AIM: To compare the retinal nerve fiber layer(RNFL)thickness in patients with different severities of obstructive sleep apnea-hypopnea syndrome(OSAHS)versus normal controls.

METHODS: This was an observational case-control study. Totally 79 patients presenting with snoring and daytime sleepiness who underwent overnight polysomnography(PSG)to determine OSAHS severity were recruited, and subsequently referred for ophthalmologic evaluation. The data including intraocular pressure(IOP), RNFL thickness etc was collected.

RESULTS: A total of 73 subjects were recruited, including 53 patients with OSAHS and 20 normal control subjects. IOP was significantly higher for the moderate and severe OSAHS group than for the control group(both P<0.05). The RNFL in the average and superior quadrants were significantly thinner for the moderate and severe OSAHS group than for the control group(both P<0.05). AHI was negatively correlated with RNFL thickness in the superior quadrants, and with average RNFL thickness(r=-0.316, -0.205; both P<0.01). Negative correlations were also identified between RNFL thickness in the superior quadrants and the ODI(r=-0.24, P=0.005). Positive correlations were identified between SaO₂ on PSG and RNFL thickness in the superior quadrants(r=0.277, P=0.001).

CONCLUSION: RNFL of the patients with OSAHS is thinned. Furthermore, it is observed that the greater severity of OSAHS, the greater the loss of RNFL. Among the four quadrants observed, the most affected quadrant was the superior quadrant.