Ischemic Optic Neuropathy 1.pptx

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1. Ischemic Optic Neuropathy Dr. Sriniwas Atal MD Resident Ophthalmology BPKLCOS, IOM

2. LAYOUT 2 INTRODUCTION ANTERIOR ISCHEMIC OPTIC NEUROPATHY BLOOD SUPPLY OF OPTIC NERVE HEAD NA-AION A-AION PION Case Report REFERENCES

3. Introduction Acute, painless optic neuropathy due to circulatory insufficiency. > 50 years of age Most frequently at the optic nerve head (intraocular insufficiency), Anterior Ischemic Optic Neuropathy (AION) Less frequently behind the optic neve head ( intraorbital insufficiency ), Posterior Ischemic Optic Neuropathy (PION) 3

4. Anterior Ischemic Optic Neuropathy Most common cause of acute optic neuropathy in older age groups. Rapid onset of painless, unilateral visual loss. Decreased visual acuity, visual field, or both. 4

5. Non- Arteritic Anterior Ischemic Optic Neuropathy (NAAION) Arteritic Anterior Ischemic Optic Neuropathy (AAION) 5

6. Non-arteritic Anterior Ischemic Neuropathy (NAAION) 90-95% of AION Mean age - 60 yrs Less severe visual loss compared to Arteritic AION. Arcuate and altitudinal visual field defects. 6

7. RISK FACTORS Crowded optic disc “Disc at risk” Small optic disc plus small or absent cup Axonal crowding and compression 7

8. Blood supply 8

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10. Blood flow The blood flow in the ONH is calculated by using the following formula ( Hayreh et al): Perfusion pressure = Mean BP – Intraocular pressure (IOP) (Mean BP = Diastolic BP + 1/3 Pulse pressure) From this formula, it is evident that the blood flow depends upon (a) Resistance to blood flow, (b) BP and (c) IOP. 10

11. Autoregulation Helps compensate for any decrease in the blood flow. Operates only over a critical range of perfusion pressure. Rise or fall of perfusion pressure beyond the critical range leads to autoregulation failure. 11

12. RISK FACTOR-MULTIFACTORIAL Noctural arterial hypotension play very imp ortant role H’RGIC SHOCK V ASOS P A S TIC DISORDER C OLL A G E N V A SU L AR DS A B S ENT CUP R A ISED IOP PROLONG PRESSURE ON EYEBALL SMALL CUP S Y S TEMIC O CU L AR 12 Drugs - Sildenafil , Amiodarone , Cocaine

13. Pathophysiology 13

14. Clinical findings Typically presents as acute painless monocular loss of visual acuity or visual field, or both, frequently upon awakening. A relative afferent pupillary defect. Normal anterior segment. 14

15. Optic disc edema ( sectoral or entire disc) Nerve fibre layer hemorrhages associated with the disc edema Crowded optic disc in fellow eye. 15

16. Visual Field Defects 16

17. Differential Diagnosis Arteritic AION Optic Neuritis Infiltrative Optic Neuropathy Compressive Optic Neuropathy Diabetic Papillopathy Neuroretinitis Disk swelling associated with retinal disorders, such as central retinal vein occlusion (CRVO). 17

18. INVESTIGATIONS Routine investigations Lipid profile Cardiac evaluation ESR (rule out AAION) MRI (rule out Optic Neuritis, Compressive ON) 18

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20. Treatment None proven Aspirin Levodopa or carbidopa Hyperbaric O2 Topical - Brimonidine 20

21. Surgical treatment Ischemic Optic Nerve Decompression Trial (IONDT) Optic nerve sheath fenestration, with drainage of perineural subarachnoid cerebrospinal fluid. No effect of surgery on visual outcome. 21

22. Prognosis Improvement may take up to 6 months ~15% risk for fellow eye involvement in 2 years < 5 % risk for recurrent AION (the same eye) A significant visual field defect persists 22

23. Goal of Management Eliminating other potential treatable optic neuropathies such as optic neuritis or a compressive optic neuropathy. Identifying any potential modifiable vascular risk factors. 23

24. Arteritic Anterior Ischemic Optic Neuropathy 24 5-10% of AION Short posterior ciliary artery vasculitis Infarction of optic nerve head Commonly seen in elderly, mean age 70 yrs Severe visual loss in majority (<6/60)

25. >50% caused by Giant Cell Arteritis (GCA) Other etiologies include: Systemic Lupus Erythematosus Wegener’s Granulomatosis Behçet's disease Churg Strauss Syndrome Polyarteritis Nodosa 25

26. Giant Cell Arteritis Granulomatous necrotizing arteritis Mainly involves large and medium-size arteries : Major aortic branches Superficial temporal artery(STA) Ophthalmic artery Posterior ciliary arteries Proximal vertebral arteries. 26

27. Headache (most common) Jaw claudication ( pathognomic ) Temporal artery or scalp tenderness Malaise, Anorexia, Weight loss, Fever Superficial temporal arteritis is characterized by pulseless , thickened, tender, inflamed and nodular arteries. 27

28. 20% of GCA patients experience severe visual loss AION is the most common ophthalmic manifestation of GCA 30% have preceding transient visual loss ( amaurosis fugax ) 54% have visual acuity of counting fingers - No perception of light >50% second eye involved within hours - weeks When temporal arteritis is suspected as the cause of visual loss , treatment should not be delayed for results of laboratory investigations or biopsy to prevent blindness in fellow eye. 28

