Macular Thickness Evaluation in Parkinson's
Disease using Spectral Domain
Optical Coherence Tomography:
A Case-control Study
NC13-NC16
Correspondence
Srinivas Phani Nakkella,
Flat No. 404, Venu Abode, Durganagar, Chandram Palem,
Visakhapatnam, Andhra Pradesh, India.
E-mail: srinivasphani44@gmail.com
Introduction: Parkinson's Disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. Its incidence is increasing worldwide, along with population aging and a longer life span. Since the retina is part of the Central Nervous System, the dopaminergic cells are present in the retina too.
Aim: To evaluate central macular thickness, average macular thickness, and macular volume changes in Parkinson's cases and compare them with age and gender matched healthy control group using Spectral Domain Optical Coherence Tomography (SD-OCT).
Materials and Methods: This was a case-control study, conducted from January 2019 to October 2020 in the Department of Ophthalmology and the Department of Neurology Outpatient Department (OPD) of Government Regional Eye Hospital, Andhra Medical College, Visakhapatnam, Andhra Pradesh, India. Total 50 diagnosed cases of PD using the United Kingdom Parkinson's Disease Society Brain Bank criteria were included in the study. Fifty age and the gender matched healthy group were included as controls. Both groups underwent retinal imaging with SD-OCT using Macular scans with 6 mm in diameter, centered at the foveola measuring macular thickness and macular volume averages for each of the nine map areas and data was incorporated into a logistic regression model to predict changes. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 22.0 (released 2013 Armonk, NY: IBM Corp.).
Results: There were 24 male and 26 female in both the groups, with maximum in the age group of 51-60 years. There was no significant difference between the various groups in terms of the age and gender. There was a significant difference between the two groups in terms of central macular thickness (W=549.0, p-value <0.001), with the median central macular thickness (μm) being highest in the control group. There was a significant difference between the two groups in terms of macular volume (cumm) (t=-5.193, p-value <0.001), with the mean macular volume (cumm) being highest in the control group. There was no significant difference between the groups in terms of average macular thickness (μm) (W=1534.000, p-value=0.050). However, for every one unit increase in duration of disease (years), the average macular thickness (μm) decreases by 2.70 units (rho=-0.64, p-value <0.001).
Conclusion: The macular thickness decreases with increasing disease duration in patients with PD patients compared to age and gender matched.