Itay Chowers, MD, Department of Ophthalmology, Hadassah University Hospital and Michal Lederman and Avraham Weiss, Hebrew University of Jerusalem-Hadassah Medical School.
Background
The most common cause of irreversible vision loss and blindness is age related macular degeneration (AMD). AMD is characterized by two stages. In the early (dry) stage the center of the retina (macula) undergoes a slowly progressing degenerative process which usually does not affect visual acuity. By contrast, the advanced (wet) stage of the disease is usually associated with severe visual loss secondary to the growth of blood vessels underneath the retina. Patients with the dry form of the disease may be periodically examined to enable early detection of conversion to the neovascular stage of the disease. However, most AMD patients are not diagnosed in the dry stage of the disease, and are first seen by an ophthalmologist only after they are symptomatic.
Currently, AMD is diagnosed clinically by means of ophthalmoscopy. Studies have also shown increased oxidative products and anti-retinal antibodies in the blood of AMD patients. Yet, these factors are not utilized for diagnosis or screening of AMD and their usefulness for this purpose is unclear.
There is a clear need for a simple, pre-symptomatic test for the early diagnosis of AMD. A test is also required to facilitate assessment of risk for progression from the dry to the wet form of the disease and for monitoring the response to therapy.
Market
AMD is a major cause of visual impairment in the US. Approximately 1.8 million Americans age 50 and older have advanced AMD, and another 7.3 million people with intermediate AMD are at substantial risk for vision loss. The US government estimates that by 2020 there will be 2.9 million people with advanced AMD.
The Innovation
The invention is based on the surprising discovery that high levels of several biological markers in white blood cells or their protein products in the blood may correlate with the disease state or a predisposition to develop AMD. The invention may increase the number of patients which will be diagnosed at the “dry” stage of the maculopathy (e.g. AMD) by performing a simple blood test. Using microarray analysis and quantitative real time RT-PCR, a group of genes which show altered expression in white blood cells of patients with AMD have now been identified. The measurement of levels of these genes at the mRNA level using real time quantitative RT-PCR demonstrated increased levels in both the dry and wet stages of AMD and may therefore serve as biomarker for the disease to facilitate its diagnosis, including at an early stage.
The present invention applied as a blood test may have several applications:
- As a screening test for identification of individuals at risk for having a maculopathy such as AMD
- To assess risk for development of a maculopathy in individuals with a normal ophthalmoscopy
- In situations where ophthalmoscopy is equivocal and diagnosis of AMD cannot be made conclusively
- To assess risk of progression from the dry to the wet stage of the disease
- To monitor the effect of treatment for the wet stage of the disease and to assess the need for additional treatment sessions
Contact
Stuart Bernstein
Business Development, Medical Devices
Tel: +972-2-6777906
Email: stuart@hadasit.co.il
