Structure-Function Relationship and Diagnostic Value of RNFL Area Index Compared With Circumpapillary RNFL Thickness by Spectral-Domain OCT

• Published in: Journal of glaucoma Vol. 22; no. 2; pp. 88 - 97
• Main Authors: Park, Hae Young L, Park, Chan Kee
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins, Inc 01-02-2013
• Subjects: Female; Glaucoma - diagnosis; Glaucoma - physiopathology; Gonioscopy; Humans; Intraocular Pressure - physiology; Male; Middle Aged; Nerve Fibers - pathology; Optic Disk - pathology; Optic Nerve Diseases - diagnosis; Optic Nerve Diseases - physiopathology; Retinal Ganglion Cells - pathology; ROC Curve; Tomography, Optical Coherence; Tonometry, Ocular; Vision Disorders - physiopathology; Visual Acuity - physiology; Visual Field Tests; Visual Fields - physiology
• ISSN: 1057-0829; 1536-481X
• DOI: 10.1097/IJG.0b013e318231202f

PURPOSE:The purpose of the study was to evaluate the structure-function relationship and diagnostic value of retinal nerve fiber layer (RNFL) Area Index from the RNFL thickness deviation map of Cirrus SD-OCT.
METHODS:A total of 84 normal control eyes, 88 preperimetric eyes, and 146 perimetric glaucoma eyes were analyzed. The area of the RNFL defect in the RNFL thickness deviation map was expressed as RNFL Area Index1−[area of superpixels coded in red/(6×6—optic disc area)]. The diagnostic performance of RNFL Area Index and that of circumpapillary RNFL thickness were compared with the area under the receiver operating characteristic curve. Regression analysis was performed with the OCT measurements and the mean retinal sensitivity of the corresponding fields.
RESULTS:The RNFL Area Index was 96.63±14.22%, 89.89±14.54%, and 81.65±17.11% in the control, preperimetric, and perimetric glaucoma group. The RNFL Area Index had the largest area under the receiver operating characteristic curve to discriminate preperimetric and perimetric glaucoma from normal eyes. The RNFL Area Index showed a strong correlation with circumpapillary RNFL thicknesses in perimetric glaucoma, however, only modest correlation was shown in preperimetric glaucoma. In preperimetric glaucoma, the RNFL Area Index had the strongest associations with mean retinal sensitivity and it was significantly different from those of circumpapillary RNFL thicknesses.
CONCLUSIONS:The RNFL Area Index showed better diagnostic performance for glaucoma detection and stronger structure-function relationships in preperimetric glaucoma. The RNFL thickness deviation map of Cirrus SD-OCT may be useful to correlate with functional loss in early glaucomatous eyes.