A 29 years old man with IDDM for the last 14 years develops sudden vision loss, has non-proliferating diabetic retinopathy, cause is
A i.e. Macular edema Bleeding from newly formed vessels (neovscularization) is the commonest cause of spontaneous vitreous haeomorrhage in diabetic adultsQ. MaculopathyQ is m.c. cause of visual loss among the patients with NPDR. Involvement of fovea by edema & hard exudates or ischemia (diabetic maculopathy) is the most common cause of visual impairment in diabetic patients paicularly those with type 2 diabetes (NIDDM) Type I diabetics (IDDM) are at paicular risk of developing PDR. And vitreous haemorrhage is most common cause of visual loss in patients with PDRQ. Almost all type I diabetic patients develop retionapathy in about 15 years. In those with type II diabetes, the risk of diabetic retinopathy increases with the duration of diabetes (most impoant-risk factor), accompanying hypeension & smoking. Diabetic retinopathy is more common in type I diabetes than in type 2. Non proliferative DR is more common than proliferative DR; type 1 diabetics are at paicular risk of developing PDR. It appears that duration is stronger predictor for proliferative disease than for maculopathy. In NP DR, macular edema (most common)Q, exudates and capillary occlusions often cause blindness but affected patients usually maintain at least ambulatory vision. On the other hand, PDR may result in severe vitreous haemorrhage or retinal detachment, with hand movement vision or worst. Macular edema or retinal thickening (d/t fluid coming from leaking microaneurysm or diffuse capillary incompetence) Is an impoant manifestation of NPDR (early) and represents the leading cause of legal blindness in diabetics. Proliferative new leaking vessels usually arise from retinal veins and grow along the route of least resistance (eg disc b/o absence of true internal limiting membrane or shallowly detached posterior vitreous). It has long been assumed that sudden vitreous contractions tear the fragile new vessels, causing vitreous haemorrhage. However, most diabetic vitreous haemorrhages occur during sleep, probably b/o an increase in blood pressur secondary to early morning hypoglycemia or to REM sleepQ. Because so few haemorrhags occur during exercise, it is not necessary to restrict the activity of patients, with proliferative DR. Haemorrhage (RBC) behind posterior vitreous face settle quickly to the bottom of eye & are absorbed. Whereas when RBCs break into vitreous body, they adhere to get & clearing may take months or years.
Macular oedema
Vitreous haemorrhage
Subretinal haemorrhage
Retinal traction