Lasers were once reserved for science fiction stories and were depicted as nothing short of destructive. Rejecting this popular depiction, the world of medicine has made use of lasers for decades now. Contrary to the destructive and otherwise painful use of lasers in science fiction epics, lasers in medicine are relatively gentle and expedite surgeries and medical procedures.
Ophthalmology uses a number of different lasers for various reasons. Two of the more common lasers used in the field of ophthalmology are 532 nm lasers, which shine with a characteristic green color, and YAG lasers.
Let’s take a look at laser technology in ophthalmology and the difference between green lasers and YAG lasers.
Laser Photocoagulation
Laser photocoagulation surgery has been used for decades now to treat a large number of eye diseases, including
- Glaucoma
- Posterior capsular opacification
- Ischemia
- Diabetic retinopathy
- Age-related macular degeneration
- Ruptured blood vessels
During the surgical procedure, a laser is applied to the eye to coagulate and seal the area of leakage. The process is very precise, and the ophthalmologist uses a fine laser and a delicate touch.
Compared to other eye surgeries, laser coagulation leaves less scar tissue and retains more of a person’s vision.
Green vs. YAG
Now that you have a general understanding of how lasers are used in ophthalmology, what’s the difference between green lasers and YAG lasers?
First off, let’s understand what “green lasers” are, because—believe it or not—YAG lasers can be and often are green in color. The color that we see is determined by the wavelength of the laser (green being 532 nanometers). The frequency and wavelength of the YAG laser can be adjusted, thus allowing for a green color.
More often than not, in the field of ophthalmology, a “green laser” refers to an argon laser, which uses argon gas to generate the laser. YAG lasers use an yttrium aluminum garnet crystal as a medium to create the laser.
In terms of application, argon lasers are used to create burns to treat retinal tears and diabetic retinopathy. YAG lasers are used to create holes and are more commonly used to treat posterior capsular opacification, an infrequent side effect of cataract surgery, and glaucoma with iridotomy. However, because the wavelength can be adjusted, a frequency-doubled YAG laser can also be used to treat diabetic retinopathy.
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