IOP spikes after cataract surgery: insights from glaucoma specialists

Glaucoma
Spring 2026

by Liz Hillman
Editorial Co-Director

Glaucoma specialists say they’re often referred post-cataract surgery patients experiencing an IOP spike, many of whom could be treated by the referring surgeon. EyeWorld spoke with two glaucoma specialists to get their insights on what to watch for and management of these cases.

“It can be a common frustration for cataract surgeons to have a cataract patient with sustained IOP elevation after cataract surgery,” said Nathan Radcliffe, MD. “The surgeon should understand that this is a rare event but that it does happen. It doesn’t mean anything went wrong with the surgery. In my opinion, it’s just the eye declaring that it has a problem with trabecular outflow that had not manifested yet. I have cared for many patients who were referred to me with this problem, and sure enough, if we follow that patient long enough, the fellow eye, whether it’s had cataract surgery or not, usually ends up getting glaucoma.”

Who’s at risk?

Valerie Trubnik, MD, FACS, said the average cataract patient with minimal risk factors for IOP spikes can be seen the day following surgery. However, she noted, most IOP spikes after this procedure are more common in the first 8–12 hours.

“Most of us are not seeing our patients during that time, so in terms of detecting an IOP spike, I would say it’s usually at 24 hours,” she said. “If you have an average cataract patient and they have minimal risk factors for IOP spikes, I think it’s OK to see them the following day, which is what I do for my patients. If you’re concerned about someone having glaucoma or significant risk factors, it’s possible to bring them back the same day to measure their pressure, but I’ve been practicing in glaucoma for a long time, and I can’t remember the last time I’ve done that. Most of the time, it’s OK to bring the patient in the morning of the following day and check their pressure.”

Dr. Radcliffe reserves same-day pressure checks for patients who already have severe optic nerve damage and whose visual fields are severely constricted. “That said, many of those patients in my practice are getting a surgery designed to reduce the pressure,” he said. “So realistically, the patients who are most in need of same-day IOP checks are people who have severe glaucoma, but for one reason or another, are not getting a trabeculectomy or a non-valved tube shunt because they have the risk of nerve damage, but their cataract surgery was not accompanied by a filtration surgery.”

In addition to preexisting or undetected glaucoma, the following factors can increase risk for a postop pressure spike, according to Dr. Trubnik: male gender, high myopia, history of exfoliation syndrome, shallow anterior chamber, short axial lengths, and thicker lenses. Dr. Radcliffe added that complex cataract surgery that involves iris manipulation or endoscopic laser is also a risk factor for a spike.

Dr. Trubnik said most patients without risk factors won’t experience true damage to the optic nerve should a pressure spike occur. “It would be exceptionally unlikely. It’s possible that very high IOPs can lead to a vein occlusion or an artery occlusion. But again, in all the years that I’ve been practicing glaucoma, I have not seen it,” she said.

The patients that merit concern over vision loss or nerve damage due to pressure spikes are those with preexisting glaucoma or undetected glaucoma, Dr. Trubnik added. As such, she said it’s now her routine to get an OCT of the macula and optic nerve preoperatively.

“If there’s any concern, we do something ahead of time, so we don’t have to worry about potential complications postop,” she said.

“The risk of damage is highest in people with severe glaucoma. I always, if I have a severe glaucoma patient, particularly if they’re not getting a tube or trabeculectomy, make sure that we have some form of a plan perioperatively,” Dr. Radcliffe said, which can include drops at the end of surgery, topical IOP-lowering drops, and oral acetazolamide. “I think oral acetazolamide is underused in prophylaxis for IOP spikes. A surgeon could use one or even a series of three oral acetazolamide tablets after high-risk cataract surgeries and go a long way to mitigate problems related to postoperative IOP spikes.”

If a pressure spike occurs days to weeks postop, Dr. Trubnik said a steroid response is often to blame.

Preventing pressure spikes

In terms of preventing pressure elevations, Dr. Radcliffe said there are things that can be done before, during, and after surgery. “You can have the patient continue their eye drops right up until the morning of surgery,” he said. “During the surgery, you can take extra time and attention to evacuate the viscoelastic from the eye. Then you can treat them afterward with both IOP-lowering drops as well as with oral acetazolamide.”

Dr. Trubnik said to prevent pressure spikes, she also keeps patients on any pressure-reducing medications they might have been on preop. If their pressure was very high preop and they’re a candidate, she offers them a MIGS procedure. This is why Dr. Trubnik said she encourages comprehensive anterior segment ophthalmologists to learn at least one MIGS that can be performed along with cataract surgery. However, not all patients want to have a MIGS procedure.

“I can’t tell you how often I’ll have patients say to me, ‘I don’t want anything else. I just want cataract surgery.’” To this, Dr. Trubnik said she tells them that she strongly advises the additional pressure-lowering procedure because “I don’t want you to have a complication or pressure spike.” Some studies, such as the HORIZON study with the Hydrus microstent (Alcon), demonstrated a MIGS device can reduce postop IOP spikes, she said.

If a patient has preexisting advanced glaucoma, then the cataract surgery needs to be paired with something more advanced like a tube shunt or trabeculectomy.

