DIABETIC RETINOPATHY

SOUMIK SEN MB140039

PROLIFERATIVE DIABETIC RETINOPATHY Proliferative diabetic retinopathy affects 5-10% of the diabetic population. Type 1 diabetics are particularly at risk with an incidence of about 60% after 30 years of onset of diabetes. Therefore it is more common in patients with juvenile onset diabetes.

PATHOGENESIS Occurrence of neovascularization is the hallmark of PDR. It occurs over the changes of NPDR. Caused by angiogenic growth factors elaborated by hypoxic retinal tissue in an attempt to revascularize hypoxic retina. These substances promote neovascularization on the retina and the optic head and occasionally on the iris. VEGF, placental growth factor and pigment epithelium derived factor appears to be of particular importance. It usually occurs along the course of major temporal retinal vessels.

DIAGNOSIS NEOVASCULARIZATION AT DISC: Describes neovascularization on or within one disc diameter of the optic nerve head. NEOVASCULARIZATION ELSEWHERE: Describes neovascularization along the course of the major vessels. FLUORESCENT ANGIOGRAPHY: Highlights the neovascularization during the early phases and shows hyper fluorescence due to leakage of dye from neovascular tissue.

NEOVASCULARISATION AT THE DISC (NVD)

NVD

NEOVASULARISATION ELSEWHERE (NVE)

NEOVASCULARISATION AT THE IRIS (NVI)

NEOVASCULARISATION AT THE IRIS

NEOVASCULAR GLAUCOMA

VITREOUS CHANGES

VITREOUS HAEMORRHAGE TRACTIONAL RETINAL DETACHMENT

FURTHER CLASSIFICATION OF PDR On the basis of high risk characteristics(HRCs) described by the diabetic retinopathy study(DRS) group, PDR can be further classified into: 1. EARLY NVD OR NVE PDR without HRCs (EARLY PDR). 2. PDR with HRCs.

HIGH RISK CHARACTERISTICS NVD 1/4TH TO 1/3RD of disc area with or without vitreous hemorrhage or pre-retinal hemorrhage. NVD <1/4TH disc area with vitreous hemorrhage or pre-retinal hemorrhage. NVE >1/2 disc area with vitreous hemorrhage or pre-retinal hemorrhage.

DIABETIC MACULOPATHY

Most common cause of visual impairment in diabetic patients, particularly type 2. Diffuse retinal edema is caused by extensive capillary leakage and localized edema is caused by focal leakage from microaneurysms and dilated capillary segments. The fluid is initially located between outer plexiform and inner nuclear layers; later it may also involve the inner plexiform and the nerve fibre layers, until eventually the entire thickness of the retina becomes edematous.

WHY IS DIABETIC MACULAR EDEMA SO IMPORTANT? The macula is responsible for central vision. Diabetic macular edema may be asymptomatic at first. As the edema moves in to the fovea (the center of the macula) the patient will notice blurry central vision. The ability to read and recognize faces will be compromised.

CLINICO-ANGIOGRAPHIC CLASSIFICATION OF DIABETIC

MACULOPATHY 1. FOCAL EXUDATIVE MACULOPATHY 2. DIFFUSE EXUDATIVE MACULOPATHY 3. ISCHAEMIC MACULOPATHY 4. MIXED MACULOPATHY

FOCAL EXUDATIVE MACULOPATHY SIGNS: Micro aneurysm, hemorrhages and well circumscribed macular edema and hard exudates arranged in a circinate pattern. FA: Focal area or hyperfluorescence due to leakage and good macular perfusion.

DIFFUSE EXUDATIVE MACULOPATHY SIGNS: Diffuse retinal edema and thickening throughout the posterior pole with relatively few hard exudates. FA: Extensive hyper fluorescence at the posterior pole due to leakage.

ISCHAEMIC MACULOPATHY It occurs due to microvascular blockage. SIGNS: micro aneurysms, dot and blot hemorrhage, mild or no macular edema and few hard exudates. FA: capillary non perfusion at the fovea and frequently other areas of capillary non-perfusion at the posterior pole and periphery.

CLINICALLY SIGNIFICANT MACULAR EDEMA

It is diagnosed if one of the following three criteria are present on slit lamp examination with 90D lens. 1. Thickening of the retina at or within 500 µm of the center of the fovea. 2.Hard exudates at or within 500 µm of the center of the fovea, if associated with thickening of the adjacent retina. 3.Area of retinal thickening 1 disc diameter or larger in size, within 1 disc diameter of the center of the fovea.

CSME

Retinal oedema within 500 microns of centre foveaHard exudates within 500 microns of fovea if ass with adjacent retinal thickening

Retinal oedema > 1 disc diameter, any part is within 1 disc diameter of centre of fovea

ADVANCED DIABETIC EYE DISEASE Serious vision-threatening complications of DR. Occurs in pts who have not had laser therapy or in whom laser photocoagulation has been unsuccessful. Complication:1. Persistent vitreous hemorrhage2. Tractional retinal detachment3. Opaque membrane formation4. Neovascular glaucoma Treatment: Pars plana vitrectomy. Poor prognosis

MICROANEURYSMS

DOT AND BLOT HEMORRHAGE

HARD EXUDATES

COTTON WOOL SPOTS

VENOUS BEADING

IRMA