All about peripheral iridotomy and selective laser trabeculoplasty

Glaucoma, commonly known as the "silent thief of vision," encompasses a range of eye conditions that harm the optic nerve, resulting in permanent loss of eyesight. One of the critical aspects in managing glaucoma is controlling intraocular pressure (IOP), as elevated IOP is a significant risk factor for the progression of the disease. Laser therapy has emerged as a valuable tool in the armamentarium of treatments for glaucoma. In his latest article, Mr Venki Sundaram explores the main types of laser procedures used in the management of glaucoma: peripheral iridotomy (PI) and selective laser trabeculoplasty (SLT).

Peripheral iridotomy (PI):

Peripheral Iridotomy is a laser procedure primarily utilised to prevent acute angle-closure or angle-closure glaucoma. These conditions occur due to a shallow anterior chamber, where the drainage angle between the cornea and the iris becomes narrowed, predisposing the eye to sudden or gradual increases in intraocular pressure. PI involves creating a small hole in the iris using a laser, facilitating the circulation of fluid within the eye and preventing the closure of the drainage angle.

During a PI procedure:

Patients receive topical anaesthesia to ensure comfort during the procedure. A laser is used to create a small opening in the iris, typically requiring 1 or 2 brief laser shots per eye. Post-procedure care involves the use of steroid eye drops for a week and monitoring for potential complications such as inflammation, raised eye pressure, or localised cataract formation.

Selective laser trabeculoplasty (SLT):

SLT is a minimally invasive laser procedure aimed at reducing intraocular pressure by improving the outflow of aqueous humour from the eye. Unlike PI, which targets the iris, SLT focuses on the trabecular meshwork, the primary drainage system of the eye. By applying low-energy laser pulses to this tissue, SLT selectively targets pigmented cells, stimulating a biological response that enhances fluid outflow.

Key points regarding SLT:

• It is effective for patients with newly diagnosed glaucoma, those on drop therapy with persistently elevated eye pressure, or individual’s intolerant to glaucoma medications.
• The procedure is well-tolerated and typically takes 5-10 minutes per eye.
• While complications are rare, patients should be aware of potential side effects such as transient eye discomfort or elevated eye pressure, which can usually be managed with medication.

Mr Venki Sundaram is an esteemed consultant ophthalmologist. You can schedule an appointment with Mr Sundaram on his Top Doctors profile.