Treatments
Overview
Intravitreal Injection
Laser Treatments
Vitrectomy
Scleral Buckle
Cryotherapy
B-scan Ultrasonography
Optical Coherence Tomography
Fluorescein Angiography

Laser Treatments

What is Laser Photocoagulation?
Lasers create a uniform beam of light that has very high intensity. Medically they are used to burn tissue giving the name photo (light) + coagulation (burn). When using lasers to treat retinal disease, the function is very different than the lasers used in vision correction. Retinal lasers accomplish two goals, damaging the retina and forming an adherent scar between the retina and underlying layers of the eye. These effects are employed differently depending on the disease being treated.
 

 
How is the procedure performed?
The laser energy is formed in a central unit and then directed to the eye by a special slit lamp microscope attached to a table or an indirect ophthalmoscope that can be worn on the head. Most commonly, retinal lasers use a 532nm wavelength green laser to burn the retinal tissue.  Different lenses are used to focus the laser energy on the retina to produce the desired effect, some are handheld and others are contact lenses that fit directly on the surface of the eye. The focused laser energy striking the retina heats the tissue and forms a burn. Since the tissue is burned there can be some pain during the treatment so an anesthetic can be injected under the skin of the eye to minimize the discomfort.
 

What procedures are performed with Laser Photocoagulation?

Laser Retinopexy
This procedure forms a “pexy” or fixation of the retina to the underlying layers of the eye. This is used in situations where the retina has been damaged that could result in a retinal detachment, most commonly from retinal tears due to a Posterior Vitreous Detachment. In this instance, the laser energy is applied to burn the retina around the retinal tear that then heals and forms a scar that adheres the retina to the wall of the eye, similar to spot welding the retina in place. The scar tissue is strong enough to prevent the retina from detaching, even if there is still traction on the retina from the vitreous gel. The strength of the scar forms during the healing process and initially has almost no additional strength, over the course of 10-14 days the scar becomes full strength. During this healing time the retina is still at risk of detaching and symptoms should be closely monitored.
 
Pan-Retinal Photocoagulation (PRP)
Diseases that affect the retinal blood vessels, diabetes and vessel blockages, can cause the retina in the far periphery to not receive adequate blood supply. This sick retina then responds by sending signals that drive the formation of new, abnormal blood vessels. These vessels are dangerous and can result in bleeding, scarring, and permanent vision loss. Unfortunately, the blood supply cannot be re-established to supply this area of retina, in order to control the growth of these dangerous vessels the retina that is damaged is treated. With the laser treatment the amount of retina is decreased to balance the nutritional requirement with the amount of blood flow available to the tissue. The area that is treated is far in the periphery and not used for vision. There is no way to determine how much laser must be applied, the treatment is performed and the eye is carefully monitored. If the abnormal vessels regress then no additional treatment is required, if they persist, then additional laser is needed until a balance is reached. With good control of the underlying systemic disease the retina will stabilize for the long-term, however, if additional damage occurs there may be the need for more laser treatment in the future.
 
Focal Photocoagulation
In addition to poor blood flow, damaged blood vessels often leak fluid, protein, lipid, and blood that will accumulate in the retina. This disrupts the retinal layers and can cause decreased vision, especially if they affect the central retina in the macula. While the leaking can be treated with medications, it is often beneficial to treat the leaking areas focal photocoagulation. This form of laser is applied using the slit lamp microscope to provide high magnification and a special contact lens that focuses the energy to pinpoint accuracy. After treatment, the damaged blood vessel can seal and the retina will absorb the fluid and stabilize. The risk of the procedure is that the adjacent retina receives some of the laser energy and is damaged. Since the treatments are very small the damage typically does not affect the vision. The major advantage of the focal laser is that the treated area has a much more long-term effect than medical therapy.
 

What is the recovery like?
Since there are no incisions made in the eye the eye does not need to wear a patch and no eye drops are necessary. The light is very intense and will make the vision temporarilly dim for about 20-30 minutes after the procedure before returning to the level it was before the procedure. It is recommended to have a driver on the day of any procedure for safety while traveling.
 
The laser burn turns to scar over the course of 10 days. If a retinal tear was treated then the retina is still at some risk of detaching until the scar has full strength and decreased activity is recommended. For PRP and focal laser treatments normal activity can be maintained during the retinal healing; however, for these procedures the effect can take longer to become apparent.
Dr Kruti Dajee Dr Jawad Qureshi Dr Johnathan Warminski