Enhanced Vitreal Imaging of the Vitreoretinal Interface in Normal Eyes Using Swept-Source OCT

Abstract

 

Purpose

 

To demonstrate enhanced vitreal imaging (EVI) of the vitreoretinal interface using three-dimensional (3D) swept-source optical coherence tomography (SS-OCT) in normal subjects..

 

Methods

 

22 subjects with normal vision and no history of retinal disease, optic nerve abnormalities, or ocular surgery were included in this study. One randomly selected eye for each subject was imaged using a prototype 1050nm SS-OCT system with 6µm resolution, 3.6mm imaging range, and 100kHz axial scan rate. Up to eight orthogonal raster scanned volumes were acquired for each eye over 12mm×12mm retinal area (~40°) with 500×500 axial scans. The acquisition time per volume was <3 seconds. A registration algorithm was applied to remove motion artifacts and merge multiple volumes into a single dataset with improved signal. Enhanced vitreal imaging (EVI) was performed by adjusting threshold and contrast in the merged volumetric data.

 

Results

 

We obtained motion-corrected 3D OCT datasets from 22 normal eyes. Standard image display enabled visualization of retinal and deep choroidal features. Features observed with EVI include vitreous separation from the retina (18 eyes, 81.8%), hyaloid detachment near the optic nerve head (13 eyes, 59.1%), Bergmeister papilla (6 eyes, 27.3%), posterior precortical vitreous pocket (15 eyes, 68.2%), space of Martegiani (15 eyes, 68.2%), vitreous strands (13 eyes, 59.1%), and cellular aggregation (11 eyes, 50%).

 

Conclusions

 

Swept-source OCT with motion correction and EVI provides wide-field 3D information about vitreous structure, enabling detailed observations of the vitreoretinal interface. SS-OCT has an advantage over SD-OCT for vitreal imaging because it maintains high sensitivity over a long imaging range. The high speed of SS-OCT combined with motion correction and merging enables wide-field volumetric imaging. This method could be useful for imaging the 3D structure of the vitreous in patients with disorders of the vitreomacular interface, as well as assessing treatment response after vitrectomy or pharmaceutical vitreolysis.

 

 

3D SS-OCT imaging of the vitreous. A.Wide-field OCT fundus image. B.Center frame with standard display. C.Center frame with enhanced vitreal imaging (EVI) by adjusting threshold and contrast. Blue asterisk-posterior precortical vitreous pocket. Red arrow-hyaloid adhesion at the optic nerve region. Yellow asterisk-space of Martegiani. Green arrows-vitreous separation.

 

Keywords: 763 vitreous • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 550 imaging/image analysis: clinical