Abstract
Abstract: :
Purpose: Optical coherence tomography (OCT) is a noninvasive, imaging technique for obtaining high-resolution cross-sectional images of the retina in vivo. A single highly reflective layer that is believed to correspond to the choriocapillaris and retinal pigment epithelium defines the outer retinal border. Using grayscale OCT images, we intend to better define the outer retinal border on normal subjects and patients with different eye diseases. Methods: Normal subjects, patients with clinical diagnosis of full thickness macular hole (MH) and patients with clinical diagnosis of neurosensory detachment (NSD) of different etiologies who were examined with OCT, were evaluated. The OCT raw data images were examined using a macro program of our own design for the Scion Image for Windows program without color or other computer processing. Results: All 30 normal subjects were observed to have a double line at the level of the RPE choriocapillaris. This double line consisted of a thin inner line and a thicker outer line. Fifteen eyes of 14 MH patients had a double line at the borders of the MH and only the outer line was present at the level of the hole. Three eyes of two patients with MH showed a single line in the scan. Four eyes of 4 patients with CSR and 5 eyes of 5 patients with NSD from different etiologies had a double line at the border of the NSD. In 2 CSR patients and in 5 NSD patients of different etiologies, the inner line appears to detached from the outer line together with the rest of the retina. In two eyes of patients with CSR, the inner line could not be seen at the level of the serous detachment. In two patients with NSD only a single line was observed through out the scan. Conclusion: Gray scale OCT images permitted to differentiate two lines in the outer border of the retina; the internal one appears to belong to the neurosensory retina and should be accounted in retinal thickness measurements.
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 430 imaging/image analysis: clinical • 554 retina