Endophthalmitis After Cataract Surgery: Warning Signs, Incidence, and Modern Prevention

Endophthalmitis is an infection inside the eye that can develop in the days to weeks after cataract surgery. It is rare, it is real, and it is one of the few true emergencies in eye care. In modern series that use intracameral antibiotic prophylaxis, it occurs in roughly 0.03 to 0.1 percent of cataract operations (ESCRS Endophthalmitis Study Group, JCRS 2007; Haripriya, Ophthalmology 2017). Treatment works, and it works far better when it starts within hours rather than days. If your eye becomes more painful, redder, or blurrier after cataract surgery, call your surgeon the same day. Do not wait for your next scheduled visit.

Warning signs: call your surgeon the same day

This section comes first on purpose. Everything else on this page is context. This is the part that changes outcomes.

Call your surgeon immediately, the same day, if you notice any of the following after cataract surgery:

• Pain that is increasing rather than settling, or pain out of proportion to what you were told to expect. This most often appears on day three through day seven. Normal postoperative discomfort improves each day. Infection does the opposite.
• Vision that gets worse after having been better. A sudden or rapid drop in vision is the most important single symptom.
• Redness that deepens instead of fading, especially with the eye becoming intensely red around the cornea.
• Discharge, particularly thick, white, yellow, or green material from the eye.
• A white or yellow layer visible in the front of the eye below the iris. This is a hypopyon, a collected layer of inflammatory cells, and it is a hallmark finding.
• A shower of new floaters, marked light sensitivity, or a swollen lid, especially in combination with the symptoms above.

Do not talk yourself out of calling. Do not stop or change any prescribed drop on your own. If you cannot reach the office, go to an emergency department and say that you had cataract surgery and are concerned about an eye infection. Being seen for something that turns out to be ordinary healing costs you an afternoon. Waiting two days on an infection can cost vision. Some of these symptoms overlap with ordinary cataract surgery side effects, which is exactly why we would rather examine you than guess over the phone.

What endophthalmitis actually is

Endophthalmitis is a bacterial or, less often, fungal infection of the inside of the eye, involving the aqueous fluid in the front chamber and the vitreous gel behind the lens. It is not an infection of the surface, like conjunctivitis, and it is not the same thing as ordinary postoperative inflammation.

The organisms almost always come from you, not from the operating room. Coagulase-negative staphylococci, chiefly Staphylococcus epidermidis, normally live on every human eyelid and lash line, and they account for the large majority of culture-positive cases. Staphylococcus aureus, streptococci, and gram-negative organisms make up a smaller share and generally behave more aggressively. That biology explains why prevention centers on the ocular surface rather than the air in the room. It also explains why endophthalmitis is not a marker of a poorly performed operation. It can follow a technically flawless case.

How common is it after cataract surgery?

Modern rates with intracameral prophylaxis

Reported incidence in contemporary series clusters in the 0.03 to 0.1 percent range where an intracameral antibiotic is given at the end of surgery, which works out to roughly one case in one thousand to one in three thousand operations. Series without intracameral prophylaxis generally report higher figures. Rates also vary by population and case complexity, so any single published number describes a specific cohort rather than a universal truth. We quote a range for that reason.

The ESCRS Endophthalmitis Study Group and what it changed

The pivotal evidence is a randomized trial run by the European Society of Cataract and Refractive Surgeons across 24 centers in nine countries, published in the Journal of Cataract & Refractive Surgery in 2007. Among more than 16,000 patients, eyes that did not receive an injection of cefuroxime into the anterior chamber at the close of surgery had close to five times the risk of endophthalmitis compared with eyes that did (PubMed). That result moved intracameral antibiotic prophylaxis from a regional habit to a mainstream standard across much of the world.

