Baseline retinal nerve fiber layer thickness and macular volume quantified by OCT in the North American phase 3 fingolimod trial for relapsing-remitting multiple sclerosis.
BACKGROUND
Patients with multiple sclerosis (MS) demonstrate thinning of peripapillary retinal nerve fiber layer (RNFL) and decreased macular volume as measured by optical coherence tomography (OCT). To our knowledge, there are no previous reports from a large MS OCT database with strict quality control measures that quantitate RNFL and macula in patients with relapsing-remitting multiple sclerosis.


METHODS
The University of California Davis OCT Reading Center gathered OCT data at baseline as part of the North American phase 3 trial of fingolimod (Gilenya). Average RNFL thickness (RNFLT) and macular volume (TMV) were measured using time domain OCT (TD-OCT). RNFL quadrants, clock hours, and macular subfields were included. With strict quality control and accounting for signal strength differences, scans were categorized as "reduced" or "not reduced" for each field, based on being less than 5th percentile for age-matched controls derived from the normative database in the scanner software. Patients were deemed "abnormal" if at least 1 eye had reduced values for a given parameter. Patients with abnormalities in corresponding RNFL and macular subfields were compared by cross-tabulation.


RESULTS
The TD-OCT data were prospectively collected from 939 of the 1,083 trial patients, 712 of whom met all final quality and data inclusion criteria. Of the final cohort, 242 (34.0%) demonstrated reduced (less than 5th percentile) average RNFLT in at least 1 eye. One hundred seventy-eight (25.0%) patients had reduced TMV. One hundred twenty-eight (18.0%) demonstrated both reduced TMV and RNFLT in the same eye, whereas 42 (5.8%) had reduced TMV and RNFLT in both eyes. Of the 242 patients with reduced average RNFL thickness, 128 (52.9%) also had reduced TMV. Fifty patients had reduced TMV in the absence of reduced RNFLT in at least 1 eye, a cohort prevalence of 7.0%. Quadrant and subfield analysis showed a predominance of temporal and inferior RNFL thinning, with inferior macular thinning corresponding best to RNFL thinning.


CONCLUSIONS
RNFL and macular thinning/volume loss is common at baseline in relapsing-remitting multiple sclerosis, as measured by TD-OCT. When the RNFL is thin, the macular volume is reduced in more than half of the patients. There is a population of reduced TMV without any reduction in RNFLT. Documenting the prevalence and distribution of these structural abnormalities supports recent reports and suggests new retinal areas to probe for functional vision changes in MS.
Department of Ophthalmology (KMW), Veterans Administration Medical Center, Portland, Oregon; Department of Ophthalmology and Vision Science (KMW, JSW, KEC, JLK), Division of Biostatistics (DJH), Department of Public Health Sciences, and Departments of Neurology and Neurosurgery (JLK), University of California Davis School of Medicine, Davis, California; Carl Zeiss Meditec, Inc (MKD), Dublin, California; Department of Neurology (LJB), New York University Langone Medical Center, New York, New York; and Department of Neurology (PAC), Johns Hopkins University School of Medicine, Baltimore, Maryland.
Kimberly M
KM
Winges
John S
JS
Werner
Danielle J
DJ
Harvey
Kimberly E
KE
Cello
Mary K
MK
Durbin
Laura J
LJ
Balcer
Peter A
PA
Calabresi
John L
JL
Keltner
D000293:Adolescent; D000328:Adult; D005260:Female; D000068876:Fingolimod Hydrochloride; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008266:Macula Lutea / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy* / Q000473:pathology*; D009412:Nerve Fibers / Q000187:drug effects / Q000473:pathology; D009656:North America; D011409:Propylene Glycols / Q000627:therapeutic use*; D012160:Retina / Q000473:pathology; D012189:Retrospective Studies; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D041623:Tomography, Optical Coherence; D055815:Young Adult
D007166:Immunosuppressive Agents; D011409:Propylene Glycols; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine