Approach to the Patient with Decreased Vision Flashcards
how many degree of central vision does the Amsler grid test
20 degrees (10 degrees radius from fixation)
what do the different roman numerals in a Goldmann perimetry test indicate
Size of stimulus object 0: 1/16 mm^2 I: 1/4 mm^2 II: 1 mm^2 III: 4 mm^2 IV: 16 mm^2 V: 64 mm^2
degrees of visual field tested in Goldmann perimetry
60 degrees from fixation in every direction except 90 degrees from fixation temporally
thresholds for reliability in static perimetry
25% false positives, 25% false negatives
good office test to distinguish between optic v retinal causes of visual loss
photostress testing (will be delayed in macular but not optic nerve dysfunction)
Name the visual field defect:
- involves fixation only
- extends from fixation to blind spot
- involves a region next to but not involving fixation
- involves a region symmetrically surrounding but not involving fixation
- central scotoma
- cecocentral scotoma
- paracentral scotoma
- pericentral scotoma
Ddx for optociliary shunt vessels
chronic papilledema, optic sheath meningioma, old CRVO, chronic glaucoma
symptoms in IIH
headache that improves with lying down, nausea, TVOs, diplopia (from abducens nerve palsy), pulsatile tinnitus
drugs that can cause elevated ICP
tetracyclines, OCPs, steroid use or withdrawal, cyclosporine, vitamin A and its derivatives, lithium
tests to order for all patients with expected increased ICP
MRI, MRV, LP
treatment for IIH
weight loss, acetazolamide. can use topiramate or furosemide as well. surgery includes ONSF (this helps protect ON from further damage but will not treat headache or affect ICP), and CSF shunting procedure (better for treating headache and lowering ICP but complications include infection, occlusion, need for re-operation)
ICP cutoff to diagnose IIH
> /= 25 cm H2O of opening LP pressure in lateral decub, for adults
% female and % obese in adult IIH
90% each
differences between adult and pediatric IIH
peds: affects boys more. usually not obese. often do not have headache. may have multiple cranial neuropathies
compare/contrast AAION and NAION in age, sex, presenting symptoms, visual acuity, disc appearance, FA findings, natural history, and treatment
- mean age: AAION 70, NAION 60
- sex: AAION F>M, NAION F=M
- Sx: AAION- TVOs, headache, jaw claudication, scalp tenderness, weight loss, fatigue, myalgias. NAION- none
- disc: both swollen, but AAION pale and NAION hyperemic. also, cotton wool spots w/ AAION. C/D 20/200 60% NAION
- FA: delayed choroidal filling for AAION; disc delay for both
- progression: fellow eye involvement 54-95% AAION and 12-19% NAION
- Tx: systemic steroids for AAION. nothing with proven benefit for NAION
what are Foster-Kennedy syndrome and pseudo-Foster Kennedy syndrome
Foster-Kennedy syndrome: intracranial mass compressing one optic nerve and causing elevated ICP, leading to an ipsilateral pale nerve and contralateral swollen nerve
pseudo-Foster Kennedy syndrome: NAION occurring in fellow eye, with previous eye pale and affected eye swollen and hyperemic
risk factor for NAION
small c/d, HTN, HLD, DM
differentiate NAION and optic neuritis
- age: NAION >50, optic neuritis M
- VF defect: altitudinal for NAION, central for ON
- disc edema: 100% NAION and pale, 35% ON and may be hyperemic
- retinal heme: common NAION, rare ON
- FA: delayed disc filling NAION, normal ON
- MRI: optic nerve enhancement with ON but not NAION
70 yo diabetic p/w blurred vision OS. disc is swollen and hyperemic OS with dilated vasculature but no leakage into vitreous on FA. remainder of fundus exam is normal. enlarged blind spot on HVF. diagnosis?
diabetic papillopathy
70 yo diabetic p/w blurred vision OS. disc is swollen and hyperemic OS with dilated vasculature but no leakage on FA. remainder of fundus exam is normal. diagnosis?
diabetic papillopathy
28 yo otherwise healthy female p/w blurred vision OD. vision 20/30, no RAPD, color normal. VF shows blind spot enlargement. disc is swollen with dilated, tortuous veins and scattered flame heme. FA shows circulatory slowing without regions of occlusion. diagnosis and work up?
papillophlebitis (basically a mild CRVO in young healthy patient that should resolve with little or no sequelae in 6-12 months). Can consider hypercoaguability work up
T or F regarding optic disc drusen:
- rarely affect nonwhites
- equal sex prevalence
- bilateral in 50%
- secondary neovascularization can occur in rare cases
- RAPD may be present
- visual acuity often is affected
- can cause vessel obscuration at the disc margin
- hyperemia and dilation of surface microvasculature can occur
- can produce visual field defects
- can be detected on B-scan and OCT
- autofluoresce on FA
- can cause disc leakage on FA
- usually become more visible over the years
- true
- true
- false; b/l 75-86%
- true
- true
- false; acuity rarely affected
- false; vessel obscuration suggests disc edema and not drusen
- false; these findings can occur with certain causes of disc edema but not drusen
- true (example: nasal step)
- true
- true
- false; disc leakage suggests disc edema
- true
differentiate disc drusen from astrocytic hamartomas involving the disc
astrocytic hamartomas begin at disc margin and extend into peripapillary retina, they arise in deeper layer of retina and thus typically obscure disc vessels, they may have a fleshy/pink color, they do not autofluoresce, and they may show tumor-like vascularity on FA
acute, severe, painless monocular vision loss in 20 yo male. disc appears hyperemic and elevated but does not leak on FA. peripapillary telangiectasias are present and there is tortuosity of the medium sized retinal arterioles. diagnosis, inheritance, workup, and treatment
Leber hereditary optic neuropathy. mitochondrial inheritance but only affects males (possible protective effect of estrogen). If no family history, should order MRI to eval for optic neuritis or mass. no treatment has been proven beneficial
most common position for point mutation in LHON? worst prognosis? highest rate of spontaneous improvement?
11778 most common and worst prognosis. 14484 best chance of spontaneous recovery. 3460 is other location
most common hereditary optic neuropathy? gene and chromosome? when does it present? classic disc finding?
autosomal dominant optic neuropathy. OPA gene, chromosome 3, involved in mitochondrial membrane integrity. 1st decade of life. cookie-cutter temporal atrophy
bilateral small and grayish appearing optic discs. MRI reveals absence of septum pellucidum: diagnosis, other findings, and management
septo-optic dysplasia (aka de Morsier syndrome). may have pituitary hypoplasia, with dwarfism from decreased growth hormone most common. requires endocrine consult
bilateral optic nerve hypoplasia with symmetrical inferior altitudinal VF defect: diagnosis and etiology
superior segment hypoplasia, caused by maternal diabetes