Diagnosis, Evaluation, and Treatment
The diagnosis of glaucoma can often be nuanced and requires meticulous attention to details over time. Given that glaucoma is a progressive condition, there are situations where diagnosis will not be possible until your doctor has had time to follow you over time. Typically in this situation, your doctor will identify you as a “glaucoma suspect” and follow you closely to ensure you are treated if you show any clear signs of glaucoma in the future. Alternatively, there are cases where glaucoma can be clearly identified and needs to be treated more urgently.
Given that glaucoma typically does not cause any symptoms, everyone should get routine yearly comprehensive eye examinations starting at age 40. Prior to this, we recommend healthy individuals without any visual complaints get a full eye examination every 2-4 years, outside the standard age-appropriate eye health and visual screenings.
A glaucoma evaluation typically takes several hours and includes various glaucoma diagnostic tests including an eye pressure check, visual field test, an optic nerve imaging study, and a corneal thickness measurement. This is typically paired with a gonioscopic evaluation of the “angle” of the eye and a full dilated funduscopic examination to evaluate the optic nerve and the entire eye.
Initial treatment for glaucoma typically involves the use of medicated eye drops that help to lower eye pressure. In later stage glaucoma, patients may need laser treatment or even surgery to help control their eye pressures.
The gold standard for functional glaucoma testing involves computer automated visual field testing (perimetry). These visual field tests help a physician identify and manage worsening peripheral vision. The tests have high variability and requires a physician to have a trained eye to help identify early subtle changes. Additionally, not all visual field tests are created equal. Depending on the patient, visual field tests need to be tailored and customized to ensure that ongoing visual field loss is caught in a timely fashion.
Imaging tests for glaucoma traditionally involved yearly photographs of the optic nerve to monitor for changes. Newer optical coherence tomography (OCT) allows for additional precision in monitoring for changes that a photograph could not catch. These scanners measure changes at the level of microns which is a unit of measurement 1/1000th the size of a single millimeter. Similar to visual fields, OCT results can be subtle and a comprehensive understanding of the complex data is imperative to accurately assess for glaucoma.
There are many different types of laser treatments for glaucoma. The decision to advance treatment to laser therapy is a personal one and needs to be customized to each individual patient.
There are three main types of laser treatments used in glaucoma:
- SLT: Selective laser trabeculoplasty: A low energy laser that is focused at the drain of the eye (trabecular meshwork) to help increase outflow and subsequently lower eye pressure.
- LPI: Laser peripheral iridotomy: A laser that is used to create a small opening in the peripheral iris to help decrease the risk of an acute angle closure attack.
- Micropulse cyclophotocoagulation: A thermal laser is applied through the sclera of the eye and absorbed by the tissue that creates fluid within the eye (ciliary body). This lowers fluid production inside the eye and subsequently lowers eye pressure.
Minimally Invasive Glaucoma Surgery
Minimally Invasive Glaucoma Surgery
Minimally invasive glaucoma surgeries (MIGS) is a group of glaucoma surgeries that help lower a patient’s eye pressure while not subjecting them to all the risks and side effects of traditional glaucoma filtering surgery. In general, to be termed “minimally invasive” a specific glaucoma surgery should have the following:
- If an incision is required, it should be micro-incisional and typically through the cornea.
- Minimal trauma to normal anatomy and physiology
- Reliable lowering of eye pressure.
- High safety profile (low side effects and risk of complications)
- Rapid post-op recovery, with minimal need for follow-up
There are many different types of MIGS procedures and studies are still ongoing on many of them. In general, your glaucoma specialist will evaluate if you are a good candidate for a MIGS procedure.
Glaucoma Filtering Surgery
Traditional glaucoma filtering surgery typically involves the creation of a hole in wall of the eye (trabeculectomy) or placing a tube (tube shunt) inside the eye. These surgeries help to lower the pressure in the eye (and control glaucoma) by draining the fluid from within the eye to the outside of the eye. Although traditional glaucoma surgery represents the most invasive treatment for glaucoma, it also provides the greatest pressure lowering of all the treatment options.