Bilateral lateral rectus palsies in high altitude illness.

A 50-year-old man with high altitude illness had bilateral lateral rectus palsies when he went to the Himalaya at 5,000 meters. He had no other neurological signs, except headache. He received acetazolamide, prednisone, and spent time in a hyperbaric chamber; but unfortunately he showed no improvement. Two months later, his diplopia completely resolved itself without any treatment, after his descent to a lower altitude.

Sjögren-like syndrome after bone marrow transplantation.

OBJECTIVE: To study the incidence of dry eye in Sjögren-like syndrome, graft-versus-host disease (GVHD) in hematological patients undergoing bone marrow transplantation (BMT). MATERIAL AND METHOD: Prospective, cross-sectional study in twenty-six patients that were planned for BMT (group I). Twenty-nine patients undergoing BMT before study were classified as group II no GVHD (9), and group III with GVHD (20). Thirty-two normal subjects were controls. All subjects were examined by slit lamp biomicroscopy and had their tear samples analyzed about tear osmolarity. They were also evaluated for aqueous tear production by phenol red thread test, Schirmer test without anesthesia, tear film stability by tear break-up time (TBUT), and rose bengal staining 2 weeks before BMT (for group I) as well as 6 weeks, 3 months, and 6 months after BMT. The patients with GVHD were followed up 1 month later. Main outcome measures were amount of tear production, tear film stability, and dry eye symptoms. RESULTS: Average aqueous tear production in group III was less than control and group II (p < 0.001). Mean TBUT in group III was faster than control (p < 0.001) and group I before BMT (p = 0.001). Mean score of rose bengal staining in group III was more than control and group I before BMT (p < 0.001). Keratoconjunctivitis sicca and red eye developed in 27.5%, and 20% of group III, with incidence of dry eye by Schirmer test without anesthesia (67.5%). This compares with group II having incidence of dry eye of 16.7%. However, 42.3% of group I before BMT had dry eye compared with 9.4% in the controls (p < 0.001). CONCLUSION: Trend of dry eye in patients with BMT and GVHD were higher than no-GVHD group. Doctors should be aware of ocular symptoms and signs of dry eye in patients with BMT and follow-up for proper management.

Pediatric optic neuritis.

OBJECTIVE: Describe the clinical characteristics of pediatric optic neuritis. MATERIAL AND METHOD: Retrospective observational case series was performed on patients < or = 12 years of age with optic neuritis at Childrens Hospital Los Angeles. RESULTS: Thirty-one patients (48 eyes) were identified. Mean follow-up was 2.7 years. There were 17 preadolescents (< 10-years-old) in group I, and 14 adolescents (10--12-years-old) in group II. Females comprised 59% of group I, and 71% of group II. Bilateral cases comprised 65% from group I, and 43% from group II. Five patients from group I had acute disseminated encephalomyelitis (ADEM). Two patients from group II had multiple sclerosis (MS). No other patients developed MS. There was no difference in initial or final vision for the eyes with or without steroid treatment. CONCLUSION: Pediatric optic neuritis has no gender or racial predilection, is usually bilateral, and is associated with ADEM rather than MS.

Orbital pseudotumor: clinical features and outcomes.

To describe the clinical characteristics of orbital pseudotumor, a retrospective analysis was performed on patients with orbital pseudotumor at Siriraj Hospital for ten years. Forty-nine patients (24 males and 25 females; 62 eyes) with a mean age of 43.75 years were included (a mean follow-up of 25 months). Thirty-six patients (73.5%) had unilateral disease. The clinical features were proptosis (79.6%), ocular motor deficit (61.2%), pain (51%), lid swelling or lid mass (44.9%), ptosis (24.5%), and chemosis (18.4%). The most common presenting sign was proptosis (49%). All were treated with corticosteroids with clinical improvement in 40 (81.6%) patients. Ten (83.3%) of 12 patients with visual loss improved with mean recovery time of 10.3 days. Ocular motility recovered in 24 (80%) patients, occurring an average of 17.8 days after initiation of therapy. It is concluded that the clinical features of orbital pseudotumor are varied. Most patients were improved with corticosteroids treatment.

Factors associated with insensitivity to pyridostigmine therapy in Thai patients with ocular myasthenia gravis.

The objective of this study was to determine factors associated with pyridostigmine therapy in patients with ocular myasthenia gravis (OMG). This retrospective study included eighty-five patients with OMG who have been treated with pyridostigmine. Patients were excluded if they were diagnosed as generalized myasthenia gravis within a month after diagnosis or were treated with other medications. Forty-two patients responded to pyridostigmine and 43 patients did not. There were no significant differences in gender, age, the duration of symptoms before treatment, the dosage of pyridostigmine, and the initial presentations of ptosis or diplopia between the two groups. However, an initial presentation of concurrent ptosis and diplopia and the presence of systemic involvement after follow up were significant factors associated with an insensitivity to pyridostigmine in patients with OMG (p = 0.001 and p = 0.01, respectively). Determining these factors could help predict the pyridostigmine response in patients with OMG.

A comparative study of visual evoked potentials in optic neuritis and optic neuritis with multiple sclerosis.

