Epidemiological Survey of Optic Neuritis in Italy in the Years from 1958 to 1962

Incidence of Optic Neuritis in Stockholm, Sweden, 1990-1995

“…In a review of the literature, we found 10 articles in English with data regarding ON seasonal variations. 2,12,[20][21][22][23][24][25][26][27] The quality of these studies varied. Regard- ing quality of diagnosis, it would be difficult to interpret data from a 1958-1962 national survey in Italy, 23 since the highest incidences of both retrobulbar neuritis (RN) and papillitis were observed in a group whose age range was 51 to 60 years; 50% of the cases of RN and 45% of the cases of papillitis occurred in patients older than 50 years.…”

“…2,12,[20][21][22][23][24][25][26][27] The quality of these studies varied. Regard- ing quality of diagnosis, it would be difficult to interpret data from a 1958-1962 national survey in Italy, 23 since the highest incidences of both retrobulbar neuritis (RN) and papillitis were observed in a group whose age range was 51 to 60 years; 50% of the cases of RN and 45% of the cases of papillitis occurred in patients older than 50 years. From 3 articles published in the 1950s and 1960s and based on reviews of hospital records, [20][21][22] the highest number of cases was seen in spring (April-June) [20][21][22] and the lowest in winter, 20,21 showing good agreement with our results.…”

“…The highest rates occurred in spring 2,[20][21][22]24,25,27 and the lowest occurred in autumn 2,24 or winter, 20,21,25 despite the considerable heterogeneity of these studies regarding (1) the completeness and details of diagnostic criteria, 20,21,23,24 the period of case-finding, 20,25 and the definition of seasonal time intervals 23,24 ; (2) the inclusion of MON, 2,12,22,25-27 RN, 21,23 or RN criteria after excluding MS 20 or disregarding the presence of MS 24 ; (3) the bases of study (either hospital-based 12,[20][21][22][23]25 or populationbased 2 ); (4) the sources of diagnosis identified by neurologic 22 or ophthalmologic 12,23,25 specialists or both 2,24 ;…”

“…(5) the measures of seasonal variability 24 ; and (6) the assessment of statistical significance. 2,[21][22][23]25,26 The relationship between seasonal MON risk reported worldwide and climatic changes was not addressed in prior studies. We obtained information on monthly proportions of new ON/RN cases or recorded attacks and on climatic data for selected studies 2,20,21,25 and reports.…”