Optic neuritis 22786 226062139 2008-07-16T17:36:34Z Stevenfruitsmaak 247845 /* Causes */ update references with final publication from trial collaborators {{DiseaseDisorder infobox | Name = Optic neuritis | ICD10 = {{ICD10|H|46||h|46}} | ICD9 = {{ICD9|377.3}} | ICDO = | Image = | Caption = | OMIM = | MedlinePlus = 000741 | eMedicineSubj = radio | eMedicineTopic = 488 | DiseasesDB = 9242 | MeshID = D009902 | }} '''Optic [[neuritis]]''' is the [[inflammation]] of the [[optic nerve]] that may cause a complete or partial loss of vision. ==Causes== The [[optic nerve]] comprises [[axon]]s that emerge from the [[retina]] of the [[eye]] and carry visual information to the primary visual nuclei, most of which is relayed to the [[occipital lobe|occipital cortex]] of the [[brain]] to be processed into vision. [[Inflammation]] of the optic nerve causes loss of vision usually because of the swelling and destruction of the [[myelin]] sheath covering the optic nerve. Direct axonal damage may also play a role in nerve destruction in many cases. The most common etiology is [[multiple sclerosis]]. Up to 50% of patients with MS will develop an episode of optic neuritis, and 20% of the time optic neuritis is the presenting [[Multiple sclerosis signs and symptoms|sign of MS ]]. The presence of demyelinating white matter lesions on brain [[MRI]] at the time of presentation of optic neuritis is the strongest predictor for developing clinically definite MS. Almost half of the patients with optic neuritis have white matter lesions consistent with multiple sclerosis. At five years follow-up, the overall risk of developing MS is 30%, with or without MRI lesions. Patients with a normal MRI still develop MS (16%), but at a lower rate compared to those patients with three or more MRI lesions (51%). From the other perspective, however, almost half (44%) of patients with any demyelinating lesions on MRI at presentation will not have developed MS ten years later.<ref name="pmid18541792">{{cite journal |author= |title=Multiple sclerosis risk after optic neuritis: final optic neuritis treatment trial follow-up |journal=Arch. Neurol. |volume=65 |issue=6 |pages=727–32 |year=2008 |month=June |pmid=18541792 |doi=10.1001/archneur.65.6.727 |url=http://archneur.ama-assn.org/cgi/pmidlookup?view=long&pmid=18541792}}</ref> Some other causes include viral-bacterial infections (e.g. [[herpes zoster]]), [[autoimmune disorder]]s (e.g. [[Lupus erythematosus|lupus]]), [[chloramphenicol]] and the inflammation of vessels ([[vasculitis]]) nourishing the optic nerve. [[Ethambutol]], an antitubercular [[drug]], can also cause optic neuritis. ==Symptoms== Major symptoms are sudden loss of vision (partial or complete), or sudden blurred or "foggy" vision, and [[Pain|pain]] on movement of the affected eye. Many patients with optic neuritis may lose some of their color [[Visual perception|vision]] in the affected eye, with colors appearing subtly washed out compared to the other eye. A study found that 92.2% of patients experienced pain, which actually preceded the visual loss in 39.5% of cases.<ref>{{cite journal |author=Boomer JA, Siatkowski RM |title=Optic neuritis in adults and children |journal=Seminars in ophthalmology |volume=18 |issue=4 |pages=174–80 |year=2003 |pmid=15513003 | doi = 10.1080/08820530390895172 <!--Retrieved from CrossRef by DOI bot-->}}</ref> On medical examination the head of the optic nerve can easily be visualised by an [[ophthalmoscope]]; however frequently there is no abnormal appearance of the nerve head in optic neuritis, though it may be swollen in some patients. In many cases, only one eye is affected and patients may not be aware of the [[color vision deficiency|loss of color vision]] until the doctor asks them to close or cover the healthy eye. [[Image:OpticNeuritisExample.jpg|right|thumb|Example of how optic neuritis affected one eye of a patient with multiple sclerosis]] ==Epidemiology== Optic neuritis typically affects young adults ranging from 18–45 years of age, with a mean age of 30–35 years. There is a strong female predominance. The annual incidence is approximately 5/100,000, with a prevalence estimated to be 115/100,000.<ref>{{cite journal |author=Rodriguez M, Siva A, Cross SA, O'Brien PC, Kurland LT |title=Optic neuritis: a population-based study in Olmsted County, Minnesota |journal=Neurology |volume=45 |issue=2 |pages=244–50 |year=1995 |pmid=7854520}}</ref> ==Treatment and prognosis== In most cases, visual functions return to near normal within eight to ten weeks, but they may also advance to a complete and permanent state of visual loss. Therefore, systemic intravenous treatment with [[corticosteroid]]s, which may quicken the healing of the optic nerve, is often recommended, but it does not have a significant effect on the visual acuity at one year, when compared against placebo. Intravenous corticosteroids have also been found to reduce the risk of developing MS in the following two years in those patients who have [[MRI]] lesions; but this effect disappears by the third year of follow up.<ref>{{cite journal |author=Beck RW, Cleary PA, Trobe JD, Kaufman DI, Kupersmith MJ, Paty DW, Brown CH |title=The effect of corticosteroids for acute optic neuritis on the subsequent development of multiple sclerosis. The Optic Neuritis Study Group |journal=N. Engl. J. Med. |volume=329 |issue=24 |pages=1764–9 |year=1993 |pmid=8232485 | doi = 10.1056/NEJM199312093292403 <!--Retrieved from CrossRef by DOI bot-->}}</ref> Paradoxically it has been demonstrated that oral administration of corticosteroids in this situation may lead to more recurrent attacks than in non-treated patients (though oral steroids are generally prescribed after the intravenous course, to wean the patient off the medication). This effect of corticosteroids seems to be limited to optic neuritis and has not been observed in other diseases treated with corticosteroids.<ref>{{cite journal |author=Beck RW, Cleary PA, Anderson MM, Keltner JL, Shults WT, Kaufman DI, Buckley EG, Corbett JJ, Kupersmith MJ, Miller NR |title=A randomized, controlled trial of corticosteroids in the treatment of acute optic neuritis. The Optic Neuritis Study Group |journal=N. Engl. J. Med. |volume=326 |issue=9 |pages=581–8 |year=1992 |pmid=1734247}}</ref> Very occasionally, if there is concomitant increased [[intracranial pressure]] the sheath around the optic nerve may be cut to decrease the pressure. When optic neuritis is associated with MRI lesions suggestive of [[multiple sclerosis]] (MS) then general [[immunosuppressive]] therapy for MS is most often prescribed (IV methylprednisolone may shorten attacks; oral prednisone may increase relapse rate). ==See also== * [[Optic neuropathy]] ==References== {{reflist|2}} {{Eye pathology}} [[Category:Neurological disorders]] [[Category:Autoimmune diseases]] [[Category:Ophthalmology]] [[de:Neuritis nervi optici]] [[nl:Neuritis optica]] [[pt:Neurite óptica]]