As with any surgical procedure, complications may occur before, during, and after cataract surgery. The risks of cataract surgery include infection, swelling of the retina, cloudy vision, and retinal detachment.

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Approximately half of all Americans who are 75 years old have cataracts.

The eye’s lens is a transparent, curved structure located just behind the pupil. A healthy lens has the lowest water content in the human body.

Cataracts form when:

  • changes occur in the ionic components of the lens
  • compacted lens material accumulates deep within the lens
  • pigmentation discolors the lens
  • the lens proteins break down

Each of the above factors interferes with the lens’ ability to transmit focused light rays to the retina.

This article explores the risks and complications associated with cataract surgeries, the recovery, and answers to some commonly asked questions about the procedure.

Surgery is the safest, most effective, and only approved way to remove cataracts.

During cataract surgery, an ophthalmologist makes a small, painless incision along the edge of the clear cornea, removes the cloudy lens using small instruments, and replaces it with an artificial lens implant.

The surgery is safe and low risk, but the risk of many postoperative complications relates to the overall health of the individual’s eyes.

Visual outcomes will differ for people with other vision issues, such as:

Most postoperative complications are easy to diagnose, and prompt treatment usually delivers favorable outcomes. If someone suspects they may be experiencing a complication following cataract surgery, they should consult their ophthalmologist immediately.

Postoperative infections are uncommon. Bacteria may enter the eye during or after the surgery can result in an infection.

Endophthalmitis is one of the most severe complications after cataract surgery and is an urgent health matter. It occurs when microorganisms enter the eye and infect the fluids or tissues inside the eyeball.

The most common symptoms of endophthalmitis include:

  • eye pain that gets worse after eye surgery
  • white or yellow pus discharge
  • red eyes
  • swollen or puffy eyelids
  • reduced or blurred vision, or loss of vision

Treatments

Doctors treat the condition by injecting antibiotics or antifungal medication into the eye. They may also inject steroids to control the inflammation. Serious infections may require surgery.

Inflammation and swelling are expected results after surgery, especially if a person has dense or large cataracts or the surgery becomes prolonged. A person may continue to have foggy or blurred vision immediately after surgery, most frequently due to swelling of the clear cornea (corneal edema).

Treatments

Treating postoperative corneal edema with nonsteroidal anti-inflammatory drug (NSAID) eye drops can help reduce swelling within a few days or a week. Additional surgery may become necessary if vision does not improve.

While rare, blood vessels supplying blood to the retina may bleed during surgery. Left untreated, severe bleeding can lead to vision loss.

Suprachoroidal hemorrhage (SCH) is a rare but potentially blinding complication of inner eye surgeries. It requires prompt management to prevent vision loss. The sudden drop in intraocular pressure during or after surgery is its most important risk factor.

Treatments

Early recognition of SCH and prompt closure of surgical incisions stabilizes eye pressure. Excess blood can be safely drained to protect the ocular contents.

The following are management and treatment techniques for SCH:

  • Wound closure: Early detection of SCH is important to stop bleeding. Doctors may need to surgically remove prolapsed tissue to promote wound closure.
  • Deepening of the anterior chamber: The anterior chamber is the part of the eye between the iris and cornea. Doctors can deepen this chamber by injecting gel or air into it.
  • Drainage: Surgical drainage may be an option in some cases of SCH. Doctors will determine the best line of treatment.

Unclear or blurry vision days or weeks after cataract removal is a common side effect. It often happens because of uncorrected refractive errors or swelling in the clear cornea.

However, blurry vision can also be a symptom of more serious complications such as intraocular lens dislocation or posterior capsular opacification.

Treatments

Treatment of persistent blurriness after cataract surgery depends on its cause. The surgeon may prescribe anti-inflammatory drops to help clear up a person’s vision. Some complications may require additional surgery.

Light sensitivity can occur after cataract surgery due to eye dryness.

However, when the eyes reflexively squint or close after exposure to light, the person may have iritis. Iritis is the swelling and irritation of the colored part of the eye.

Treatments

Doctors treat this with steroid eye drops. Experts will also recommend sunglasses to help some people.

Cystoid macular edema is the swelling of the retina. It only occurs in 1–2% of cataract surgery cases.

It is the most common complication in uncomplicated cataract surgeries and occurs 6–8 weeks after the operation.

  • distorted vision
  • reduced vision
  • loss of central vision

Treatments

The treatments for the condition include topical steroids and NSAID eye drops.

