Acute Vision Loss

1. Acute Vision Loss Dan Mayer, MD Professor of Emergency Medicine Albany Medical College

2. Introduction - True emergencies • Immediate ophthalmologic evaluation: • Central retinal artery occlusion • Retinal detachment • Next day ophthalmologic evaluation: • Central retinal vein occlusion • Branch artery occlusion • Vitreous hemorrhage • Maculopathies • Other causes (toxins and trauma)

3. Anatomy of Vision - Normal visual axis/anatomy of the eye

4. Anatomy of Vision - Normal visual axis/anatomy of the eye

5. Anatomy of Vision - Anatomic Classification • 4. Macula/Retina • a) Macula-photopic vision • b) Peripheral fields scotopic vision • c) Anterior chamber • 5. Lens • Brain • Optic nerve • Blood vessels • Ophthalmic artery • Choriocapillaris • Central retinal artery • Cileoretinal artery

6. Examination for Vision Loss • Visual acuity • Pupillary reaction • Marcus-Gunn Pupil • Irregular pupil • Anterior chamber • Ophthalmoscope • Slit lamp

7. Examination for Vision Loss • Fundus – indirect and direct ophthalmoscopy • Direct examination as a screening tool • Indirect examination to better see peripheral retina • Extra ocular motion • Cornea

8. Central Retinal Artery Occlusion • Total painless monocular vision loss • May be preceded by brief transient episodes • Caused by micro emboli

9. Causes of Central Retinal Artery Occlusion • Atherosclerotic plaque in the carotid • Embolus from a cardiac valve • Systemic vascular disease • Hyperviscosity syndromes • Trauma – fat emboli • Oral contraceptives • Systemic diseases – DM, syphilis, sickle cell disease • Injections of medications around the head and neck • Temporal arteritis • Drug abuse

10. Examination for CRAO • Visual acuity – finger counting, light perception, or nothing • Pupillary reaction – consensual but not direct\ • Fundus – pale with dark veins and narrow arteries • Fovea intact – cherry red spot • ‘Box car’ appearance of retinal arteries

11. Treatment of CRAO • Relief of vasospasm – increase pC02 by: • Paper bag rebreathing • Breathe a mixture of 95% 02 and 5% C02 • Attempt to dislodge clot – direct occular massage • Acetazolamide or mannitol IV. Aspirin and acetazolamide continued for two weeks • Immediate ophthalmologic consultation for anterior chamber paracenteses • Anesthetize lens • 27G needle – corneal limbus at 4 & 7 o’clock • Allow 2 - 3 drops of aqueous to escape

12. Outcomes of CRAO • Low success rate - 35% achieve any useful vision • Check sed rate – (if over 50 in person over 50) = steroids • Branch artery occlusion • Amaurosis fugax • “flight blindness” • “curtain coming down” • Transient unilateral vision loss • Platelet-fibrin emboli from ulcerated/stenotic carotid • “Hollenhorst plaques” • Examination • May be normal • Check for carotid bruits, cardiac murmers, or dysrhythmias • Treatment • Follow up with neurologist or internist • Interval treatment with aspirin and dipyridamole

13. Retinal Detachment - Pathophysiology • Separation of the outer retinal pigment epithelium from the inner sensory layer • Fluid accumulation between the layers causes the separation

14. Retinal Detachment - classification • Rhegmatogenous – most common; caused by breaks in the retina • Liquid into the hole with enough force to separate the layers of the retina • Hole caused by vitreous collapse • Also caused by degeneration of the retina • Other intrinsic defects • Traction – pulling force on the retina creates a subretinal space without a tear • From fibrous vitreo-retinal bands • From diabetic neuropathy or old trauma • Exudative – chorioretinal vessel leak

15. Causes of Retinal Detachment Rate is 10 per 100,000 people per year • More common in men • Average age 56 years • Bilateral in up to one third • Associates with: • Degenerative myopia – related to degree of myopia • Aging with lattice degeneration of the vitreous • Aphakia – post cataract surgery • Absence of the lens (aphelia), diabetes, sickle cell disease, toxemia of pregnancy, severe kidney disease, trauma with up to 40 year latency after the trauma

16. Clinical Features of Retinal Detachment Gradual or total loss of vision • Cloudy or smoky vision – shadow or curtain • Flashes of light-photopsia, or floaters • Visual acuity normal until macula is involved Examination • Fundoscopic examination with indirect ophthalmoscope • Grey retina with folds and abnormal choroidal pattern • Holes, tears or undulating appearance of the retinal vessels Always check other eye

17. Treatment of Retinal Detachment Surgical treatment in rhegmatogenous detachment: • Seal holes with lasers or cryotherapy cautery • Scleral buckle or banding • External drainage of subretinal fluid • Bed rest with elevation of the head Visual recovery is time dependent • Depends on whether and for how long the macula is involved • If pre-op 20/50 or better, 90% same or better • If macular sparing, 80% got 20/50 or better • Macular involvement causes rapidly decreasing vision at first then slower loss • Only 2% of macular involved cases got back to 20/20