29. Optic disc pallor (pallid, chalky optic disc edema ) Choroidal ischemia may be seen - peripapillary pallor and edema deep to retina Disc of fellow eye is normal Cotton wool spots 29 Fundus Examination

30. CRAO Anterior Ischaemic syndrome Ophthalmic artery occlusion Delay in choroidal perfusion or non-perfusion PION can occur 30

31. Fluorescein fundus angiography In early stage shows filling defect in optic disc, peripapillary choroid or choroidal watershed area 31

32. INVESTIGATIONS Westergren sedimentation rate C-reactive protein (reliable indicator than ESR) Complete blood count Fluorescein angiography Temporal artery biopsy - ‘gold standard’ 2-3 cm specimen taken to avoid skip lesion 32

33. Treatment Steroids Methotrexate Aspirin Rheumatology consultation & follow-up 33

34. Regimen IV Methylprednisolone 1 g/day for 3 days. Followed by oral Prednisolone 1-2mg/kg/day for 3 days. Then 50-60mg/day (not less than 0.75mg/kg/day) for 4 weeks until symptom resolution and ESR/CRP normalisation. Then tapering by 10mg/day every 2 weeks until 20mg/kg. Tapering then titrated against ESR/CRP and symptoms. 34

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36. Posterior Ischemic Optic Neuropathy(PION) Uncommon No disc edema The mechanism of ischemia is presumed to be insufficiency of pial arterial vascular supply to the optic nerve distal to the optic nerve head. 36

37. Diagnosis Rule out other types of retrobulbar optic neuropathies, including traumatic, infiltrative, inflammatory, toxic, radiation, and compressive types. 37

38. CLINICAL FEATURES Sudden, painless unilateral or bilateral vision loss. Relative afferent pupillary defect in unilateral cases as well as in bilateral cases when the degree of vision loss is unequal between the two eyes. Normal disc at presentation. Optic disc atrophy ensues in 4-6 weeks. 38

39. Subtypes (Sadda et al) Arteritic PION ( associated with temporal arteritis ) Non- arteritic PION 39

40. Subtypes Within hours to days Mainly spinal , cardiac bypass s urgery PERIOPERATIVE Associated with GCA Poor visual prognosis ARTERITIC Same risk factor as NAION Not associated with crow d ed optic disc NONARTERITIC 40

41. Pathogenesis P ION D E C REASED OXYGEN CARRYING CAPACITY HY P O TENSION LEADS TO D E CREASED PERFUSION PRESSURE INCREASED RESISTANCE TO BLOOD FLOW 41

42. Non- arteritic PION Occurs following a variety of surgical procedures or is associated with systemic vascular disease. Spinal surgery, cardiac bypass surgery and heart or lung transplantation surgery. Intraoperative risk factors - hypotension, hypovolemia , hypoxia, anemia , and blood loss 42

43. INVESTIGATIONS Routine investigations ESR CT/MRI VEP - shows decreased amplitude 43

44. TREATMENT No effective treatment Steroid Aspirin IOP lowering agents Hemodynamic correction 44

45. Case of A-AION 45 A 77-year-old Chinese man complained of bilateral, simultaneous onset vision loss for 5 days, accompanied by severe headache on right side and jaw pain. The visual acuities were no light perception in both eyes.The bilateral superficial temporal arteries were palpable and tenderness.

46. 46 Fundus photographs at presentation of the patient showing severe bilateral optic disc swollen, with “chalky white” pallid appearance; there are splinter hemorrhage and cotton wool spots on the retina in the right eye. The choroid showing diffused atrophy around the optic disc

47. 47 The orbital fat-suppression T1-weighted magnetic resonance imaging with contract showing the enhancement of the optic nerve sheath in the right eye, (a):axial and (b): sagittal . The white arrows indicate the optic nerve sheath; the MRA of the cerebral vascular is unremarkable (c)

48. 48 The right temporal artery biopsy was performed and revealed the occlusion of the luminal owing to the intimal proliferation and infiltration Methylprednisolone 1 g/d was intravenousfor 3 days followed by prednisone 1 mg/kg/d. The vision acuity maintained NLP bilateral after treatment, whereas the headache and jaw pain disappeared. The oral prednisone was weaned and methotrexate was added as the immunosuppressive agent for long treatment.

49. Take Home Message ION is an ophthalmic emergency. Patients with GCA+ION are in danger of catastrophic, irreversible, bilateral blindness that may be prevented by prompt treatment with corticosteroids. Thus, any patient > 50 presenting with ION an immediate workup to rule out GCA. 49

50. There is no effective treatment for ION. Limited efficacy for prophylaxis. Aspirin 100mg daily. Control of cardiovascular risk factors. Suspect GCA !!! Avoid prolonged surgical time and dramatic shifts in body perfusion during surgrey . 50

51. References Walsh and Hoyt's  Clinical Neuro-ophthalmology, 6 th edition. Volume 3. Myron Yanoff and Jay S. Duker . Ophthalmology, 5 th edition 2019. Elsevier. Albert and Jakobiec’s , Miller, Azar , Bloo Principle and Practice of Ophthalmology. Volume III. Elsevier. AAO. Basic and clinical science course. Neuro-ophthalmology .Volume 5, 2019-20 Tian et al. BMC Ophthalmology (2018) 18:282 https ://doi.org/10.1186/s12886-018-0953-5 51