The natural history of amaurosis fugax with minor degrees of internal carotid artery stenosis

Redefining amaurosis fugax

Amaurosis fugax is a common term fraught with different interpretations. Disparities inunderstanding appear to be related to professional training. A new framework to facilitateinterdisciplinary communication and clinical research is presented.

Sleep, health and visual impairment in the elderly

This study was undertaken in order to analyse the relationship between visual impairment and sleep in an elderly population. All 10?216 members of the pensioners' association in two Swedish counties were asked to participate in a questionnaire survey. The questionnaire included questions on civil status, the general state of health, the occurrence of somatic diseases and symptoms, sleep, medication and vision. 6143 evaluable questionnaires were received, of which 39.5% were from men. The mean (s.d.) ages of the male and female participants were 73.0 (6.0) and 72.6 (6.7) years, respectively. Visual impairment was reported by 20.9% of the men and 32.9% of the women. The proportion of visual impairment increased with age and was more common in women in each age group. Poor sleep occurred in 14.4% of the men and 27.9% of the women. Among subjects with visual impairment, poor sleep, frequent awakenings and difficulties to fall asleep after awakening at night were all more common in both men and women. In a multiple logistic regression analysis, significant independent correlates of poor night's sleep among the men were: visual impairment (odds ratio (OR) 1.3 95%, confidence interval (CI) 1.0-1.8) and poor health (OR 2.2, CI 1.6-3.0). Age, circulatory organ disease and diabetes were deleted by the logistic model. The significant independent correlates in women were: visual impairment (OR 1.6, CI 1.3-2.0) poor health (OR 2.6, CI 2.1-3.3) and circulatory organ diseases (OR 1.5 CI, 1.2-1.8). Age and diabetes were deleted by the logistic model. The results suggest that visual impairment could be an underestimated cause of sleep deterioration in the elderly.

Prognostic value of carotid ultrasound lesion morphology in retinal ischaemia: result of a long term follow up

The importance of carotid plaque morphology in the prognosis of retinal ischaemia was investigated in a group of 165 patients followed for 2-7 years (mean 3.3 years). All patients had an initial carotid duplex ultrasound examination, with the results expressed in terms of the degree of stenosis caused by the lesion, and the lesion morphology. Lesions were divided into two groups, (a) combined homogeneous and simple heterogeneous structures, and (b) complex heterogeneous plaques. Complex heterogeneous plaques had a low echo pool within the lesion and/or an irregular surface pattern. A total of 144 (87%) patients were successfully followed, and of these 37 (26%) had cerebrovascular, cardiovascular, or retinal ischaemic events in the follow up period; 14 (10%) cerebrovascular accidents (eight fatal), 17 (12%) myocardial infarctions (10 fatal), two episodes of amaurosis fugax, and one of tunnel vision caused by a retinal embolus were recorded. There was no report of subsequent blindness. The percentage stenosis caused by the carotid lesions, although more severe in the vascular event group, was not significantly different between the groups. However, a significant difference (p < 0.1) was found in the morphological characteristics of the carotid lesions between the groups. Patients who suffered a vascular event in the follow up period had significantly more complex heterogeneous lesions compared with simple heterogeneous/homogeneous lesions, than those patients who remained alive and well. Carotid endarterectomy and antiplatelet therapy were equally distributed between the event and non-event groups. This suggests that the criteria for selection for treatment should be based on the lesion morphology as well as the degree of stenosis.

Ultrasound morphology of carotid lesions in retinal ischaemia

The extracranial carotid arteries of 165 patients with retinal ischaemic symptoms were examined with duplex ultrasound. Both the degree of stenosis and the morphological appearance of the lesions were examined. Ipsilateral carotid artery disease was found in 88% of patients. Degrees of stenosis of between 50-99% were found in 33% of patients, the majority of these lesions being complex heterogeneous in nature. Stenosis of < 50% was found in 40% of arteries. The majority of lesions causing < 20% stenosis were homogeneous in nature. However, in stenosis of 20-49%, 63% of lesions were found to be complex heterogeneous. A similar distribution of lesions was found in the contralateral carotid arteries. It is important to examine both ipsilateral and contralateral arteries, and to evaluate the morphological characteristics of all lesions causing > 20% stenosis.

Amaurosis fugax: is it innocuous?

A 10 year retrospective study of 103 patients with amaurosis fugax was done. Sixty-two patients with symptoms of amaurosis fugax underwent arteriography, which demonstrated ulcerated carotid plaque in 36 and hemodynamically significant stenoses (greater than 75% diameter reduction) in 26. These 62 patients underwent carotid endarterectomy. The other 41 patients who had proven ulcerated plaque (33 patients) or hemodynamic stenoses (eight patients) were not treated surgically and served as a control series. No strokes or deaths occurred in the immediate postoperative period. Follow-up of the 62 operated patients extending to 10 years (mean 4.2 years), revealed one (1.6%) patient with recurrent amaurosis fugax symptoms, two (3.2%) with transient ischemic attacks, and one (1.6%) with a stroke in the operated hemisphere. In the nonoperated group, despite aspirin or warfarin treatment, four (9.7%) patients had ongoing amaurosis fugax symptoms, and two (4.8%) developed transient ischemic attacks that led to carotid endarterectomy. One (2.4%) other patient developed sudden, permanent monocular blindness, and two (4.8%) suffered hemispheric strokes, one of which was fatal. The cumulative morbidity (ongoing ocular or transient ischemic attack symptoms, perioperative and late stroke) in the operated group was 6.4% (four patients), while the cumulative morbidity in the nonoperated group was significantly higher at 21.9% (nine patients) (p = 0.02). When patients present with symptoms of amaurosis fugax and have demonstrable carotid bifurcation disease, carotid endarterectomy is recommended. Amaurosis fugax should be regarded as a harbinger of monocular blindness and stroke.