The Aravind moxifloxacin experience

The second landmark data set is observational but enormous. Haripriya, Chang, and Ravindran reported the Aravind Eye Hospital system's transition to intracameral moxifloxacin, first in JCRS in 2016 and then in an analysis of roughly 600,000 surgeries in Ophthalmology in 2017. The endophthalmitis rate fell several-fold after intracameral moxifloxacin was adopted, on the order of 0.07 percent down to 0.02 percent (PubMed). Two independent bodies of evidence, one randomized and one very large and consecutive, point the same direction.

The typical timeline: acute, delayed, and chronic

Acute endophthalmitis is the classic and most common presentation: onset within six weeks of surgery, and most often on day three through day seven. It announces itself with pain, redness, and falling vision over hours to a day or two, and it is the form that demands same-day care.

Delayed and chronic endophthalmitis appears more than six weeks out and can surface months later. It is caused by slow-growing, low-virulence organisms, classically Cutibacterium acnes (formerly Propionibacterium acnes) and occasionally fungi, which can sequester in the lens capsule. It looks like a smoldering inflammation that improves on steroid drops and relapses whenever they are tapered, sometimes with a white plaque on the capsule. Because it is quiet, it is frequently mistaken for ordinary postoperative uveitis, and the tell is the relapsing pattern.

How endophthalmitis is diagnosed

Diagnosis begins with a slit-lamp examination, the microscope you sit at during an eye exam. We look for the specific combination that separates infection from routine inflammation: heavy cells in the anterior chamber, a hypopyon, fibrin, a hazy vitreous, corneal edema, and a wound that may be leaking. When the vitreous cannot be seen because the eye is too inflamed or too hazy, B-scan ocular ultrasound is used to image the vitreous cavity indirectly and look for the debris and membranes that infection produces.

The confirmatory step is a vitreous tap: a small sample of vitreous fluid, and often aqueous fluid, withdrawn with a needle in a sterile setting and sent for Gram stain and culture. Critically, treatment is not delayed while cultures incubate. The tap and the first antibiotic injection happen in the same sitting, and the culture result later refines the plan. Suspected endophthalmitis is treated on clinical suspicion.

How endophthalmitis is treated

Intravitreal antibiotics

The immediate treatment is antibiotic injected directly into the vitreous cavity, which achieves concentrations no drop or oral pill can reach. The standard combination is vancomycin to cover gram-positive organisms plus ceftazidime to cover gram-negatives, with amikacin substituted for ceftazidime in patients with a serious beta-lactam allergy. Injections may be repeated at 48 to 72 hours depending on the response. Because organism, allergies, and severity all vary, the specific regimen is your treating surgeon's judgment call, not something to select from a page like this one.

The Endophthalmitis Vitrectomy Study and when surgery is added

The Endophthalmitis Vitrectomy Study (EVS), published in Archives of Ophthalmology in 1995, randomized 420 patients with postoperative endophthalmitis and remains the framework surgeons still use. It produced two durable findings. First, immediate pars plana vitrectomy, in which the infected vitreous is surgically removed, clearly benefited the subgroup whose vision at presentation was light perception only: those eyes had roughly three times the chance of achieving 20/40 and about half the rate of severe vision loss. For eyes presenting with better than light perception, a tap with intravitreal antibiotics did just as well. Second, intravenous antibiotics added no benefit, which is why systemic therapy is no longer routine (PubMed). Vitrectomy techniques have advanced substantially since 1995, and many surgeons now intervene earlier than EVS strictly required, but the principle that presenting vision guides the decision still holds.

Adjunctive steroids

Corticosteroids are sometimes added, intravitreally or systemically, to blunt the inflammatory damage the infection causes. The practice remains debated, since the same inflammation is part of the immune response, and it is used selectively rather than universally.

What prevention looks like in a modern operating room

Povidone-iodine antisepsis

Povidone-iodine applied to the lids, lashes, and conjunctival surface before surgery is the single prevention measure with essentially universal agreement behind it, dating to work by Speaker and Menikoff published in Ophthalmology in 1991. A 5 percent solution on the ocular surface with adequate contact time, plus a stronger preparation of the surrounding skin, reduces the bacterial load at the source. Cochrane reviews of perioperative antisepsis support it. If you are allergic to iodine, tell us before your surgical date so an alternative can be planned.

