Imaging Retinal Pathologies Using High–Speed, Ultrahigh Resolution OCT With Spectral / Fourier Domain Detection

Abstract

Purpose: : To perform a cross–sectional study of retinal pathology using high–speed UHR OCT. To investigate three–dimensional scanning protocols and image rendering methods for retinal pathologies. To identify situations where high–speed, UHR OCT yields information not available with standard OCT imaging.

Methods: : A research prototype high–speed UHR OCT using spectral/Fourier domain detection was developed for clinical use and can achieve ∼3 um axial image resolution with speeds of ∼25,000 axial scans per second. This is a ∼3–4 times improvement in resolution and ∼60 times improvement in speed compared to standard OCT instruments. High imaging speeds enable high transverse pixel density, high–definition OCT images to be acquired as well as dense raster scans covering a large retinal area. Three–dimensional image processing and rendering are performed to enable visualization of three–dimensional retinal structure. High–speed UHR OCT and standard resolution StratusOCT imaging are performed in the same patients and results are correlated with standard ophthalmoscopic clinical examination.

Results: : High–speed UHR OCT imaging has been performed in >350 patients with a cross section of retinal diseases. Retinal pathologies including macular holes, macular edema, diabetic retinopathy, age–related macular degeneration, epiretinal membrane, and central serous chorioretinopathy are surveyed. Compared with commercial StratusOCT and standard UHR OCT, high–speed UHR OCT enables detection of true retinal topography without motion artifacts, and improves retinal coverage and image quality by increasing transverse pixel density to obtain high–definition images. This enables better visualization of intraretinal architectural morphology such as the inner limiting membrane, ganglion cell layer, photoreceptor inner and outer segments and retinal pigment epithelium. Three–dimensional imaging using high–speed UHR OCT enables virtual rendering of pathology to visualize its three–dimensional structure.

Conclusions: : High–speed UHR OCT significantly improves visualization of intraretinal morphology and enables three–dimensional rendering and imaging of retinal pathology. These advances promise to enable new ophthalmic imaging applications for basic research and clinical diagnosis.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • retina