Retinal nerve fiber layer thickness changes in Parkinson disease: a meta-analysis

Area of Science:

• Ophthalmology
• Neurology
• Medical Imaging

Background:

• Parkinson disease (PD) involves the loss of dopaminergic neurons.
• Optical coherence tomography (OCT) is used to assess retinal nerve fiber layer (RNFL) thickness.
• Previous studies on RNFL thickness in PD have yielded inconsistent results.

Purpose of the Study:

• To conduct a meta-analysis evaluating RNFL thickness in PD patients using OCT.
• To synthesize findings from existing case-control studies on RNFL thickness and PD.

Main Methods:

• Systematic electronic search of Cochrane Controlled Trials Register, PUBMED, and EMBASE.
• Inclusion of 13 case-control studies with 644 PD patients and 604 healthy controls.
• Calculation of weighted mean difference (WMD) and 95% confidence intervals (CI) for RNFL thickness.

Main Results:

• Significant reduction in average RNFL thickness in PD patients versus controls (WMD = -5.76, P = 0.0005).
• Significant RNFL thinning observed in superior, inferior, nasal, and temporal quadrants in PD patients.
• All quadrant-specific differences were statistically significant (P < 0.01).

Conclusions:

• OCT demonstrates a significant reduction in RNFL thickness in Parkinson disease patients.
• The noninvasive nature of OCT suggests its potential utility in monitoring PD progression.
• OCT may serve as a valuable tool for assessing disease progression in Parkinson disease.