Functional Visual Loss - Swedish

Neuro-ophthalmic Consultants Northwest

Functional Visual Loss

Steven R. Hamilton, M.D. Neuro-ophthalmology

Swedish Neuroscience Institute Seattle, WA


Malingering versus conversion disorder

• Malingering – Willfully misleading the existence or

seriousness of a disease for secondary gain (financial)

• Conversion disorder (previously hysteria) – Subconscious expression of symptoms without

organic findings – Precipitated by psychological stress or trauma

(eg. sexual abuse)


Common functional presenting complaintsKeltner et al., Ophthalmol 1985;92:428

• Blurred vision" " " 74/84 "(88%) • Headaches" " " 26/84 "(31%) • Miscellaneous complaints" 15/84 "(18%) • Decreased peripheral vision" 10/84 "(12%) • Binocular double vision" 9/84 " (11%) • Change in color vision"" 6/84 " (7%) • Monocular double vision" 6/84 " (7%)


Factitious abnormalitiesKeltner et al., Ophthalmol 1985;92:428

– Decreased visual acuity 61/84 (73%) – Abnormal visual fields 43/84 (51%) – Decreased near vision 24/84 (29%) – Abnormal color vision 17/84 (20%) – Other 14/84 (17%) – Abnormal stereo acuity 6/84 (7%) – Voluntary nystagmus 2/84 (2%)

How do you approach the patient suspected of functional

visual loss?


Total binocular blindness

• Observation of patient’s movement in office • Signature • Proprioceptive maneuvers • Menace reflex • Pupillary responses • Optokinetic nystagmus

– Positive OKN: visual acuity at least 20/200 – Can be suppressed by patient

• Mirror tracking


OKN drum demonstration


Mirror tracking


Total monocular blindness

• No RAPD (afferent defect) • Patch good eye and test

– OKN response – Mirror tracking

• Fogging of good eye at phoropter • 10 prism diopter base out prism test


Total monocular blindness

• Color tests – Red/green duochrome with projector – Polaroid glasses and vectographic slides – Worth 4-dot test

• Stereoscopic tests – 40 seconds of arc compatible with 20/20 acuity


Red/green duochrome testing


Stereoscopic Titmus test


Sudden visual loss in right eye

• 19-year-old woman with sudden total loss of vision OD at home

• Followed by severe headache without visual recovery

• Head scan normal at local ER • Family history of migraines


Neuro-ophthalmic exam

• Visual acuity" " NLP"" " 20/20 • Pupils" " " Normal" " Normal • Stereo acuity" " 40 seconds of stereopsis • Motility"" " Normal" " Normal • Fundus" " " Normal" " Normal • GVF" " " No response" Normal


Diminished acuity (monocular or binocular)

• Toothpaste refraction • Vary visual angle (10 vs 20 feet) • Multiple lenses adding to plano • May need to rely on visual fields

accompanied by normal objective examination


Blurry vision in left eye

• 14 year-old boy with visual loss OS after boxing match

• Struck behind left ear prior to visual loss • Patient briefly dazed without

unconsciousness • Vision OS has remained blurry for 1 week



• Visual acuity" " 20/20" " 20/200 • Near acuity" " 20/20" " 20/800 • Color plates" " Full" " " None • Pupils" " " Normal" " Normal • Motility"" " Normal" " Normal • Fundus" " " Normal" " Normal


Fogging at the phoropter

• Binocular visual acuity with +5.00 lens OD and plano OS = 20/25


Binocular visual field defects

• Normal binocular VF = 180 degrees wide • True monocular blindness

– Loss of temporal crescent of blind eye • Functional monocular blindness

– Full visual field seen • Functional bitemporal hemianopia

– Narrow island of vision • Binasal hemianopia

– Usually from optic nerve/retinal disease


“I have progressive visual loss”

• 51-year-old woman with lupus on multiple medications

• Decreased acuity thought secondary to maculopathy or optic neuropathy

• Mild disturbance of rod and cone function on ERG



• Visual acuity" " 20/70" 20/70 • Color vision" " Solids" Solids • Pupils" " " Normal" Normal • Fundus" " " Normal" Normal


The importance of repeat testingFirst set of HVF

Second set of HVF



Monocular visual field defects

• Tunnel fields at tangent screen • Spiraling isopters • Crossing isopters • Monocular temporal hemianopia that

persists with binocular testing


Tangent screen

• Still very useful (underutilized) • Plots the central 30 degrees of VF • For paracentral scotomas, malingering • Test at 1 and 2 meter distances


Tangent screen


Spiraling isopters


Overlapping isopters


Hysterical hemianopia


“My vision is blurry with headaches”

• 16-year-old girl 6 weeks post-partum • History of premature labor • Blurry vision for 2 years • Constant headaches with occasional tunnel

vision



• Visual acuity" " CF" " CF • Color vision" " Control" Control • Pupils" " " Normal" Normal • Motility"" " Normal" Normal • Fundus" " " Normal" Normal


