The early ocular manifestations of diabetes mellitus are referred to as background diabetic retinopathy (BDR). Fundus findings include flame or splinter hemorrhages (located in the superficial nerve fiber layer) or dot and blot hemorrhages (located deeper in the retina), hard exudates, retinal edema, and microaneurysms. If these signs are located in the macula, the patient’s visual acuity may be decreased or at risk of becoming compromised, requiring laser treatment. Preproliferative diabetic retinopathy can show BDR changes plus cotton wool spots, intraretinal microvascular abnormalities, and venous beading. Proliferative diabetic retinopathy is demonstrated by neovascularization at the disk (NVD) or elsewhere (NVE). These require laser therapy owing to risk of severe visual loss from sequelae: vitreous hemorrhage, tractional retinal detachment, and severe glaucoma.
Many vascular and hematologic diseases—such as collagen vascular disease, sickle cell trait, hypertension, hypotension, anemia, leukemia, and inflammatory and infectious states—and ocular conditions can be associated with some or all of the above signs.
Background Diabetic Retinopathy. An example of diabetic maculopathy with a typical circinate lipid ring. (Photo contributor: Richard E. Wyszynski, MD.)
Background Diabetic Retinopathy. Hard exudates, dot hemorrhages, blot hemorrhages, flame hemorrhages, and microaneurysms are present. Because these changes are located within the macula, this is classified as diabetic maculopathy. (Photo contributor: Richard E. Wyszynski, MD.)
Proliferative Diabetic Retinopathy. In addition to the signs seen in background and preproliferative diabetic retinopathy, neovascularization is seen here coming off the disk. (Photo contributor: Richard E. Wyszynski, MD.)
Management and Disposition
Routine ophthalmologic referral for laser or surgical treatment is indicated.
Periodic ophthalmologic evaluations are recommended for all diabetic patients.
Microaneurysms typically appear 10 years after the initial onset of diabetes, although they may appear earlier in patients with juvenile diabetes.
Control of blood sugar alone does not prevent the development of retinopathy.
Blurred vision can also occur from acute increases in serum glucose, causing lens swelling and a refractive shift even in the absence of retinopathy.