Diabetic Retinopathy

The stages

• Mild non-proliferative retinopathy: small bulges in the capillary walls (microaneurysms) and dot hemorrhages. No symptoms; monitored yearly
• Moderate non-proliferative retinopathy: more hemorrhages, leakage of fat and fluid, and some closed vessels. Monitored every six months, with attention to the macula
• Severe non-proliferative retinopathy: widespread hemorrhage and closed vessels starving the retina of oxygen. Monitored every three months; a retina specialist is involved because progression is likely
• Proliferative retinopathy: the starved retina releases growth signals and fragile new vessels grow on its surface and into the gel of the eye, where they bleed and pull, causing hemorrhage and retinal detachment. Treated urgently

Diabetic macular edema, swelling of the central retina from leaking vessels, can occur at any stage and is the most common reason for vision loss.

Symptoms

None, for most of the course. Later: blurred or fluctuating vision, dark spots or floaters from bleeding, distortion of straight lines from macular swelling, and, with a large hemorrhage or detachment, sudden loss of vision. Because symptoms come late, screening is what finds the disease in time.

Diagnosis and monitoring

A dilated examination with retinal photography and OCT of the macula, repeated at the interval the stage requires. OCT detects and measures macular edema and is the main guide to treatment. Fluorescein angiography, a dye test performed by a retina specialist, maps leakage and closed vessels when treatment is being planned.

Treatment

Control of blood sugar, blood pressure and lipids slows every stage and is the foundation. When retinopathy threatens sight, treatment is performed by a retina specialist, to whom we refer promptly and with whom we co-manage: injections of anti-VEGF medication into the eye, which shrink new vessels and dry macular edema and are the main treatment today; laser to the peripheral retina in proliferative disease, which reduces the growth signal; steroid implants for some cases of edema; and vitrectomy surgery for non-clearing hemorrhage or detachment. Treated in time, most patients keep useful vision.

Retinopathy and cataract surgery

Cataracts come earlier in diabetes, and cataract surgery can temporarily worsen macular edema. The macula is imaged before surgery, edema is treated first, and anti-inflammatory drops are used more intensively afterward. Lens choice avoids multifocal optics in eyes with macular damage.