Retinal damage could be due to subclinical inflammation in optic nerve

[frodo]

Retinal and brain damage during multiple sclerosis course: inflammatory activity is a key factor in the first 5 years

https://www.nature.com/articles/s41598-020-70255-z

The mechanisms by which the retina is damaged in MS may involve primary retinal degeneration, trans-synaptic degeneration due to lesions in the posterior afferent visual pathway and retrograde degeneration due to inflammation (clinical or sub-clinical) in the optic nerve.

The close time relationship observed in our study between focal brain inflammatory activity and retinal changes suggests a fundamental role of sub-clinical micro-inflammation in the optic nerve for retinal neuro-axonal damage in the first years of MS onset

[frodo]

Characterization of Retinal vascular changes in Multiple Sclerosis using Adaptive Optics and OCTA

https://iovs.arvojournals.org/article.a ... id=2768856

Abstract

Purpose : Characterize microstructural retinal vascular changes in humans MS using AO-SLO.

Methods : This prospective, observational study enrolled 6 stable RRMS and 5 stable SPMS subjects (age 26-74 years, 9 (82%) female, MS duration 1.2-35.3 years, EDSS 0-7). 1 eye in each group had history of optic neuritis (ON). OCTA was used to measure RVD for the area around the optic nerve and in superficial and deep layers of the macula. Multiple AO-SLO techniques, including confocal reflectance and split-detection, were used to image the retinal vessels. Presence and degree of AO-SLO retinal changes were compared with regards to markers of MS disease progression.

Results : Two kinds of vascular changes were observed on AO-SLO in MS eyes:

- Paravascular changes, consisting of hyporeflective lines radiating from the vessel along the nerve fiber layer were seen along the small retinal vessels of 3/11 eyes in RRMS without history of ON and 2/8 SPMS without history of ON.

- Focal thickenings of the vascular wall were found in 2/8 SPMS eyes without ON and 2/11 RRMS eyes without ON.

The eyes with history of ON did not show either of these changes. There was no difference in OCTA measures between eyes with and without qualitative AO-SLO vascular changes. AO-SLO changes occurred almost exclusively in eyes with advanced RRMS or early SPMS.

Conclusions :

AO-SLO demonstrates focal retinal vessel changes in living human MS eyes without history of optic neuritis. These may correspond with microscopic retinal vascular changes previously observed in post-mortem samples.

Periphlebitis, a qualitative retinal vascular changes on clinical exam and retinal vessel density (RVD) decreased on OCTA have been observed in people with multiple sclerosis (MS). Focal microscopic changes in both inflamed and non-inflamed retinal vessels have been observed postmortem.

Adaptive optics scanning laser ophthalmoscopy (AO-SLO) facilitates viewing of the in vivo human retina with microscopic resolution and has not been widely applied in MS.