1 / 98

Vision Loss

Vision Loss. KHADER M.FARWAN. Objectives. Review of eye anatomy Refine history and examination of the eye Work through emergent causes of sudden monocular vision loss in a case-based format. Spelling Review. Op h th a lmology. Anatomy Review. Function & transperancy. Anatomy Review.

kellsie
Download Presentation

Vision Loss

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Vision Loss KHADER M.FARWAN

  2. Objectives • Review of eye anatomy • Refine history and examination of the eye • Work through emergent causes of sudden monocular vision loss in a case-based format

  3. Spelling Review Ophthalmology

  4. Anatomy Review Function & transperancy

  5. Anatomy Review

  6. Anatomy Review • Eyelids • Tears • Cornea • Aqueous • Lens • Vitreous

  7. Anatomy Review • Retina • Fovea / “Macula” • Central retinal artery supplied by branch of ophthalmic artery (1st major branch of internal carotid)

  8. Anatomy Review • Optic nerve or retinal lesions do not respect vertical meridian • Defects that clear or start at vertical midline signify lesion at chiasm or beyond http://eyesite.ucsd.edu/viewpoint/images/glaucoma.jpg

  9. Vision Loss • Categorization • Total or Partial • One or Both eyes • Sudden or Gradual • Painful or Painless

  10. History • Question Danger Signs • How long ago? Recent • How sudden? Sudden: ischemia or bleed • Course? Worsening

  11. History • What do they see? • Flashes or floaters • “Curtain” rising or falling • Central patch or distortion • Key symptoms • Pain or headache • Nausea / Vomiting

  12. History • In addition to general Hx/Px: • Usual corrective glasses / contacts? Still in? • Previous transient episodes? • Trauma?

  13. Examination • Visual acuity • Visual field testing • Swinging light test • Direct ophthalmoscopy • Dilating the eye • Tonometry

  14. Examination • Visual acuity • Snellen chart • 20 feet distance • Credit for a line if most letters correctly identified • If acuity poorer than largest letter (eg 20/200), measure distance pt can read it (eg 5/200 at 5 feet)

  15. Examination • Visual acuity • Practically, if that poor, acuity described by • Finger-counting • Hand-motion • Light perception

  16. Examination • Visual acuity To correct refractive error: • Use pin hole • Use ophthalmoscope

  17. Examination • Visual field testing • Confrontation • With the patient looking at your nose, ask if your nose and other facial features are seen clearly • Inability to clearly see your: Nose => central scotoma Eyes or lips => paracentral scotoma Ears => peripheral visual field defect

  18. Examination • Swinging light test • Relative Afferent Pupillary Defect (RAPD) • See http://www.richmondeye.com/apd.htm • “Marcus-Gunn Pupil” • Significant retinal or optic nerve disease, in one eye more than the other • Very helpful for Ophtho to know in consult

  19. Examination • Direct ophthalmoscopy • Close as possible • Remove your glasses • Switch viewing eye • Start at zero correction • Or to correct observer refraction (eg – 4 diopters) • Rotate counter-clockwise for near-sighted pt Better use of the ophthalmoscope. Luff A, Elkington A. Practitioner. 236(1511): 161-5

  20. Examination • Direct ophthalmoscopy • Red Reflex • Compare brightness and color at 1-2 feet • Indicates media free of opacity • Not always easy to do, helpful if (N) • “Eight-ball” Vitreous hemorrhage • Move in along line of red reflex • Aim for opposite mastoid process • Often brings optic disc straight into view

  21. Examination • Direct ophthalmoscopy • Place free hand on forehead • Prevents facial contact • Resting own forehead on thumb stabilises image • Able to lift upper lid if necessary • Comfort • Encourage subject to keep breathing during examination • Sit patient up, avoid hunching

  22. Examination • Direct ophthalmoscopy • Use anti-glare filter • Try red-free filter for better vessel visualization

  23. Examination • Direct ophthalmoscopy • PanOptic Ophthalmoscope • Greater field of view • “5x larger view of fundus” • USD $400 range

  24. Anatomy Review Optic disc • Color: Yellow-orange, central cup whiter • Size: Cup less than half diameter of disc • Margin: Sharp (may be less sharp nasally) imc.gsm.com/integrated/ bcs/heent/page14.html

  25. Anatomy Review Fovea / “Macula” • Color: Slightly darker, devoid of retinal vessels • Size: Same as disc • Location: Temporal and slightly inferior to disc imc.gsm.com/integrated/ bcs/heent/page14.html

  26. Anatomy Review Vessels • Size: 3:2 Vein:Artery • Caliber: look for abnormal tortuosity • 4 main vascular arcades • Superior- & Inferior- • Nasal & Temporal Cilioretinal artery imc.gsm.com/integrated/ bcs/heent/page14.html

  27. Examination • Direct ophthalmoscopy • Four quadrant scan • Follow vessels to periphery (may need to re-focus) • Get pt to look at the light to see macula

  28. Examination • Dilating the eye • Especially important for suspected • Intraocular FB • Central retinal artery occlusion • Retinal detachment • Hesitancy amongst non-ophthalmologists

  29. Examination • Dilating the eye Tropicamide 1% Mydriasis and glaucoma: exploding the myth. A systematic review. Pandit RJ, Taylor R. Diabet Med. 2000 Oct;17(10):693-9 “Risk of inducing acute glaucoma following … tropicamide alone close is to zero, no case being identified” Near fatal anticholinergic intoxication after routine fundoscopy. Brunner GA, et al. Intensive Care Med. 1998 Jul;24(7):730-1.

