Purchase this article with an account.
Imre Lengyel, Lajos Csincsik, Nicola Quinn, Tom MacGillivray, Timothy Shakespeare, Sebastian Crutch, Tunde Peto; Ultrawide-field retinal imaging markers for atypical and typical Alzheimer's disease. Invest. Ophthalmol. Vis. Sci. 2019;60(9):2198.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Posterior Cortical Atrophy (PCA) is a neurodegenerative syndrome that is characterized by progressive degeneration of parietal and occipital lobe with associated cortical visual impairment. The most common cause of PCA is Alzheimer`s disease (AD). Retinal nerve fibre layer (RNFL) atrophy, changes in retinal vessel calibres and an increase in drusen deposition have been associated with typical AD (tAD). In this study, we examined images of the retina of patients with PCA and compare these to tAD and healthy controls (HC) to uncover whether the visual impairments in PCA could be partly due to changes in the retina.
Ultra-wide-field colour and autofluorescence images (UWFI) and optical coherence tomography (OCT) scans were acquired of 33 PCA (MMSE<24), 28 tAD (MMSE<20) patients and 71 HC (MMSE>28) using OPTOS P200Tx scanning laser ophthalmoscope (SLO) and OPTOS OCT-SLO. Images with poor quality were removed from analysis. UWFI were analysed using the so-called Machester grid and the Vampire software while OCT scans were analysed using the OPTOS OCT Viewer (v1.89) and OCTseg (v0.4) software. The study had full local Ethical Committee approval. Images were graded for absence/presence of pathological abnormalities by two independent graders masked to the group the images were acquired from. Statistical analysis was carried out using STATA and SPSS.
UWFI detected lower prevalence of reticular pseudodrusen in PCA (10%) than in tAD (30%) or HC (17%) [χ2=6.879, df=2, p=0.032]. There was a lower prevalence of far-peripheral hyper-fluorescence changes in tAD (24%) compared to PCA (44%) or HC (43%) [χ2=5.736, df=2, p=0.057]. More tortuous retinal vasculature was observed in tAD (45%) compared to PCA (22%) or HC (18%) [χ2=15.545, df=2, p<0.001]. Analysis of OCT scans showed a significant reduction in peripapillary outer plexiform-inner nuclear layer thickness in patients with PCA compared to HC (64.15µm±7.45µm vs 68.7µm ±9.45µm, p=0.049) and a significant increase in total ppVC in both PCA (457.05µm ±89.85µm) and tAD (478.4µm±83.4) compared to HC (411.15µm ±82.75µm) (p<0.05).
In this cross-sectional prospective study, we found several retinal changes associated with both PCA and tAD, suggesting that monitoring retinal changes could become an inexpensive, well tolerated and readily repeatable marker for monitoring progression of dementia.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
This PDF is available to Subscribers Only