Intracameral antibiotic at the close of the case

Placing an antibiotic directly into the anterior chamber as the operation ends is the practice that changed modern rates. In Europe a licensed cefuroxime preparation is used. In the United States, moxifloxacin is the common choice and is used off-label from a compounded or diluted commercial preparation, and ASCRS Clinical Survey data show a steadily growing majority of surgeons now use some intracameral antibiotic. Practice varies between surgeons and countries, and it is a fair question to ask at your consultation.

Wound construction, sterile technique, and bilateral same-day surgery

A watertight incision matters, because a leaking wound lets surface fluid and bacteria in during the vulnerable first hours. Surgeons construct clear-corneal incisions with a stepped, self-sealing architecture and test them at the end of the case, placing a suture if there is any doubt. Sterile draping isolates the lashes and lid margin, the main bacterial reservoir. When both eyes are done on the same day, an approach called immediate sequential bilateral cataract surgery, the protocols published by the international ISBCS group require complete separation of the two operations: fresh instrument sets from different sterilization loads, separate lots of every drug and viscoelastic, a full re-prep and re-drape, new gown and gloves, and intracameral antibiotic in each eye. The purpose of that rigor is to make bilateral simultaneous infection effectively impossible.

Topical antibiotics around surgery

Most practices prescribe a topical antibiotic drop before and after surgery. The evidence for drops is weaker than for povidone-iodine and intracameral antibiotic, which is why the field shifted its emphasis. Use them exactly as prescribed and do not stop early on your own.

Risk factors that raise your individual risk

Endophthalmitis is uncommon in every group, and none of these factors is a reason not to have cataract surgery. They are reasons to prepare.

• Diabetes, which impairs the local immune response, particularly when blood sugar control is poor.
• Blepharitis, meibomian gland disease, or an active lid or surface infection. This is the most modifiable factor on the list, and treating it before the surgical date is worth doing.
• Immunocompromise, from medication or disease.
• Posterior capsule rupture with vitreous loss, which removes the barrier between front and back of the eye and raises risk several-fold. It is also why complex cases get closer follow-up.
• A long or difficult case, or one complicated by conditions such as floppy iris syndrome that extend operating time.
• A wound that leaks postoperatively, or eye rubbing and trauma in the first days.
• Advanced age and, in some series, male sex, both weak associations rather than actionable ones.

"I would rather see fifty patients whose eyes turn out to be healing normally than have one wait a day and a half because they did not want to bother me. Pain that is getting worse instead of better is never something to sleep on." Brent Bellotte, MD

What outcomes look like after treatment

Outcomes span a wide range, and we will not narrow that range dishonestly. Three factors drive it: how quickly treatment started, the organism, and the vision at presentation. Cases caused by coagulase-negative staphylococci, the most common group, generally do best, and many such eyes regain reading vision. Streptococcal and gram-negative infections are more destructive and carry worse prognoses even with prompt treatment. In the EVS cohort, a substantial share of treated eyes achieved 20/40 or better, while a minority ended with severe permanent loss.

Some eyes need more than one intravitreal injection, some need vitrectomy, and recovery of vision unfolds over weeks to months as inflammation clears. Cataract surgery recovery in these eyes departs from the standard recovery timeline, and secondary problems can follow, including macular swelling of the sort described in our article on cystoid macular edema after cataract surgery, elevated eye pressure, or later capsule clouding treated with YAG laser capsulotomy. The variable most under your control is the interval between your first symptom and your phone call.

