Laser peripheral iridotomy is a surgical technique that uses a laser to treat or prevent some forms of glaucoma, mainly narrow-angle and closed-angle glaucoma. It's a disease that develops when the aqueous humor, the fluid inside the eye, can't drain well because the eye's drainage canal is narrow or obstructed. It causes the pressure inside the eye, the intraocular pressure (IOP), to rise over time due to the humor accumulation.
A high IOP damages the tissue (optic nerve) that transmits visual images to the brain, resulting in irreversible loss of vision. In some cases, the IOP increases suddenly, causing red eyes, distorted vision, nausea, vomiting and pain (also known as an acute angle-closure attack).
The LPI procedure uses a focused laser beam to create a microscopic hole in the iris, the colored eye area. It modifies the iris's shape, which unblocks the eye's drainage system, improving the fluid flow. The treatment can help to prevent a sudden glaucoma attack, which can cause irreversible blindness. It is essential to remember that the procedure doesn't improve or restore vision.
Preparation & Expectation Before Surgery
Generally, LPI is recommended for patients with acute angle-closure glaucoma, narrow angles, or narrow-angle glaucoma. The eye surgeon will take the complete patient's medical history, including medication the patient is taking. The patient must inform the surgeon about all the medication, including prescription drugs, over the counter medicines and dietary supplements they are using. S/he will also undertake a comprehensive eye exam to determine if LPI is a suitable treatment option.
The patient can ask the surgeon about the treatment and seek clarification on any concerns they might have. The patient should come with someone or organize for transport home after the surgery, because their vision may be temporarily distorted.
Types, Purpose & Procedure
The LPI enables the humor to flow directly from the back chamber of the eye into the front chamber, bypassing the pupil. It decreases the chances of the drainage pathway closing and prevents a rapid rise in IOP due to humor buildup.
LPI is an outpatient procedure that can be carried out in an outpatient surgery center or in the eye surgeon's office. A technician will check the patient's eye pressure before the operation as a safety measure. S/he will also apply eye drop medications to reduce pupil size and prevent bleeding or an increased IOP following the surgery.
The surgeon will administer an anesthetic eye drop to numb the eye and sit the patient in front of the laser machine. S/he will then place a specialized lens (microscope) on the patient's eye to keep it still and focus the laser beam on the iris. The microscope is coated with a clear gel to protect the eye surface and better focus laser light into the eye. S/he will apply the laser on the iris, and during the treatment, the patient may see brief light flashes. The surgeon may use two laser machines to perform the surgery, where the patient's iris is unusually thick. The laser procedure takes about five minutes per eye to complete.
The patient's eye pressure will be rechecked after about an hour and they will be allowed to go home if it's stable.
Risks, Side Effects & Complications
LPI is associated with a few risks, including:
- Loss of vision
- Inflammation of the iris
- Temporary IOP increase after the treatment
The patient may experience a mild headache after receiving the eye drop medication before the procedure. The gel used in the surgery will remain in the eye for about an hour and may cause a heaviness feeling. The patient will have eye irritation, blurred vision, and increased light sensitivity that may last for a day or two.
Complications arising from the procedure are rare but may involve additional surgery especially where the hole is too small, incomplete, or scar closed. In sporadic cases, the patient may see ghost images through the hole or experience glare and increased light, but these may improve over time.
After Care, Recovery & Results
In most cases, the surgeon will prescribe eye drops to prevent infection and help the eye heal. The patient should apply the medication four times a day for a week or as directed by the doctor.
S/he may want to see the patient the day after treatment or after a week. The number and frequency of the follow-up visits will depend on the condition of the patient. Usually, the patient continues taking all of their glaucoma medications as prescribed before the surgery.
LPI treatment is successful in most of the cases. However, about 15 percent of the patients may need other medical or surgical procedures because the shape of the front eye area or the IOP may not improve.