Blood Factors and Diabetic Retinopathy

Participants with a range of severity of diabetic retinopathy and healthy volunteers will be
evaluated once for serum levels of cell adhesion molecules, chemokines and vascular
endothelial growth factor. This study may lead to a better understanding of the pathogenesis
of diabetic retinopathy and the identifying of possible targets for treatment. All study
participants will undergo an ocular exam and ophthalmic photography. Blood is drawn for the
analysis of these serum factors.

- VOLUNTEER INCLUSION CRITERIA:

Volunteers will be able to enroll if they:

- Have the ability to understand and sign an informed consent.

- Are able and willing to give a blood sample.

- Are healthy as determined by study Investigator.

- Have no chronic diseases.

- Do not exhibit any clinical indications of diabetes.

PARTICIPANT INCLUSION CRITERIA:

Participants will be able to enroll if they:

- Have the ability to understand and sign an informed consent.

- Are able and willing to give a blood sample.

- Have a clinical diagnosis of diabetes based on any one of the following criteria:

1. Documented history of plasma glucose value greater than or equal to 210 mg/dl on
three different occasions.

2. Fasting blood sugar greater than or equal to 150 mg/dl on three different
occasions.

3. Documented history of ketoacidosis.

4. Insulin dependency.

5. Documented history of abnormal glucose tolerance test.

EXCLUSION CRITERIA:

Neither volunteers nor participants will be eligible if they:

- Are under the age of 10.

- Have severe systemic disease(s) that compromise our ability to obtain an adequate
examination.

- Have any of the following ocular characteristics or conditions in both eyes:

1. Opacities of the ocular media, limitations or pupillary dilation or any other
problems sufficient to preclude good, quality stereo fundus photographs.

2. Ocular disease which confounds assessment of diabetic retinopathy such as
advanced age-related macular degeneration, central serous choroidopathy, optic
atrophy, retinal vein occlusion, active uveitis, significant explained or
unexplained visual field loss, or any other type of retinopathy or retinal
degeneration.

3. Chronic requirement for any ocular medication for other diseases, such as
glaucoma.