Severity of Obstructive Sleep Apnea Syndrome and RNFL Thickness
Japanese researchers conducted this prospective study to determine whether there is a
significant correlation among the peripapillary retinal nerve fiber layer (RNFL) thickness,
foveal thickness, total macular volume and severity of obstructive sleep apnea syndrome.
They studied 124 consecutive subjects who underwent polysomnography and used optical
coherence tomography (OCT) to measure the peripapillary RNFL, foveal thickness and total macular
volume. The researchers also used the Pearson correlation coefficient to determine the
relationship between the apnea-hypopnea index and OCT and other parameters. Additionally, they
used multiple regression analysis to determine the independent factors for the RNFL sectors that
were the most strongly correlated with the apnea-hypopnea index.
The apnea-hypopnea index was significantly and negatively correlated (right eye, r=–0.31,
p=0.0004; left eye, r=–0.39, p<0.0001) with the nasal RNFL thickness
(Pearson correlation analysis), the researchers found. They discovered that foveal thickness and
total macular volume were not correlated. The researchers also observed that intraocular pressure,
body mass index, plaque score and incidence of hypertension were negatively correlated, and the
lowest oxygen saturation and mean oxygen saturation were positively correlated with the nasal
RNFL thickness in the left eye. Multiple regression analysis showed that the apnea-hypopnea index
and age were independent contributors to the nasal RNFL thickness in the left eye (apnea-hypopnea
index, standard regression coefficient, =–0.30, t value, –2.76, p=0.007;
age, –0.24, –2.36, 0.02, respectively). Furthermore, the study researchers found that
the nasal RNFL thickness in both eyes decreased significantly based on the severity of the
obstructive sleep apnea syndrome.
They determined that exacerbation of obstructive sleep apnea syndrome may produce unique
retinal neurodegenerative disorders that decrease the nasal RNFL thickness.