RETINAL VASCULAR DISEASES

1. RETINAL VASCULAR DISEASES Dr. Sinan Tatlıpınar

2. Objective • Most systemic diseases have ocular signs and symptoms and that serious sequele may result from these diseases. • It is important to know when it is appropriate to refer a patient to an ophthalmologist for consultation or treatment.

7. RETINAL VASCULAR DISEASES • Diabetic retinopathy • Retinal vein occlusion Branch Central • Retinal artery occlusion Branch Cilioretinal Central • Hypertensive retinopathy • Sickle-cell retinopathy • Retinopathy of prematurity • Retinal telangiectasias • Retinal artery macroaneurysm • Radiation retinopathy

8. A frequent cause of blindness in patients aged 20-64 years. The prevalence of all types of retinopathy in the diabetic population increases with the duration of diabetes and patient age. Diabetic retinopathy is rarely found in children younger than 10 years of age, regardless of the duration of diabetes. The risk of developing retinopathy increases after puberty. After 20 years of diabetes, nearly 99% of patients with type 1 and 60% with type 2 have some degree of diabetic retinopathy. DIABETIC RETINOPATHY

9. DIABETIC RETINOPATHY-Pathogenesis • Increased platelet adhesiveness • Increased erythrocyte aggregation • Abnormal serum lipids • Defective fibrinolysis • Abnormal levels of growth hormone • Upregulation of vascular endothelial growth factor (VEGF) • Abnormalities in serum and whole blood viscosity

10. DIABETIC RETINOPATHY-Pathogenesis

11. Consequences of retinal ischemia

12. DIABETIC RETINOPATHY-Adverse risk factors • Long duration of diabetes • Poor metabolic control • Pregnancy • Hypertension • Renal disease • Other Obesity Hyperlipidemia Smoking Anemia

13. DIABETIC RETINOPATHY-Stages • Nonproliferative diabetic retinopathy (NPDR) • Microaneurysms, dot-and-blot hemorrhages, hard exudates, retinal edema, dilation and beading of retinal veins, intraretinal microvascular abnormalities (IRMA), nerve fiber layer infarcts,arteriolar abnormalities, and areas of capillary nonperfusion • Mild,moderate,severe,very severe • Proliferative diabetic retinopathy (PDR) Neovascularization on the optic disc or elsewhere on the retinal surface, vitreous hemorrhage and tractional retinal detachment Early, high-risk, advanced

14. Conditions Associated With Potential Visual Loss from Diabetic Retinopathy • Sequelae from ischemia-induced neovascularization • Diabetic macular edema • Ischemic macularchanges

15. Consequences of chronic leakage

16. Location of lesions in nonproliferative diabetic retinopathy (NPDR)

23. Treatment • Laser photocoagulation • Intravitreal steroid and/or anti-VEGF injections • Pars plana vitrectomy

24. Central Retinal Vein Occlusion (CRVO) • Dilated and tortuous retinal veins, a swollen optic disc, intraretinal hemorrhages and retinal edema. • 90% patients are older than 50 years at the time of onset. • Systemic associations include: systemic arterial hypertension diabetes mellitus open-angle glaucoma • Ischemic and non-ischemic types.

25. Central Retinal Vein Occlusion (CRVO) • Thrombosis of the central retinal vein at and posterior to the level of the lamina cribrosa. • An atherosclerotic central retinal artery may impinge on the central retinal vein, causing turbulence, endothelial damage, and thrombus formation.

26. Branch Retinal Vein Occlusion (BRVO) • Superficial hemorrhages, retinal edema, cotton-wool spots (nerve fiber layer infarcts)in a sector of retina drained by the affected vein. • The mean age of patients at the time of occurence is in their sixties. • Risk factors for the development of BRVO: History of systemic arterial hypertension Cardiovascular disease History of glaucoma Increased body mass index at 20 years of age.

27. Branch Retinal Vein Occlusion (BRVO) • Common adventitia binds the artery and the vein together at the arteriovenous crossing and that thickening of the arterial wall compresses the vein, resulting in turbulence of flow, endothelial cell damage, and thrombotic occlusion.

28. Central Retinal Artery Occlusion (CRAO) • Sudden, severe, painless loss of vision. • CRAO is often caused by atherosclerosis-related thrombosis occuring at the level of the level of the lamina cribrosa. • Studies in the nonhuman primates have suggested that irreversible damage to the sensory retina occurs after 90 minutes of complete CRAO. • The leading cause of death in patients wih retinal arterial obstruction is cardiovascular disease.

29. Branch Retinal Artery Occlusion (BRAO) • Occlusion at any site is a result of embolization or thrombosis of the occluded vessel. • Three main varieties of emboli are recognized: Cholesterol emboli arising in the carotid arteries Platelet-fibrin emboli associated with large-vessel arteriosclerosis Calcific emboli arising from diseased cardiac valves

30. Hypertensive Retinopathy • Systemic arterial hypertension is defined as a minimum diastolic pressure of 90 mm Hg or a minimum systolic pressure of 140 mm Hg. • Modified Scheie Classification of Hypertensive Retinopathy: Grade 0 No changes Grade 1 Barely detectable arterial narrowing Grade 2 Obvious arterial narrowing with focal irregularities Grade 3 Grade 2 plus retinal hemorrages and/or exudate Grade 4 Grade 3 plus disc swelling

31. Sickle-cell Retinopathy • Sickle cell hemoglobinopathies are most often seen in the black population. • Sickle cell ocular abnormalities are caused by intravascular sickling, hemolysis,hemostasis and thrombosis. • Nonproliferative sickle cell retinopathy • Proliferative sickle cell retinopathy

32. Retinopathy of Prematurity (ROP) • Normal retinal vascularization proceeds from the optic disc to the periphery and is complete in nasal quadrants at approximately 36 weeks of gestation and on the temporal side at 40 weeks. • Current understanding of ROP is incomplete • Exposure to excessive concentrations of oxygen, low birth weight, short gestational period increase the risk of developing the disease. • At least two dilated fundoscopic examinations using binocular indirect ophthalmoscopy for all infants with a birth of 1500 g or with a gestational age of 28 weeks or less, as well as for selected infants between 1500 and 2000g with an unstable clinical course who are believed to be at high risk by their attending pediatrician is recommended.

33. Retinopathy of Prematurity (ROP)

34. Retinopathy of Prematurity (ROP) • ROP is a transient disease in the majority of infants, with spontaneous regression occuring in 85% of eyes. • Associated conditions: Myopia with astigmatism Anisometropia Strabismus Amblyopia Cataract Glaucoma Retinal detachment

35. Idiopathic Juxtafoveolar Retinal Telangiectasis • Clinically apperent retinal telangiectasis and ectasia of the capillary bed, confined to the juxtafoveolar region of one or both eyes, may result in vision loss from capillary incompetence and exudation. • Histopathologic evidence suggests that this is not a true telangiectasia but rather consists of structural abnormalities similar to diabetic microangiopathy, with deposits of excess basement membrane within the retinal capillaries.

36. Retinal Macroaneurysm • Retinal arterial macroaneurysms are acquired retinal vascular abnormalities. • They are associated with systemic arterial hypertension in about two thirds of cases.

37. Radiation Retinopathy • Ionizing radiation from external beam radiography or local sources (radioactive eyewall plaques) can induce a retinopathy that closely resembles diabetic retinopathy clinically and pathologically. • Treatment for intracranial, orbital, nasopharyngeal, and cutaneous tumors may lead to radiation retinopathy. • Radiation retinopathy results from damage to the endothelial cells of the retinal blood vessels.