Correlations between retinal nerve fiber layer thickness and cognitive progression in Parkinson's disease: A longitudinal study

Abstract

Background: Retinal abnormalities measured by optical coherence tomography (OCT) have been detected in both Parkinson's disease (PD) and Alzheimer's disease (AD). Cognitive impairment is not only found in AD, but 75-90% of PD patients will also develop dementia in the late stage of disease. We assessed whether baseline retinal nerve fiber layer (RNFL) thickness predicted worsening of cognitive status over time and the correlation between RNFL thickness and the detailed impaired cognitive domains in PD. Methods: RNFL thickness was measured using high-definition OCT in 78 non-dementia PD patients. Clinical and cognitive assessments were performed at baseline and at 3.61 ± 0.65 years follow-up. Linear mixed-effects models were used to examine associations between RNFL thickness and the changes in cognitive test scores, after adjusting for age, sex, disease duration and education. Results: Analysis of outcomes according to baseline RNFL tertiles showed worse performance in global cognitive tests, delayed memory, and executive functions in patients with a thin RNFL. During follow-up, greater cognitive deterioration was found in thin RNFL tertile patients. Lower baseline average RNFL thickness was associated with greater annualized decline in Mini-Mental State Examination and Montreal Cognitive Assessment. Conclusion:The correlation between RNFL thickness and cognitive dysfunction suggests that OCT may be useful for predicting cognitive dysfunction in PD patients.

Quantitative study of peripapillary retinal nerve fiber layer thickness and peripapillary vessel density in patients with different stages of Parkinson’s disease

“…Mitochondrial dysfunction in PD patients, such as mitochondrial DNA mutations and deletions, will severely affect the retinal oxygen supply [14] . The above pathological process will damage the optic nerve, resulting in a reduced ability of the optic nerve to transmit visual information to the brain, and this upstream nerve damage will exacerbate the progression of PD [15] . As a non-invasive imaging technique, OCTA can rapidly measure and analyze pRNFL thickness and blood flow to evaluate the degree of optic disc neurofibrillary cell loss and vascular degeneration in PD patients.…”

Parkinsonism and dementia

“…Furthermore, retinal abnormalities as measured by optical coherence tomography (OCT) appear to be promising in PDD. Studies have shown a correlation between retinal nerve fiber layer thickness or macular ganglion cell-inner plexiform layer complex thickness and cognitive dysfunction implying that OCT may be useful for predicting cognitive dysfunction in PD patients [71,72].…”

Will Artificial Intelligence Replace the Movement Disorders Specialist for Diagnosing and Managing Parkinson’s Disease?

“…The validation strategies used for clinical scales and questionnaires, where a new instrument must correlate with another already-validated measure, may not be sufficient for the validation of AI-generated outputs. While recognizing that the use of a “biomarker” identified from a population might not be appropriate for application to an individual [ 8 ], researchers may still need to compare AI outputs with those of established techniques such as quantitative MRI/SPECT [ 9 ], corneal confocal microscopy [ 10 ], camera tremor magnification [ 11 ], and retinal nerve fiber layer thickness [ 12 ].…”