Abstract
Purpose :
To assess the differences between the retinal thickness, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), choroidal (Ch) thicknesses and intracranial pressure in patients with Alzheimer's disease (AD), normal tension glaucoma (NTG), and healthy contols.
Methods :
12 early stage AD, 21 NTG patients and 15 healthy controls underwent neurophysiological and comprehensive ophthalmic evaluation. Retinal, RNFL, GCL and Ch thicknesses were evaluated in macular and peripapillary regions with SS-OCT (Topcon, DRI OCT Triton). Intracranial pressure (ICP) was measured using non-invasive transcranial doppler device (Vittamed). A single eye (left one) from each patient was chosen to perform the analysis. The level of significance p<0.05 was considered significant.
Results :
Non-invasive ICP was 8.71(3.2)mmHg in AD, 7.5(2.7)mmHg in NTG and 9.94(2.6)mmHg in control group (significant difference was found between NTG and healthy controls,p=0.02). There was a tendency of RNFL and GCL to be thinner in both macular and peripapillary regions in NTG than AD and healthy controls. Significant differences were found in outer superior and nasal retinal thicknesses and GCL outer and inner layers in macular area, superior and inferior RNFL between NTG and healthy controls (p<0.05). The retinal and GCL thicknesses in the central macular region were significantly lower in AD patients compared to healthy controls (p=0.048). GCL thickness was signifficantly lower in inner macular regions in NTG compared to AD patients (superior p=0.049; inferior p=0.04; temporal p=0.02). There was a tendency of lower Ch thickness in AD patients compared to NTG and healthy controls in both macular and peripapillary regions, however the differences were not significant (p>0,05). AD patients had significantly lower nasal peripapillary Ch thickness compared to healthy controls (p=0.04). ICP was correlated with peripapillary Ch thickness in nasal quadrant (r=0.64, p=0.03) in AD patients.
Conclusions :
NTG patients had lower RNFL and GCL thickneses, while AD patients tended to have lower Ch thikness. AD patients had lower retinal and GCL thicknesses centraly, while NTG patiens had changes in GCL inner parts compared to healthy controls. Higher ICP was associated with thicker Ch in AD patients. Further prospective studies are needed to evaluate retinal changes in AD patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.