Retinal Nerve Fiber Layer Thickness in Chronic Obstructive Pulmonary Disease: An Optical Coherence Tomography Study
Background: To evaluate changes in the retinal nerve fiber layer (RNFL) thickness in patients with chronic obstructive pulmonary disease (COPD) using optical coherence tomography (OCT).
Methods: In this case-controlled study, COPD subjectswith various disease durations andseverity were recruited. The standard global initiative for chronic obstructive lung disease (GOLD) criteria was used to determine the severity of COPD in the subjects.Healthy individuals were recruited as the control group. Peripapillary RNFL thickness was measured using spectral domain OCT.
Results: Seventy oneeyes of71 COPD patients and 71 eyes ofhealthy controls were examined. The RNFL in all quadrants and the average RNFL were significantly thinner in patients with COPD compared to the control group (p<0.05). There were significant correlationsbetween severity of COPD and RNFL thickness (p<0.05) for the average RNFL (r=0.831) and RNFL in all quadrants(superior RNFLr=0.736, inferior RNFL r=0.681, nasal RNFL r=0.600, andtemporal RNFL r=0.353). Similar significant correlations were found between RNFL thickness and duration of COPD (p<0.005) for the average RNFL(r=-0.674) and RNFL in all quadrants (superior r=-0.615, inferior r=-0.472, nasal r=-0.484, and temporal r=-0.323). The risk of having a thin RNFL (odds ratio) was 13 fold higher in patients with COPD.
Conclusions: These results suggest that COPD causes thinning of the RNFL, and severe retinal nerve fiber injury occurs more frequently in advanced COPD.