LASER THERAPY

• Definition: "Laser therapy” is any treatment using intense beams of light to precisely cut, burn, or destroy tissue. The term laser is an acronym for "light amplification by stimulated emission of radiation.”

CONSTRUCTION

Principal components:1.Active laser medium2.Laser pumping energy3.Mirror(100%)4.Mirror(99%)5.Laser beam

Working

• A laser is composed of an active laser medium, or gain medium, and a resonant optical cavity. The gain medium transfers external energy into the laser beam. It is a material which amplifies the beam by the quantum mechanical process of stimulated emission.

APPLICATIONS• Consumer electronics, information technology,

science, medicine, industry, law enforcement, and the military.

Medicine• In medicine, the laser scalpel is used for laser

vision correction and other surgical techniques. • Lasers are also now used in dentistry for caries

removal, as well as tooth whitening and oral surgery procedures.

• To treat some skin conditions, including to remove tattoos, birthmarks, scars, wrinkles

• To remove tumors• To prevent blood loss by sealing small blood vessels

ANATOMY OF EYES

Eye surgery, also known as ophthalmic surgery or ocular surgery, is surgery performed on the eye, typically by an ophthalmologist.

Types of eye surgeries

Cataract surgeryGlaucoma surgery

Laser trabeculoplasty

IridotomyTube-shunt surgery or drainage

implant surgeryRefractive surgery

NEARSIGHTEDNESS

FARSIGHTEDNESS

ASTIGMATISM

REFRACTIVE ERRORS

The first in the line of laser procedures for vision correction was

Photorefractive Keratectomy or PRK.

PRK is a laser vision correction procedure that uses an excimer laser to treat mild to moderate levels of nearsightedness, farsightedness and astigmatism. Rather than making cuts in the cornea, the PRK process uses an excimer laser to sculpt an area of 5 to 9 millimeters in diameter on the surface of the eye.

Then came in the world of refractive surgery – LASIK

LASIK, or Laser Assisted In Situ

Keratomileusis

The procedure, which is performed on an outpatient basis under local anesthesia, corrects moderate to high levels of nearsightedness, farsightedness, and astigmatism.

LASIK Laser Eye Surgery

LASIK is an acronym for LASer In-situ Keratomileusis, which simply means "to shape the cornea within using a laser."

Preoperative:Patients wearing soft contact lenses typically are instructed to stop wearing them approximately 7 to 10 days before surgery. The day before surgery, you should stop using:• creams • lotions • makeup • perfumes

After Surgery :

• Your eye may burn, itch, or feel like there is something in it.

• You may experience some discomfort, or in some cases, mild pain and your doctor may suggest you take a mild pain reliever.

• Both your eyes may tear or water.• Your vision will probably be hazy or

blurry.

Bilateral Treatment (Both Eyes) You may choose to have LASIK surgery on both eyes at the same

time or to have surgery on one eye at a time.

Possible Side Effects/Complications

A subconjunctival hemorrhage is a common and minor post-LASIK complication.

• The flap can be dislodged by any direct injury to the eye after treatment. 

• Clarity and quality of vision can de diminished if flap conditions occur. 

• Poor night vision is the most common side effect.  • Light sensitivity

Factors affecting surgery

Low oxygen-permeable contact lenses reduce the cornea's absorption of oxygen, which sometimes results in the growth of blood vessels into the cornea, a process known as corneal neovascularization.

Advantages of LASIK

a pain free recovery. quick restoration of eyesight and better results for severe short sight. The inner eye is not pierced during the procedure and stitches are not required. Clarity of vision within hours of surgery Extremely predictable No more daily cleaning rituals or recurring costs as with visual aids Increases self-confidence Broad range of treatable prescriptions Both eyes treated on the same day

INTRALASIK • The Intralasik technique is very similar to Lasik but

utilizes a laser, rather than a blade, to create a corneal flap. For Intralasik, its only advantage is consistency of flap depth and reduced risk of flap complication. It may be advertised as a "bladeless" procedure, but it is certainly not "flapless" or without an incision!

Epi-LASEK Laser Eye Surgery Epi-LASEK involves lasering the surface of the

cornea under the epithelium.  It is a combination of surface PRK and Epiflap. 

The Treatment

After Treatment

Bandage Lenses

Possible Side Effects

But now, a new approach to refractive surgery- Wavefront Guided Custom

LASIK-

Instead of just correcting defocus (spherical and cylindrical) errors, we can now take a wavefront image- literally a 'fingerprint' of each person's optical pathway- and use the information to reduce or even eliminate higher order aberrations.

Glaucoma

• Definition: Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP).

• There are four major types of glaucoma

Open angle (chronic) glaucoma Angle closure (acute) glaucoma Congenital glaucoma Secondary glaucoma

The same view with advanced vision loss from glaucoma

A normal range of vision.

TREATMENT

Laser trabeculoplasty

Laser Iridotomy

Peripheral iridoplasty and Pupilloplasty

Complications :• A brief period of inflammation of the colored part of the eye (iris).

• Cloudiness of the clear covering (cornea) over the iris. This usually does not last long.

• Blockage of the drainage angle when the cornea and the iris stick together.

• Pain.

• Decreased vision.

Laser ciliary body

Cataract surgery

Cataract surgery

Cataract A cataract is an opacification or cloudiness of the eye's crystalline lens due to aging, disease, or trauma that typically prevents light from forming a clear image on the retina.

Light passes through the clear lens implant

•Capsule thickening

Laser makes a small hole in the capsule. Light can then pass directly onto the retina, without being scattered.

LASER TREATMENT

• After laser

Complications :

• Less often, the laser can disturb the retina.• Very rarely a little fluid can build up in the retina.• flashes of light during the daytime • floaters in your vision (it is normal to have these in the weeks after the laser)

Floaters after laser capsulotomy

Laser Treatment Highly Effective in Treating Diabetic

Retinopathy Laser photocoagulation for diabetic retinopathy

• Laser photocoagulation uses the heat from a laser to seal or destroy abnormal, leaking blood vessels in the retina. One of two approaches may be used when treating diabetic retinopathy:

Focal photocoagulation

Focal treatment is used to seal specific leaking blood vessels in a small area of the retina, usually near the macula. The ophthalmologist identifies individual blood vessels for treatment and makes a limited number of laser burns to seal them off.

Focal treatment uses the laser to seal up tiny bulges in capillaries near the fovea

Scatter (pan-retinal) photocoagulation : Scatter treatment is used to slow the growth of new abnormal blood vessels that have developed over a wide area of the retina. The ophthalmologist may make hundreds of laser burns on the retina to stop the blood vessels from growing

Panretinal treatment reduces growth of new capillaries throughout the retina.

Risks

Laser photocoagulation burns and destroys part of the retina and often results in some permanent vision loss. Treatment may cause mild loss of central vision, reduced night vision And decreased ability to focus Pain in or around the eye Retinal bleeding Watery eyes Dilated pupils Mild headache Double or blurry vision

What are the advantages of laser therapy?

Less pain, bleeding, swelling, and scarring.

With laser therapy, operations are usually shorter.

In fact, laser therapy can often be done on an outpatient basis.

It takes less time for patients to heal after laser surgery, and they are less likely to get infections.

What are the disadvantages of laser therapy?

Laser therapy is expensive and requires bulk equipment.

In addition, the effects of laser therapy may not last long, so doctors may have to repeat the treatment for a patient to get the full benefit.