The Australian drugs regulator has told sponsors of 10 products to stop marketing them for macular degeneration, a prevalent but difficult to treat eye condition affecting the elderly.

Following reviews that began in 2017, the Therapeutic Goods Administration (TGA) found 13 eye health medicines “inappropriately referenced macular degeneration” without enough supporting clinical evidence to back the claims, and 10 were still being sold when the review finished.

Macular degeneration is caused by damage to the nerves in the eye and symptoms range from blurred vision to blindness. It can affect all ages but mainly people over the age of 65.

According to Opthea (ASX:OPT), a company developing a drug for wet-aged related macular generation (wet-AMD) which is an advanced form of the most common macular condition, there are few treatments available.

This is the main reason the biotech switched from cancer to eye conditions; it delivered a successful phase 2b clinical trial on its wet-AMD treatment last year, which gave the company a billion-dollar market cap.

There is no cure for AMD, the early dry form or later wet version where new blood vessels bleed or leak fluid, causing scarring of the retina.

Opthea says treatments include drugs injected into the eyeball called Lucentis and Eylea for the wet form which only works for half of the patients who use it. Yet these drugs still made $US3.7bn and $US6.2bn in 2018 respectively, since there are few other viable options.

Other drugs include Avastin and other therapies include a laser therapy called photodynamic therapy (PDT), combining injection of a photosensitive drug called verteporfin into the bloodstream followed by laser treatment to seal leaky blood vessels, and laser photocoagulation which uses a concentrated beam of high energy laser light.

Some respected institutions such as the Mayo Clinic recommend vitamins and supplements to enhance general health as a preventative as well.


Carrots can’t help you see in the dark

The TGA reviews were around the effect of different antioxidants and other nutritional supplements on the progression of age-related macular degeneration and cataracts.

A large study called the Age-Related Eye Disease Study (AREDS), followed by another called AREDS2, looked at 13 medicines: two were cancelled when the TGA asked for information and one just before the review was finished.

Claims made by the final 10 medicines were not supported by evidence.

About 5 per cent of people aged 65 years and over have some kind of AMD and this increases to 14 per cent among people aged 85 years and over. Approximately 10 per cent of people over 55 years have early age-related maculopathy, which can lead to macular degeneration.

Macular degeneration is a “restricted representation”, meaning it’s such a serious condition that diagnosis, treatment and management has to be done with the advice of medical professionals.