Having droopy eyelids (ptosis) is common after surgery and is more common in people with swollen eyelids after the surgery. It typically resolves on its own within 6 months.

A lid retraction injury happens due to the stretching of aging upper eyelid muscle fibers by the instrument that spreads the eyelids to better expose the eye during surgery.

Treatments

Most individuals recover without treatment. Doctors can reverse persistent lid droop with an outpatient surgical procedure.

While many people will have significantly improved vision after surgery, some may continue having visual complaints. They may see unwanted optical images, such as shadows, glares, and starbursts.

These symptoms may result from issues with the intraocular lens or changes to the transparent lens capsule intentionally left behind after surgery.

Treatments

Treatments include:

  • intraocular lens (IOL) repositioning
  • IOL substitution
  • reopening the lens capsule with a clinical laser procedure

Increased intraocular pressure (IOP), or ocular hypertension, is a well-known transient complication happening within 24 hours after eye surgery.

This change may be short term or permanent. Doctors cannot predict whether the pressure will rise or fall after cataract surgery.

Treatments

Depending on the cause of increased eye pressure, doctors may reverse postoperative IOP elevation with the following:

  • pressure-lowering eye drops
  • anti-inflammation eye drops
  • outpatient laser treatment

Posterior cataract opacification (PCO), or secondary cataract, is when the posterior capsule — the membrane that holds the artificial lens following surgery — becomes cloudy.

It can occur weeks or months after the surgery but most frequently appears years after the cataract removal.

Treatment

A treatment called YAG laser capsulotomy is a quick and safe laser procedure that can help treat PCO and restore vision.

During the surgical operation, a hole may develop in the posterior capsule. This may cause the gel behind the eye (vitreous humor) to leak, which increases the risk of other complications, such as retinal detachment and glaucoma.

Treatments

Early detection of capsular rupture is vital for preventing further damage. Doctors remove any vitreous gel that enters the front of the eye. The surgeon may implant the artificial lens in a different position or delay inserting a lens implant.

The retina may peel away from the back of the eye, causing a tear or total detachment. This is more common in very nearsighted individuals, males, and younger people. Symptoms of retinal detachment include:

  • flashes of light
  • curtain or shadow appearing on the peripheral vision
  • burst of floaters

Treatments

This requires urgent surgery to restore vision by repairing the tear or reattaching the retina.

Rarely, the lens implant may move or dislocate. This can happen when the posterior capsule ruptures or breaks. It can cause double vision or a significant decrease in visual acuity.

Treatments

A surgeon may perform a second surgery to correct the placement of the implant. Some surgeons may use a different lens or sew the lens in place.

After surgery, the person may experience the following expected side effects:

  • scratchy or gritty feeling in the eye
  • sticky or uncomfortable feeling in the eye
  • excessive tearing

Doctors typically give people topical antibiotics, corticosteroids, or NSAID eye drops that they should use for 1–4 weeks.

Vision may still get blurry, but a person will see better in as little as 1–3 days after surgery. However, it could take 3–10 weeks to see its full effect. Following surgery, a person may still need to wear eyeglasses, especially when reading.

Below are some frequently asked questions about the risks of cataract surgery.

Is cataract surgery high risk?

Any surgery carries some risk, but cataract surgery is generally safe and low risk.

What are the negatives of cataract surgery?

One potential disadvantage of cataract surgery is the cost. Medicare and private insurance will usually cover 80% of cataract surgery with a standard IOL implant.

For individuals seeking enhancements such as femtosecond laser cataract removal and premium IOL implantation, average out-of-pocket costs run between $3,000 and $6,000 per eye.

While uncommon, complications may also occur up to 3 years after the operation.

What is the success rate for cataract surgery?

Cataract surgery has a high success rate compared with other types of surgeries. An older study of 221,000 cataract surgeries found that 99.5% had no serious complications.

What percentage of cataract surgeries have complications?

Technological advancements have led to a significant decline in complications associated with cataract surgeries. Despite this, about 2% of people who undergo cataract surgery may experience complications.

Cataract surgery is a safe and low risk procedure with a high success rate. People may experience typical side effects after the surgery and should follow their doctor’s advice to keep them manageable.

It may also carry potential complications such as inflammation, secondary cataract, posterior capsule rupture, torn or detached retina, and dislocated lens implants. Some resolve independently, while others are serious and require urgent treatment.