Too Young to Undergo Temporal Artery Biopsy? Calciphylaxis-Related Anterior Ischemic Optic Neuropathy.

A 39-year-old male patient with end-stage renal failure presented with unexplained isolated unilateral anterior ischemic optic neuropathy, high sedimentation rate, and high CRP. Despite the relatively young age of the patient, an ipsilateral temporal artery biopsy was performed, disclosing calciphylaxis, a highly morbid condition associated with end-stage renal failure, which requires urgent, specific management.

Unusual optic disc infarction in a case of arteritic anterior ischaemic optic neuropathy (AAION).

Herein, we report another case of arteritic anterior ischaemic optic neuropathy from Singapore, in which the initial optic disc swelling was extreme and the sequential disease resolved because the patient was already on maximum treatment. As the management of this biopsy-proven giant cell arteritis case was complicated by the presence of a number of other medical conditions, including end-stage renal failure, monitoring of the response to treatment proved problematic.

Non-arteritic anterior ischaemic optic neuropathy (NA-AION): outcome for visual acuity and visual field defects, the Singapore scene 2.

We report the six months follow-up findings in relation to visual acuity and visual field defects in a series of Singaporean patients with non-arteritic anterior ischaemic optic neuropathy seen in the neuro-ophthalmology service of the Singapore National Eye Centre. 90% of the patients were Chinese, and the most common vascular risk factor was hypertension. Visual acuity was normal at the outset in 40% of cases and unchanged in 85%, and the assessment of visual acuity alone was not found to be a satisfactory method to determine prognosis. Visual field defects were found in all the affected patients, the most common being in the inferior fields. After six months, visual field defects were found to be unchanged in 77% of cases, improved in 15.5% and worse in 7.5%. Overall visual function (visual acuity plus visual field) was unchanged in 81% of cases, and no patient had complete recovery.

Giant cell (temporal) arteritis in Singapore: an occult case and the rationale of treatment.

Further observations in respect of giant cell arteritis (GCA) as encountered in a local neuro-ophthalmology service established in Singapore ten years earlier are reported. The rarely seen occult form of the disease is described along with an illustrative case report concerning an 80-year-old woman. The overall management of GCA is discussed in respect of four clinical scenarios and their treatment.

Mistaken diagnosis of optic neuritis and the possible role of phosphodiasterase-5 inhibitors (Sildenafil/Viagra).

The diagnosis of optic neuritis and particularly retrobulbar optic neuritis when atypical and not responsive to corticosteroid treatment may need to be revised. This is now especially so in male patients who should be questioned regarding their taking a phosphodiasterase-5 inhibitor in particular Viagra. The case history of such a patient is presented who sustained posterior ischaemic optic neuropathy mistaken for retrobulbar neuritis resulting in bilateral severe visual loss.

Optic neuritis in Singapore.

INTRODUCTION: Optic neuritis (ON) is the commonest optic neuropathy encountered in the younger group of patients from the Singapore Neuro-Ophthalmology Study Group. Previous surveys in Asia and our study suggest that ON in Singapore differs from that in Western populations where the majority of cases are associated with multiple sclerosis (MS). METHODS: Patients satisfying our entry criteria for ON seen between September 2002 and June 2004 were enrolled in the study. The data collected was recorded in a central database and analysed two years later. RESULTS: The majority (60 percent) of our patients had anterior ON with optic disc swelling (papillitis), were idiopathic in 49.1 percent, and associated with MS in only 25.5 percent. Bilateral cases comprised 16.4 percent of our series and were usually of the anterior variety and mostly idiopathic, although it is still essential to rule out secondary causes. Recurrent ON is indicative of an underlying disease process. CONCLUSION: The pattern of ON as seen in Singapore differs from that reported in Caucasian studies and from the seminal Optic Neuritis Treatment Trial. We found a higher incidence of optic disc swelling, i.e. anterior ON (papillitis), and a lesser association with MS; visual recovery is similarly good but our recurrence rate is lower.

Ischaemic optic neuropathy: the Singapore scene.

The commonest cause of an optic neuropathy in Singapore is ischaemia, and ischaemic optic neuropathy (ION) is one of the commonest causes of permanent loss of vision in elderly patients, especially in those with diabetes mellitus, hypertension and hyperlipidaemia. ION in our practice is almost invariably of the anterior variety and non-arteritic in origin, i.e. NA-AION. Posterior ION comprises less than two percent of our cases. Three patients with different patterns of NA-AION are described, and in the discussion, how the condition can be distinguished clinically from optic neuritis. With respect to posterior ION, the necessity of excluding a compressive cause before this diagnosis can be made is emphasised.

Giant cell arteritis (temporal arteritis, cranial arteritis) and a case from Singapore.

Giant cell arteritis as the underlying cause of blindness in the elderly is common in the West but is not seen except on rare occasions in South East Asia. We describe an 86-year-old Chinese man from Singapore who presented with a central retinal artery occlusion. Biopsy of a prominent superficial temporal artery established the underlying cause to be giant cell arteritis which was also the eventual cause of death as the condition resulted in rupture of a dissecting aneurysm of the aorta. Giant cell arteritis should be considered in all cases of ischaemic eye disease in the elderly. The importance of early diagnosis lies in the very high incidence of second eye involvement within days or at most weeks in untreated patients. A high index of suspicion is required for diagnosis of this condition which is likely under-diagnosed in our local context.

The presentation, aetiology, management and outcome of optic neuritis in an Asian population.

