Abstract
Purpose: :
Optical coherence tomography (OCT) is a noninvasive imaging technique clinically used for visualization of in vivo structures such as the human retina. Using statistical analyses, this study compares the retinal thickness (RT) measurements between two different spectral-domain optical coherence tomography (SD-OCT) devices (Cirrus HD-OCT, and the OPKO Spectral OCT/SLO) in both healthy and diseased maculas.
Methods: :
Eighty-eight eyes of 69 consecutive patients with macular diseases and 22 eyes of 11 healthy subjects were scanned on the same day by an experienced OCT operator using two different SD-OCT device protocols: Cirrus HD-OCT macular cube 512 x 128 software version 4.5 (Carl Zeiss Meditec, Inc, Dublin, CA, USA) and OPKO Spectral OCT/SLO model E 3-D retinal topography international beta software (OPKO Health, Inc, Miami, FL, USA). The 88 eyes representing macular diseases included the following diagnoses: age-related macular degeneration (n = 52), diabetic macular edema (n = 13), retinal vascular obstruction (n = 9), posterior uveitis (n = 4), other macular diseases (n = 3), epiretinal membrane (n = 3), central serous retinopathy (n = 2), and macular hole (n = 2). The RT in nine regions based on Early Treatment Diabetic Retinopathy Study (ETDRS) areas in addition to the total average RT were analyzed and compared between the two devices with a P value < 0.05 considered statistically significant.
Results: :
When both healthy and diseased macular states were examined together, the total average RT in addition to eight of the nine ETDRS areas were statistically significantly different in RT between the two devices (P = 0.0002 in the nasal outer ETDRS area, P < 0.0001 in the remaining seven ETDRS areas, and P < 0.0001 in the total average RT). The RT of the inferior inner ETDRS area did not show statistical significance (P = 0.0564). The total average RT for the healthy subjects subset alone was not statistically different between the two devices (P = 0.54). However, the total average RT for the subset of patients with macular diseases was highly statistically significant between the two devices (P < 0.0001). The degree of difference between the devices varied according to the specific macular disease analyzed and the ETDRS area evaluated.
Conclusions: :
Statistically significant differences were found in the comparison of RT measurements obtained from the Cirrus HD-OCT and the OPKO Spectral OCT/SLO. Differences in the automated segmentation software utilized by the respective devices may play a role, and these differences may be exacerbated by specific macular diseases.
Keywords: retina • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)