Comparison between the measurements of different parameters obtained from optic nerve head analysis by using Heidelberg retinal tomography (HRT3) and Optical coherence tomography (Stratus OCT)

Abstract

Purpose: A cross-sectional prospective nonrandomized study was undertaken to find out whether Heidelberg retinal tomography (HRT3) and Optical coherence tomography (Stratus OCT) could be used interchangeably for the measurement of different parameters of optic nerve head in clinical practice. Materials and Methods: Measurements of disc area, cup area, rim area and cup-disc area ratio were obtained with the HRT3 and Stratus OCT printouts in 18 patients aged 20 to 70 years. True agreements between methods in measuring disc area, cup area, rim area and cup-disc area ratio were assessed using Bland-Altman statistical analysis. Eighteen patients with a mean age of 27.05 ± 5.04 years were enrolled. Result: Differences between mean (bias) were -0.81 ± 0.58 mm2 for disc area, -0.31 ± 0.32 mm2 for cup area,-0.50 ± 0.64 mm2 for rim area, -0.04 ± 0.09 for cup-disc area ratio while using HRT3 and Stratus OCT, respectively. Conclusion: Large range of differences were observed in measurements of disc area, cup area, rim area and cup-disc area ratio with HRT3 and Stratus OCT.