Trial Information

Ultrasonic Evaluation of Ocular Tissues

This study involves the diagnosis of several eye diseases, as follows:

Glaucoma:

1. Morphometry and spectral parameter assays: Clinical correlative studies in primary and
secondary glaucoma subgroups: This is a volunteer study to obtain volumetric
measurements of age-related changes in the ciliary body and individual ciliary muscle
components. The study will provide baseline values for treatment monitoring studies of
glaucoma therapeutics. There is minimal risk that the ultrasound procedure may reveal
an occult ocular disease process, but the probability is very small. Patients will be
informed and assisted in obtaining appropriate care if any abnormality is seen.

2. Morphometry and spectral parameter assays: Ciliary body drug interactions in patients
with initial diagnosis of open angle glaucoma: This study will attempt to document
changes in anterior segment functional anatomy related to medical management of
glaucoma. We hypothesize that several classes of anti-glaucoma drugs produce permanent
modification of ciliary muscle vasculature that is related in turn to loss of drug
efficacy over time. Data from COAG patients will be compared with age and sex matched
normals. Participation in the study will not effect the ongoing glaucoma therapy of
patients.

Accommodation:

3. Accommodative function in young emmetropes and transitional presbyopes: This is a
volunteer study to develop a descriptive model of the human eye's focusing mechanism
based on ultrasound morphometric measurements and spectral parameter assays. This
study will measure dynamic changes in ciliary body spectral assays (size, CQ2) during
calibrated accommodative tasks in volunteers with good amplitude of accommodation and
those with accommodative loss do to aging and model 3-D conformal changes in anterior
segment structures during accommodation. There is minimal risk that the ultrasound
procedure may reveal an occult ocular disease process, but the probability is very
small. Patients will be informed and assisted in obtaining appropriate care if any
abnormality is seen.

Ocular Tumors

4. Tumors of the iris and ciliary body: This is an observational study of growth pattern
changes in anterior melanoma for the purpose of identifying prognostic variables
associated with rapid tumor growth. A percentage of small melanomas are observed for
periods of up to several years before demonstrable growth will suggest more aggressive
treatment. In the clinical ultrasound practice many patients with these tumors are
seen at 3 to 6 month intervals to provide the ophthalmic oncologist with updated tumor
volume data. We will examine changes in the ultrasound scattering structure of these
tumors over time and their correlation with volume changes. The on-going research data
are not released as part of the clinical ultrasound report.

Age-related Macular Degeneration

5. Posterior examinations: age-related macular degeneration: This study will examine the
use of higher frequency (20-30 MHz) ultrasound in the early diagnosis of Age-related
macular degeneration. Our hypothesis is that early changes in the choriocapillaries
and choroid vascular density and conformation can be detected with high-frequency
spectral assays. We will obtain ultrasound scans at frequencies of 20 MHz or more, as
well as OCT and fundus photographs. Similar numbers of age-matched control subjects
will be examined. Measurements of retinal and choroidal thickness profiles in the
peri-macular region will be made. Spectral data will be used for morphologic vascular
analysis (size and shape). Statistical comparison will be made using parametric and
non-parametric methods between control and AMD groups.