PURPOSE: To analyse the presentation, aetiology, management and outcome of patients with optic neuritis (ON) in Singapore. METHODS: This was a retrospective study involving consecutive patients with ON presentng at the Singapore National Eye Centre between January 1997 and May 1999. The presenting features, investigatons, treatment and visual outcome after 6 months were studied. RESULTS: A total of 31 patents (39 eyes) presented with ON during this period, 17 of whom had anterior ON. No aetiology was found in 26 patients (83.9%), two patients (6.5%) had multiple sclerosis, one had active syphilis, one had rheumatoid arthritis and another had pan-sinusitis. Seventeen patients (54.8%) were treated with intravenous methyl-prednisolone followed by oral prednisolone. Within the follow-up period 26 of 31 eyes (83.9%) wth idiopathic ON attained visual acuity of 6/12 or better with 12 (38.7%) recovering to 6/6 or better and only one eye ending with less than 6/60 visual acuity. The one patient with syphilis recovered 6/6 visual acuity bilaterally. Both patients with multiple sclerosis also had good visual recovery at 6 months. The visual outcome in those cases of ON associated with rheumatoid arthritis and pan-sinusitis was poor with visual acuity of less than 6/60 at 6 months follow up in each instance. CONCLUSION: The majority of the cases of ON in this study were idiopathic. There was a low association with multiple sclerosis. Most patients had good visual recovery within 6 months.

A novel vented microisolation container for caging animals: microenvironmental comfort in a closed-system filter cage.

We designed a closed-system cage with vent ports that would allow continuous airflow in the occupied cage to ensure adequate ventilation and gas exchange. In this system, the metabolic heat loads of mice generate upward thermal air currents. Heat exits via the exhaust port, and room air enters via the intake port, providing adequate ventilation. Simulations based on computational fluid dynamics (CFD) helped us to optimize the cage's design. CFD simulations and smoke visualizations with a feeder-trough assembly illustrated the one-pass air circulation pattern and the lack of air recirculation, turbulence, and dead air space in our system. We used hot-film anemometry and smoke-test methodologies to show that adequate ventilation was provided. In a room with still air (0 air changes per hour [ACH]), a cage fitted with double wire-cloth filters (40 mesh size) and occupied by five mice has at least 12 ACH, whereas the same cage occupied by one mouse has 6 ACH. After five mice had occupied the cage for a week, its average temperature was 0.58C, relative humidity was 34%, and ammonia concentration was 3 ppm higher than that of the room. Our novel vented microisolation cage provides adequate intracage ACH, isolates mice from environmental contaminants, and contains allergenic particles within the cage in an environment appropriate for the species.

Binasal field defects in primary empty sella syndrome.

Two cases of radiologically proven primary empty sella syndrome with binasal field defects are described. The association of these two entities is discussed.

Mikulicz syndrome and disease: 2 case reports highlighting the difference.

We present 2 case reports highlighting the essential differences between Mikulicz syndrome and Mukulicz disease. A review of the literature appears to show some confusion over the terminology and we therefore also present an historical account of the evolution of the two terms and review their relative merits and relationship with other disorders. In conclusion, we would not advocate the use of the term Mikulicz syndrome and suggest that Mikulicz disease be replaced by the title 'Benign Lymphoepithelial Lesion'.

Fucithalmic, chloramphenicol or no treatment after squint surgery in children. A single blind randomised study.

One hundred and four children undergoing strabismus surgery were randomised post-operatively to one of three treatment groups; 1) fucithalmic drops twice daily; 2) chloramphenicol (chlormycetin) ointment twice daily; 3) no treatment. Allocation to the 'no treatment' group had to be stopped after 3 of the first 8 patients in the group developed severe mucopurulent conjunctivitis. A parental questionnaire and clinical assessment, carried out in a single blind fashion revealed that nearly all parents were able to apply the prescribed treatment and that both treatments were effective in preventing bacterial conjunctivitis. Post-operative antibiotics seem to be necessary following squint surgery in children, and fucithalmic viscous drops are a useful alternative to chlormycetin ointment.

Low contrast visual acuity changes in human immuno-deficiency virus (HIV) infection.

A pilot study of low contrast visual acuity testing using Regan Charts has been undertaken in 34 patients seropositive for Human Immuno-Deficiency Virus and 20 normal control subjects. Low contrast visual acuities of the HIV (+) patients both with and without HIV retinopathy were found to be significantly lower than the age-matched controls (p < 0.01). This finding is probably attributable to pathology related to HIV in the visual pathways/Central Nervous System. Lowest contrast Chart (Chart C) was found to be a useful diagnostic tool for HIV retinopathy and presumed neuropathy.

Pattern of arterial involvement of the head, neck, and eyes in giant cell arteritis: three case reports.

The findings of two post-mortem examinations and one CT scan of patients with biopsy proved giant cell arteritis (GCA) are presented. The presence or absence of intracranial involvement in GCA is discussed.

Case of penetrating orbitocranial injury caused by wood.

A case of retained intraorbital and intracerebral wooden foreign body following an orbitocranial penetrating injury through the lower lid of an adult is described. Initial failure to recognise the true nature of the injury led to intracerebral abscess formation and monocular blindness. Diagnosis and management of such cases are discussed.

Red colour comparison perimetry chart in neuro-ophthalmological examination.

A new test chart has been developed as a quick, alternative and supplementary method of perimetric evaluation of the central 25 degrees of the visual field to test for the presence of relative and absolute scotomas as part of a routine eye and neurological examination. The result of a comparison of this test with formal perimetry in 107 patients is described and discussed.