18. Pathophysiology of Central Retinal Vein Occlusion • Vision loss more gradual than that seen with Retinal Artery Occlusion • Degenerative disease of the venous endothelium • External compression • Venous stasis • Ischemic vs. non-ischemic types • Non-ischemic has benign clinical course • Ischemic – 50% go on to develop blindness

19. Causes of CRVO • Atherosclerotic vascular disease • Arterial hypertension • Diabetes • Hyper viscosity • Open angle glaucoma, trauma, closed angle glaucoma, vascular hypertension • 6. Painless monocular visual loss • Branch occlusion-partial vision loss • Preceded by transient decrease in vision • Blurred vision getting better throughout the day

20. Differential diagnosis CRVO • Diabetes • Blood dyscrasias • Congenital tortuosity • AVM and retinal vascular angiomas • Papilledema • Pseudotumor cerebrii • Congenital heart disease • Shaken baby syndrome

21. Examination of CRVO Visual acuity – near normal or markedly decreased Visual fields – central or peripheral field cut Funduscopic examination: • Engorged venules • Retinal hemorrhages • Retinal edema • “Blood and thunder” fundus – large and small hemorrhages and cotton wool patches

22. Treatment of CRVO Treat underlying disease No proven treatment but spontaneous resolution common Laser photocoagulation to prevent neovascularization Ischemic CRVO

23. Pathophysiology Vitreous Hemorrhage May start in retinal vessels, choroid or ciliary body Visual loss depends on the amount of bleeding • Minor – “floaters” • Moderate – black streaks/black dots • Major – profound painless visual loss Blood clots rapidly and sinks in 1-3 days

24. Causes of Vitreous Hemorrhage Proliferative retinopathy • Diabetic – 34-40% • Sicle cell – 1% Retinal tear – 12-22% Rhegmatogenous retinal detachments – 6-15% Vein occlusion – 10-13% Posterior vitreous detachment – Up to 12%\ Intraocular lens – Up to 3% Miscellaneous – Up to 7% • Trauma • Hypertension Retinal detachment – Up to 10% Idiopathic – Up to 7%

25. Examination Vitreous Hemorrhage • Anterior chamber cells and flare • Rubeosis iridis – vessels on anterior iris • Red reflex absent or decreased • Retinal details not seen • Color of hemorrhage from red to black to white • Hemorrhage may appear as dispersed blood, sheets, or focalized ‘clots’ • Ultrasonography to detect if retinal tear is present

26. Treatment of Vitreous Hemorrhage • Bed rest with elevation of the head • Photocoagulation • Surgery • Clears in days to weeks depends on size and recurrence • Complications – glaucoma and connective tissue proliferation

27. Pathophysiology Maculopathy • Destruction of the macula • Causes • Inflammatory • Bacterial • Viral • Portozoan • Autoimmune • Degenerative • Primary – genetically determined • Secondary – trauma, radiation, vascular disease, inflammation and other degenerative disorders • Macular degeneration of aging – most common cause of blindness in elderly • Retinal Drusen

28. Maculopathy • Hemorrhagic – Retinal Hemorrhage • Trauma, vascular, obstruction, vasculitides, neovascularization, degeneration of the retina, and high myopia • Systemic causes – Diabetes, hypertension or blood dyscrasias • Visual loss depends how much macula is involved • Involvement away from the macula – floaters • Pain or heaviness of the eye with anterior chamber involvement • May present with gradual loss of vision; metamorphopsia – straight lines appear curved; micropsia – objects appear smaller than they are • Sudden painless loss of vision if hemorrhage Diabetic retinopathy

29. Examination Maculopathy Fundoscopic examination depends on etiology of inflammation • Exudation and inflammatory cells in the vitreous • Inflammation destroys the retinal pigment epithelium the choroid appears bright red Visual acuity is best test for macular involvement Hemorrhagic type of maculopathy, shape=site SITEDESCRIPTION Superficial retina Large meniscus Superficial nerve fiber layer Linear Substance of retina Punctate Layer between retina and choroid Large and red Pigment layer Large and dark

30. Maculopathy • Lab – Skin testing for histo and tbc, CF testing, viral titres including HIV, and HLA typing • Treatment • Inflammatory – treat underlying inflammation • Photocoagulation in some cases of hemorrhage • Treatment directed to the underlying disease

31. Toxins • Neurogenic toxicity to the ganglion cells of the retina, optic nerve fibers, or secondary vascular disturbance • Causes • 400 medications which have toxic effects on vision • Accidental or intentional • Methanol • Quinine • Ergot derivatives • Salicylate • Complications of therapy • Cisplatinum • Combined endocrine agents • Combined antihypertensives • Deferoxamine • Ergot derivatives • Hexamethonium • Parenteral steroids

