Functional and Structural Optical Coherence Tomography for Glaucoma

Project: Research project

Project Details

Description

PROJECT SUMMARY
Glaucoma is a leading cause of blindness. Early diagnosis and close monitoring of glaucoma are important
because the onset is insidious and the damage is irreversible. Advanced imaging modalities such as optical
coherence tomography (OCT) have been used in the past 2 decades to improve the objective evaluation of
glaucoma. OCT has higher axial spatial resolution than other posterior eye imaging modalities, and it has
relatively good diagnostic accuracy and reproducibility in the measurement of neural structures damaged by
glaucoma. However, the measurement of structure alone, with any imaging modality, has limited sensitivity for
detecting early glaucoma and only moderate correlation with visual field (VF) loss. Using high-speed OCT
systems, we have developed new methods to image and measure optic nerve head (ONH) and retinal blood
flow. Preliminary results showed that VF loss was more highly correlated with retinal blood flow as measured
by OCT than any neural structure measured by OCT or other imaging modality. Accordingly, the goal of the
proposed project is to improve the diagnostic and prognostic evaluation of glaucoma by further developing
novel functional OCT measurements using ultrahigh-speed (70-100 kHz) OCT technology. The specific aims are:
1. Improve Doppler OCT measurement of retinal blood flow. Multi-circular scans of peripapillary retinal arteries and veins measure total retinal blood flow in 2 seconds. The use of faster OCT systems will allow automated measurement with improved reproducibility.
2. Develop quantitative OCT angiography of the ONH. Three dimensional (3D) OCT angiography has been made practical (3x3 mm scan in 3 seconds) by a novel split-spectrum amplitude-decorrelation algorithm. Preliminary results showed dramatic loss of ONH microcirculation in early glaucoma. Algorithmic improvement in angiography, segmentation, quantification, and automation are planned.
3. Measure nerve structure from the ONH to retinal ganglion cells. By registering several volumetric scans, we have demonstrated complete 3D characterization of the retinal fiber pathway from the ONH to the macula. Fully automated quantification of these structures will be developed.
4. Evaluate advanced OCT technologies in clinical studies. The utility of functional and structural OCT in glaucoma will be evaluated in a longitudinal observational study of 150 glaucoma and healthy subjects. The effect of IOP-lowering surgery on blood flow will be studied in 40 subjects. Retinal blood flow, ONH circulation, optic disc rim volume, peripapillary nerve fiber layer volume, and
macular ganglion cell complex volume are all pieces of the same glaucoma puzzle. This project will develop
novel imaging methods that allow us to look at the whole picture using one tool - ultrahigh-speed OCT.
StatusFinished
Effective start/end date9/30/138/31/17

Funding

  • National Institutes of Health: $734,129.00
  • National Institutes of Health: $750,111.00
  • National Institutes of Health: $733,374.00
  • National Institutes of Health: $748,341.00

ASJC

  • Medicine(all)

Fingerprint Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.