Hypertensive Retinopathy

Description about HTN retinopathy

1. HYPERTENSIVE RETINOPATHY Reeta Karki B Optom , 2 nd year 1

2. INTRODUCTION Hypertension , also known as high blood pressure, is a  long-term medical   condition in which the blood pressure  in the arteries is persistently elevated .  High blood pressure usually does not cause symptoms .  It is, however, a major risk factor for  stroke,   coronary artery disease, heart failure . HTN affects the eye causing 3 types of ocular damage: Retinopathy Choroidopathy O ptic neuropathy It represents ophthalmic findings of end-organ damage. 2

3. In United States, HTN , affects > 65 million Americans, 25% of all adults 60% of > 60 years are hypertensive Nepal : 34% of elderly persons affected Nearly 1% of hypertensive patients develop malignant hypertension Men are affected more than women until age 50 when women have a higher prevalence Sharma SS et al . P revalence o f Hypertension , Obesity , Diabetes and Metabolic syndrome in Nepal . Int J Hypertens . 2011; 2011: 821971 3

4. In the Beaver Dam Eye Study, which evaluated hypertensive patients without coexisting vascular diseases, the incidence of hypertensive retinopathy was about 15%. 8% showed retinopathy, 13 % showed arteriolar narrowing, and 2% showed arteriovenous nicking. Diagnosing systemic hypertension from ophthalmic findings on examination was only 47–53% 4

5. Relationship of hypertensive vascular changes with arteriosclerotic vascular disease. It is complex and related to: Duration of HTN Severity of dyslipidemia Smoking history Age of patient 5

6. Average time required to develop retinopathy was 6.73 yrs Significantly higher in >50 yrs hypertensive patient Higher in those with duration of HTN more than 5 yrs Mondal RN, Matin MA, Rani M, Hossain ZM, Shaha AC, et al. (2017) Prevalence and Risk Factors of Hypertensive Retinopathy in Hypertensive Patients. J Hypertens 6: 241. doi:10.4172/2167-1095.1000241 6

7. The major risk for arteriosclerotic hypertensive retinopathy is the duration of elevated BP. The major risk factor for malignant hypertension is the amount of BP elevation over normal. Ocular changes in malignant hypertension can be Disc edema C horoidal infarction, and Retinopathy . Changes from chronic hypertension are more subtle, affecting primarily the retinal vasculature. 7

8. 8

9. Blood V essels Anatomy 9

10. Few Anatomical C onsiderations Retinal arteries are histologically arterioles with 100 μ m caliber , with no internal lamina or muscular coat . Retinal arterioles & capillaries exhibit autoregulatory mechanism and tight junction to maintain blood-ocular barrier . The resistance of flow is equivalent to fourth power of luminal diameter . Features of retinal arterioles Lumen – 8 to 15 μ m Media – 1 to 2 layer of smooth muscle cells Adventitia - poorly developed 10

11. Features of retinal arteries Diameter of major branches -100 μ m Intima – single layer endothelial cells with no internal elastic lamina Media – 5 to 7 layers of smooth muscle cells near optic disc, 2-3 layers in equator, 1-2 in periphery Adventitia - thin 11

12. Features of choroidal arteries Diameter – 20 to 90 μ m Intima – endothelium, internal elastic lamina Media – single layer of smooth muscles Adventitia Features of choroidal arterioles Intima – internal elastic lamina absent Media – layer of smooth muscle discontinuous Adventitia – very less connective tissue 12

13. 13

14. Pathogenesis Vasospasm Vasospasm of retinal arterioles occur in young patients, & affected by pre-existing involutional sclerosis in older one. Vasospasm of choroidal vessels & peripapillary choroid> ischaemia > HTN choroidopathy & HTN optic neuropathy. 2. Arteriosclerotic changes Increased vascular permeability 4. Raised intracranial pressure 14

15. 15

16. Clinical features Benign or chronic HTN retinopathy Malignant HTN retinopathy 16

17. Benign or Chronic HTN Retinopathy HTN with involutionary sclerosis Comprise augmented arteriosclerotic retinopathy 2. Chronic HTN with compensatory arteriolar sclerosis Albuminuric or renal retinopathy 17

18. Fundus changes in HTN retinopathy Generalized arterial narrowing a . Vasoconstrictive phase : Due to diffuse vasospasm characterised by increased in retinal arteriolar tone . b. Sclerotic phase : Cause due to hypoplasia of tunica media, hyaline degeneration & characterised by increased arteriolar narrowing with tortuosity . 18

19. 2 . Focal arteriolar narrowing: seen within ½ disc diameter of its margin zone . 3. Arteriovenous nicking Salu’s sign : deflection of vein at arteriovenous crossings Bonnet sign : banking of vein distal to AV crossing Gunn sign : tapering of veins on either side of crossings . 19

