The Relationship between Age-Related Macular Degeneration and Olfactory Function

Abstract

Background: Olfactory dysfunction is a common symptom of many neurodegenerative diseases, and age-related macular degeneration (AMD) is a late-onset neurodegenerative disease. Objective: Thus, the aim of this study was to investigate olfactory functions in patients with AMD. Methods: A total of 69 subjects with AMD and 69 age- and sex-matched healthy controls were enrolled. After a complete ophthalmic evaluation, the AMD patients were subclassified as early- and late-stage AMD. Psychophysical testing of olfactory function was performed using the validated Sniffin' Sticks test. Results: This study was carried out in 138 subjects, with a mean age of 74.3 ± 8.9 years (range 51-89). The current investigation showed the following two major findings: (1) patients with AMD had decreased olfactory abilities, especially in odor discrimination and odor identification, even at early stages compared to controls, whereas patients had decreased olfactory abilities in all subtasks of olfactory testings in advanced stages of AMD disease, and (2) as the visual acuity of AMD patients decreased, the olfactory abilities of these patients worsened. Conclusion: This study demonstrated that AMD had significant negative effects on all orthonasal olfactory tasks, particularly in advanced stages. Similar to other neurodegenerative diseases, odor discrimination and identification seemed to be more affected than odor detection threshold tasks.