Multimodal retinal imaging in multiple sclerosis with and without optic neuritis

Abstract

Purpose: To correlate multiple spectral domain OCT (SD-OCT) measures to microperimetric data in patients with multiple sclerosis (MS), with and without previous optic neuritis (ON).

Methods: Patients with relapsing-remitting MS, with and without history of ON, with uni-or bilateral pale optic disc were enrolled. Each patient was studied by SD-OCT (Spectralis HRA+OCT Heidelberg, Engineering, Heidelberg, Germany) to measure central retinal thickness, retinal nerve fibre layer thickness in the peripapillary area (pRNFL) and in the papillomacular bundle (PMB). Using dedicated SD-OCT software individual retinal layers were identified and measured (thickness) in the perifoveal area. Each patient underwent microperimetry (MP1 Microperimeter, Nidek, Gamagori, Japan) to assess retinal sensitivity in the peripapillary and macular area. All patients underwent a complete neurological and ophthalmological examination. An age-matched group of healthy subjects was used as control.

Results: Thirty-eight patients (mean age 37 ± 8 years; 25 female and 13 male; 76 eyes) with relapsing-remitting MS were enrolled: 19 patients had a history of at least one episode of ON (ON-MS), in 19 patients a pale optic disc was present at the fundus examination with no history of ON (POD-MS). The control group consisted of 20 healthy subjects (40 eyes) (mean age 36 ± 9 years). Mean pRNFL and PMB were significantly thinner in the MS patients versus controls (pRNFL: 89.83 ± 13.06 μm vs 97.83 ± 8.56, p= 0.021; PMB: 48.72 ± 11.17 μm vs 58.41 ± 5.89, p= 0.000). The retinal ganglion cell layer was significantly thinner in the ON-SM than in POD-MS patients (7 ± 4.9 μm vs 9.4 ± 2.3 μm, p= 0.0252). The reduction of mean retinal sensitivity, and peripapillary and macular sensitivity were significantly correlated to pRNFL and PMB thinning and to ON history. Retinal sensitivity reduction in the macular area was correlated to the thickening of the retinal outer plexiform layer.

Conclusions: MS induces variable changes inside the retina. These changes involve not only the inner retina, but also the outer retinal layers and are correlated to the reduction of retinal sensitivity. These findings suggest that retinal reorganization occurs after degeneration of individual retinal layers with secondary functional alterations.

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 642 perimetry • 688 retina