Fundus Perimetry Can Reveal Central Micro Scotomas in Early Stages of Multiple Sclerosis

Abstract

Abstract: : Purpose: to investigate central retinal sensitivity in young adults with early stages of Multiple Sclerosis (MS). Methods: Retinal sensitivity was assessed by Nidek MP–1 Fundus Perimetry projecting a pattern of 50 white, GI size stimuli (4–2–1 strategy and 200 ms duration) within the central 15 degrees of the visual field of both eyes in each subject. Three Group of patient are mentioned in this study: a control group of 10 healty young volonteers (age range: 21 to 40 years old), 13 young adults (mean age:36,2 yrs old, range 22 to 56) with early stages of MS (Group A) and 2 patients with retrobulbar optic neuritis as first symptom that lead to the dignosis of MS (Group B). Patients in the Group A have been recently diagnosed with MS and are currently enrolled in the multicenter randomized clinical trial COGIMUS evaluating the effectiveness of ß interferon on cognitive deficits in course of MS. Fixation location and stability was assessed by Nidek MP–1. Standard central 30–2, GIII static perimetry (Humphrey analyzer) was also performed in each subject. Results: All patients had central and stable fixation. In the control Group traditional static perimetry with Humphrey analyzer showed no abnormalities and mean retinal sensitivity on Fundus Perimetry (average of the 50 stimulation) was 14,89 dB +/– 2,03 (range 12,4–18,2). In Group A visual function was good in each subject exept 1 presenting horizontal nystagmus and two with partial lens opacity; 4 eye had suffered from optic neuritis; static 30–2 perimetry showed no scotomas while Fundus Perimetry did it in 3 out of 13 cases (23%), mean retinal sensitivity was 10,1 dB +/– 3,31 (range 5,3–14,5). Higher incidence of dense scotomas in Group A respect to control Group is obviously statistically significant (chi² test). In Group B the two patients presented with sudden monolateral visual loss (BCVA 20/200), had large central scotomas on both Humphrey and fundus perimetry (mean retinal sensitivity 1,2 dB +/–0,2). Conclusions: Fundus perimetry can detect central micro–scotomas (less than 5° in size) in early stages of Multiple Sclerosis while no visual loss or standard 30–2 GIII static perimetry abnormalities are detectable. Retinal sensitivity was found reduced in course of MS. Both this parameters could be used to follow up the disease of young patient with MS while assessing treatment effectiveness or predicting general, neurologic or ocular recurrences.

Keywords: neuro-ophthalmology: diagnosis • perimetry • optic disc