OCT parameters of the optic nerve head and the retina as surrogate markers of brain volume in a normal population, a pilot study

Abstract

The relationship between optical coherence tomography (OCT) measurements of the retinal structures has been described for various neurological diseases including Multiple Sclerosis (MS), Alzheimer's disease (AD) and Parkinson's disease (PD). Brain volume changes, both globally and by area, are associated with some of these same diseases, yet the correlation of OCT and disease is not fully elucidated.Our study looked at normal subjects, at the correlation of OCT measurements and brain volumes, both globally and for specific regions including the pericalcarine grey matter, entorhinal grey matter, and cerebellar volume using a retrospective, cross-sectional cohort study design.Thickness of the retinal nerve fiber layer (RNFL) as measured by OCT, correlated with volume of the pericalcarine grey matter, when adjusted for age and gender. Similarly, thickness of the ganglion cell layer-inner plexiform layer complex may be associated with both entorhinal grey matter volumes and total cerebellar volumes, although our pilot study did not reach statistical significance. This suggests that both eye and brain volumes follow a similar trajectory and understanding the inter-relationship of these structures will aid in the analysis of changes seen in disease. Further studies are needed to longitudinally demonstrate these relationships.

The relationship between retinal layers and brain areas in asymptomatic first-degree relatives of sporadic forms of Alzheimer’s disease: an exploratory analysis

“…Chua et al, in a large population-based study (2131 participants) aged between 40 and 69 years old, also found that GCL thinning and total macular thickness were significantly associated with smaller hippocampal volume [ 49 ]. These findings are consistent with another study in 20 cognitively healthy, younger patients (50.5 ± 14.1 years old), where it was found that entorhinal gray matter volume was correlated with the GC-IPL complex [ 50 ]. In our FH− ApoE ɛ4− group, there was a significantly inverse correlation in the IPL between the volumes of the outer nasal macular sector and the volumes of the left parahippocampal region, the right entorhinal region, the right and left medial temporal lobule, the right and left hippocampus, the right lingual gyrus, the left cuneus, the right ventral diencephalon, and the left amygdala (Table 7 ).…”

Changes in retinal multilayer thickness and vascular network of patients with Alzheimer’s disease

“…Furthermore, the inner retina and brain share a common embryonic origin, which can directly reflect the characteristics of brain neurons. The OCT parameters of both global and specific retinal regions are needed to evaluate the accuracy of brain trajectory test [ 40 , 41 ].…”

Retinal Vasculopathy in Alzheimer’s Disease

“…Paquet et al (2007) further described a significant reduction of retinal NFL thickness in MCI, mild AD, moderate AD, and severe AD patients compared to healthy controls. Subsequently, numerous studies verified these early studies and reported decreases in NFL, ganglion cell layer (GCL), and macula thickness correlating with cognitive decline (Kromer et al, 2014;Doustar et al, 2017;Ferrari et al, 2017;Polans et al, 2017;Polo et al, 2017;Bulut et al, 2018;Janez-Escalada et al, 2019;Salobrar-Garcia et al, 2019;Czako et al, 2020;Dumitrascu and Koronyo-Hamaoui, 2020;Mejia-Vergara et al, 2021;Yan et al, 2021). OCT-adaptive optics is a relatively newer advancement of this technology which provides ultra-high-resolution images, including of blood vessel walls, that warrants further testing in the AD retina (Snyder et al, 2021).…”