Value of AMD genetic testing clarified in new study

A new study has looked at how certain gene variants may predict whether an individual is likely to develop age-related macular degeneration (AMD).

This eye disease affects over nine million Americans, but it has been found that certain genes do not estimate how patients will react to Lucentis and Avastin, which are the  two most common medications to treat the "wet" form of the condition.

Data from the Comparison of AMD Treatment Trials (CATT) has been published in the Opthmalmology journal, with findings showing there to be no association between four gene variants and outcomes that measured patients' treatment responses.

Patients were evaluated for the four gene variants related to AMD risk, CFH, ARMS2, HTRA1 and C3, before patients' genotypes were compared to their responses to Lucentis or Avastin.

Both of these medications are anti-vascular epithelial growth factor therapies and work in similar ways to reduce or prevent abnormal blood vessel growth and leakage.

However, the researchers found no significant associations among the four gene variants and the outcomes that measured the patients' responses to treatment. These outcomes were improvement or loss of visual acuity, the status of retinal anatomy and the number of injections given.

Stephanie Hagstrom, Ph.D., at the Cole Eye Institute at the Cleveland Clinic, led the study, noting: "Our genetic research team remains hopeful that gene variants that predict patient response to AMD treatments will be identified soon.

"This would enable a significant leap forward in ophthalmologists' ability to individualize treatment and care plans for their patients."

The main CATT study was a multi-centre clinical trial, funded by the National Institutes of Health and led by Daniel F Martin, Chairman of the Cole Eye Institute at the Cleveland Clinic.

Wet AMD, which is also known was neovascular AMD can severely damage vision if it is not treated in time, with around ten per cent of patients suffering from this form of the condition.

Posted by Neil Clark