What to bring up before your surgery

• Tell us about any current eyelid crusting, styes, redness, or discharge. We would rather move your date by two weeks and treat it than operate through it.
• Report an iodine or antibiotic allergy well before the day of surgery so alternatives can be arranged.
• Bring your full medication list, including immunosuppressants, steroids, and your most recent diabetes numbers.
• Ask what prophylaxis your surgeon uses, specifically about povidone-iodine prep and whether an intracameral antibiotic is given. Both are reasonable questions and you should get a direct answer.
• Get the after-hours number before you leave, and confirm who to reach on a weekend.
• Know the drop schedule and the symptoms to watch for, and keep the warning list above somewhere you can find it.

This article was prepared by the surgical team at Modern Cataract Surgery, including Brent Bellotte, MD. To discuss your surgery and how we prepare for infection risk, schedule a cataract evaluation. Our cataract surgeon directory covers what to ask when you are choosing a surgeon. If you have symptoms right now, stop reading and call your surgeon.

Frequently Asked Questions

How likely is endophthalmitis after cataract surgery?

Uncommon. Modern series that use intracameral antibiotic prophylaxis report rates in roughly the 0.03 to 0.1 percent range, meaning about one case in one thousand to one in three thousand surgeries. The ESCRS randomized trial and the Aravind Eye Hospital experience are the two largest data sets behind those figures.

When is endophthalmitis most likely to appear?

Acute cases usually present three to seven days after surgery, and by definition within six weeks. A less common chronic form caused by slow-growing organisms can appear months later as a low-grade, steroid-responsive inflammation. The pattern that matters most is pain or vision getting worse rather than better.

Is some pain and redness normal after cataract surgery?

Mild scratchiness, light sensitivity, and pink appearance are common in the first days and should improve steadily. The concerning pattern is the reverse: pain that increases, redness that deepens, discharge, or vision that drops after having been clear. Any of those warrants a same-day call to your surgeon.

Can endophthalmitis be prevented entirely?

No surgeon can promise prevention, because most infections come from the patient's own eyelid and surface bacteria. Published series show that povidone-iodine antisepsis and intracameral antibiotic at the end of surgery substantially lower the rate. Prevention reduces risk to a small number rather than to zero.

Will my vision recover if I get endophthalmitis?

Outcomes vary widely and depend on how quickly treatment begins, the organism, and the vision at presentation. In the Endophthalmitis Vitrectomy Study, many treated eyes regained reading vision, while eyes infected with more aggressive organisms did worse. Rapid presentation is the single factor most under your control.

References

1. ESCRS Endophthalmitis Study Group. Prophylaxis of postoperative endophthalmitis following cataract surgery: results of the ESCRS multicenter study and identification of risk factors. Journal of Cataract & Refractive Surgery. 2007;33(6):978-988. PubMed.
2. Endophthalmitis Vitrectomy Study Group. Results of the Endophthalmitis Vitrectomy Study: a randomized trial of immediate vitrectomy and of intravenous antibiotics for the treatment of postoperative bacterial endophthalmitis. Archives of Ophthalmology. 1995;113(12):1479-1496. PubMed.
3. Haripriya A, Chang DF, Ravindran RD. Endophthalmitis reduction with intracameral moxifloxacin prophylaxis: analysis of 600,000 surgeries. Ophthalmology. 2017;124(6):768-775. PubMed.
4. Haripriya A, Chang DF, Namburar S, et al. Efficacy of intracameral moxifloxacin endophthalmitis prophylaxis at Aravind Eye Hospital. Ophthalmology. 2016;123(2):302-308.
5. Speaker MG, Menikoff JA. Prophylaxis of endophthalmitis with topical povidone-iodine. Ophthalmology. 1991;98(12):1769-1775.
6. American Academy of Ophthalmology. Cataract in the Adult Eye Preferred Practice Pattern, 2021. aao.org.
7. Gower EW, Lindsley K, Tulenko SE, et al. Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery. Cochrane Database of Systematic Reviews. 2017;(2):CD006364.
8. American Society of Cataract and Refractive Surgery. ASCRS Clinical Survey, intracameral antibiotic use. ascrs.org.
9. International Society of Bilateral Cataract Surgeons. General Principles for Excellence in ISBCS. isbcs.org.