Abstract
Purpose:
To evaluate the thickness of the macular Ganglion Cell Complex (GCC) and peripapillary Retinal Nerve Fiber Layer (pRNFL) with Spectral Domain Optical Coherence Tomography (SD OCT) in Multiple Sclerosis (MS) patients
Methods:
66 MS consecutive patients, of whom 42 with history of monocular/binocular Optic Neuritis (ON), 24 without ON, and 22 healthy control patients were recruited. Exclusion criteria were: age > 45 yrs, EDSS score >4.5, ON episode in the last 6 months prior to enrollment, refractive error/astigmatism of ≥ 5.00 D, retinal diseases and other optic neuropathy including glaucoma, previous eye surgery and amblyopia. Eyes were written in 4 groups: 44 MS-ON eyes, 40 contralateral non affected MS-ON group eyes, 48 MS-non-ON group eyes, 44 healthy control eyes. GCC and pRNFL measurements were performed by SD-OCT (Optovue). Results were compared using T-Student Test
Results:
pRNFL and GCC thicknesses were significantly decreased in MS-ON eyes compared to control group (p<0,0001). Same results were found in MS-ON eyes compared to MS-non-ON eyes (p<0.0001). GCC thickness was considerably decreased in contralateral non affected MS-ON group eyes compared to control group (p=0.0001) whereas pRNFL values were not statistically significant (Temporal p=0.003, Superior p=0.394, Nasal p=0.723, Inferior p=0.034). Contralateral non affected MS-ON group eyes compared to MS-ON eyes were highly decreased in GCC and RNFL values (p<0.0001). pRNFL thickness was not significantly lower in the MS-non-ON eyes compared to controls (Temporal p=0.210, Superior p=0.376, Nasal p=0.282, Inferior p =0.659), while GCC average thickness was considerable decreased (p=0.0005). GCC was thinner in the Inferior part (p<0.0001) and showed a statistically significant Focal Loss Volume (FLV%)
Conclusions:
GCC thickness was decreased in MS patients compared to healthy control group, regardless of any previous ON episode. As opposed to GCC, RNFL was reduced only in MS-ON patients. Those results confirmed that retrograde axonal degeneration is always present in MS regardless of symptomatic ON. SD OCT and GCC protocol in particular, could allow a more accurate view in MS research providing understanding of the pathophysiology, detection of occult neuro-degeneration and monitoring of neuroprotective therapies
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
531 ganglion cells •
610 nerve fiber layer