Analysis of macular retinal thickness in polyarteritis nodosa using spectral domain optical coherence tomography

Purpose: To identify the macular retinal layer thickness changes in polyarteritis nodosa (PAN) patients without pathological findings appearing in color fundus photography (CFP), and to investigate the correlations with disease durations.

Methods: A total of 24 PAN patients who had been for 3 years or more and underwent SD-OCT were recruited from the UK Biobank, with exclusions for diabetes, eye disease, or abnormal CFP findings. Only the right eyes were included, with each PAN patient paired one-to-one with a control matched for age, sex, and ethnicity. Paired t-tests or Wilcoxon Signed-Rank tests were used to assess the differences in thickness of different retinal layers between groups, followed by linear regression analysis to evaluate the correlations with disease durations.

Results: PAN patients had significantly thinner retinal nerve fiber layer (RNFL) by 12.27% (mean ± standard deviation = 27.39 ± 8.94 μm for PAN patients and 31.22 ± 5.57 μm for controls, p = 0.048) and thinner outer plexiform and outer nuclear layers (OPL-ONL complex) by 10.67% (44.93 ± 6.59 μm for PAN patients and 50.31 ± 7.60 μm for controls, p = 0.032). Visual acuity and the whole macular thickness showed no statistical difference. The RNFL was thinned by 1.22 μm per year of disease progression (95% confidence interval: 0.12, 2.32, p = 0.042).

Conclusions: PAN patients without visual impairments or abnormal CFP findings may exhibit significant thinning in RNFL and OPL-ONL complex. SD-OCT may serve as a useful tool for early screening of ophthalmic changes in PAN.