BackgroundAlzheimer's disease (AD) pathology precedes symptoms and its detection can identify atrisk individuals who may benefit from early treatment. Since the retinal nerve fiber layer (RNFL) is depleted in established AD, we tested whether its thickness can predict whether cognitively healthy (CH) individuals have a normal or pathological cerebrospinal fluid (CSF) Aß 42 (A) and tau (T) ratio. MethodsAs part of an ongoing longitudinal study, we enrolled CH individuals, excluding those with cognitive impairment and significant ocular pathology. We classified the CH group into two sub-groups, normal (CH-NAT, n = 16) or pathological (CH-PAT, n = 27), using a logistic regression model from the CSF AT ratio that identified >85% of patients with a clinically probable AD diagnosis. Spectral-domain optical coherence tomography (OCT) was acquired for RNFL, ganglion cell-inner plexiform layer (GC-IPL), and macular thickness. Group differences were tested using mixed model repeated measures and a classification model derived using multiple logistic regression. ResultsMean age (± standard deviation) in the CH-PAT group (n = 27; 75.2 ± 8.4 years) was similar (p = 0.50) to the CH-NAT group (n = 16; 74.1 ± 7.9 years). Mean RNFL (standard error) was

The current study evaluated retinal function using electroretinography (ERG) in cognitively healthy (CH) participants with preclinical Alzheimer’s disease (AD), as classified by cerebral spinal fluid (CSF) Aβ42/Tau ratio. Individuals with normal retinal morphology ascertained by spectral-domain optical coherence tomography were enrolled. Full-field ERG, pattern PERG, and photopic negative response (PhNR) were performed in 29 adult participants (58 eyes). Amplitude and implicit times of the ERG wave components were analyzed. Preclinical AD participants showed marked retinal ganglion cell dysfunction relative to controls. The PhNR was significantly diminished in preclinical AD relative to controls. PhNR amplitude and N95 implicit time differentiated CH individuals with CSF biomarkers of AD pathology with 87% sensitivity and 82% specificity. These quantitative electrophysiologic findings expand our understanding of early retinal functional changes that precede cognitive decline in AD. Retinal ganglion cell dysfunction, as detected by ERG, may be a clinically useful, non-invasive in vivo biomarker for early disease detection, which is necessary for ultimately pursuing early intervention.

PurposePeripapillary vascular alterations have been classically described as hallmarks of Leber's Hereditary Optic Neuropathy (LHON). We recently demonstrated microvascular pathology involving the macula in patients affected with chronic LHON using optical coherence tomography angiography (OCTA). Macular vascular pathology in acute LHON has not previously been reported.MethodsThe macular superficial vasculature of an asymptomatic carrier and an affected patient with acute LHON, mitochondrial DNA mutation 3460, was assessed by OCTA.ResultsSimilar findings of peripapillary microangiopathy and vascular telangiectasias were seen the affected patient, but in the parafoveal macula. These changes were most prominent nasally and inferiorly, corresponding to the proximal portions of the papillomacular bundle. The foveal avascular zone was markedly enlarged in the affected patient relative to the asymptomatic mother.ConclusionsThese findings in acute LHON further supports the clinical utility of vascular parameters and suggest that further studies focused on macular pathology may be warranted to assess the natural history of LHON.