title: Macular Ganglion Cell-Inner Plexiform Layer and Retinal Nerve Fiber Layer Thickness in Eyes With Primary Open-Angle Glaucoma Compared With Healthy Saudi Eyes: A Cross-Sectional Study.
abstract: OBJECTIVE
  We compared the thickness of the ganglion cell-inner plexiform layer at the macula (mGCIPL) and the thickness of the retinal nerve fiber layer (RNFL) in different regions of the retina in eyes with primary open-angle glaucoma (POAG group) and normal eyes (control group).
  
  
  METHODS
  This was a cross-sectional study performed in 2014.
  
  
  METHODS
  Spectral domain optical coherence tomography (SD-OCT) was used to measure mGCIPL and RNFL thickness. Age-adjusted means and standard deviation were calculated. Age, sex, refractive status, corneal thickness, and stage/severity of glaucoma (defined by vertical cup-to-disc ratio and visual field changes) were associated to outcomes. Statistical significance was indicated by P < 0.05.
  
  
  RESULTS
  There were 50 eyes in the POAG group and 52 eyes in the control group. The difference in age between patients in both groups was statistically significant (P < 0.001). The age-adjusted measurements were thinner for POAG with a mean difference (DF) of 11.1 μm for mGCIPL and 8 μm for mRNFL. The mGCIPL to mRFNL ratio was 2.1 in the POAG group and 1.9 in the control group (degrees of freedom = 0.2, P = 0.001). The mGCIPL and RNFL thickness decreased as the severity of glaucoma increased. The mGCIPL to mRNFL ratio was a predictor of the severity of field defects in POAG (AUROC = 0.66, P = 0.0002). Age and myopia were confounders to the association of OCT findings and the visual field changes in POAG (P = 0.07).
  
  
  CONCLUSIONS
  There was generalized thinning of retinal layers in eyes of nondiabetic Arab patients with POAG. OCT parameters can be important for detecting and monitoring glaucoma cases.
authors.affiliation: From the *Imam Mohammed bin Saud Islamic University, College of Medicine; †Department of Ophthalmology, Specialized Medical Center; and ‡Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.
authors.forename: Tariq
authors.initials: T
authors.lastname: Alasbali
authors.forename: Nancy Maher
authors.initials: NM
authors.lastname: Lofty
authors.forename: Saeed
authors.initials: S
authors.lastname: Al-Gehaban
authors.forename: Abdulrahman
authors.initials: A
authors.lastname: Al-Sharif
authors.forename: Hisham
authors.initials: H
authors.lastname: Al-Kuraya
authors.forename: Rajiv
authors.initials: R
authors.lastname: Khandekar
mesh_terms: D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000473:pathology*; D006801:Humans; D008266:Macula Lutea / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D012029:Refraction, Ocular / Q000502:physiology; D012044:Regression Analysis; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012307:Risk Factors; D012529:Saudi Arabia; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods; D014786:Vision Disorders / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology