Korelacija vrijednosti inicijalne vidne oštrine i vidnih evociranih potencijala kod bolesnika s optičkim neuritisom sa znakovima demijenilizacije i bez njih

Idiopatski opticki neuritis predstavlja idopatsku upalu vidnoga živca koja se može razviti odvojeno ili u kontekstu rasprostranjene demijelinizirajuce bolesti. Dijagnoza klinicki definirane multiple skleroze zahtjeva najmanje dvije odvojene epizode neurološke simptomatologije, kao i dvije anatomski i vremenski odvojene lezije demijelinizacije. Zbog toga je magnetska rezonanca mozga najznacajniji cimbenik kod donošenja dijagnoze multiple skleroze. Cilj rada bio je utvrditi povezanost inicijalne vidne oštrine i vrijednosti vidnih evociranih potencijala (VEP) kod bolesnika s klinickim nalazom optickog neuritisa (ON) sa simptomima demijelinizacije i bez njih, te evaluacija terapije i prognoze u smislu povecanog rizika za nastanak multiple skleroze. U ovu smo retrospektivnu studiju ukljucili 56 bolesnika hospitalizarnih na Klinici za ocne bolesti KBC Split u razdoblju od 1. sijecnja 2004. do 31. prosinca 2007. godine. Kriterij za ukljucivanje je bila klinicka slika akutnog optickog neuritisa. Vidna oštrina ispitivana je pomocu Snellenovih optotipa. Medu ostalim pretragama izvršeno je snimanje vidnih evociranih potencijala (VEP) i magnetne rezonance (MR) mozga. Incidencija optickog neuritisa na našoj Klinici iznosila je za ispitivano razdoblje 2,8/100000. Inicijalna vidna oštrina iznosila je od osjeta svjetla i projekcije do l,0, a srednja vrijednost iznosila je 0,32. Vrijednosti latencije VEP-a kretale su se od 82-164 ms, a srednja vrijednost iznosila je 126,82 ms. Pozitivan nalaz MR mozga u smislu demijelinizacije ustanovljen je kod 34 bolesnika (61,7%). Nadena je statisticki znacajna razlika u vrijednostima latencije VEP-a izmedu pacijenata s pozitivnim nalazom MR mozga i onih s urednim nalazom (Mann-Whitney U test, Z = 3,062, p = 0,002), dok postoji razlika u vrijednostima inicijalne vidne oštrine u istim dvjema grupama pacijenata, ali nije statisticki znacajna (Mann-Whitney U test, Z = -1,124, p = 0,261). Rezultati ove studije upucuju na znacajno vecu ucestalost težih oblika optickog neuritisa kod bolesnika s demijelinizirajucim promjenama na mozgu u odnosu na one s urednim MR nalazom mozga, koji se ocituju u smanjenoj vidnoj oštrini i znacajno produženoj VEP latenciji tih ispitanika, te se u kontekstu ovih ispitivanja može raspravljati o prognostickom segmentu rizika nastanka klinicki definirane multiple skleroze (CDMS). Ujedno se na osnovi ovih rezultata može uspješnije modulirati buduca terapija, narocito u svjetlu aktualizacije promptne primjene imunomodulatora u cilju prolongiranja nastanka CDMS.

Idiopathic optic neuritis is an idiopathic optic nerve inflammation which can develop separately or together with disseminated demyelizing disease. The diagnosis of clinically defined multiple sclerosis demands at least two separate episodes of neurological symptoms and two anatomically and time separated demyelination lesions. That is the reason why brain magnetic resonance is one of the most important factors for multiple sclerosis diagnosis. The aim of this study was to determine the correlation between initial visual acuity and visual evoked potentials in patients with and without positive findings on brain magnet resonance, and to evaluate the therapy and prognosis of an elevated risk of developing multiple sclerosis. This retrospective study included 56 patients hospitalized in the Department of Ophthalmology between 1st January 2004 and 31st December 2007. The criterion needed to be included was the presence of acute optic neuritis. Visual acuity was determined with Snellen optotypes. Among other clinical testing, we performed visual evoked potential recording and brain magnet resonance. The incidence of optic neuritis in our department was 2,8/100000 inhabitants. Initial visual acuity ranged from light perception to 1,0, and the mean value was 0,32. Visual evoked potential latencies ranged from 82 to 164 ms, and the mean value was 126,82 ms. Positive brain magnet resonance findings for demielination were found in 34 (61.7%) of patients. Statistically significant difference in visual evoked potential latencies was found among patients with positive and negative brain magnet resonance findings (Mann-Whitney U test, Z = 3,062, p = 0,002), while there was a difference in initial visual acuity in the same groups, but it was not statistically significant (Mann-Whitney U test, Z = -1.124, p = 0.261). The results of this study indicate that the incidence of more severe optic neuritis is greater in patients with brain demyelinating lesions than in those with normal brain MR findings, which have lowered visual acuity and significantly prolonged VEP latencies. In the contest of this study, we can appraise the prognostic value and the risk of developing clinically defined multiple sclerosis (CDMS). According to these results, future therapy can be adjusted with more success, especially today when prompt immunomodulatory therapy is being proposed with the goal of prolonging the development of CDMS.