Glaucoma is characterized by progressive damage to the optic nerve, often linked to elevated intraocular pressure (IOP) inside the eye. Glaucoma stent surgery, a category of Minimally Invasive Glaucoma Surgery (MIGS), uses microscopic devices to create an alternative pathway for fluid drainage. These stents bypass the dysfunctional natural drainage system, reducing IOP and protecting the optic nerve from further damage. Although MIGS offers advantages like quicker recovery and a lower risk profile compared to traditional filtration surgeries, it remains a surgical intervention. Patients should understand the potential adverse effects and complications associated with the procedure.
Immediate Post-Operative Expectations
Following glaucoma stent surgery, patients should anticipate a period of adjustment where certain temporary symptoms are common signs of healing. Blurred vision is a frequent occurrence immediately after the procedure and can persist for several days or even up to six weeks as the eye stabilizes. This visual fluctuation is normal as the eye pressure adjusts to the new stent and the effects of post-operative inflammation subside.
Patients often experience mild eye discomfort, irritation, or a gritty sensation. This feeling usually responds well to over-the-counter pain relievers. Redness, tearing, and minor swelling of the eyelid are also expected during the initial days of recovery as the tissue reacts to the surgery.
The eye requires frequent application of specific prescription eye drops in the weeks following surgery. These drops, typically including an antibiotic and a steroid, are fundamental for managing inflammation and preventing infection. Adherence to this medication schedule is necessary, even if the eye feels comfortable, as the drops regulate the post-operative environment. Most of these minor, transient symptoms typically resolve within the first few weeks.
Acute Complications
Acute complications manifest shortly after the procedure, usually within the first few weeks, and often require immediate medical management. One common issue is a temporary spike in intraocular pressure (IOP). This can occur due to retained viscoelastic material used during surgery or initial inflammation. Severe, transient hypertension may necessitate additional topical glaucoma medications or other intervention.
Conversely, some patients may experience hypotony, which is an excessively low IOP that occurs when the new drainage pathway works too effectively. Mild hypotony often resolves on its own. However, persistent or severe cases can lead to hypotony maculopathy, a condition that affects central vision.
Another common acute complication is hyphema, which is bleeding into the anterior chamber of the eye. Since the stent is placed near blood vessels in the drainage angle, bleeding can occur as the pressure is lowered. Hyphema is usually transient and self-limiting, but significant blood can block vision or obstruct the stent itself. Severe inflammation, or iritis, is also an acute risk and must be managed with steroid drops to protect the long-term success of the stent.
Delayed and Structural Complications
Delayed complications emerge weeks, months, or years after surgery, related to the body’s long-term interaction with the implanted device. The most frequent delayed issue is the obstruction of the stent, which prevents proper fluid outflow and causes the IOP to rise again. This blockage can be caused by the ingrowth of surrounding tissue, such as the iris, or by fibrin and cellular debris.
Stent obstruction may require a secondary procedure, such as laser treatment or surgical revision, to clear the blockage. Stent migration or displacement is a structural complication where the device moves out of its intended position. If the stent shifts, it may no longer function properly, potentially leading to a failure to control IOP or causing irritation to surrounding ocular structures.
In rare instances, the stent can cause tissue erosion or become exposed. Conjunctival erosion occurs when the stent material begins to wear through the surface tissue. Long-term device failure, whether from obstruction or migration, may ultimately necessitate a more invasive traditional glaucoma surgery to maintain adequate pressure control.
Managing and Reporting Adverse Events
Patients play an important part in managing their recovery by strictly following the post-operative instructions provided by the surgeon. Adherence to the prescribed schedule for antibiotic and anti-inflammatory eye drops is necessary to minimize infection risk and control inflammation. Patients should also avoid activities that increase pressure, such as heavy lifting, bending over, or strenuous exercise, for the first few weeks.
Recognizing warning signs is necessary for prompt intervention should a serious complication arise. An urgent call to the eye surgeon is warranted if the patient experiences sudden, severe, unremitting pain in the eye. Other urgent symptoms include a sudden and significant loss of vision, new shadows in the visual field, or the appearance of pus or thick discharge from the eye.
These signs may indicate issues such as severe infection or a significant pressure event, requiring immediate professional evaluation. Patients should also report any excessive or worsening redness, swelling, or persistent nausea, as these could signal problems with healing or pressure control.