Laser iridoplasty is a surgical technique used to widen/open the front eye chamber's angle by moving the peripheral iris away from the trabecular meshwork which is the drainage tissue. The procedure is effective in treating abnormalities involving appositional closure of chamber angle, such as plateau iris syndrome, iris cysts and nanophthalmos.
It is used as the initial treatment for acute angle-closure glaucoma, followed by definitive treatment with laser iridotomy (LI). It lowers intraocular pressure (IOP) significantly and more rapidly than medical treatment and can be conducted despite corneal clouding, unlike iridotomy. Initial therapy with ALPI stabilizes the eye and adequately clears the surgeon's view to allow definitive treatment. Thus, the technique is useful for opening the chamber angle where other procedures, such as LI, cannot be carried out or are ineffective. The treatment may also help prevent peripheral anterior synechiae (PAS) formation due to extended appositional closure in an inflamed eye. It can also open a narrowed angle to allow for trabeculoplasty treatment.
Krasnov developed ALPI in 1977, and it was refined by Kimbrough and others over time. Nowadays, the technique is no longer widely practiced because of its long-term ineffectiveness in chronic disorders, and the emergence of newer and more effective treatments. However, it's still useful in angle-closure glaucoma management in some instances, particularly in non-pupillary block angle closure.
Glaucoma leads to progressive impairment of the nerve tissue (optic nerve), which is responsible for transmitting images from the eye to the brain. The disease is usually linked to high IOP and often presents as peripheral vision loss. Without treatment, it can progress to central vision loss and irreversible blindness.
Also Known As
- Peripheral iridoplasty
- Argon laser peripheral iridoplasty
Before the Procedure
The eye surgeon will establish a detailed patient's medical and surgical history. The patient must inform the surgeon about any medical condition and all the medication they take, including prescription drugs, over the counter medicines and supplements. S/he will also undertake a comprehensive eye examination, including an IOP check, physical evaluation, gonioscopy, and imaging tests, such as ultrasound biomicroscopy.
ALPI is most often recommended in patients with plateau iris syndrome. The condition arises due to an anteriorly positioned or extensive ciliary process that pushes the peripheral iris onto the trabecular meshwork blocking the chamber angle.
The patient should bring someone along or arrange to be driven home after the surgery, because their vision may be temporarily hazy.
ALPI is an outpatient procedure usually conducted in the eye surgeon's office or an outpatient surgery center with an argon laser and topical anesthesia. The surgeon will conduct pre-surgery tests and administer eye drop medication to dilate the pupil and prevent bleeding. S/he will apply an anesthetic eye drop to numb the eye and position the patient in front of the laser machine. S/he will place ocular Instruments on the patient's eye to keep it still, and focus the laser light on the peripheral iris. The treatment takes about five minutes per eye.
After the procedure, the surgeon will instill a glaucoma eye drop to reduce the risk of a sudden IOP spike. The patient will be escorted to the recovery room to rest for 30 to 60 minutes. A nurse will recheck the IOP before the patient goes back home.
Risks & Complications
The procedure is relatively safe with rare risks, including:
- Iris atrophy
- Inflammation of the iris
- Diffuse endothelial corneal burn
- Temporary IOP spike after the treatment
The patient may have a mild headache after receiving the medication administered before the procedure. The patient may experience increased light sensitivity, eye irritation and blurred vision, that will resolve in a day or two.
There are uncommon complications that may arise from the treatment, including pigmented scars and a permanently dilated iris.
After Care & Recovery
The patient will apply an anti-inflammatory eye drop for about four to five days, along with visiting the doctor a week after the surgery for a follow-up. S/he will check the patient's IOP and conduct gonioscopy to re-examine the front chamber angle. The second follow up visit usually comes after about six weeks. Retreatment may be necessary in some cases.
ALPI is a safe and effective procedure for relieving appositional angle closure. It can consistently deliver long-term benefits for plateau iris syndrome patients, including where angles remain narrow after iridotomy. Acute angle-closure glaucoma patients may also profit from ALPI in situations where immediate laser iridotomy I isn't possible. Thus, ALPI contributes to the success of other procedures like iridotomy.