Changes in Retinal Nerve Fiber Layer Thickness in Patients With Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Purpose

The purpose of this study is to evaluate the relationship between retinal nerve fiber layer (RNFL) thickness and the onset as well as progression of chronic obstructive pulmonary disease (COPD).

Methods

Database searches were conducted in PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang Data, VIP Database, and CBM, covering the period from each database's inception to March 2024.

Results

This meta-analysis included 15 studies from 2016 to 2023, comprising a total of 1455 participants (801 in the COPD group and 654 in the health group). The results showed a significant reduction in RNFL thickness across all quadrants (average, inferior, nasal, superior, and temporal) in the COPD group compared to the health group (MD: −4.46; 95%CI: −7.77 to −1.14; p = 0.008; MD: −8.17; 95%CI: −11.36 to −4.99; p < 0.00001; MD: −4.69; 95%CI: −7.22 to −2.16; p = 0.0003; MD: −4.83; 95%CI: −8.45 to −1.21; p = 0.009; MD: −2.89; 95%CI: −5.35 to −0.43; p = 0.02). In the mild/moderate COPD group, only the inferior RNFL (MD: −2.32; 95%CI: −4.40 to −0.24; p = 0.03) showed a significant reduction. However, in the severe COPD group, all quadrants were significantly reduced (MD: −5.89; 95%CI: −7.40 to −4.38; p < 0.0001; MD: −6.74; 95%CI: −10.71 to −2.77; p = 0.0009; MD: −4.29; 95%CI: −5.95 to −2.64; p < 0.0001; MD: −2.34; 95%CI: −4.30 to −0.37; p = 0.02; MD: −4.84; 95%CI: −8.82 to −0.86; p = 0.02).

Conclusion

Based on current evidence, the average RNFL thickness and the thicknesses of various RNFL regions in COPD patients are significantly lower than those in healthy subjects, and these reductions are closely associated with disease severity. The inferior RNFL may be the first to show changes with the onset and progression of COPD.