Assessment of the retinal nerve fiber layer in individuals with obstructive sleep apnea

Abstract

BackgroundThe effect of obstructive sleep apnea (OSA) syndrome in the peripapillary retinal nerve fiber layer (RNFL) thicknesses remains unclear. The purpose of this study was to assess RNFL measurements acquired using scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in patients with OSA.MethodsThe sample of this cross-sectional study included 40 OSA patients and 45 age-matched controls, consecutively and prospectively selected. All participants underwent at least one reliable standard automated perimetry (SAP) test, while RNFL measurements were obtained using the SLP and OCT. The OSA group was divided into 3 sub-groups based on the apnea/hypopnea index (AHI): mild, moderate, or severe OSA. SAP, SLP, and OCT outcomes were compared between the control and OSA groups. The relationship between AHI and RNFL parameters was also evaluated.ResultsAge was not different between both groups. Mean deviation of SAP was −0.47 ± 0.9 dB and −1.43 ± 2.3 dB in the control and OSA groups, respectively (p = 0.01). RNFL thickness measured with OCT was similar between groups. OSA patients showed increased nerve fiber indicator (NFI; 20.9 ± 7.9 versus 16.42 ± 7.82; p = 0.01) and decreased superior average (59.74 ± 10.35 versus 63.73 ± 6.58; p = 0.03) obtained with SLP compared with healthy individuals. In the total sample, NFI and AHI were moderately correlated (r = 0.358; p = 0.001). In severe OSA subjects (n = 22), NFI and AHI had a Spearman correlation coefficient of 0.44 (p = 0.04).ConclusionRNFL thickness measured with OCT did not differ significantly between groups. Severe OSA was related to a reduction of the RNFL thickness assessed by SLP.

Contributions of the Melanopsin-Expressing Ganglion Cells, Cones, and Rods to the Pupillary Light Response in Obstructive Sleep Apnea

“…83 Our results did not show any reduction of RNFL thickness or VF in the OSA group, in agreement with previous studies by Salzgeber et al, 87 Ferrandez et al, 85,86 and Yu et al, 88 which did not find significant thinning of the RGC layer or macular thickness in OSA patients. Various authors have found affected values of MD and PSD in OSA patients, [89][90][91] and Ferrandez et al 85 have reported an impairment in the VF evaluated by SAP, suggesting dysfunction but not the death of the RGC. Findings by Yu et al 88 suggest that the vascular changes might occur before changes in RNFL thickness and vascular impairment of the vessel densities, which are more prominent in the peripapillary area in moderate OSA.…”

“…7,[19][20][21][80][81][82][83][84] Studies of electrophysiology and RNFL thickness have reported conflicting findings in OSA patients, some showed significant reduction of the RNFL thickness, 9,19,21,71 pattern electroretinogram (PERG), 82,84 and visual evoked potential (VEP), 83,84 while others found no decrease [85][86][87] or alterations of ERG. 83 Our results did not show any reduction of RNFL thickness or VF in the OSA group, in agreement with previous studies by Salzgeber et al, 87 Ferrandez et al, 85,86 and Yu et al, 88 which did not find significant thinning of the RGC layer or macular thickness in OSA patients. Various authors have found affected values of MD and PSD in OSA patients, [89][90][91] and Ferrandez et al 85 have reported an impairment in the VF evaluated by SAP, suggesting dysfunction but not the death of the RGC.…”

Peripapillary retina nerve fiber layer thickness and macular ganglion cell layer thickness in patients with obstructive sleep apnea syndrome

“…Similarly, a study performed in Turkish population reported that RNFL thickness did not differ between healthy and OSAS subjects. 35 Another study by Ferrandez et al 36 reported that RNFL thickness measured with OCT did not differ significantly between groups. There may be several factors responsible for the varying results among the studies.…”

Ocular Manifestations of Obstructive Sleep Apnea

“…OSA predisposes the optic nerve head to ischemia and damage through episodes of hypoxia, hemodynamic changes to retinal blood vessels, oxidative stress, mitochondrial dysregulation, and inflammation. 18,20,21 This proclivity to damage leads to the nerve fiber dysfunction and degeneration seen in glaucoma. Patients with OSA may possess optic nerve heads more sensitive to mechanical damage given their poor perfusion and potential for ischemic changes.…”