Assessment of Optic Nerve Head and Retinal Nerve Fibre Layer Changes and Evaluation of Frequency of Glaucoma in Patients with Alzheimer's Disease

Purpose: : Several studies have shown that patients with Alzheimer’s Disease (AD) have a significantly increased rate of glaucoma occurrence. The purpose of the study was to evaluate the frequency of glaucoma and changes of the optic nerve head (ONH) morphology and/or retinal nerve fiber layer (RNFL) thickness in patients with AD. Methods: : 94 eyes of AD subjects and 127 eyes from age-matched controls underwent a complete eye examination including measurements of IOP, central corneal thickness and visual field testing using a Matrix FDT. ONH and RNFL assessment was performed both by slit lamp biomicroscopy and HRT III examination. The diagnosis of glaucoma was based on the presence of at least two of the following criteria: visual field defects characteristic of or compatible with glaucoma, specific ONH alterations and/or changes of HRT parameters. Results: : The Glaucoma Probability Score and Moorfields Regression Analysis (Mann Whitney U test: 0,004 and 0,001, respectively) and HRT3 stereometric parameters Rim Vol, RNFL thickness (ANOVA Tests of Between-Subjects Effects: 0,039 and 0,001, respectively) resulted significantly different along with the Matrix parameters MD (ANOVA: 0,001), PSD and GHT (Mann Whitney U test: 0,001 and 0,001 respectively) in patients with AD compared to the controls. The IOP mean value resulted to be significantly reduced (ANOVA: 0,001) in AD compared to controls. The frequency of glaucoma in AD patients (25,5 %) was significantly higher than in control group (5,5%) (p= 0.001). Conclusions: : The study confirmed that patients with AD have a higher frequency of glaucoma in the absence of elevated IOP levels. HRT III seems to be an useful tool in detecting ONH and RNFL changes in AD patients.