Novel Diagnostics for Ocular Structure

Objective:

The purpose of this research is to evaluate a new technology, optical coherence tomography
(OCT), to image diseases of the eye and to compare the measurements obtained using OCT with
those of other imaging and visual field devices. OCT may be useful for the early diagnosis
and monitoring of a variety of eye diseases such as age-related macular degeneration (ARMD),
glaucoma, diabetic retinopathy, macular edema, and other pathologies.

Specific Aims:

There are three sub-studies: cross-sectional, longitudinal and reproducibility. The
cross-sectional and longitudinal arms study the effectiveness of the OCT technology in terms
of detecting and monitoring eye diseases. The reproducibility study is designed to test the
measurement likeness of the OCT.

Background:

This is a continuation of an ongoing study from the New England Eye Center (NEEC), Tufts
Medical Center, Boston, MA. This study started when our research group was located at NEEC
and in collaboration with the Massachusetts Institute of Technology (MIT) where we conducted
the first clinical studies with OCT. The first investigation using OCT was published in
Science in 1991 and showed in vitro imaging of the human retina and atherosclerotic plaque.
We developed an OCT prototype system for performing preliminary ophthalmic clinical studies
and in 1993, began clinical OCT imaging studies.

The prototype ophthalmic OCT instrument acquired OCT images of the retina with an axial
resolution of 10µm within an acquisition time of 2.5 sec. The OCT imaging system was
integrated with a slit-lamp biomicroscope for in vivo tomography of the anterior and
posterior eye. The beam is directed into the eye using computer controlled galvonometric
scanners, which can scan arbitrary transverse patterns. The beam focus is coincident with the
slit-lamp image plane to permit simultaneous scanning and visualization of the eye through
the slit-lamp or via a CCD camera. For tomography of the anterior eye, the microscope is
focused directly on the structure, while for retinal imaging, a lens relay images of the
retina onto the slit-lamp image plane. A computer provides real-time display of the tomogram,
image processing, and data management.

OCT technology was patented and subsequently transferred to industry (Zeiss Humphrey Systems,
CA). Our prototype ophthalmic OCT system was developed into a clinical instrument and was
introduced into the ophthalmic market in 1996. The commercial OCT technology has an axial
resolution of 10 µm and can acquire a 100 transverse pixel retinal tomogram in 1 second. A
third generation ophthalmic OCT imaging device, OCT3, was introduced three years ago. OCT
imaging is now used as a standard diagnostic procedure as part of an ophthalmic examination
for many retina and glaucoma patients at the University of Pittsburgh Medical Center (UPMC)
Eye Center and New England Eye Center (NEEC). OCT imaging is in use in major research and
clinical centers internationally. The OCT has been approved by the Food and Drug
Administration for use in ophthalmology.

Significance:

OCT enables tissue pathology to be imaged in situ and in real time with a resolution
approaching that of conventional histopathology but without the need for excising and
processing specimens. OCT provides a quantitative method of directly measuring ocular
structures with high precision and could provide an objective, early diagnosis for glaucoma,
age related macular degeneration (ARMD), diabetic retinopathy, macular edema, and other
pathologies. Extensive studies have been performed with OCT in cross-sectional as well as
longitudinal setting. In this ongoing protocol, our objective is to continue these studies
using the commercial ophthalmic OCT imaging instruments to develop methods for early
detection and improve longitudinal assessment for the above mentioned ocular pathologies.

Inclusion Criteria:

1. Age older than or equal to 18 years old

2. Macular Degeneration, Diabetic Retinopathy, and/or glaucoma patients.

3. Normal control subjects

Exclusion Criteria:

1. Media opacity (lens, vitreous, cornea)

2. Strabismus, nystagmus, or a condition that would prevent fixation.

3. Inability to understand informed consent