Intraoperatively, Dr. Trubnik said it’s critical to remove all the viscoelastic at the end of the case. Dr. Radcliffe echoed this, saying that it’s especially important to be cognizant of viscoelastic removal in cases with floppy iris where it could be missed.

Dr. Trubnik said she uses carbachol or acetylcholine, if there are no contraindications. This constricts the pupil, so they have better vision postop day 1, but it also lowers their IOP in the short term. Patients who are at higher risk can also receive a fixed-dose combination agent like brimonidine-timolol or dorzolamide-timolol immediately postop in Dr. Trubnik’s practice.

“One drop right after surgery blunts an IOP spike,” she said. Going further, if she’s concerned about an increased risk for IOP spikes (like preexisting glaucoma or someone who has had an anterior vitrectomy), she gives acetazolamide, provided there are no contraindications.

Treating pressure spikes

Dr. Trubnik said she considers a clinically meaningful postop pressure spike in an “average” patient to be 30–35 mm Hg. If this were to occur, she gives the patient a drop in the office and tells them they likely have retained viscoelastic that will take a day or two to subside. She provides these patients with her email and phone number in case they need to call. Performing a paracentesis in the office in those situations is also a viable option.

A clinically meaningful pressure spike in a glaucoma patient is based on what their target pressure should be. “If they’re 30–40% over their target pressure on day 1, then you start to worry,” Dr. Trubnik said. If the pressure is below 30 mm Hg, she gives them a drop in the office, or if they have higher risk factors, she may give them a sample drop or prescribe a fixed-dose combination drop to take at home for a few days.

Dr. Radcliffe said that typically a clinically meaningful IOP spike is one that is 10 mm Hg or more above baseline.

“For me, a clinically meaningful IOP spike is an intraocular pressure in the postoperative period, which if sustained for a week or so, would be likely to cause damage to the patient’s optic nerve and vision,” he said. He added that he has a low threshold for introducing a topical therapy, especially if given in the office.

In patients with glaucoma or glaucoma suspects whose pressure goes above 35 mm Hg, who might have microcystic edema, a headache, and/or blurry vision, Dr. Trubnik treats with a paracentesis in the office. “We call it ‘burping the wound’ to get any retained viscoelastic out,” she said. “I find that after you do the paracentesis first, they respond to the topical drops much better.” She may give these patients a couple doses of oral acetazolamide as well.

Dr. Radcliffe also advocated for a paracentesis on postop day 1, especially for pressures at 30 mm Hg or above. “There’s a couple of reasons why the anterior chamber paracentesis is reasonable in this setting. One is that I think that once the pressure is high, the pressure drops don’t get absorbed as well, and it creates a cycle. Lowering the pressure with an AC paracentesis and applying a round of drops can do a good job of keeping the pressure down. Additionally, if there is retained viscoelastic, letting fluid out of the anterior chamber will get rid of some of that retained viscoelastic,” he said.

Oral agents, if he hasn’t given them prophylactically, Dr. Radcliffe reserves for patients who have had a paracentesis and topical therapy and whose pressure is still high or even climbing upon reassessment.

If a pressure spike occurs due to a steroid response in the days to weeks after cataract surgery, Dr. Trubnik said the patient needs to be weaned off the steroid, which can take weeks and require a bridge with an NSAID. “We want to prevent CME postop, but we also want to get them off the topical steroid to reduce their IOP. You’re stuck between a rock and a hard place. It helps to wean these patients off slowly. It’s been rare that I have had to resort to surgical intervention for someone who had an IOP spike, whether within the first 24 hours or days to weeks later.”

If weaning a patient off of steroids doesn’t help, there could be a retained nuclear fragment, which Dr. Trubnik said is rare. “Don’t be afraid to do gonioscopy to look for retained fragments,” she said.

“I think the comprehensive or anterior segment surgeon who doesn’t typically do glaucoma can get very concerned about what to do with these patients,” Dr. Trubnik said. “It’s important to be patient with them.”

Dr. Trubnik said she tells all her cataract patients that if they experience changes in vision or headache to call the office because it may be a sign of raised intraocular pressure.

Overall, Dr. Radcliffe said it’s also important to recognize that some glaucoma patients have such damaged outflow systems that even a normal cataract surgery can overwhelm the trabecular meshwork and cause sustained IOP spikes. “I think this occurs all the time, even if a trabecular MIGS procedure is performed at the same time as a cataract surgery. In some cases, the IOP spike may just be, with or without a previous history of glaucoma, declaring that it has trouble regulating its intraocular pressure,” Dr. Radcliffe said, which can be a first sign that an eye is developing glaucoma.

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About the physicians

Nathan Radcliffe, MD
New York Ophthalmology
New York Eye Surgery Center
New York, New York

Valerie Trubnik, MD, FACS
OCLI Vision
Manhasset and Mineola, New York

Relevant disclosures

Radcliffe: Alcon, Allergan, Glaukos, New World Medical, Sight Sciences
Trubnik: Glaukos

Contact

Radcliffe: drradcliffe@gmail.com
Trubnik: vtrubnik@ocli.net