title: Comparative evaluation of optical coherence tomography in glaucomatous, ocular hypertensive and normal eyes.
abstract: BACKGROUND
  To correlate the findings of optical coherence tomography (OCT) evaluation of retinal nerve fiber layer (RNFL) thickness with visual field changes in glaucomatous, ocular hypertensive and normal eyes.
  
  
  METHODS
  Thirty consecutive normal, 30 consecutive ocular hypertensive and 30 consecutive glaucomatous eyes underwent a complete ophthalmic examination, including applanation tonometry, disc evaluation, (30-2) Humphrey field analyzer white on white (W/W) perimetry and short- wavelength automated perimetry. Thickness of the RNFL around the optic disc was determined with 3.4 mm diameter-wide OCT scans. Average and segmental RNFL thickness values were compared among all groups. A correlation was sought between global indices of perimetry and RNFL thickness.
  
  
  RESULTS
  Of the 90 eyes enrolled (mean age of patients 52.32+/-10.11 years), the mean RNFL thickness was significantly less in ocular hypertensive (82.87+/-17.21 mm; P =0.008 and glaucomatous eyes (52.95+/-31.10 microm; P < 0.001), than in normals (94.26+/-12.36 microm). The RNFL was significantly thinner inferiorly in glaucomatous eyes (64.41+/-43.68 microm; P<0.001). than in normals (120.15+/-14.32 microm) and ocular hypertensives (107.87+/-25.79 microm; P<0.001). Ocular hypertensives had thinner RNFL in the nasal, inferior and temporal quadrants (P<0.001) when compared to normals. Global indices in ocular hypertensives on SWAP showed Mean Deviation (MD) of 5.32+/-4.49, Pattern Standard Deviation (PSD) 3.83+/-1.59 and Corrected Pattern Standard Deviation (CPSD) 2.84+/-1.85. The RNFL thickness could not be significantly correlated with global indices of visual fields in ocular hypertensives.
  
  
  CONCLUSIONS
  Optical coherence tomography is capable of detecting changes at the level of RNFL in ocular hypertensive eyes with normal appearance of discs and W/W perimetry fields.
authors.affiliation: Institute of Ophthalmology, Joseph Eye Hospital, Tiruchirappalli, Tamil Nadu, India. umasujata@yahoo.com
authors.forename: Sujata
authors.initials: S
authors.lastname: Subbiah
authors.forename: S
authors.initials: S
authors.lastname: Sankarnarayanan
authors.forename: Philip A
authors.initials: PA
authors.lastname: Thomas
authors.forename: C A
authors.initials: CA
authors.lastname: Nelson Jesudasan
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D009898:Optic Disk / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*