Evaluation of Single Nucleotide Polymorphisms (SNPs) in Patients With and Without Diabetic Macular Edema

This study has been terminated.
Information provided by:
National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:
First received: July 22, 2010
Last updated: February 19, 2014
Last verified: August 2013


- Diabetic macular edema (DME) is a common condition in people with diabetes. DME occurs when blood vessels in the eye leak fluid, resulting in swelling inside the back of the eye and progressive vision loss. Research has shown that good blood sugar control can reduce the risk and severity of DME. However, not all diabetic patients with poor blood sugar control develop DME, and some patients develop DME despite excellent blood sugar control. This suggests that other factors, such as genes or inherited traits, may predispose or protect a diabetic patient from developing DME.


- To investigate genetic factors that may influence the development of diabetic macular edema.


- Individuals at least 18 years of age who have type 2 diabetes, with or without diabetic macular edema.


  • The study will require one visit to the National Institutes of Health eye clinic.
  • Participants will be screened with a medical history and basic eye examination. Individuals who have certain eye diseases other than DME may not be allowed to enroll in the study.
  • Participants will provide a blood sample, and will receive fluorescein angiography (an injection of fluorescein dye, after which a camera will take pictures of the dye as it flows through the blood vessels in the eye).
  • No treatment will be provided as part of this protocol.

Diabetic Retinopathy
Diabetic Macular Edema

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Evaluation of Single Nucleotide Polymorphisms (SNPs) in Patients With and Without Diabetic Macular Edema

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Primary Outcome Measures:
  • Genotype frequency of SNP in the study genes of DME participants and control participants.

Secondary Outcome Measures:
  • Secondary outcomes are ophthalmic measurements, including visual acuity, FA and OCT data, to investigate associations between detected genetic polymorphisms and response to conventional diabetic retinopathy treatment.

Enrollment: 68
Study Start Date: July 2010
Estimated Study Completion Date: August 2013
Detailed Description:


The objective of this study is to test the hypothesis that genetic polymorphisms of vascular endothelial growth factor (VEGF), erythropoietin (EPO), endothelin-1 (EDN1) and receptor for advanced glycation end product (RAGE) genes are associated with the development of diabetic macular edema (DME).

Study Population:

Two hundred case participants with DME and 200 diabetic controls without DME will be enrolled.


This is a longitudinal, genetic association study evaluating whether single nucleotide polymorphisms (SNPs) in VEGF, EPO, EDN1 and RAGE genes affect the development and progression of DME. All participants will provide a blood sample, undergo an eye examination, optical coherence tomography (OCT) and fluorescein angiography (FA) and discuss their medical, family and social history. Case participants with DME and diabetic control participants without DME will be allowed to receive standard-of-care treatment at the NEI under this protocol.

Outcome Measures:

The primary outcome variable is the genotype frequency of SNPs in the above specific genes of DME and control participants. Secondary outcomes are serum levels of VEGF, EPO, EDN1 and AGE, plasma biomarkers such as mRNA and ophthalmic measurements (visual acuity and imaging results such as FA and OCT results). The longitudinal outcome measure includes investigating associations between the studied genetic polymorphisms and the long-term response to standard-of-care therapy.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

All participants must meet the following criteria:

Participant is diagnosed with type 2 diabetes prior to enrollment.

Participant must understand and sign this protocol s informed consent document and agree to provide a blood sample for analysis.

Participant must be 18 years of age or older.< TAB>

DME Participants (cases):

Participant is diagnosed with active DME defined by fluorescein leakage associated with either central retinal thickness greater than 260 microns on spectral domain OCT or cystic changes present on OCT.


Participant has evidence of focal laser scars indicative of prior DME Investigators will verify the laser therapy was performed for DME via medical records, fluorescein angiograms or photographs.

Non-DME Participants (controls)

Participant has no evidence of DME defined fluorescein leakage associated with either central retinal thickness greater than 260 microns on spectral domain OCT or cystic changes present on OCT.

Participant has no evidence of focal laser scars indicative of prior DME.


Participant has another retinal disease that may confound the evaluation of the DME. Examples include vein occlusions, uveitic macular edema or neovascular age-related macular degeneration.

Participant has opacities of the ocular media, limitations of pupillary dilation or other problems sufficient to preclude adequate dilated examination.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01168258

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Eye Institute (NEI)
Principal Investigator: Catherine Meyerle, M.D. National Eye Institute (NEI)
  More Information

ClinicalTrials.gov Identifier: NCT01168258     History of Changes
Other Study ID Numbers: 100169  10-EI-0169 
Study First Received: July 22, 2010
Last Updated: February 19, 2014
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Diabetic Retinopathy
Single Nucleotide Polymorphism (SNP)
Diabetic Macular Edema

Additional relevant MeSH terms:
Diabetic Retinopathy
Macular Edema
Retinal Diseases
Cardiovascular Diseases
Diabetes Complications
Diabetes Mellitus
Diabetic Angiopathies
Endocrine System Diseases
Eye Diseases
Macular Degeneration
Retinal Degeneration
Signs and Symptoms
Vascular Diseases

ClinicalTrials.gov processed this record on May 30, 2016