Photocoagulation is typically an outpatient procedure, so it will probably take place at an ophthalmologist’s office or an outpatient surgical center. There is no need to stay overnight in a hospital. Patients should arrange for transportation home after photocoagulation because their vision may be too impaired to drive safely. They are also instructed to bring sunglasses to protect their eyes from the sun, as the pupils will be dilated with drops.

Prior to photocoagulation, the patient will be seated in a chair that is similar to the type used for regular eye examinations. Then, anesthetic eye drops will be administered to allow painless placement of a lens on the eye, and additional drops will be administered to widen (dilate) the pupil. In rare cases, patients may require a numbing injection in the region around the eye.

The patient’s chin and forehead will be placed in a slit lamp, which is a special microscope with an attached light that allows the ophthalmologist to clearly view specific portions of the eye. A special lens will be positioned between the patient’s eyelids to prevent blinking and help focus the laser onto the portions of the retina (the light-sensitive tissue at the back of the eye that relays information to the brain) that require treatment.

Ophthalmologists may choose to take fluorescein angiography photographs before any laser treatment to identify the leaking blood vessels and map the locations where the laser should be directed. For these images, a special dye is injected into the arm, which will eventually flow to the blood vessels in the rear of the eye, and photographs are taken with special filters to allow the blood vessels to be seen more clearly.