lifestyle, and pharmacologic education. Patients in the group with pharmacist-managed care remained stable or improved on the retinopathy scale.5 These outcomes offer insight on a unique opportunity for pharmacists to be involved on an interdisciplinary health care team to prevent diabetic eye diseases.

EYE DISEASE PREVENTION STRATEGIES
Pharmacists can provide important counseling points to patients with diabetes on strategies to prevent eye disease. As previously mentioned, patients should be encouraged to see an eye specialist for a dilated and comprehensive eye exam, with continuous monitoring. Pharmacists should also advise patients that they may not experience symptoms in the early stages of eye disease. Therefore, it is extremely important to keep up with eye exams to catch any problems so that conditions may be treated right away. Simple reminders about eye exams can be done when patients pick up their medications at the community pharmacy setting or at hospital discharge.

Because uncontrolled diabetes can cause eye diseases, pharmacists can assist patients with maintaining good control over their blood glucose levels through close monitoring. This includes ensuring that patients are compliant with their medications and adjusting therapy regimens based on blood glucose and hemoglobin A1C values. Smoking also increases the risk of diabetic retinopathy and other eye diseases, so pharmacists should educate patients on the importance of smoking cessation, including nicotine replacement therapy.5 Pharmacists should also recommend regular exercise, as this helps lower glycated hemoglobin and blood glucose levels, which can prevent eye complications.6
 
Jennifer Gershman, PharmD, CPh, is a drug information pharmacist and Pharmacy Times® contributor who resides in South Florida.


REFERENCES
  1. Turbert D. Diabetic eye disease. American Academy of Ophthalmology web- site. aao.org/eye-health/diseases/diabetic-eye-disease. Published January 28, 2019. Accessed September 28, 2019.
  2. CDC. Keep an eye on your vision health. CDC website. cdc.gov/features/healthyvi- sion/index.html. Updated July 26, 2018. Accessed September 25, 2019.
  3. American Diabetes Association. 11. Microvascular complications and foot care: Standards of Medical Care in Diabetes-2019. Diabetes Care. 2019;42(suppl 1):S124-S138. doi: 10.2337/dc19-S011.
  4. Eppley SE, Mansberger SL, Ramanathan S, Lowry EA. Characteristics associ- ated with adherence to annual dilated eye examinations among US patients with diagnosed diabetes [published online June 15, 2019]. Ophthalmology. doi: 10.1016/ j.ophtha.2019.05.033.
  5. Weber ZA, Kaur P, Hundal A, Ibriga SH, Bhatwadekar AD. Effect of the pharma- cist-managed cardiovascular risk reduction services on diabetic retinopathy outcome measures. Pharm Pract. 2019;17(1):1319. doi: 10.18549/PharmPract.2019.1.1319.
  6. Top five steps to help prevent diabetic eye diseases. American Academy of Ophthalmology website. aao.org/eye-health/tips-prevention/top-five-diabetes-steps. Published October 29, 2014. Accessed September 28, 2019.