Assessment of macular thickness changes by OCT in asymptomatic subjects at high genetic risk of developing Alzheimer’s disease

Abstract

PurposeAlzheimer’s diseases is a neurodegenerative disease, whose signs can appear decades before clinically detectable symptoms. In addition to age, genetic factors are one of the most important risk factors. The aim of the present study was analyzed the macular thickness changes by optical coherence tomography (OCT) in subjects who have a first‐degree family history of AD and are carriers of ɛ4 allele for the ApoE, which are two of the main risk factors for developing the disease.MethodsA complete eye examination and a macular OCT were performed in 64 participants, who were free of ocular pathology. The two study groups were formed by 35 subjects with a family history of AD (FH+) and ApoE ɛ4 carriers and 29 age‐matched control subjects without a family history of AD (FH‐) and ApoE ɛ4 non‐carriers.ResultsWe found a statistical significant thinning (p < 0.05) in FH+ ApoE ɛ4 carriers compared to FH‐ ApoE ɛ4 non‐carriers in the next sectors and layers: the foveal area of the macular retinal nerve fiber layer (11.89 ± 1.95, FH+ vs 12.86 ± 1.62, FH‐); the inferior and nasal sectors, both in the outer (26.77 ± 2.74, FH+ vs 28.17 ± 2.82, FH‐) (29.49 ± 2.89, FH+ vs 30.93 ± 3.85, FH‐) and inner (40.49 ± 2.51, FH+ vs 42.10 ± 3.48, FH‐) (41.94 ± 2.74, FH+ vs 43.52 ± 3.57, FH‐) macular ring in the inner plexiform layer; the foveal area (18.82 ± 3.61, FH+ vs 21.21 ± 3.88, FH‐) and the inferior sector in the outer macular ring (30.91 ± 2.72, FH+ vs 32.10 ± 2.81, FH‐) in inner nuclear layer, and the inferior sector of the outer macular ring (27.60 ± 2.75, FH+ vs 29.97 ± 3.82, FH‐) in outer plexiform layer.ConclusionsThe slight retinal thickness changes measured by OCT, that appear in the macular area in asymptomatic subjects at high genetic risk for the development of AD, could be used as an early biomarker of the disease.