Amaurosis fugax in a Danish community: a prospective study.

Abstract

A prospective study of amaurosis fugax was carried out in a Danish community (population 481,000); case ascertainment was based on the collaboration of practicing ophthalmologists and general practitioners. Over a 3-year period we registered 131 cases; the annual incidence of "first amaurosis fugax episodes coming to medical attention" was 8.6 and 6.2 per 100,000 population for men and women, respectively. On the basis of a comparison of the age-incidence curves for cerebral and retinal ischemic attacks, the "true" incidence of amaurosis fugax is estimated to be approximately 14/100,000/yr, or 25-30% of the reported Incidence of transient ischemic attacks. Clinical and/or radiologk signs of a carotid lesion on the appropriate side were present in 56% of the patients, and an additional 27% had symptoms or signs of other organic cardiovascular disorders. Forty-three (68%) of the 63 patients who underwent arteriography had an atheromatous lesion apparently amenable to carotid endarterectomy. In spite of the case-finding procedures employed in the study, cases of amaurosis fugax suitable for carotid surgery were thus ascertained at a rate of only 3/100,0O0/yr. This suggests that surgical treatment of patients with retinal ischemic attacks is of minor importance as a preventive measure against stroke in the community. (Stroke 1988; 19:196-199)

Incidence of Transient Ischemic Attack in Rochester, Minnesota, 1985–1989

“…The percentage of carotid cases is considerably higher than that reported in Japan 8,14 but is similar to that reported in Oxfordshire. 5 The incidence of TMB in the present study is higher than that reported in a prospective study from Denmark, 16 but the frequency of TMB among all TIA cases (19%) is similar (17%) to that reported from Oxfordshire during 1981-1986. 5 The incidence rates for cerebral infarction and TIA lead to an estimation of the number of people in a defined population that may require diagnostic evaluation to characterize the mechanism of an ischemic event.…”

“…The incidence rates for Rochester used in prior comparisons were an underestimate of the true TIA incidence because of failure to detect some TIAs with the use of the medical record linkage system. 2,3,16 The present study, with ascertainment of cases simultaneously with stroke cases and with the use of a diagnosis index rubric that had been shown to detect additional cases that would have previously been missed, led to higher and more accurate incidence rates. Comparison of age-and sex-adjusted incidence rates with other sites from throughout the world (Table 4) shows much higher rates in Rochester.…”

“…Although these data may be best compared with cohort data 3,16 reported from 1960 -1972 with different methods of case ascertainment, a prior study indicates that methods of case ascertainment using the medical records linkage system utilized during 1985-1989 should provide comprehensive case detection equivalent to the cohort study results.…”

Jugular Venous Reflux Affects Ocular Venous System in Transient Monocular Blindness

“…The most well-recognized, but not the most common, etiology of TMB is carotid atherothromboembolism [1,2,3,4,5,6]. Therefore, transient ischemic attack should be considered in patients with TMB, and they should be managed promptly [1,2,3,4,5,6]. Although TMB is known to be attributed to ischemia and associated with many conditions, the pathogenesis of TMB remains obscure in up to 66% of these patients [1,2,3,4].…”

The Hisayama Study-A 30-Year Experience on Stroke Epidemiology in Japan

“…Table 4 indicates the crude incidence of TIAs reported from community based studies, which is reproduced from the paper of Dennis et al (22), and to which three other studies (21,23,24) couple of studies. Extracranial atherosclerosis has been reported to be less common in the Japanese than in white, leading us to the presumption that the incidence of TIAs is lower in the Japanese.…”