32. Methanol Toxic metabilites – formate act on the optic nerve • General symptoms – Mausea, vomiting, abdominal pain, headache, dizziness, delerium, stupor and coma • Visual disturbances ‘like a snowstorm’ • Sudden with permanent complete blindness • Impaired pupillary light reflex and accomodation • 24 hours for fundoscopic examination to become abnormal – then get hyperemia of the disk, retinal edema and engorgement of retinal vessels • Management • Ethanol level to 100mg% • Dialysis • Bicarbonate therapy

33. Quinine Cinchona alkaloid • Cinchonism – flushed diaphoretic skin, visual disturbances, tinnitus, headache, confusion, delerium. Coma, seizures, nausea, vomiting, diarrhea, hypotension, and cardiac conduction abnormalities • 42% had visual disturbances • Sudden loss or deterioration of vision bilaterally • Constricted visual fields, scotomata, night blindness, decreased color perception, and photophobia • Dilated unreactive pupils, with normal or pale optic nerve atrophy • Mild poisoning – reversible • Severe poisoning – some residual • Permanent blindness if there is vasospasm

34. Ergot Derivatives • Poisoning – ingestion of large amounts of produce abortion • Alpha adrenergic blocker and direct stimulation of peripheral and cranial blood vessel smooth muscles • Headache, vomiting, diarrhea, dizziness, hypotension, hypertension, drowsiness, convulsions, and coma • Reduced vision and constriction of peripheral field • Pupils are dilated and poorly reactive to light • Fundi Normal, or slight edema with narrowing of the retinal arteries • Treatment is with usual poisoning treatment and vasodialtors. Loss is usually reversible

35. Salicylates • Vision loss and tinnitus • Direct toxicity to the ganglion • Decreased vision, headache, tinnitus, dizziness, decreased hearing, confusion • Nystagmus, dilated pupil which is reactive, and with constricted visual field • Fundus is normal or with constricted arteries • Treatment – alkalinization of the urine, and dialysis in severe overdose – recovery is the rule

36. Optic Neuritis • MS most common cause – 13 to 36 % • 27 – 37 % of MS patients will get it • Retrobulbar pain • Other causes • Tobacco-alcohol amblyopia (nutritional cause) • Vision loss with central scotoma and retrobulbar pain • Collagen vascular disease or parachiasmal meningioma • Examination • Marcus-Gunn Pupil • Fundus is usually normal • When optic nerve involved – blurred, hyperemic, elevated, and may look like papilledema • Usually unilateral, more decreased vision than in papilledema • CBC, Sed rate, Glucose, CT of the head, LP, MRI (test of choice for MS) • Treatment • Gradual partial improvement • Steroids and ACTH may speed resolution

37. Migraines • Retinal migraines cause spasm of the retinal artery • Examination – will be normal or show some pale retina with macular sparing • Treatment – standard treatment for migraines (Thorazine/Thorazine-DHE/Metoclopramide-Naproxyn)

38. Temporal Arteritis • Muscle aches and pains, recurrent headache, and jaw claudication, and systemic symptoms such as fever, weight loss and anemia • Marcus Gunn pupil and engorged disk with dilated capillaries • Tenderness over the temporal artery may not be present • Suspect in any patient over 50 years of age • Lab workup includes CBC, Glucose, Sed rate, VDRL, fibrinogen, and lipid survey • Treat empirically if any suspicion and elevated sed rate • Use of steroids can result in sparing of vision • Use 60mg of prednisone • Treat before results of biopsy are available

39. Hyphema and other trauma • Retinal detachment & vitreous hemorrhage • Commotio retinae (edema) • Complications – pain, photophobia, acute and chronic glaucoma, blood staining of the cornea, vitreous bleed, hemophthalmitis, inflammatory reaction • Grading of hyphemas • I – 1/3 of anterior chamber is filled • II – 1/3-1/2 filled • III- over ½ filled Edwards 1973 – 184 patients with unilateral hyphema • Age: 1-61 with mean age of 12 years • Complications: 35% - rebleed, 52% return of 20/50 or better vision. Complication rate higher if rebled • Rebleed rate and return of vision depends on grade Spontaneous bleed Grade % Rebleed % Return ≥ 20/50 I 23 80 II 35 70 III 65 30

40. Examination of Eye Trauma Slit lamp examination – anterior chamber blood CT scan or ultrasound of the globe Periodic reevaluations as the blood clears to check for retinal tears Treatment – Gorn 1979 • Aspirin increases the rate of bleeding • Put the eye at rest with sedation and elevation of the head • Dilatation decreases the rate of rebleeding • Small hyphemas with very reliable patients, home rest with patching and close follow up

41. Complications of Trauma Rebleeding with the formation of secondary glaucoma or pigment staining of the cornea with visual loss Delayed retinal detachment – 80% seen within two years of the trauma and usually with ora serrata tears. Require surgical treatment – scleral banding

42. Hysteria • Functional rather than organic disorder • Subconscious expression of nonorganic signs or symptoms • Usually very little insight is present • Examination • Normal pupillary reaction and fundus • Red/green glasses test • Opticokinetic nystagmus response • Magic drop test

43. QUESTIONS?