Abstract
Purpose:
To determine the relationship of retinal thickness measurements and outer retina integrity (ORI) with visual acuity in patients with diabetic macular edema by comparing two commercially available spectral domain (SD)-OCT instruments.
Methods:
Case series. All participants underwent OCT imaging with Cirrus and Spectralis devices in the same visit. Scanning with the Cirrus HD OCT was performed with the 512 x 128 scan pattern and HD 5 line raster. Scans performed with Spectralis consisted of a 25-line horizontal raster covering 20 x 20 degrees, centered on the fovea. Central retinal thickness (CRT) and ORI were calculated and compared. The CRT was measured with the central line raster of each device. The ORI defects were measured with a computer software . The main outcome was to observe diagnostic accuracy and sensitivity of the association between outer retina abnormalities in diabetic macular edema and their association with visual acuity.
Results:
Thirty eyes with clinically significant diabetic macular edema were studied. The patients had a mean age of 51 years and average logMAR visual acuity of 0.54. Outer retina abnormalities were visible on both scanning devices in all patients. Mean CRT was 362.38 um in Cirrus and 387.82 um in Spectralis. ORI defects showed significant correlation with visual acuity (Pearson correlation, r= -0.76 and -0.66, both P<0.001). With a minimal difference, the highest correlation was seen between Spectralis and visual acuity.
Conclusions:
Differences in acquisition and segmentation algorithms of two SD-OCT devices may affect CRT values in patients with diabetic macular edema. However, sensitivity and specificity of both OCT devices are similar to detect irregularities of the ORI that are associated with visual acuity in patients with diabetic macular edema.
Keywords: 550 imaging/image analysis: clinical •
498 diabetes •
585 macula/fovea