Know your glaucoma surgery for better comanagement
Patients are looking more to ODs to manage their glaucoma care, including postop
Treating and managing chronic glaucoma can be rewarding as an optometrist. The frequency of office visits to monitor this chronic disease provides ODs an opportunity to develop a close relationship with their patients while providing medical eye care. More than ever, patients are looking to optometrists to manage all of their glaucoma care, including postoperative management of glaucoma surgical procedures.
Recent advances in microinvasive surgical techniques and devices that improve aqueous outflow have revolutionized the surgical glaucoma treatment algorithm. It is critical that optometrists become knowledgeable in all the surgical glaucoma options available to patients so they can facilitate and coordinate care with a glaucoma specialist when their intervention is necessary. It is also important to establish a relationship with your local glaucoma specialist if you are planning to comanage surgery. I recommend observing them in their clinic and during surgery in order to get to know their surgical techniques and management preferences. This also will build mutual trust when comanaging patients because glaucoma management carries higher liability for both parties. If you and your surgeon are not on the same page about postsurgical treatment and management, it can leave you both open to increased risk of litigation, especially in cases of advanced glaucoma.
Laser iridotomy in narrow-angle or angle-closure glaucoma
Laser peripheral iridotomy (LPI) is the definitive treatment for angle-closure glaucoma (ACG) due to pupillary block as well as ACG preventative treatment in those with narrow angles.
In patients presenting with ACG, an LPI should be performed after you have broken the attack using oral and topical agents. Initiate an in office “glaucoma cocktail” and give 500 mg of oral acetazolamide (Diamox, Wyeth). Then add one drop of topical glaucoma agents of each pharmaceutical class every 10 minutes until the pressure starts to fall below 30 mm Hg. The glaucoma surgeon and the patient alike will appreciate you for breaking the attack prior to seeing the surgeon same day.
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An LPI establishes an alternative route for aqueous flow between the anterior and posterior chambers and is typically done using a YAG laser which allows quicker penetration with less total energy.1 After diagnosing narrow angles with gonioscopy, you need to determine whether the angles are at risk for closure. If the iris is touching the trabecular meshwork, there is risk of closure, and the patient should be referred for an LPI.
The patient is given 1% pilocarpine and either brimonidine (Aphagan P, Allergan) or aproclonidine (Iopidine, Alcon) 10 minutes prior to the LPI to prevent postoperative intraocular pressure (IOP) spike. Many surgeons are now placing the iridotomies temporal to reduce linear dysphotopsias postoperatively.2 (See Figure 1.) Despite location under the lid for superior and inferior PIs, it is hypothesized the tear prism at the edge of the lids bend light, allowing it to reflect back through to the retina, causing glare.3 After the patient has the LPI, he will be placed on a topical anti-inflammatory for five to seven days to prevent postoperative inflammation. The surgeon will recheck IOP one hour later to ensure no spike and return the patient to you in one week pending no complications.
At the one-week follow up, look for patency of the iridotomies. This can be done by retro illumination. If the iris was dense, or a localized bleed prevented visualization during the procedure, the iridotomy may not achieve patency. Refer back to the surgeon for repeat treatment if nonpatent. Late closure can also occur up to six weeks postoperatively.4 Gonioscopy is also performed to ensure the angle has opened. If the angle has not opened or IOP remains elevated, then plateau iris is suspected. The patient should be referred back to the surgeon for argon laser iridoplasty.
ODs should then evaluate for adjunctive topical therapy based on the amount of glaucomatous damage at discovery. Clinical correlation of disc assessment, visual fields, and nerve fiber layer evaluation is critical in determining if IOP is ideal to prevent further change over time.