Diabetic Retinopathy Initial Assessment

Clinical Presentation

The earliest clinical manifestations of diabetic retinopathy are microaneurysms and hemorrhages. The initial clinical signs of diabetic retinopathy include thickening of the retinal basement membrane, appearance of microaneurysms (or hypercellular outpouchings of retinal capillaries with weakened walls due to pericyte loss), and leakage of lipid and proteinaceous material (hard exudates). Signs that would lead to visual impairment include the presence of macular edema, NVD or NVE, manifestations of severe nonproliferative diabetic retinopathy (eg extensive retinal hemorrhages or microaneurysms, venous beading, and intraretinal microvascular abnormalities [IRMA]), and vitreous or preretinal hemorrhage. Typical retinal microvascular lesions of diabetic retinopathy include microaneurysms, hard exudates, IRMA, new vessels or neovascularization, hemorrhages, cotton wool spots, venous beading, and fibrous tissue.

History

History taking in patient includes considering the chronicity of DM, especially when it is uncontrolled, non-compliance to antidiabetic medications, poor glycemic control (HbA1c level), medical history (eg obesity, renal disease, hypertension), and ocular history (eg ocular injections, trauma, surgery).

Physical Examination

Ocular Exam  

Visual acuity determines the extent of effect in the central vision. Slit-lamp biomicroscopy is used to examine the posterior pole and the midperipheral posterior pole, thus assessing the presence and severity of diabetic retinopathy. Intraocular pressure (IOP) measurement determines the presence of glaucoma. Gonioscopy is performed to detect anterior chamber neovascularization, particularly in cases of iris neovascularization or elevated IOP. Dilated fundoscopy, including stereoscopic examination of the posterior pole, may also be done. Regarding this, the use of 0.5–1% Tropicamide and/or 2.5% Phenylephrine for pupil dilation is considered safe and markedly increases the sensitivity of diabetic retinopathy screening.

Diabetic Retinopathy_Initial Assesment

Screening

Regular eye examinations for diabetic retinopathy are essential for all patients with DM with the following recommended schedule:  

• Adults with type 1 DM should have the first exam 3-5 years after the onset of the disease then yearly thereafter
• Adults with type 2 DM should have the first eye exam at the time of diagnosis of DM then yearly follow-up
• Pregnant patients prior to conception or early in the first trimester should have eye screening for diabetic retinopathy with follow-up every 3-12 months for those with no retinopathy or mild to moderate nonproliferative diabetic retinopathy and every 1-3 months follow-up for those with severe nonproliferative diabetic retinopathy or worse
• Children with type 1 DM with 5-year history, eye exam is at 9 years old; those with 2 years history have it at 12 years old then yearly follow-up
• Children with type 2 DM, the eye exam is at the time of diagnosis then yearly follow-up

Any abnormal findings during these screenings may warrant more frequent monitoring.