20. 20 SALUS SIGN

21. 4 . Arteriolar Reflex C hanges Bright and thin, linear blood reflex seen because of blood column in arteriole, as vessel wall is transparent . More diffuse and less bright reflex due to thickening of vessel wall, representing grade I & II HTN retinopathy Copper wiring, reddish brown reflex due to progressive sclerosis and hyalinization, sign of grade III . Silver wiring, opaque-white reflex due to continued sclerosis, seen in grade IV HTN retinopathy. 21

22. 22 Retinal arterioles appear orange or yellow instead of red (copper wiring), If become occluded (silver wiring)

23. 5. Superficial retinal haemorrhages Due to disruption of capillaries in RNFL layer. Disappear in 3-5 weeks . 23

24. 6. Hard Exudates Lipid deposits in OPL of retina due to leaky capillaries Appear as yellowish waxy spots with sharp margins . Disappear in 3-6 weeks. 24

25. 7. Cotton wool spots Fluffy white lesions, are the infarcts of RNFL layer . Termed as soft exudates caused by capillary obliterations in severe HTN retinopathy. 25

26. Malignant hypertensive retinopathy Acute HTN Retinopathy Marked arteriolar narrowing due to spasm of arteriolar wall. Superficial retinal haemorrhages in posterior pole Focal intraretinal periarteriolar transudates due to deposition of macromolecules lead to breakdown of blood retinal barrier following dilatation of arterioles. Cotton wool spot more marked. Microaneurysms , shunt vessels & collaterals 26

27. Acute hypertensive choroidopathy Acute focal retinal pigment epitheliopathy, due to ischaemic change in choriocapillaries characterised by focal white spots. Elschnig’s spot formed due to clumping & atrophy of infarcted pigment epithelium. They are small black spots surrounded by yellow halos. Siegrist streaks formed due to fibrinoid necrosis. Serous neurosensory retinal detachment due to accumulation of fluid beneath retina. 5. Manifest as exudative bullous retinal detachment with shifting subretinal fluid. 27

28. 3. Acute hypertensive optic neuropathy Disc edema and haemorrhages on disc & peripallary retina. Disc pallor 28

29. KEITH & WAGENER STAGING OF HTN RETINOPATHY 29

30. 30

31. MODIFIED SCHEIE CLASSIFICATION 31 STAGING OF RETINOPATHY CHANGES GRADE 0 NO CHANGES GRADE 1 BARELY DETECTABLE ARTERIAL NARROWING GRADE 2 OBVIOUS ARTERIAL NARROWING WITH FOCAL IRREGULARITIES GRADE 3 GRADE 2 PLUS RETINAL HAEMORRHAGES & EXUDATES GRADE 4 GRADE 3 PLUS DISC SWELLING

32. STAGING OF LIGHT REFLEX CHANGES GRADE 0 NORMAL GRADE 1 BROADENING OF LIGHT REFLEX WITH MINIMAL AV COMPRESSION GRADE 2 LIGHT REFLEX CHANGES & AV CROSSINGS CHANGES MORE PROMINENT GRADE 3 COPPER WIRE APPEARANCE & MORE PROMINENT AV COMPRESSION GRADE 4 SILVER WIRE APPEARANCE & SEVERE AV CROSSING CHANGES 32

33. MITCHELL WONG CLASSIFICATION 33

34. Ocular Complications of Hypertension Branch retinal vein occlusion Central vein occlusion 34

35. Central retinal artery occlusion Branch artery occlusion Ocular Complications of Hypertension 35

36. Differential Diagnosis High altitude retinopathy Diabetic retinopathy Radiation retinopathy Retinal vein occlusion 36

37. Treatment and Outcome Diagnosis of malignant hypertensive crisis represents a medical emergency. Untreated mortality rate is 50% at 2 months and 90% at 1 year. Treatment of malignant hypertensive retinopathy, choroidopathy , and optic neuropathy consists of lowering blood pressure in a controlled fashion to a level that minimizes end-organ damage 37

38. Too rapid decline can lead to ischemia of the optic nerve head, brain, and other vital organs Medications used to treat hypertensive emergencies include sodium nitroprusside , nitroglycerin, calcium channel blockers, beta blockers, and angiotensin-converting enzyme inhibitors 38

39. Lifestyle modification Reducing weight, alcohol consumption, salt intake Increased activity level is recommended Reducing stress Adopting Dietary Approach to Stop Hypertension (DASH) Increase in calcium and potassium intake 39

40. Summary Understanding hypertension and its ocular sequela is important. Its direct effects on the retinal vessels may indicate the severity and chronicity of hypertension in patients. Hypertensive retinopathy predicts CHD in patient independent of blood pressure and other risk factor. Counseling patients to control their blood pressure optimally will benefit not only the overall management of their ocular conditions but more importantly protect them from life-threatening cardiovascular and cerebrovascular conditions. 40

41. References American Academy of Ophthalmology. Section 12- Vitreous and Retina Kanski JJ. Clinical Ophthalmology-A Systemic Approach. 9th ed. ELSEVIER Yanoff M, Duker JD. Ophthalmology. 3rd edition Comprehensive Ophthalmology, Ak Khurana 41

42. 42