“I am not seeing well after my surgery”

• 54-year-old woman s/p bilateral blepharoplasties

• Hx amblyopia OD (BA 20/400) • Pre-op acuity OS was 20/25+ • Mild post-operative swelling OU



• Visual acuity" " HM" " 20/400 • OKN responses" Normal" Normal • Color vision" " None"" Solids • Pupils" " " Normal" Normal • Fundus" " " Normal" Normal


Humphrey visual field OS


Goldmann visual fields


Differential diagnosis of constricted visual fields

• End-stage glaucoma • Occipital strokes • Optic disc drusen • Retinitis pigmentosa • Chronic papilledema • Conversion disorder/malingering


“I have a problem with my vision”

• 39-year-old man with poor peripheral vision • Frequent headaches • History of hypertension



• Visual acuity" " 20/25+" 20/20 • Color plates" " Full" " Full • Pupils" " " Normal" Normal • Motility"" " Normal" Normal


Conditions misdiagnosed as functional visual loss

• Amblyopia • Keratoconus • Cone-rod dystrophy or RP sine pigmento • Central serous chorioretinopathy • Early Stargardt’s disease • Chiasmal tumor • Cortical blindness


Progressive visual loss with headaches

• 8-year-old girl with one year history of headaches

• Failed school eye exam in September • Subsequently seen by 3 ophthalmologists • Vision progressively failed, then stabilized • Initially thought to be functional,

subsequently Stargardt’s diagnosed



• Visual acuity" " 20/200" 20/400 • Color vision" " Control" Control • Pupils" " " Normal" Normal • Motility"" " Normal" Normal • SLE" " " Normal" Normal • Fundus" " " Normal" Normal


Other forms of functional eye disease

• Monocular diplopia (check pinhole acuity) • Functional dyschromatopsia or micropsia • Voluntary gaze palsies • Voluntary blepharospasm • Functional ptosis • Ocular Munchausen’s syndrome


“My right eye went numb”

• 26-year-old woman with numbness of right face with ptosis

• No diplopia or headache • Weak legs and fainted twice


Evaluation and workup

• Normal exam aside from ptosis • Normal CT scan, MRI/MRA scans • Normal lumbar puncture results • Normal cerebral angiogram!


Voluntary nystagmus

• Irregular, rapid frequency, horizontal pendular eye movements

• 8% of normal people can do this • Usually bilateral and conjugate • Poorly maintained longer than 10-20

seconds • May be familial


Convergence spasm

• Episodes of convergence with miosis, accommodation, and induced myopia

• Key findings – Pupils constrict on attempted lateral gaze

• Treatment difficult with patching, atropine, bifocals


Pupils with convergence spasm


“I see double after my injury”

• 58-year-old man with closed head injury • Normal CT scan, minimal MRI findings • Currently patching one eye • Disabled from work



• Visual acuity" " 20/25" 20/25 • Color vision" " Normal" Normal • Pupils" " " Normal" Normal • Cover test" " Variable esotropia • Fundus/VF" " Normal" Normal


The fixed, dilated pupil

• If isolated, usually not a true emergency! • Differential

– Pharmacologic blockade – Adie’s pupil – Third nerve palsy

• Testing with 0.1% and 1% pilocarpine


“My left pupil won’t stop being dilated”

• 21-year-old construction worker • CaCl pellet in left eye at work • Treated for mild chemical conjunctivitis OS • Left eye remained dilated since ER visit 3

weeks previously



• Visual acuity" " 20/15" 20/15 • Color plates" " Full" " Full • Motility"" " Normal" Normal • Fundus" " " Normal" Normal


0.1% pilocarpine trial


1% pilocarpine trial


The California SyndromeKeltner et al., Ophthlamol 1985;92:427-435

• 84 patients with functional visual loss – 59 adults, 25 children

• 90% afferent visual system abnormalities • 53% had organic problems with functional

overlay • Adults

– 86% had a monetary secondary gain


Establishing functional abnormalitiesKeltner et al., Ophthalmol 1985;92:429

• Inconsistent visual fields" " 56/84 "(65%) • Repeat examination" " " 40/84 "(47%) • Testing at varying distances" " 11/84 "(13%) • Normal stereoacuity" " " 7/84 " (8%) • OKN with NLP or HM acuity" 4/84 " (5%) • Monocular loss

– Normal pupil exam 17/18 (95%) – Polaroid or red/green slide test 8/18 (44%)


Treatment and natural history of functional visual loss

• Emphasize the normal aspects of the exam • Avoid confrontation if possible • 27-55% of patients demonstrate a chronic

course • Beware of the coexistence of organic and

functional disease!

Functional Visual Loss - Swedish

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