Posterior Seg

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Posterior Seg
2013-02-23 18:22:01
Ocular Disease

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  1. Differentiate between drusen at the ONH and papilledema
    • Drusen: calcified material (detected with B-scan), have scalloped margin, surface vessels are not obscured, absence of hyperemia, normal spontaneous venous pulse
    • Papilledema: increased intracranial pressures (MRI), ONH margin is feathery
  2. ONH disorders that are at risk of developing retinal detachments?
    • 1. Congenital Pits of ONH (deep pit in ONH looks grayish, adjacent retina is elevated)
    • 2. Morning Glory Disc
  3. ONH disorders with visual field defects?
    • 1. Drusen in ONH
    • 2. Congenital optic nerve hypoplasia
    • 3. Congenital coloboma (larger blind spot)
    • 4. Demyelinating optic neuritis (diffuse or arcuate)
  4. ONH with pupil defects?
    1. Congenital optic nerve hypoplasia (afferent pupil defect)
  5. Differentiate between megalopapilla and glaucoma
    • Megalopap: normal NFL, could follow ISNT rule, normal IOP
    • Glaucoma: VF affected, high/normal IOP
  6. Define optic neuritis
    inflammatory, infectious, or demyelinating process affecting nerve
  7. Types of optic neuritis
    • 1. Retrobulbar neuritis -disc normal, adults affected, often with MS (demyelination)
    • 2. Papillitis -ONH swollen, hyperemia/edema, flame hemorrhages, children affected
    • 3. Neuroretinitis -ONH swollen and NFL affected, less common, viral infection NOT demyelinating disease
  8. Treatment for optic neuritis
    • Intravenous methyprednisolone (steroid) 3 days followed by oral prednisolone 11 days
    • -delays MS, speeds recovery but does not improve long term VA
    • -Oral steroids alone doubles optic neuritis recurrance
  9. Causes of infectious optic neuritis (neuroretinitis)
    • -sinus related
    • -cat scratch fever
    • -syphilis
    • -lyme disease
    • -cryptococcal (meningitis in AIDS Px)
    • -varicella zoster
  10. Non-arteritic anterior ischemic optic neuropathy (NAION)
    • -occlusion of short posterior ciliary arteries -> infarction of ONH
    • -middle-aged/elderly Px with smaller optic discs**, systemic HTN, diabetes, collagen vascular disease, high blood lipids, cat surgery
    • -Most common cause of optic nerve-related visual loss in elderly
    • -sudden, painless monocular vision loss
    • -diffuse disc edema and splinter hemorrhages
    • -altitudinal VF defect (frequently inferior)
  11. Drugs causing toxic optic neuropathies
    • 1. alcohol and tobacco usage
    • 2. ethambutol -TB Tx
    • 3. Amiodorione -Cardiac arrhythmia Tx (also causes vortex keratopathies)
    • 4. Methotrexate -autoimmune Tx (ie. arthritis)
    • 5. Tamoxifen -breast cancer therapy
  12. Stage of papilledema with no visual Sxs, normal VA, disc hyperemia with slight elevation, indistinct disc margins, loss of spontaneous venous pulse (only 20%)
    • early papilledema
    • -if pulse is present, papilledema is unlikely. Absent pulse does NOT meat raised intracranial pressure
  13. Stage of papilledema where you see severe disc hyperemia, moderate elevation, optic cup and small vessles obscured, hemorrhages
    • established
    • -also have transient vision obscurations and VA is normal or reduced
    • -indistinct disc margins
  14. Stage of papilledema with variable VA, marked disc elevation, no hemorrhages or CWS
  15. Stage of papilledema with severe vision loss, and gray-white disc with slight elevation
  16. Progression of papilledema
    • 1. Early -flattening (cup disappears), partial halo
    • 2. Advanced -complete halo around disc, increased disc swelling
    • 3. End-stage -severe disc edema, vessels crossing disc obscured (because NFL is opacified)
  17. Tx for benign intracranial pressure with ONH involvement (papilledema)
    • 1. Diuretics (CAI disrupt CSF production, corticosteroids reduce ICP inflammation)
    • 2. Surgery of optic nerve sheath fenestrations to allow fluid drainage or surgery with lumbar peritoneal shunt to drain CSF from lower spine to abdomen lowering brain pressure
    • 3. weight loss and reduce salt intake
  18. Explain how fundus autofluorescence works
    • -low excitation wavelength stimulates lipofuscin autofluroescene to monitor RPE integrity
    • -hyperfluorescence = RPE dysfunction, early in disease
    • -hypofluorescence = PR loss, later in disease
  19. Classic triad of signs in retinitis pigmentosa
    • 1. retinal bone-spicule pigmentation
    • 2. arteriolar attenuation
    • 3. waxy disc pallor
  20. Potential macular changes associated with retinitis pigmentosa
    • 1. cystoid macular edema (70%)
    • 2. atrophy
    • 3. epiretinal membrane
    • 4. cysts and bulls eye
    • 5. choroidal neovascularization
  21. Diagnostic tests for retinitis pigmentosa
    • 1. subnormal EOG (light peak absent)
    • 2. ffERG (reduced scotopic response then photopic response)
    • 3. VF (superior pheripheral VF/small scotomas then classic rind scotoma and island of central vision)
    • 4. fluorescein angiography (atrophy and smaller vasculature and CME)
    • 5. fundus autofluorescence (RPE and PR atrophy)
    • Retinitis puncta albescens
    • AR progressive retinal dystrophy concentrated in equatorial area sparing the macula.
