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Diagnosis and Associated Comorbidities
Diabetic retinopathy (DR) is the most common cause of vision loss in working-age adults, affecting one in three people with diabetes.1,2 Early recognition allows for timely treatment and improved visual prognosis.1,2 Many people with nonproliferative diabetic retinopathy (NPDR) do not experience symptoms until the retinopathy is severe.1
However, despite a person with diabetes having good vision, they may still have significant retinal disease, making regular eye screenings essential.1 Unfortunately, only around 60% of people with diabetes have recommended yearly screenings for diabetic retinopathy.1
Symptoms of NPDR may include:3
- Decreased visual acuity
- Difficulty reading
- The appearance of “floaters”
- Changes in color perception
- Poor night vision
- Metamorphopsia
Diagnosis of NPDR involves a complete eye exam, including dilated fundus exam; only 50% of eyes are correctly diagnosed through undilated pupils.1 Care should be taken to examine the mid-peripheral and peripheral retina as an estimated 30% of people with NPDR have retinal abnormalities outside the posterior pole.4 Additional testing with optical coherence tomography (OCT) or fluorescein angiography (FA) may be indicated, especially if there is a concern for diabetic macular edema (DME).3 The follow-up schedule depends on the severity of NPDR and the presence of DME, along with individual patient factors.1
The primary risk factor for DR is the severity and duration of diabetes.1 Elevated sugar levels cause microvascular damage and corresponding exam findings including:2
- Microaneurysms
- Dot and blot hemorrhages
- Cotton-wool spots
- Hard exudates
- Retinal thickening and edema
- Venous beading
- Intra-retinal microvascular abnormalities (IRMA)
DME can occur at any stage of DR but is more commonly noted with increasing retinopathy severity.8 Reports of DME incidence are as high as 25% to 29% among people with type 2 and type 1 diabetes, with overall estimated US prevalence in persons with diabetes anywhere from 2.7% to 3.8%; if left untreated, DME can lead to significant vision loss.8
Recent guidelines classify DME into two types: center-involved and non-center-involved DME.2 Center-involved DME demonstrates retinal thickening within the 1 mm diameter central subfield, whereas non-center involved DME does not involve this area.2 Optical coherence tomography (OCT) findings include retinal swelling, cystoid macular edema, and subretinal fluid.8
Associated comorbidities with NPDR include hypertension and hyperlipidemia; either condition increases the risk of developing DR.1,2 People with metabolic syndrome (a collection of risk factors that increase the risk of developing heart disease, diabetes, and stroke) have a higher risk of DR progression.1
References
- Flaxel CJ, Adelman RA, Bailey ST, et al. Diabetic Retinopathy Preferred Practice Pattern®. Ophthalmology. 2020;127:P66-P145.
- Wong TY, Sun J, Kawasaki R, et al. Guidelines on Diabetic Eye Care: The International Council of Ophthalmology Recommendations for Screening, Follow-up, Referral, and Treatment Based on Resource Settings. Ophthalmology. 2018;125:1608-1622.
- Gregori, NZ. Diabetic Retinopathy: Causes, Symptoms, and Treatment. AAO EyeSmart®. https://www.aao.org/eye-health/diseases/what-is-diabetic-retinopathy
- Silva PS, Cavallerano JD, Haddad NM, et al. Peripheral lesions identified on ultrawide field imaging predict increased risk of diabetic retinopathy progression over 4 years. Ophthalmology. 2015;122:949-956. https://pubmed.ncbi.nlm.nih.gov/25704318/
- EntoKey. Retinal vascular disease. https://entokey.com/retinal-vascular-disease-3/
- Tabandeh H. Venous loop in severe nonproliferative diabetic retinopathy. Retina Image Bank. 2014;14622.
- Kaplan HJ. Severe NPDR. Retina Image Bank. 2013;3543. https://imagebank.asrs.org/file/5343/severe-npdr
- Jacoba CM, Mitzner MG, Vavallerano J, et al. Diabetic Macular Edema. American Academy of Ophthalmology®. EyeWiki® https://eyewiki.org/Diabetic_Macular_Edema
All URL’s accessed 5/9/22.
