Glaucoma and Lasers
One of the best things about the IEI is its comprehensive service offerings. A patient who is diagnosed with angle closure glaucoma on the first floor in Primary Care can take the elevator up to the second floor and receive laser treatment in Advanced Care. During third year, you’ll learn just about everything you’ve ever wanted to know about glaucoma. You’ll learn about all the flavors and forms it comes in, who it affects, what factors put an individual at risk, and how to analyze endless visual fields and scans of the optic nerve and nerve fiber layer.
What is glaucoma? Short definition, it’s a blinding eye disease that clinically manifests as damage to the optic nerve and retina, causing a gradual loss of vision that begins peripherally and ends centrally. A lot of the time, this damage to the optic nerve and retinal tissue is due to high intraocular pressure. At this point, my classmates and I have had Glaucoma I and II. I feel confident in my knowledge of glaucoma and rumor has it, it’s one of the few sections on NBEO exams that everyone answers unhesitatingly.
Most commonly, glaucoma is managed with the use of pharmaceutical eye drops that work to decrease intraocular pressure and hopefully halt or slow progression of the disease. Less known is that glaucoma can also be managed with laser and surgical treatments. At the IEI, laser treatment is offered in office. The two main used laser treatments for glaucoma are laser peripheral iridotomy (LPI) and selective laser trabeculoplasty (SLT). LPI is used for angle closure glaucoma and SLT is used for open angle glaucoma.
Last month, I had the pleasure of working in Advanced Care alongside three attending doctors–one ophthalmologist and two optometrists–with patients scheduled to receive laser treatment. As a student clinician, my tasks included working up SLT and LPI patients. We also saw patients post-op to see how their treatments were or weren’t working for them. Since it was a work up for laser treatment, the slew of entrance testing we normally do in Primary Care wasn’t necessary. After patients signed the treatment consent forms, I asked them about their current condition and concerns, and I then performed a couple of tests. These included examining entering visual acuities, checking intraocular pressures, and doing a thorough slit lamp exam to assess ocular health.
For SLT, patients were given a drop of brimonidine pre-op. Brimonidine is an alpha agonist used prophylactically to prevent post-op pressure spikes. For LPI, patients were given drops of brimonidine and pilocarpine. Pilocarpine is a miotic agent that works to constrict the pupil and stretch the iris making LPI easier. After working up patients, I observed a number of procedures and watched as laser was applied using a slit lamp and gonioscopy lens. During SLT, a laser beam is used to burn areas of the trabecular meshwork. This increases outflow and helps decrease intraocular pressure. During LPI, little openings are made in the periphery of the iris allowing a decrease in eye pressure by an increase in outflow.
All in all, this experience in Advanced Care gave me great insight into what happens when a patient is referred for laser surgery.
Editor’s note: Optometrists do not have the ability to perform laser surgery in Illinois at the moment. At the IEI, these treatments are performed by ophthalmologists.