Clinical comparison of the Keeler Pulsair 3000 with Goldmann applanation tonometry.

AIM: To confirm the accuracy of the Pulsair 3000 before introducing the instrument into clinical practice. METHOD: A masked study by two experienced tonometrists comparing the mean of the Goldmann intraocular pressure (IOP) readings against the Pulsair 3000 reading (average of four puffs). Results of 150 eyes were compared with an IOP range of 10 mm Hg-44 mm Hg. RESULTS: Correlation between the two Goldmann tonometry results was 0.9830 with a standard deviation of 1.1085 mm Hg. Correlation between the mean of the two Goldmann readings against the Pulsair 3000 reading was 0.982 with a standard deviation of 1.1179 mm Hg. Bland-Altman analysis confirms a satisfactory outcome. CONCLUSION: The Pulsair 3000 provides an accurate and objective method of measuring IOP with many advantages over traditional Goldmann tonometry.

The relationship between obesity and idiopathic intracranial hypertension.

OBJECTIVES: To evaluate the association between obesity and idiopathic intracranial hypertension (IIH) and establish whether there is a relationship with visual outcome. To calculate the prevalence and degree of obesity in a group of patients with IIH. METHODS: 34 patients (31 female and 3 male) were recruited between 1993 - 1997 with a diagnosis of IIH. Assessment included visual acuity, visual field assessment (Humphrey automated and Goldmann manual perimetry), fundus assessment and measurement of body mass index (BMI). Obesity was defined as a BMI of 30 kg/m2. RESULTS: 70.5% of patients were obese. The relative risk for obesity and IIH was significant at 8 (95%CI: 2,29). This increased to 17 (95%CI: 5,62) for obese females aged 16 to 24 years and 10 (95%CI: 3,35.5) for obese females aged 25 to 34 years. Morbid obesity (BMI > 40) was significantly associated with poor visual outcome. Serial obesity measures showed generally little change in weight over time and there was no correlation between weight change and visual improvement. CONCLUSIONS: This study has documented a relationship between obesity and IIH. A high degree of obesity was associated with a poor visual function and identified as a risk factor for poor outcome. Obesity may be an aetiological factor in this condition although it is unlikely to be the sole cause but more probably a precipitating factor. Weight loss is recommended although failure to lose weight is common. Any weight reduction programme must therefore be actively encouraged and monitored.

Assessment of visual function in idiopathic intracranial hypertension: a prospective study.

The visual function of 35 patients with a diagnosis of idiopathic intracranial hypertension was assessed prospectively over a 3 year period. In assessing the visual function of cases of idiopathic intracranial hypertension a number of tests were employed including visual field assessment with Humphrey and Goldmann perimeters and documentation of visual acuity and contrast sensitivity. Loss of visual function is the only serious complication and may occur early or late in the course of the condition. An appropriate and sensitive clinical assessment regime is therefore of importance in the outpatient situation. Visual field assessment was documented as the most sensitive to detection of visual loss, with statistically greater sensitivity in comparison with visual acuity and contrast sensitivity testing. Detection of asymptomatic visual loss indicates the necessity for visual monitoring to ensure detection of insidious visual loss. The types of visual field defects noted in this study were typical of anterior optic nerve pathology of raised intracranial pressure and commonly included arcuate defects, nasal steps and global constriction. Visual loss was noted at presentation and during follow-up in up to 87% of patients using Goldmann perimetry and up to 82% of patients using Humphrey perimetry. The visual status improved significantly throughout the follow-up period and the final visual outcome was excellent or good in 83% of patients.

Intracerebral metastases from ocular melanoma.

A blind painful eye may harbour an unsuspected malignant melanoma. We report a case of ocular melanoma that presented with confusion owing to direct extension via the optic nerve into the anterior cranial fossa.

Optic disc drusen and episodic visual loss.

A case is reported in which recurrent episodes of visual loss occurred over a period of 26 years in a patient with bilateral optic disc drusen. Visual field loss was associated with episodes of ischaemic optic neuropathy. The possible mechanism is discussed.

Assessment by fluorescein angiography of surgical treatment of occlusive carotid artery disease.

Fundus fluorescein angiography was performed in 10 cases of occlusive carotid artery disease at presentation and after surgery or medical treatment. An improvement in the microcirculation of the retina was observed in 4 cases after carotid endarterectomy and in 1 case after carotid endarterectomy and extracranial-intracranial bypass. Improvement was not observed in 2 cases after extracranial-intracranial bypass alone or in 3 cases in which surgical intervention was not undertaken. Our results suggest that carotid endarterectomy is a more effective procedure than extracranial-intracranial bypass in improving retinal perfusion when compromised by ipsilateral carotid obstruction.

Optic nerve sheath meningioma: diagnostic features and therapeutic alternatives.

Twenty-two cases of optic nerve sheath meningioma were reviewed. The clinical features included slowly progressive visual loss in every case. Orbital signs of limited ocular movements and mild proptosis were present in only a third of cases; gaze-evoked amaurosis occurred in 3 cases. The disc was abnormal in every case, usually swollen if vision was 6/12 or better, atrophic if the vision worse than 6/12. Optociliary shunt vessels occurred in 5 patients and were of diagnostic significance. The diagnosis was made by a high-resolution CT scan of the orbits showing tubular expansion of the optic nerve sheath. Calcification of the optic nerve was present in 12 cases. Tubular expansion of the optic nerve sheath may occur in raised intracranial pressure, optic nerve glioma, granuloma, lymphoma or metastatic disease. In the absence of calcification these alternative diagnoses must be considered. Surgery, undertaken for the intracranial component of the tumour, did not halt progressive visual loss.

Fluorescein angiography in carotid disease.

Twenty four cases in whom occlusive disease of the carotid artery was proven by digital subtraction angiography or direct carotid arteriography were studied. In five cases venous stasis retinopathy was evident ophthalmoscopically. Fluorescein angiography was abnormal in 19 cases. The abnormalities found were microaneurysms (16 cases); slow arteriovenous transit time (8 cases); macular oedema (8 cases); leakage from the arterioles (3 cases); disc new vessels (4 cases). The differences between this retinopathy and diabetic retinopathy are discussed.

Convergence spasm.

Convergence spasm, when it is part of the near-response, is accompanied by accommodation and miosis. The differential diagnosis of bilateral sixth nerve palsy, divergence insufficiency, bilateral gaze palsy may be distinguished by clinical examination. In a review of 12 cases, 8 of whom were re-examined after a mean interval of 8.3 years, no organic disease became manifest. We suggest that extensive neurological investigation is not necessary in this group of patients. Treatment with cycloplegia and glasses gave symptomatic relief in 5 cases.

Silicone tube and gutter in advanced glaucoma.

We performed a new drainage operation in 20 cases of advanced glaucoma. A silicone tube was inserted into the anterior chamber and its outer end buried under an encircling gutter. After a mean follow up of 10 months, in 13 cases (65 per cent) the eye was comfortable, the intraocular pressure less than 25 mm Hg, and the tube was in a satisfactory anatomical position. The authors recommend this procedure rather than destructive operations in eyes with advanced uncontrolled glaucoma.

Ocular disease in immunosuppressed patients.

New therapies and diseases causing immunosuppression have provoked new and devastating ocular diseases. The possible reasons for the vulnerability of the retina to opportunistic infections are discussed. The clinical patterns of disease caused by common opportunistic agents are described, and current treatment available is reviewed.