Sub-clinical atrophy of the retinal nerve fibre layer in multiple sclerosis.
OBJECTIVE
This study aimed to evaluate the presence of abnormalities in the retinal nerve fibre layer (RNFL) in multiple sclerosis (MS) patients with normal ophthalmic examination, and to compare the ability of optical coherence tomography (OCT) and scanning laser polarimetry (GDx) to detect axonal loss.


METHODS
Patients with MS and disease-free controls were invited to enrol in the study from 1 February 2007 to 30 June 2008. Ophthalmic examination, including evaluation of visual acuity (VA) and visual field (VF), showed normal results in all subjects. Retinal nerve fibre layer properties were measured by means of OCT and GDx. Visual evoked potentials (VEPs) were also recorded.


RESULTS
Forty eyes of 40 MS patients and 20 eyes of age- and sex-matched controls were included in the study. Despite normal VA and VF results, significant differences between the two groups were observed in VF mean deviation (MD), most of the RNFL measurements provided by OCT and GDx, and VEP P100 latency and amplitude. There was a significant correlation between OCT and GDx parameters, and between these parameters and VEP results. Nineteen MS eyes (35.7%) showed RNFL abnormalities detected either by OCT or GDx.


CONCLUSIONS
Sub-clinical ganglion cell loss can be detected in MS patients with normal visual function. Both OCT and GDx are useful complementary tools with which to identify this damage.
Pueyo
Victoria
V
Ophthalmology Department, Miguel Servet University Hospital, Zaragoza, Spain. vpueyo@salud.aragon.es
Ara
Jose Ramon
JR
Almarcegui
Carmen
C
Martin
Jesus
J
Güerri
Noemi
N
García
Elena
E
Pablo
Luis Emilio
LE
Honrubia
Francisco Manuel
FM
Fernandez
Francisco Javier
FJ
D000328:Adult; D000368:Aged; D001284:Atrophy; D001369:Axons / Q000473:pathology*; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000503:physiopathology; D009412:Nerve Fibers / Q000473:pathology*; D011930:Reaction Time; D012160:Retina / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D057109:Scanning Laser Polarimetry; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D014794:Visual Fields; D055815:Young Adult