    • Maintain good VA until >50yo, abnormal ERG
    • Mx: low vision aids, counseling
    • Sector retinitis pigmentosa
    • RP in bilateral inferior quadrants asymmetrical
    • -reduced VF in superior, nyctalopia ~20yo
    • -slow progression until ~50yo
    • -Mx: low vision aids, counseling
  22. Risk factors for age related macular degeneration
    • 1. smoking (promotes oxidative damage and vasoconstriction)
    • 2. cardiovascular disease (elevated plasma cholesterol with wet AMD)
  23. Dry AMD
    • -more common (90% of AMD Px)
    • -nonexudative
    • -have drusen (due to impaired transport and phagocytosis of nutrients, O2 and waste products)
    • -may have geographic atrophy (end stage, PR death due to drusenoid pigment epithelium detachment)
    • -can progress to wet AMD
  24. Wet AMD
    • -more severe vision loss (due to drusenoid pigment epithelial detachment)
    • -exudative (choroidal neovascularization into subretinal space blurs and distorts central vision) -> vessels leak blister-like subretinal fluid
    • -fibrosis -> impedes transport of nutrients -> PR death -> loss of central vision
  25. Type 1 choroidal neovascularization
    • -in wet AMD when new vessels continue to grow under RPE
    • -hidden from fluorescein angiography
  26. Type II choroidal neovascularization
    • -CNV vessels leak between RPE and Bruch's membrane and breaks into subretinal space
    • -still hidden from fluorescein angiography
  27. Management of ARM?
    • Early- yearly dilated fundus exam
    • Dry AMD -lifestyle and diet (green leafy vegs and NO smoking)
    • Intermediate/advanced -ARED formula (zinc, antioxidants, betacarotene -contraindicated for smokers)
    • Wet AMD Classic subfoveal CNV -photodynamic therapy (vision improves or stabilizes)
  28. contraindications/side effects of AREDS (Age-Related Eye Disease Study) formula for treating AMD
    • -consult physician if Px is taking an anticoagulant before giving vit E
    • -lots of stomach upset
    • -contraindicated for smokers
  29. Define Angiogenesis
    • capillaries form from existing blood vessels, controlled by VEGF
    • -Anti-VEGF drugs are used to inhibit CNV growth in wet AMD
  30. pegaptanib (Macugen)
    • -anti-VEGF ocular injection for wet AMD Tx
    • 27% greater change of avoiding moderate vision loss
  31. bevacizumab (Avastin)
    -Tx for colon cancer, off label usage as an anti-VEGF drug for wet AMD
  32. ranibizumab (Lucentis)
    • -anti-VEGF drug (modified version of Avastin with higher affinity -smaller Ab penetrates all retinal layers)
    • -monthly ocular injection
    • -can reverse visual loss
  33. squalamine lactate (Evizon)
    • -natural aminosterols that are administered as an ocular injection for cancers and wet AMD
    • -shows stabilized or improved vision
    • Leber congenital amaurosis -salt and pepper appearance
    • -mental retardation, deafness, seizures, skeletal abnormalities, renal/muscular abnormalities
    • -nystagmus, sluggish pupillary response, oculodigital sign, light sensitivity, blindness
    • -Mx: pedigree and genetic counseling, low vision, block short wavelengths to minimize photophobia
    • -poor prognosis as disease targets outer nuclear and PR layers
  34. Congenital diseases that cause retinitis pigmentosa?
    • 1. Usher disease
    • 2. Leber Congenital Amaurosis
  35. How to differentiate between choroideremia and retinitis pigmentosa?
    -choroideremia has large patches of RPE atrophy as opposed to RP which has bone spicules
    • Choroideremia
    • -progressive degeneration of the RPE, choroid, and choriocapillaris
    • -late optic atrophy and BV attenution
    • -CNV can occur at fovea
    • -Sxs: nyctalopia, light sensitivity, constricted VF
    • Gyrate atrophy
    • -inherited metabolic disorder of gene encoding ornithine degradation enzyme
    • *Note: transitions between atrophic zones are abrupt unlike choroideremia
  36. Both Stargardt disease and fundus flavi are characterized by subretinal yellow pisciform flecks at the RPE. What is the difference between Stargardt disease and fundus flavi?
    • -fundus flavi tends to have later onset than Stargardt
    • -Stargardt affects the MACULA and posterior pole whereas fundus flavi affects everywhere else!

  37. Your 30 yo Px's fundus images OD and OS are as follows. Px has 6/60 VA, decreased central vision, and peripheral vision is intact. What is your diagnosis?
    • Early Stargardt disease
    • -because it's a bilateral macular degeneration (meaning it's hereditary) with yellow pisciform flecks
    • -early because peripheral vision is intact
  38. You believe your 15yo Px has Stargardt Disease, the most common hereditary macular degeneration. You want to evaluate the macular function to determine how far the disease has progressed. What is the best test to evaluate macular function?
    • mfERG
    • -you will be able to detect the decrease in the amplitude of foveal response before visual acuity is even affected
  39. Management of Stargardt Disease or Fundus Flavi?
    • -no effective Tx
    • -sun protection
    • -monitor proression
    • -monitor for development of CNV
    • -counseling and low vision aids

  40. Your Px has the following fundus images and OCT.
    • Best Vitelliform Disease, Phase 2
    • -hereditary maculopathy
    • -typical "egg yolk" lesion, a well-circumscribed yellow lesion located under the RPE
  41. Your 20yo Px has 6/12 and some pseudohypopyon that is classic of Best Disease. You want to do additional tests to test for Best Disease. What additional diagnostic test could be done on your Px?
    • EOG and ERG (EOG is abnormal and ERG is normal in Best Disease)
    • Arden Ratio (is reduced <1.8 in Best Disease)
  42. Your 20yo Px has 6/12 VA and the following fundus appearance.
    • Best Disease, Phase 4
    • -an autosomal dominant, slowly progressive maculopathy
    • -typical scrambled egg appearance -lesion and cysts break apart and scatter throughout posterior pole
  43. Eales Disease
    • -Idiopathic bilateral perivasculitis (vein sheathing -> nonperfusion -> edema) mostly affecting veins associated with¬†mycobacterium tuberculoprotein hypersensitivity
    • -men, 20-30yo
    • -anterior uveities and/or vitritis, floaters, edema, vitreous hemorrhage, RD, ME
    • -Tx: vitrectomy (vitreous hem), photocoagulation (ME)
  44. Behcet disease
    • recurrent systemic occlusive vasculitis
    • -increased HLA-B5
    • -ulcers, erythema nodosum, polyarthritis, GI lesions
    • -bilateral inflammation (iridocyclitis, retinitis, periphlebitis, ON edema, vitritis)
    • -Tx: topical and periocular sterior, cyclosporin immunosuppressant, plasma exchange
  45. Acute retinal necrosis syndrome
    • vasculitis or peripheral arteries of retina and choroid associated with Herpes
    • -occlusive vasculitis, vitreous inflammation, progressive retinal necrosis
    • -Tx: acyclovir, aspirin, systemic steroids, laser
  46. Frosted branch angiitis
    • bilateral (occassionally unilateral) venular periphlebitis (stasis and occlusion) due to immuosuppression or Heres
    • -rapid vision loss
    • -Mx: retinal consultant, oral prenisolone 80mg/day with taper, IV steroids (if severe), monitor for neovascularization
  47. Stages of sickle cell retinopathy
    • Non-proliferative:
    • 1-peripherial arterial occlusion
    • 2-arterio-venous anastomoses (joining because of occlusions)
    • Proliferative:
    • 3-neovascularization and sea fan configuration
    • 4-vitreous hemorrhage
    • 5-fibrovascular proliferation and retinal detachment
    • Non-proliferative and proliferative sickle cell retinopathy
    • -NP: venous tortuosity, salmon patches (superficial retinla hem), sunburst lesions (RPE hyperlasia), angioid streaks
    • -Pro: anastomoses, neovascularization and hem, fibrotic scaffolding
  48. How does ROP most commonly develop?
    • -incomplete vascularized temporal retina due to oxygen damage in pre-term infant (temporal retina is most susceptible because bvs are not developed until 1 mth after delivery)
    • -risk factors: low birth weight, prematurity, oxygen supplementation
  49. Coats disease
    • -unilateral, most severe form of retinal telangiectasis
    • -~5yo males
    • -severe vision loss, affects MACULA, retinal detachment, glaucoma
  50. Using IVFA, how is ischemic BRVO classified?
    • 5DD of non-perfusion detected on IVFA
    • **You need to watch if BRVO Px goes from perfused to non-perfused (ischemic) state. Primary care doctor must be involved (complete examination, carotid artery assessment, and hyperviscosity assessment) because systemic cause.