Cataract surgery is a common procedure that restores vision by removing a cloudy lens and replacing it with an artificial one. While generally successful, eye pressure, known as intraocular pressure (IOP), can fluctuate after the operation. These changes are temporary and can be managed effectively with appropriate medical care.
Causes of Increased Eye Pressure After Surgery
A common reason for a temporary rise in eye pressure after cataract surgery involves retained viscoelastic material. This gel-like substance is used during the procedure to maintain space within the eye and protect its delicate structures. If small amounts are not completely removed, they can temporarily obstruct the eye’s natural drainage system, called the trabecular meshwork, leading to elevated pressure. This elevation peaks within 3 to 7 hours after surgery and resolves within the first 24 hours or up to a week or two as the remaining material dissolves.
Post-surgical inflammation, also known as uveitis, is another factor contributing to increased eye pressure. The eye naturally responds to surgery with some inflammation. This response can cause cells and proteins to accumulate in the drainage angle, impeding the normal outflow of aqueous humor, the fluid that fills the front of the eye.
Steroid eye drops are commonly prescribed after cataract surgery to reduce inflammation and promote healing. However, some individuals are sensitive to these medications and may experience a “steroid response,” where the drops cause their eye pressure to rise. This pressure spike occurs later in recovery, around 10 days to two weeks after steroid treatment begins, as the medication affects the eye’s drainage pathways.
Individuals with pre-existing eye conditions may also be more susceptible to elevated eye pressure after surgery. For instance, patients diagnosed with glaucoma or ocular hypertension have a compromised drainage system, making them more prone to pressure spikes. Other risk factors include exfoliation syndrome, high myopia, or previous glaucoma treatment.
Causes of Decreased Eye Pressure After Surgery
While less common than elevated pressure, a decrease in eye pressure, known as hypotony, can also occur after cataract surgery. The primary cause is a wound leak from the surgical incision. Modern cataract surgery uses very small incisions, which seal themselves without stitches.
If the incision does not seal completely, a small opening can allow aqueous humor to seep out of the eye. This continuous leakage reduces the volume of fluid inside the eye, leading to a drop in intraocular pressure. Patients with complicated surgeries, mature cataracts, or zonular weakness may have an increased risk of wound leaks.
Recognizing Pressure-Related Symptoms
Patients may experience various symptoms if their eye pressure becomes too high after cataract surgery. These include eye pain and a headache. Vision may appear blurry or hazy, and halos around lights can be seen. In severe instances, nausea can also occur.
If eye pressure drops too low, symptoms can include blurry or distorted vision and a dull ache in the eye. Significant changes in eye pressure, whether high or low, do not always produce noticeable symptoms. Because symptoms are not always noticeable, attending all scheduled follow-up appointments with your eye surgeon is important. They will measure your eye pressure to detect any silent fluctuations. Contact your surgeon immediately if you experience any of these symptoms.
Treatment and Management Strategies
Treating elevated eye pressure after cataract surgery involves several approaches aimed at reducing fluid inside the eye or improving its outflow. Eye drops are the first line of treatment; these include medications like beta-blockers, alpha-agonists, or prostaglandin analogs, which work to either decrease fluid production or enhance drainage. Oral medications, such as acetazolamide, can also be prescribed to quickly lower pressure by reducing aqueous humor production. If retained viscoelastic is the cause, an in-office procedure might be performed to release fluid from the incision, or additional surgery may be needed to remove the material. If steroid-induced pressure spikes occur, your doctor may adjust or discontinue the steroid drops, potentially switching to a nonsteroidal anti-inflammatory drug.
Managing low eye pressure after surgery primarily focuses on addressing the underlying wound leak. For minor leaks, conservative measures may be used, such as applying a bandage contact lens to cover and help seal the incision. A pressure patch over the eye can also encourage the wound to close. Reducing anti-inflammatory eye drops may be considered if inflammation contributes to decreased aqueous production. If conservative methods are insufficient or the leak is more significant, surgical intervention to place a stitch in the incision may be necessary to ensure a proper seal and normalize eye pressure.