OBJECTIVE: To compare the visual evoked potentials (VEP) in patients with acute optic neuritis, recurrent optic neuritis, and optic neuritis with multiple sclerosis. MATERIAL AND METHOD: The authors retrospectively reviewed VEP latency records of the patients with optic neuritis in Siriraj Hospital from 1995 to 2005 and divided them into three groups, acute optic neuritis, recurrent optic neuritis, and optic neuritis with multiple sclerosis (ON/MS). The patients with non-recordable VEP in the analysis were excluded. Comparison of the mean latency of the VEP in affected eyes among the three groups was statistically analyzed by a nonparametric independent sample test. RESULTS: Twenty-two patients with acute optic neuritis, 8 patients with recurrent optic neuritis, and 22 patients with ON/MS participated in this study. The mean age among the three groups was not statistically significant. The median value of the latency of flash VEP (fVEP) and pattern reversal VEP (PRVEP) in the acute optic neuritis group was shorter than that of the recurrent optic neuritis group, and statistically significant (fVEP p = 0.012; PRVEP, p = 0.004). The median value of the latency of PRVEP in the acute optic neuritis group was shorter than that of the ON/MS group, and statistically significant (PRVEP p = 0.002). The median value of the latency of both fVEP and PRVEP in the recurrent optic neuritis group and ON/MS group were delayed with no statistical significance (fVEP p = 0.458; PRVEP, p = 0.403). CONCLUSION: The VEP can be used to demonstrate the demyelinating mechanism of optic neuritis and optic neuritis with multiple sclerosis, but cannot determine the susceptibility of the patients with acute ON to become MS. The significantly delayed latency of VEP in recurrent optic neuritis is possibly caused by severe damage of the optic nerve conduction from recurrent attacks.

A traumatic bitemporal hemianopia with macular sparing.

Traumatic chiasmal syndrome is a rare complication of closed head trauma. It often presents as bitemporal hemianopia and may be associated with other neurological signs. The authors report a case of a 47-year-old man who had sustained severe frontal head trauma from a motor vehicle accident that caused multiple cranial fractures and prolonged loss of consciousness. He was subsequently diagnosed with traumatic chiasmal syndrome. Tangent field testing revealed bitemporal hemianopias with some macular sparing. Macular sparing was not found on the central 30-2 pattern of Humphrey visual field test.

Optic neuritis: characteristics and visual outcome.

OBJECTIVE: To determine clinical characteristics of patients with optic neuritis and visual outcome after intravenous methylprednisolone treatment. METHOD: A total of 81 patients with optic neuritis were reviewed retrospectively with regard to their clinical characteristics by dividing into two groups as follows: group I had isolated optic neuritis and group II had optic neuritis with demyelinative disease. The visual outcome in these patients before and after intravenous methylprednisolone treatment was analyzed. RESULTS: Of 81 patients with optic neuritis, 63 patients (77.8%) had isolated optic neuritis and 18 (22.2%) patients were optic neuritis with demyelinative disease. The ages of the patients ranged from 16 to 59 years (mean = 35.3 years) in patients with isolated optic neuritis and from 16 to 73 years of age (mean = 35.8 years) in patients with optic neuritis with demyelinative disease. After treatment, 45 patients (52 eyes) with isolated optic neuritis and 14 patients (25 eyes) with optic neuritis with demyelinative disease who were followed-up for more than 10 days were studied. After treatment, 60 per cent of the isolated optic neuritis patients and 24 per cent of the optic neuritis patients with demyelinative disease had a visual acuity of 6/12 or better respectively. The isolated optic neuritis who had an onset interval to treatment of less than 8 days had a visual acuity better than 6/9 in 75 per cent. CONCLUSION: The final visual outcome in patients with isolated optic neuritis who received earlier treatment was better than those who received treatment later.

A prospective randomized trial of megadose methylprednisolone and high dose dexamethasone for traumatic optic neuropathy.

PURPOSE: To determine whether the improvement in visual acuity obtained when using high dose dexamethasone in the treatment of traumatic optic neuropathy was comparable to that of megadose methylprednisolone. METHOD: A total of forty-four patients with traumatic optic neuropathy were prospectively randomized and selected to receive intravenous high dose dexamethasone or megadose methylprednisolone within 2 weeks of injury. Age, gender, cause of injury, interval from injury to treatment, initial, post-pulse, and final visual acuity were analysed statistically to compare the dexamethasone and methylprednisolone groups. RESULTS: The mean interval to treatment was not significantly different (p=0.28) for the dexamethasone group at 5.5 days compared to the methylprednisolone group at 4.1 days. Visual improvement of at least two lines of the Snellen chart or two levels of unmeasured visual acuity was shown in 9 patients (37.5%) of the dexamethasone group and 10 patients (50%) of the methylprednisolone group. There was no statistically significant difference between the initial and post-pulse visual acuity (p=1.0) and the initial and final visual outcome (p=0.60) in the dexamethasone group compared with the methylprednisolone group. CONCLUSION: There was no significant difference in the visual acuity obtained after treatment with intravenous dexamethasone or methylprednisolone for traumatic optic neuropathy.