Pattern electroretinographic findings in patients with obstructive sleep apnea syndrome: a cross-sectional study

This study aimed to compare pattern electroretinography (PERG) responses between patients with obstructive sleep apnea syndrome (OSAS) and controls and to examine their associations with the apnea–hypopnea index (AHI). This cross-sectional study included 80 participants: 20 healthy controls and 60 patients with obstructive sleep apnea syndrome (OSAS) stratified as mild, moderate, and severe ( n = 20 each) based on apnea–hypopnea index (AHI) obtained by overnight polysomnography. Pattern electroretinography (PERG) recordings were obtained using a Metrovision MonPack One system with DTL electrodes. Only the right eye of each participant was included in the analysis. PERG parameters including P50 amplitude, N95 amplitude, and P50 implicit time were recorded. Eighty participants were included, with 20 in each group. Mean P50 amplitudes in the control, mild, moderate, and severe OSAS groups were 6.04 ± 1.38, 6.58 ± 1.40, 3.48 ± 0.42, and 2.41 ± 0.42 µV, respectively; corresponding N95 amplitudes were 7.34 ± 1.32, 7.82 ± 1.25, 5.26 ± 0.37, and 4.39 ± 0.46 µV. Welch’s ANOVA showed significant between-group differences in both amplitudes (both p < 0.001), whereas P50 peak time did not differ significantly ( p = 0.308). Games–Howell comparisons showed lower amplitudes in moderate and severe OSAS than in controls and mild OSAS, with an additional reduction in severe versus moderate OSAS (all p < 0.001). Control–mild differences were not significant for P50 or N95 amplitude ( p = 0.613 and p = 0.642, respectively). In the pooled cohort of 60 patients with OSAS, AHI correlated inversely with P50 amplitude ( r = − 0.811, p < 0.001) and N95 amplitude ( r = − 0.790, p < 0.001). Lower PERG P50 and N95 amplitudes were associated with greater AHI-defined OSAS severity; these findings do not establish an independent effect of OSAS or a hypoxemia-mediated mechanism. Further longitudinal studies accounting for potential confounders are needed to clarify the clinical significance of these findings and the potential role of PERG in assessing patients with OSAS.