Retinopathy is a pathological process affecting the retina, with changes observable on ophthalmoscopy; dilatation of the pupil aids observation of the peripheral retina. Common causes include:
- Diabetes mellitus: various abnormalities may occur, in both insulin- dependent (IDDM) and noninsulin dependent (NIDDM) patients. "Background" diabetic retinopathy is manifest as microaneuryms, dot and blot hemorrhages, hard exudates, and diffuse retinal edema, all of which may be asymptomatic. Edema and hard exudates at the macula are a common cause of visual impairment. Proliferative retinopathy is characterized by neovascularization of the disc due to retinal hypoxia, typically in IDDM, with the risk of vitreous hem- orrhage, traction retinal detachment and irreversible visual loss. Laser treatment of new vessels is the treatment of choice.
- Hypertension: hypertensive retinopathy may cause arteriolar con- striction, with the development of cotton-wool spots; and abnormal vascular permeability causing flame-shaped hemorrhages, retinal edema and hard exudates; around the fovea, the latter may produce a macular star. Optic disc swelling may be seen in malig- nant hypertension. Arteriosclerosis, thickening of vessel walls with prolonged hypertension, may cause changes at arteriovenous cross- ings ("AV nipping"). Systemic hypertension is associated with an increased risk of branch retinal vein and central retinal artery occlusion.
- Drug-induced, for example, antimalarials (chloroquine); chlorpromazine.
- Retinitis pigmentosa (q.v.).
- Serous retinopathy or chorioretinopathy: leakage of fluid into the subretinal space, causing unilateral sudden nonprogressive visual loss.
- Cancer-associated retinopathy: arteriolar narrowing, optic atrophy.
- "Salt and pepper" retinopathy of Kearns-Sayre syndrome (mitochondrial disorder)
An electroretinogram (ERG) may be helpful in confirming the presence of a retinopathic disorder.