Spectralis HRA+OCT Imaging of the Retina With Autofluorescence in Sickle Cell Disease

Study Description

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Brief Summary:

To determine the retinal and choroidal thickness in patients with sickle cell disease compared to age, race matched population without sickle cell disease to allow a better understanding of the clinical manifestations of sickle cell retinopathy. The purpose of this research study is to evaluate the relationship between sickle cell disease and the eye. The research study is recruiting African American population with or without Sickle Cell Disease. The investigator in charge of this study is Dr E. Bowie. Approximately 60 subjects of both sexes will be enrolled at the Medical University of South Carolina.

Condition or disease
Sickle Cell Disease

Detailed Description:

About 10% of African Americans have an abnormal hemoglobin gene. About 8% of African Americans are heterozygous for Hb S. In the United States, sickle cell anemia primarily occurs in the black population, with approximately 0.2% of African American children afflicted by this disease. The prevalence in adults is lower because of the decrease in life expectancy. The Storm Eye Institute at the Medical University of South Carolina (MUSC) is uniquely situated geographically and epidemiologically to study the interaction between sickle cell disease and the retina. The frequency of sickle cell trait (Hb AS) in African-Americans of Charleston County is 16%, twice the national average of 8% in African-Americans. This is thought to be due to the autosomal recessive inheritance of sickle cell disease, and the genetic roots and relative isolation of the Sea Island Gullah population (Pollitzer 1999).

Variations in the alteration of the amino acid sequence on the globin chain produce variations in the disease's expression. The four forms of the disease are often referred to by their genotype: sickle cell trait (AS), sickle cell anemia (SS), sickle cell disease (SC) and sickle cell thalassemia (SThal).

Systemically, the sickle cell anemia variation (SS) produces the most symptoms. With respect to the eye, the sickle cell disease mutation (SC) produces the most effects.

The widely accepted pathogenesis for sickle cell retinopathy is vasoocclusion that leads to retinal hypoxia, ischemia, infarction, neovascularization, and fibrovascularization. In sickle cell anemia, the amino acid substitution valine for glutamate occurs on the beta chain at the sixth position. This substitution, combined with conditions that may promote sickling (ie, acidosis, hypoxia), triggers the deoxygenated Hb S to polymerize, making the erythrocyte rigid. This rigidity is partially responsible for the vasoocclusion.

Vasoocclusion also is in part due to the interaction between sickled cells and the vascular endothelium. The adherence of sickled cells to the endothelium triggers an inflammatory process with the release of inflammatory agents. The result of this cascade is vascular stasis, hemolysis, and vasoocclusion of the capillary beds.

Classically, posterior segment changes are classified by either nonproliferative sickle retinopathy (NPSR) or proliferative sickle retinopathy (PSR). In NPSR, the retinal changes do not involve neovascularization as they do in PSR. The use of Spectralis HRA+OCT gives us visualization of the individual layers of the retina to determine if there are underlying changes not seen clinically in the gross ophthalmic posterior segment exam. This knowledge will aid the care of African-Americans with sickle cell disease to enable greater understanding of the ocular disease progression leading to earlier eye screenings, possible novel treatments and ultimately visual loss prevention.

Study Design

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Study Type :	Observational
Actual Enrollment :	8 participants
Observational Model:	Case Control
Time Perspective:	Prospective
Official Title:	Spectralis HRA+OCT Imaging of the Retina With Autofluorescence in Sickle Cell Disease
Study Start Date :	February 2010
Actual Primary Completion Date :	July 2010
Actual Study Completion Date :	July 2010

Groups and Cohorts

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Outcome Measures

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Primary Outcome Measures :

1. Patient Care [ Time Frame: 6 months ]
   The use of Spectralis HRA+OCT gives us visualization of the individual layers of the retina to determine if there are underlying changes not seen clinically in the gross ophthalmic posterior segment exam. This knowledge will aid the care of African-Americans with sickle cell disease to enable greater understanding of the ocular disease progression leading to earlier eye screenings, possible novel treatments and ultimately visual loss prevention

Eligibility Criteria

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Ages Eligible for Study:	12 Years and older (Child, Adult, Senior)
Sexes Eligible for Study:	All
Accepts Healthy Volunteers:	Yes
Sampling Method:	Probability Sample

Study Population

Approximately 60 subjects of both sexes of African American race with or without sickle cell disease.

Criteria

Inclusion Criteria:

• SUBJECTS approximately 60 subjects of both sexes of African American race with or without sickle cell disease.

Patient Inclusion Criteria:

• Subjects MUST fulfill the following conditions to qualify for enrollment into the trial
• Twelve years of age or older.
• Patients diagnosed with sickle cell disease (n=40) and an age, race matched control group of subjects (n=20) without sickle cell disease. Sickle disease is defined as a genetic blood disease due to the presence of an abnormal form of hemoglobin, namely hemoglobin S. It includes four genotypes: sickle cell trait (AS), sickle cell anemia (SS), sickle cell disease (SC) and sickle cell thalassemia (SThal). Patients with any of these genotypes will be included.
• Willing and able to comply with scheduled visit and other study procedure

Exclusion Criteria:

• Subject must not have a history of prior intraocular retinal surgery, prior laser photocoagulation, cryotherapy, active ophthalmic disease or abnormality (e.g. blepharitis, corneal infection), clinical evidence of trauma (including scarring).
• Any clinically significant, serious or severe medical or psychiatric condition that may increase the risk associated with study participation or may interfere with the interpretation of study results.
• Participation in (or current participation) any investigational drug or device trial within the previous 30 days prior to the start date of this trial.
• Pregnant and nursing mothers.

Contacts and Locations

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Locations

United States, South Carolina
Medical University of South Carolina, Storm Eye Institute
Charleston, South Carolina, United States, 29425
MUSC Storm Eye Institute
Charleston, South Carolina, United States, 29425

Sponsors and Collaborators

Medical University of South Carolina

Investigators

Principal Investigator:	Esther M Bowie, MD	Medical University of South Carolina, Storm Eye Institute

More Information

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Study Description Study Design Groups and Cohorts Outcome Measures Eligibility Criteria Contacts and Locations More Information

Responsible Party:	Dr. Esther Bowie, Medcial University of South Carolina
ClinicalTrials.gov Identifier:	NCT01123369 History of Changes
Other Study ID Numbers:	SEI 10-001; HR#18890 ( Other Identifier: Medical University of SC )
First Posted:	May 14, 2010
Last Update Posted:	September 14, 2010
Last Verified:	September 2010

Keywords provided by Medical University of South Carolina:

Sickle Cell Disease

Additional relevant MeSH terms:

Anemia, Sickle Cell; Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia	Hematologic Diseases; Hemoglobinopathies; Genetic Diseases, Inborn