Is optic neuritis incidence rising? Evidences from an epidemiological study in Barcelona, Spain 2008-2012

Abstract

 

Purpose

 

Incidence of Optic neuritis (ON) ranges between 0.56-5.1 cases per 100,000 person-years. However, epidemiology of ON has not been updated and there are suggestions that incidence is rising. Considering new therapies for ON, it is important to update epidemiology to design clinical trials and improve health management of ON. We aim to provide prevalence and incidence rates of ON in Barcelona, Spain from 2008 to 2012.

 

Methods

 

Retrospective evaluation of hospital electronic records matching following ICD-9-CM codes: 377.3-optic neuritis, 377.30-optic neuritis, unspecific, 377.31-optic papillitis, 377.32-retrobulbar neuritis, acute, 377.39-other optic neuritis and "optic neuropathy" search-terms. Demographic and clinical data were collected from records with confirmed diagnosis of demyelinating ON, including idiopathic, Multiple Sclerosis and Neuromyelitis Optica origin.

 

Results

 

Prevalence of acute optic neuritis on 31, December 2012 was 2.75 cases per 100,000 people. Mean annual prevalence of acute ON during 2008-2012 periods was 7.87 cases per 100,000 person-years (figure 1A). Mean annual incidence was 5.36 cases per 100,000 person-years (figure 1B). ON recovery was defined as good (high contrast VA > 20/25) for 81% of patients after 12 months of follow up but 4 (5%) patients had VA less than 20/400 which is the VA considered by WHO as blindness criteria. Cumulative probability for MS progression was nearly 30% by 6 months and 45% by the end of follow-up (5 years) (figure 2).

 

Conclusions

 

Incidence of ON in Barcelona during 2008-2012 was higher than previously reported. It may be explained by evolution of diagnosis criteria, use of referral-center approach instead of population-based approach, increased awareness of demyelinating diseases and by possible true increase in its incidence.

 

 

 

Keywords: 613 neuro-ophthalmology: optic nerve