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NCT Number: NCT04067258

Choroidal Thickness in Beta-thalassemia Patients

The purpose of this study is to examine choroidal thickness in beta-thalassemia patients and compare it to the one of healthy controls.

An equal number of transfusion dependent beta-thalassemic patients and age and sex matched healthy volunteers will undergo spectral-domain optical coherence tomography utilizing the enhanced depth imaging application to visualize and measure the choroid.

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Key information

Conditions

Beta-Thalassemia Anemia Anemia, Hemolytic Anemia, Hemolytic, Congenital Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemoglobinopathies Thalassemia

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Department of Ophthalmology, General University Hospital of Patras

Pátrai, Achaea, GR26504, Greece

About this study

Beta thalassemia is an inherited hemoglobinopathy, associated with defective production of beta-chain globin resulting in problematic HbA production. It is classified according to the severity as minor, intermedia and major. Patients suffering from beta-thalassemia intermedia and beta-thalassemia major require regular blood transfusions. Transfusion related hemosiderosis in these patients necessitates the use of chelating agents to prevent iron overload in vital organs such as the liver and heart.

A number of ocular abnormalities can present in beta-thalassemia patients. Those are categorized as pseudoxanthoma elasticum (PXE)-like changes that include angioid streaks, peau d'orange like fundus and optic nerve head drusen and non-PXE-like changes such as increased venous tortuosity.

Furthermore, it is well established that prolonged treatment with some of the chelating agents such as deferoxamine are associated with ocular toxicity, namely nyctalopia, colour perception anomalies, visual field disturbances, cataract formation, optic neuropathy and pigmentary retinopathy.

The pathophysiology of those ocular manifestations has not been fully clarified. The role of the choroid has not been determined since this particular tissue was previously unaccessible to imaging. Enhanced depth imaging optical coherence tomography is able to image the choroid providing reasonable clarity compared to spectral domain optical coherence tomography.

The aim of this study is to evaluate possible alterations of choroidal thickness in beta thalassemia as compared to healthy controls.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Beta thalassemia patients undergoing blood transfusions

Exclusion criteria

  • History of glaucoma, keratoconus, retinal disease, ocular trauma, ocular surgery, uveitis, amblyopia, strabismus, ocular vascular abnormalities
  • Spherical refractive error greater than 4 diopters or cylindrical refractive error greater than 2 diopters
  • History of other systemic disease such as uncontrolled hypertension, diabetes mellitus, or connective tissue disease.

Treatment and study plan

EDI-OCT

Diagnostic Test

EDI-OCT (enhanced depth imaging spectral domain optical coherence tomography) wiil be performed in all study participants.

Three sets of measurements in the macular (horizontal and vertical) and peripapillary area will be averaged.

Primary outcomes

  1. Subfoveal choroidal thickness

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted subfoveally

Secondary outcomes

  1. Choroidal thickness nasally to the fovea

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted at anatomic locations nasally to the subfoveal point

  2. Choroidal thickness inferiorly to the fovea

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted at anatomic locations inferiorly to the subfoveal point

  3. Choroidal thickness temporally to the fovea

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted at anatomic locations temporally to the subfoveal point

  4. Choroidal thickness superiorly to the fovea

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted at anatomic locations superiorly to the subfoveal point

  5. Peripapillary choroidal thickness (inferior, superior, nasal and temporal fields)

    Time frame: 8-10 am

    Manual measurements of the choroid starting from the end of the retinal pigment epithelium throughout the outline of the sclera, will be conducted at the inferior, superior, nasal and temporal quadrants in the peripapillary area.

Sponsors and collaborators

Lead sponsor

University Hospital of Patras

Other

Registry information

Official study title

Evaluation of Choroidal Thickness in Patients Suffering From Beta-thalassemia

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Aug 26, 2019
Registry last updated
Jun 26, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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