Vitamin D Levels in Patients With Central Retinal Vein Occlusion- a Prospective Controlled Study

November 23, 2016 updated by: Anders Kvanta, St. Erik Eye Hospital

Retinal vein occlusion (RVO) is a common vascular disease of the eye. Studies have shown that the risk of venous thrombosis is higher in winter so even concerning RVO. Studies have shown a possible link between sun exposure and venous thrombosis. Vitamin D levels have been shown to have a similar seasonal variation, with a peak occurring in the summer. The primary source of vitamin D is from sunlight when ultraviolet B (UVB) radiation penetrates the skin and converts 7-dehydrocholesterol to 25-hydroxycholecalciferol vitamin D3 (25-OHVitD) via previtamin D. In Stockholm situated at latitude 59˚ 20΄ North, it is not possible to synthesize vitamin D at sufficient levels in winter and the exposure time required to reach a standard dose is impractical from at least October through March.

The aim of the study is to evaluate vitamin D levels in central retinal vein occlusion (CRVO) patients and compare them with the vitamin D levels in randomly selected control patients matched for age and month of disease onset. This is to evaluate whether vitamin D deficiency may be a risk factor in the onset of CRVO.

The hypothesis of the study is that patients with CRVO have lower levels of vitamin d than matched controls.

Study Overview

Detailed Description

The study will last one year and is expected to include 120 patients with RVO and 120 control patients. The first 10 RVO patients visiting St. Erik's Eye Hospital with disease duration of maximum 3 months will be included in the study each month. The control patients will be chosen randomly by the Central Bureau of Statistics and matched for age and gender according to disease distribution known from previous studies. The control group will receive a letter with information of the study, informed consent form and details about the blood sampling procedure. Every month 50 patients in the control group will be invited to participate in the study. Only the first 10 control subjects will be included in the study. Each month a blood sample will be taken from 10 patients with RVO and 10 subjects in the control group. All the subjects will only have one blood sample taken during the study. Blood will be analyzed to measure the vitamin D level. Vitamin D levels will be compared at the end of the study between groups and evaluated according to the time of year for sampling. All the blood sampling will be done by the laboratory at Karolinska University Hospital. Participation in the study is completely voluntary. The details of the study has been reviewed and approved by the Ethics Committee.

Study Type

Observational

Enrollment (Actual)

216

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Stockholm, Sweden, 11282
        • St Eriks Eye Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Consecutive patients with central retinal vein occlusion diagnosed at St Eriks Eye Hospital

Description

Inclusion Criteria:

Newly diagnosed central retinal vein occlusion (3 months)

Exclusion Criteria:

-

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
CRVO patients
Patients with a newly diagnosed CRVO. Maximum duration 3 months.
Control patients
Controls matched for age,gender, month of onset from the Central Bureau of Statistics Sweden

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Vitamin D levels
Time Frame: one year
one year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2013

Primary Completion (Actual)

August 1, 2014

Study Completion (Actual)

November 1, 2014

Study Registration Dates

First Submitted

February 13, 2013

First Submitted That Met QC Criteria

February 13, 2013

First Posted (Estimate)

February 15, 2013

Study Record Updates

Last Update Posted (Estimate)

November 25, 2016

Last Update Submitted That Met QC Criteria

November 23, 2016

Last Verified

November 1, 2016

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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