Abstract
Purpose: :
To compare optic disc morphology measured by spectral-domain optical coherence tomography (SD-OCT) (3D OCT-1000, Topcon, Japan), Heidelberg retina tomograph (HRT) II and stereophotograph-based planimetry, and to investigate its correlation with visual field test results in glaucomatous eyes.
Methods: :
Optic disc morphology was determined by SD-OCT, HRT II and stereophotograph-based planimetry in 77 glaucomatous eyes of 47 patients. The reference plane determining the cup parameters in SD-OCT measurements, was set at 30µm intervals from 90µm below to 210µm above the retinal pigment epithelium (RPE) layer, and values calculated with each reference plane was used for analysis. Correlation between parameters obtained by the three methods and the mean deviation (MD) of the visual field Humphrey test results was investigated.
Results: :
Average disc area calculated by the three methods was SD-OCT: 2.29±0.47, HRT II: 2.54±0.57, stereophotographs: 2.60±0.59 (mm2), respectively. Correlation between values by the three methods were good (R=0.83, P<0.001), but values differed significantly (P=0.002). Values for cup disc area ratio (CDAR) matched best between SD-OCT and HRT II measurements when the reference plane was set at 0~30µm above the RPE plane, whereas values between SD-OCT and stereophotographs matched best at 90µm above the RPE plane. Correlation between rim area measured by the three methods and MD was best with SD-OCT (R=0.52, P<0.001) (reference plane: 120µm above RPE plane).
Conclusions: :
In glaucomatous eyes, the reference plane at which CDAR measured by SD-OCT matched with that measured by HRT II and stereophotograph-based planimetry was different. Also, correlation between rim area and visual field damage was best with SD-OCT when the reference plane was set at 120µm above the RPE plane.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic disc • perimetry