This laser produces a 3 ns pulse of light which is very powerful, but with an incomprehensibly brief pulse of energy. 3 ns is 3/1000 millionths of a second. This laser is ideal in treating a specific layer of the retina, called the retinal pigment epithelium. This pigmented cell layer is under the light sensing, retinal “photoreceptors” and plays a critical role in diseases such as age-related macular degeneration (AMD). Treating this layer of cells produces positive healing changes to the deep retina, as demonstrated clinically and in laboratory experiments. The 3 ns laser has been shown in preliminary studies, to slow down the progress of early age-related macular degeneration. A randomised trial, using this laser for early AMD, was recently completed and the results will be published shortly.
The main benefit of the ultrashort burst of light is that there is no damage to the retina itself. This is because the pulse of energy is so short, that the heating of the pigmented cells does not spread into the retina. Traditional laser (constant wave) produces a much longer pulse (most commonly 0.1 seconds) which spreads into the retina, destroying the overlying light-sensitive cells. Other conditions can also respond well to this laser – particularly some cases of diabetic retinopathy and central serous chorioretinopathy. Although other short pulse lasers are being used clinically, this is the briefest energy pulse, with the best documented healing responses.
This treatment is performed in the office, with local anaesthetic drops to numb the surface of the eye. Very brief flashes of light produce some glare but no pain. There is no after-effect although it takes a couple of minutes for the dazzle to wear off (just like going from a bright summer’s day, into a darkened room or cinema).