The risk of multiple sclerosis developing in patients with isolated idiopathic optic neuritis in Brazil

Abstract

We studied 88 patients with isolated idiopathic optic neuritis (IION) in order to evaluate the rate of progression to multiple sclerosis (MS) in Brazil. The patients were reassessed from one month to nine years after the development of the IION (mean follow-up was 4.6 years). There were 52 men and 36 women with ages ranging from three to 59 years (mean 24.3 years). Bilateral optic neuritis occurred in 19 patients whereas sequential involvement of the fellow eye after an interval longer than four weeks occurred in other 19 patients. Recurrences in the same eye occurred in seven cases. Nine patients (10.8%) developed clinically definitive MS--13.9% of the women and 7.7% of the men with IION. The median age at the time of diagnosis of MS was 25 years. The mean interval between IION and the emergence of other MS signs varied from one month to five years--median one year. Sixty-seven percent of these patients developed signs of spinal cord involvement. Our findings when compared to published series in different countries are closer to figures reported in Japan than those in the West.

Manifestações oculares em pacientes com esclerose múltipla em São Paulo

“…Studies of ocular manifestations in MS are not common in Latin-American countries, and they are limited to neuroophthalmological findings such as optic neuritis 8,9 . We were able to study 64 patients due to our involvement with a multidisciplinary study of MS.…”

“…In our study the age group varied from 17 to 45 years with a higher prevalence in the fourth decade age group; our female:male ratio was exactly 3:1. Peixoto et al 8 , in a trial of 88 patients with idiopathic optic neuritis (ION), reported that 9 patients developed MS after a period that varied from one month to 5 years (mean 26 months). Alvarez et al 9 , in a similar trial, reported that one in 23 patients with ION developed MS in a mean period of 9.7 years.…”

“…This is similar to what has been published in Brazil and other oriental countries such as: China 11 , India 12 , and Korea 13 , where the prevalence of MS is low and a higher rate of visual symptoms in the beginning of the disease occur along with an involvement of the optic nerve. Environmental and genetic factors influence the prevalence of MS 8 . It may be possible that Latin-American and Asian countries share common factors that influence the diseases manifestation and the progression of ION.…”

Bilateral and Simultaneous Retrobulbar Optic Neuritis Revealing Multiple Sclerosis

“…The risk of secondary transformation to multiple sclerosis of an isolated and apparently "idiopathic" optic neuritis is estimated at 10.8%; this risk is somewhat higher for women compared to men: 13.9% versus 7.7% [12]. The period between optic neuritis and the emergence of other specific clinical signs of multiple sclerosis varies from a few days to several years [12,13].…”

“…The period between optic neuritis and the emergence of other specific clinical signs of multiple sclerosis varies from a few days to several years [12,13].…”