  30. Examination • Dilating the eye Tropicamide 1% Contraindications: • Acute head injury/coma • Acute or intermittent angle-closure glaucoma (but NOT chronic open-angle glaucoma) • Probably anyone at high risk for above (eg. Older asian lady, severely far-sighted person)

  31. Examination • Dilating the eye Tropicamide 1% • Onset 10-15 mins, duration 4-6 h • Side effects: blurred vision, light sensitvity • Safety: must not drive for 6 h The effect of pupil dilation with tropicamide on vision and driving simulator performance. Potamitis, T., et al. Eye. 2000 Jun;14 (3A):302-6

  32. Examination • Tonometry Tonopen • Contraindicated if suspected ruptured globe • Ttono = 10 – 21 mm Hg (N) • False elevation IOP • Blepharospasm (“squeezers”) • Avoid pressure on the eye by holding eyelids only against bony orbital rim

  33. Case 1 SUDDEN, TOTAL LOSS, ONE EYE • 70 yo F with HTN, DM lost vision in one eye over a few minutes earlier this morning. • No trauma. No eye pain, or N/V • Findings: • (N) External eye and EOM, red reflex • (N) Acuity on left, only hand motion right • RAPD+ • (N) Fundoscopy unaffected eye

  34. Case 1 • Retina pale • “Cherry Red Spot” fovea • Splinter hemorrhage Clinical Eye Atlas

  35. Case 1 • Diagnosis? • Treatment? • Massage eyeball • Timoptic drops • Sticking a needle in the eye Clinical Eye Atlas

  36. Central Retinal Artery Occlusion • Sudden painless monocular loss of vision • May have history of previous transient episodes. “Amaurosis fugax” http://meded.ucsd.edu/isp/1994/im-quiz/images/crao.jpg

  37. Central Retinal Artery Occlusion • Retina infarction => pallor, edema, less transparency • Irreversible damage begins at 90 mins http://meded.ucsd.edu/isp/1994/im-quiz/images/crao.jpg

  38. Central Retinal Artery Occlusion • Macula, thinnest portion, remains visible • Cherry red spot may take 24 h to develop • Visual acuity may be normal if cilioretinal vessel patent http://www.umanitoba.ca/faculties/medicine/units/ophthalmology/tutorial_folders.html/images/Cra.jpg

  39. Central Retinal Artery Occlusion • Causes • Embolic (carotid, cardiac) • Thrombosis • Temporal arteritis • Vasculitis (eg. lupus) • Sickle cell disease • Trauma www.emedicine.com/emerg/ images/521crao1.JPG

  40. Central Retinal Artery Occlusion • Treatment Attempt moving embolus distally: • Digital massage • Firm steady pressure x 15 seconds, release, repeat • IOP lowering drugs • Beta-blockers/CAI/alpha-agonists… • +/- Vasodilation techniques • Rebreathing to increase PaCO2

  41. Central Retinal Artery Occlusion • Treatment • Consult ophthalmology immediately • Paracentesis anterior chamber • ?? HBO, thrombolytics • Locate source • ESR for temporal arteritis • ECG for A. fib • Medicine consult (Carotid doppler, ECHO?…)

  42. How to Tap an Eye Anterior chamber paracentesis • Administer local anesthesia • Use a 30-gauge needle on a tuberculin syringe • Enter the eye at the limbus with bevel up • Ensure that the needle does not damage the lens • Withdraw fluid until the anterior chamber shallows slightly (0.1-0.2 cc) • Administer a topical antibiotic post-procedure http://www.emedicine.com/oph/topic387.htm

  43. Central Retinal Artery Occlusion • Complications • Vision loss • Prognosis poor in most • But up to 10% retain central vision (acuity improves to 20/50 or better in 80% of those) • Recurrent thromboemboli • CVA • Further visual loss to same or contralateral eye • Progression of temporal arteritis

  44. Case 2 PARTIAL LOSS, ONE EYE • A 60 yo M with HTN and DM complains of progressive loss of vision in one eye over the last 2 days. • No other symptoms • Painless uniform dulling of vision. • Findings: • (N) External eye and EOM • Acuity 20/25 OD, 20/200 OS • RAPD+ • (N) Fundoscopy unaffected eye

  45. Case 2 How would you manage this at 2 AM? • Immediate ophtho consult • Thrombolytic therapy • Decrease the intraocular pressure • Globe massage to dissolve clot • None of the above Clinical Eye Atlas

  46. Case 2 Unmistakable fundoscopy: • “Blood and Thunder” or “Ketchup fundus” • Dilated tortuous veins • Flame hemorrhages • Disc edema Clinical Eye Atlas

  47. Central Retinal Vein Occlusion • Key facts • 10 times more common than CRAO • Painless monocular loss of vision over hours to days • Vision may improve through the day • ? CRV impingement by lamina or atherosclerosis of CRA • Ischemic vs. non-ischemic types

  48. Central Retinal Vein Occlusion • Risk Factors • Age > 50 • Diabetes • HTN • Hyperviscosity syndromes • Glaucoma • Recurrent amaurosis fugax http://www.umanitoba.ca/faculties/medicine/units/ophthalmology/tutorial_folders.html/images/CRV_occlusion

  49. Central Retinal Vein Occlusion Non-ischemic • Good vision • RAPD absent • Fewer retinal hemorrhages • Cotton-wool spots • May resolve fully or progress to ischemic type http://webeye.ophth.uiowa.edu/dept/crvo/fig12.htm

  50. Central Retinal Vein Occlusion Ischemic • Severe visual loss • RAPD+ • Extensive retinal hemorrhage and cotton-wool spots http://webeye.ophth.uiowa.edu/dept/crvo/fig12.htm

More Related