Laser is a pure form of a particular wavelength of light which is a powerful beam. It is used for good therapeutic uses in many eye disorders. Lasers are of different varieties used in different eye conditions as follows.
In patients who have undergone modern phakoemulsification or cataract surgery, 25-30% of patients get after cataract where vision goes down due to thickening of posterior capsule. Yag laser is done to make a hole in this posterior capsule, a 15 sec outpatient procedure which gives instant result and patient's vision is restored.
Also in patients with narrow angle glaucoma, the angle of anterior chamber( from where the aqueous humor goes out) is narrow and hence the pressure of the eye rises, here doing opening by yag laser in the iris (iridotomy) opens the angle and reduces the pressure.
Green laser is used for retinal conditions. In vascular occlusions and proliferative diabetic retinopathy with high risk characteristics, scatter laser treatment is done to cause regression of new vessels and hence prevent its complications like vitreous haemorrhage and retinal detachment. It is used in diabetic macular edema to seek microanurysms and reduction of macular edema. It is also used to seal retinal tears or holes in patients as preventive treatment of retinal detachment.
Lasers are done as outpatient procedure. It may be done in two or three sittings. It is usually painless or with minimal pain and needs no aftercare. Vision may not improve immediately when done for retinal conditions.
Lasers are also used during vitreoretinal surgeries.
There are other lasers like Lasik Laser for Number reduction and Carbon dioxide laser for eyelid surgery.