he had suffered from intermittent headache for 2 months and had taken benzodiazepines and analgesics under the diagnosis of somatoform disorder at a local clinic .
he had a 5-day history of diplopia and a 3-day history of blurred vision that progressed to blindness during the preceding 24 hours . on admission
his blood pressure was 130/70 mmhg , pulse rate was 82/min , respiratory rate was 20/min , and body temperature was 36.3. on neurologic examination the patient was alert and exhibited no meningeal signs .
only light perception was possible in both eyes , but no other neurological abnormality was noted .
lumbar puncture showed the opening pressure of 160 mm h2o with clear cerebrospinal ( csf ) fluid .
csf evaluation showed 30 red blood cells / mm , 80 white blood cells / mm , 80% lymphocytes , 41 mg / dl glucose , and 114 mg / dl protein .
his body temperature increased to 38.8 1 day after admission , but cbc revealed no leukocytosis .
brain mri showed no meningeal enhancement , parenchymal lesion , or intracranial vascular abnormality supplying the optic nerve , optic chiasm , or optic tract .
the results of fundoscopic examinations were unremarkable , and visual evoked potential showed no wave formation on bilateral pathways ( fig .
an india ink smear of the csf demonstrated encapsulated yeast , and cryptococcus neoformans was cultured ( fig .
he was found to be seropositive for hiv with a high antibody titer ( 53.87 s / co ) .
he was treated with both antiretroviraland antifungal agents , and his visual acuity had improved upon discharge .
neuro - ophthalmic lesions are present in 6% of patients with hiv infection during the course of the disease , with most of them being are attributable to cryptococcal meningitis.3 cryptococcus neoformans , the cause of cryptococcal meningitis , is the fourth most common source of life - threatening infection in aids patients after infections of cytomegalovirus , pneumocystis carinii , and mycobacterium avium intracellulare.1 it is present in pigeon droppings and infects by inhalation of contaminated soil .
cryptococcal meningitis is fatal in hiv - infected patients if not treated , and hence early diagnosis is very important .
the signs and symptoms of cryptococcal meningitis include headache ( 80~92% of cases ) , meningeal signs ( 50~80% ) , nausea / vomiting ( 40~80% ) , fever ( 36~67% ) , and visual disturbances ( 33~47%).1 our patient presented with acute blindness without other definite clinical symptoms at the time of admission .
possible mechanisms for binocular blindness due to cryptococcal meningitis include direct fungal infiltration of the optic nerve , optic chiasm , or optic tracts , adhesive arachnoiditis , cerebral vasculitis , and intracranial hypertension.4 it has been suggested that rapid - onset visual loss is caused by infiltration of the optic nerve or optic chiasm , while slow - onset visual loss is due to increased csf pressure.4 a csf opening pressure exceeding 200 mmh2o and papilledema reflect intracranial hypertension , but our patient showed a normal csf opening pressure and unremarkable fundoscopic examination findings . moreover , his visual symptoms developed very early in the course of the disease .
thus , the sudden visual loss might have been due to retrobulbar fungal infiltration . whereas the prevalence of cryptococcosis is decreasing because of the widespread availability of antiretroviral therapy , cryptococcal meningitis is still a fatal complication of hiv infection .
thus , both early diagnosis of cryptococcal meningitis and detection of the underlying causes are important . in our opinion ,
unexpected sudden binocular blindness should be considered as a possible initial manifestation of cryptococcal meningitis related to hiv infection .
 ocular complications of hiv - related cryptococcal meningitis are reasonably common , but complete binocular blindness as the first manifestation of hiv is extremely rare . a 58-year - old man presented with binocular blindness . 
 he experienced blurred vision for 3 days before the blindness . 
 mild pleocytosis was present in the cerebrospinal fluid , from which cryptococcus neoformans was cultured . 
 serology revealed positivity for hiv antibody . 
 he was treated with antifungal and antiretroviral therapy . 
 this case indicates that hiv - related cryptococcal meningitis should be taken into consideration when determining the cause of unexpected sudden binocular blindness . 
CASE REPORT
DISCUSSION