OCT in Alzheimer’s disease: thinning of the RNFL and superior hemiretina
- 371 Downloads
Peripapillary retinal nerve fiber layer (pRNFL) and internal macular layer thinning have been demonstrated in Alzheimer’s disease (AD) with optical coherence tomography (OCT) studies. The purpose of this study is to compare the pRNFL thickness and overall retinal thickness (RT) in AD patients with non-AD patients, using spectral domain optical coherence tomography (SD-OCT) and determine the sectors most characteristically affected in AD.
A cross-sectional study was performed to determine the pRNFL and overall macular RT thicknesses in AD and non-AD patients, attending a tertiary hospital center. For pRNFL, the global and six peripapillary quadrants were calculated, and for overall RT values, the nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas were used. A multiple regression analysis was applied to assess the effects of disease, age, gender, spherical equivalent, visual acuity, intraocular pressure, axial length and blood pressure on pRNFL and overall macular RT.
A total of 202 subjects, including 50 eyes of 50 patients with mild AD (mean age 73.10; SD = 5.36 years) and 152 eyes of 152 patients without AD (mean age 71.03; SD = 4.62 years). After Bonferroni correction, the pRNFL was significantly thinner for the AD group globally and in the temporal superior quadrant (10.76 μm and 20.09 μm mean decrease, respectively). The RT thickness was also decreased in superior sectors S3 and S6 (mean thinning of 9.92 μm and 11.65 μm, respectively). Spearman’s correlation coefficient showed a direct association between pRNFL in the temporal superior quadrant and RT in superior S6 and S3 sectors (rS = 0.41; p < 0.001 and rS = 0.28; p < 0.001, respectively).
Patients with AD showed a significant thickness reduction in global and temporal superior quadrants in pRNFL and in superior pericentral and peripheral sectors of RT. These findings may reflect a peripapillary and retinal changes characteristic of AD, suggesting the importance of SD-OCT as a potential adjuvant in early diagnosis of AD. Further studies are needed to understand which retinal layers and macular sectors are more useful as potential ocular biomarker over time in AD.
KeywordsAlzheimer’s disease Spectral domain optical coherence tomography RNFL Retina Macula
We would like to thank Bruno Oliveira-Santos for the helpful cooperation in collecting the OCT data. We thank Dr. Paula Mota and Dr. Joana Tavares-Ferreira for the detailed reading and comments on the manuscript.
Compliance with ethical standards
No funding was received for this research.
Conflict of Interest
All authors certify that they have no affiliationswith or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
All procedures performed in studies involving humanparticipants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individualparticipants included in the study.
None of the authors have any conflict of interest.
- 2.Perl DP, Perl DP (2010) Neuropathology of Alzheimer ’ s Disease Address Correspondence to : 32–42. doi: 10.1002/MSJ
- 8.Blanks JC, Hinton DR, Sadun AA, Miller CA (1989) Retinal ganglion cell degeneration in Alzheimer’s disease. Brain Res 501:364–372Google Scholar
- 9.Parisi V, Restuccia R, Fattapposta F, et al (2001) Morphological and functional retinal impairment in Alzheimer’s disease patients. 112:1860–1867Google Scholar
- 10.Berisha F, Feke GT, Trempe CL, et al (2007) Retinal Abnormalities in Early Alzheimer ’ s Disease. 48:6–10. doi: 10.1167/iovs.06-1029
- 14.Iseri PK, Tokay T (2006) Relationship between Cognitive Impairment and Retinal Morphological and Visual Functional Abnormalities in Alzheimer Disease. 26:18–24Google Scholar
- 16.Salobrar-garcia E, Hoz R De, Rojas B, et al (2015) Findings in Mild Alzheimer ’ s Disease. 2015:17–19. doi: 10.1155/2015/736949
- 17.Ascaso FJ, Cruz N, Modrego PJ, Cristo A (2014) Retinal alterations in mild cognitive impairment and Alzheimer ’ s disease : an optical coherence tomography study. 1522–1530. doi: 10.1007/s00415-014-7374-z
- 21.Marziani E, Pomati S, Ramolfo P, et al (2016) Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness in Alzheimer ’ s Disease Using Spectral- Domain Optical Coherence Tomography. doi: 10.1167/iovs.13-12046
- 22.Ong Y, Ong Y, Ikram MK, et al (2014) Potential Applications of Spectral-Domain Optical Coherence Tomography ( SD-OCT ) in the Study of Alzheimer ’ s Disease. 23:74–83Google Scholar
- 25.Salobrar-Garcia E, Hoyas I, Leal M, et al (2015) Analysis of Retinal Peripapillary Segmentation in Early Alzheimer ’ s Disease Patients. doi: 10.1155/2015/636548
- 26.Ozdemir E, Eda O, Seda D (2015) The relationship between the degree of cognitive impairment and retinal nerve fiber layer thickness. Neurol Sci:1141–1146. doi: 10.1007/s10072-014-2055-3
- 28.Paquet C, Roger F, Dighiero P, et al (2007) Abnormal retinal thickness in patients with mild cognitive impairment and Alzheimer ’ s disease. 420:97–99. doi: 10.1016/j.neulet.2007.02.090
- 31.Coppola G, Renzo A Di, Ziccardi L, Martelli F (2015) Optical Coherence Tomography in Alzheimer ’ s Disease : A Meta-Analysis. 1–14. doi: 10.1371/journal.pone.0134750Google Scholar
- 32.Cunha JP, Moura-Coelho N, Proença RP, et al (2016) Alzheimer’s disease: A review of its visual system neuropathology. Optical coherence tomography—a potential role as a study tool in vivo. Graefe’s Arch Clin Exp Ophthalmol. doi: 10.1007/s00417-016-3430-y
- 36.Pillai JA, Bermel R, Bonner-Jackson A, et al (2016) Retinal Nerve Fiber Layer Thinning in Alzheimer’s Disease: A Case-Control Study in Comparison to Normal Aging, Parkinson’s Disease, and Non-Alzheimer’s Dementia. Am J Alzheimers Dis Other Demen. doi: 10.1177/1533317515628053
- 41.Hafkemeijer A, Möller C, Dopper EGP, Jiskoot LC (2015) Resting state functional connectivity differences between behavioral variant frontotemporal dementia and Alzheimer ’ s disease. 9:1–12. doi: 10.3389/fnhum.2015.00474
- 42.Hafkemeijer A, Christiane M (2017) A Longitudinal Study on Resting State Functional Connectivity in Behavioral Variant Frontotemporal Dementia and Alzheimer ’ s Disease. 55:521–537. doi: 10.3233/JAD-150695