Where next for AMD and Stargardt research? Part II: Lasers, ozone and acupuncturePosted: Monday 07 January 2019 at 10:31
A team from Warwick Medical School examined the evidence, or lack of it, for a wide range of physical treatments that have been tried in dry age-related macular degeneration (AMD) and Stargardt disease.
The list of possible treatments is long and diverse. One problem in judging which really work is “publication bias” – the fact that studies showing no benefit are less likely to be published than the one study suggesting a positive benefit.
The team judged that the evidence on the following is too weak to recommend:
• rheopheresis – a process similar to dialysis in which blood is removed from the body, filtered and returned over the course of a few hours. Some success was reported from a few European centres but the main trial in the USA was unsuccessful
• microcurrent stimulation – applying tiny electric shocks to the eyelids or brows
• ozone therapy.
However, trials are in progress into some more promising areas.
Intraocular lenses (IOLs) are implanted into the eye to magnify the image coming in, or direct it to a less damaged part of the retina. Unfortunately, a UK trial has recently been cancelled, but a US trial will follow 75 people with IOLs for five years.
In people having cataract surgery to replace their clouded lenses with artificial ones, there have been suggestions that blue-light filtering lenses may protect the retinas from developing AMD. A long-term study of 1,000 people in Japan will randomly assign people to have either clear or blue-filtering lenses implanted and see if there is a difference in people developing AMD.
Surprisingly, retinal cells use the most energy in complete darkness, so researchers are investigating whether wearing a headset emitting a dim green light each night for a year could slow the rate of damage.
Traditional laser treatment carries a risk of damage to the retina, so techniques using very short bursts of laser or light energy are being investigated as a way to encourage tissues to heal themselves.
Research from Australia suggests benefit, and a big trial called LEAD is underway.
Microcurrent stimulation has been tried for Stargardt disease, without producing any convincing evidence.
The best advice so far for people with Stargardt disease is to avoid exposure to bright light as this seems to slow the progress of their sight loss. In one tiny trial of five people, four of them found that their sight loss progressed less in the eye wearing a light-reducing contact lens. Light-reducing glasses or lenses are simple and affordable, so more evidence would be useful.
One of the most promising areas of research is the use of stem cells to restore sight by replacing damaged parts of the retina.
Although any future treatment would be most useful to people at an early stage, before much sight is lost, the trials in progress at the moment tend to focus on proving the safety in people with the later stages of the disease.
Research – including projects that you helped to fund – continues to make strides towards beating macular disease. We’ll keep you updated as the evidence from each of these studies mounts up.