title: Validity of the temporal-to-nasal macular ganglion cell-inner plexiform layer thickness ratio as a diagnostic parameter in early glaucoma.
abstract: OBJECTIVE
  To evaluate the diagnostic validity of temporal-to-nasal macular ganglion cell-inner plexiform layer thickness (TNM) ratio using Cirrus high definition-optical coherence tomography (HD-OCT) in patients with early glaucomatous damage.
  
  
  METHODS
  Enrolled participants included 130 normal controls, 50 patients with preperimetric glaucoma and 106 patients with early glaucoma. The patients with early glaucoma were classified into two subgroups according to the pattern of the visual field (VF) defects: the paracentral scotoma (PCS, n = 54) and the peripheral scotoma (PPS, n = 52). The thickness of the macular ganglion cell-inner plexiform layer (mGCIPL) and circumpapillary retinal nerve fibre layer (cpRNFL) was measured by Cirrus HD-OCT, and the average, superior and inferior TNM ratio was calculated. The average TNM ratio is a sum of superotemporal and inferotemporal mGCIPL thicknesses divided by the sum of superonasal and inferonasal mGCIPL thicknesses. Area under the receiver operating characteristic curve (AROC) of each parameter was compared between the groups.
  
  
  RESULTS
  The parameter with the best AROC was the average TNM ratio and inferotemporal mGCIPL thickness in the PCS group and average cpRNFL thickness in the PPS group. The AROCs of the average, superior and inferior TNM ratio (p < 0.001, p = 0.007 and p < 0.001, respectively), minimum, average, inferotemporal and inferior mGCIPL thickness (p = 0.004, p = 0.003, p = 0.002 and p = 0.001, respectively) of the PCS were significantly higher than those of the PPS. However, the AROCs of the all cpRNFL thickness parameters did not show statistically significant differences between two subgroups.
  
  
  CONCLUSIONS
  Asymmetry of temporal-to-nasal mGCIPL thickness could be an important parameter in the diagnosis of early glaucoma with paracentral VF defects.
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea.
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea.
authors.forename: Hyun-Ho
authors.initials: HH
authors.lastname: Jung
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea.
authors.forename: Hwan
authors.initials: H
authors.lastname: Heo
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea.|Center for Creative Biomedical Scientists, Chonnam National University, Gwangju, South Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D063171:Corneal Pachymetry; D042241:Early Diagnosis; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000175:diagnosis; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
keywords: early glaucoma; location of the visual field defect; macular ganglion cell-inner plexiform layer; temporal-to-nasal asymmetry