Diabetic retinopathy The American Academy of Ophthalmology practice guidelines recommend laser coagulation for people who have both mild to moderate nonproliferative diabetic retinopathy (NPDR) and clinically significant macular edema outside the
fovea; treatment with
anti-VEGF drugs is better than laser coagulation for clinically significant macular edema in the fovea. For people with severe NPDR and no macular edema, the AAO recommends laser photocoagulation for the whole retina; when there is macular edema, the laser coagulation focused on major lesions is recommended.
Macular degeneration The American Academy of Ophthalmology practice guidelines do not recommend laser coagulation therapy for macular degeneration, but said that it may be useful in people with new blood vessels in the
choroid outside of the
fovea who do not respond to treatment with anti-VEGF drugs. Argon, krypton, dye and diode lasers have been used with varying levels of energy to try to prevent
age-related macular degeneration by eliminating
drusen. A
Cochrane review published in 2015 found that while laser treatment reduces drusen, there is no difference from placebo at 2 years with respect to preventing vision loss. A 2007 Cochrane review found that laser photocoagulation of new blood vessels in the
choroid outside of the
fovea using blue-green argon, green argon, red krypton, or near-infrared diode is effective and economical method, but that the benefits are limited for vessels next to or below the fovea.
Retinal tears The laser is used to create a row of microscopic burns in the target tissue to cause scarring which will prevent the edges of the tear from detaching from the layer below. Laser photocoagulation can help prevent the deterioration of some retinal disorders and reduce the risk of future vision loss, but it cannot restore vision once it has been lost. The procedure is safe and effective for treating indicated retinal disorders, such as tears and glaucoma. It is typically an outpatient procedure lasting 15 to 20 minutes. The procedure is not entirely without risk. Damage will occur to light sensitive cells of the retina cauterised by the laser which will result in some loss of vision. Light from the laser is absorbed by the retinal pigment epithelium and by the underlying choroid, which raises the temperature by 20 °C to 30 °C. These thermal burns denature tissue protein, causing death of the affected retinal cells and coagulative necrosis.
Retinopathy caused by sickle cell disease Laser coagulation has been used in people with
sickle cell retinopathy. A 2015 Cochrane review found two clinical trials conducted in the 1980s using three approaches — one single-centre trial employed sectoral scatter laser photocoagulation using an argon laser; and in the second, two-centre trial focused on feeder vessel coagulation, one centre used an
argon laser and the other used a xenon arc laser. Based on weak evidence, it appears that laser coagulation may be effective in preventing visual loss and vitreous haemorrhage in this condition but that it does not have an effect on regression of proliferative sickle retinopathy or preventing the development of new vessel growth.
Radiation proctitis When
radiation therapy is administered to treat cancers like
cervical cancer,
prostate cancer, and
colorectal cancer,
radiation proctitis can occur, which involves chronic bleeding in the
rectum. Treatment with
Nd:YAG lasers and with Nd:YAG laser passed through a
Potassium titanyl phosphate crystal, and with an
argon laser has been studied in small clinical trials. Nd:YAG laser has been abandoned due to risks of damaging the colon wall, fibrosis, stricture formation, and recto-vaginal fistula, and severe damage in case of accidents, as well as the cost. The other two modalities were largely replaced by
argon plasma coagulation by 2011, which is safer and less expensive. == Complications ==