title: Optic disc and retinal nerve fiber layer parameters as indicators of neurodegenerative brain changes in patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  Retina is a unique part of the central nervous system (CNS) for visualizing the processes of axonal and neuronal degeneration. Optical coherence tomography (OCT) allows direct visualization and measurement of retinal nerve fiber layer (RNFL) thickness, macular volume, and optic disc (OD) parameters. One of the disorders associated with atrophy in different brain regions is obstructive sleep apnea syndrome (OSAS). In the present study, we aimed to determine OD and RNFL changes measured by OCT for investigating the progress of neurodegeneration development in OSAS, excluding all the other conditions that can directly affect RNFL thickness and optic nerve parameters.
  
  
  METHODS
  Both eyes of 101 patients with OSAS and 20 controls were investigated by OCT. Full-night polysomnography (PSG) and ophthalmologic examination including automated visual field (VF) examination and OCT were performed in all of the patients.
  
  
  RESULTS
  According to the OSAS grading, patients were grouped as mild (n=15), moderate (n=27), and severe (n=59). We found significant decrease in RNFL thickness only in the patients with severe OSAS compared with the other groups and decreased macular ganglion cell thickness in the severe OSAS group compared with the control group. VF parameters were significantly worsened in all the OSAS subgroups compared to the control group. We found different data such as normal or increased optic nerve parameters as result of subtle OD edema, which may mask possible peripapillar axonal loss.
  
  
  CONCLUSIONS
  We think that evaluation of neurodegeneration in OSAS is not always possible by examining OD and RNFL because there are difficulties due to the confounding issues of cerebral atrophy and OD edema.
authors: Department of Neurology, Medical Faculty, Kafkas University, Kars, Turkey, nergizabbas@gmail.com.
authors: Nergiz
authors: N
authors: Huseyinoglu
authors: Metin
authors: M
authors: Ekinci
authors: Serkan
authors: S
authors: Ozben
authors: Cagatay
authors: C
authors: Buyukuysal
authors: Murat Yildirim
authors: MY
authors: Kale
authors: Hilal Safak
authors: HS
authors: Sanivar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D019636:Neurodegenerative Diseases / Q000175:diagnosis* / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009900:Optic Nerve / Q000473:pathology; D010211:Papilledema / Q000175:diagnosis / Q000473:pathology; D017286:Polysomnography; D012160:Retina / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000473:pathology*; D013223:Statistics as Topic; D041623:Tomography, Optical Coherence; D014787:Vision Tests; D055815:Young Adult
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