Endophthalmitis (post-operative) (Exogenous endophthalmitis)


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Post-operative endophthalmitis is a rare but severe sight-threatening complication of ocular surgery e.g. cataract, corneal, glaucoma, retinal, and of intravitreal injections, e.g. anti-VEGF treatment.

Occurs most commonly as a complication of cataract surgery. Based on published audit data from the UK between 2010-2021, the incidence of post-operative endophthalmitis was 0.23 per 1,000 cataract operations.

A Cochrane systematic review has provided moderate certainty evidence for the benefit of perioperative antibiotics in reducing the incidence of postoperative endophthalmitis following cataract surgery. However, antibiotic prophylaxis does not appear to reduce the rate of endophthalmitis following intravitreal injection and might potentially be associated with an increased risk of infection.

Bleb-associated endophthalmitis has a reported incidence of 9 per 1,000 trabeculectomy procedures.

Organisms (examples, based on studies conducted in the USA and Europe, in descending order of frequency):

  • Staphylococcus sp. (50.5% of culture-positive cases)
  • Streptococcus sp. (12.1%)
  • Gram negative sp. (10.3%)
  • fungi (4.6%)

Onset may be acute (in first week) or chronic (in first month). 80% of cases present within 6 weeks of surgery

Post-operative endophthalmitis may also be non-infective (retention of foreign material, e.g. cotton fibres, or caused by toxic substances, e.g. component of unsuitable irrigating fluid)

Endophthalmitis is associated with significant visual morbidity (approx. 40% <6/60 after treatment)

Predisposing factors


  • combined surgical procedures
  • increased operative time
  • secondary IOL implantation
  • posterior capsular rupture
  • vitreous loss
  • wound leakage

Intravitreal injections

Sources of contamination:

  • open globe injuries, can introduce pathogens into the eye, increasing the risk of endophthalmitis
  • patient’s own bacterial flora (skin, lids, conjunctiva, lacrimal apparatus)
  • contaminated instruments, solutions, drapes, dressings, gloves
  • (in corneal transplants) donor cornea

Patient factors:

  • diabetes, immunosuppression
  • contact lens wear

Symptoms of endophthalmitis

Acute presentation:

  • visual loss
  • pain
  • redness
  • photophobia

Chronic presentation: similar, usually milder, delayed

Signs of endophthalmitis

Acute presentation (typically within first two weeks post-surgery/injection):

  • lid oedema
  • conjunctival chemosis and hyperaemia
  • corneal haze
  • cells and flare in AC; fibrinous exudate and/or hypopyon if severe
  • pupil light reflex may be sluggish or absent
  • IOP can be normal, low or raised
  • vitritis (inflammation of the vitreous) may eliminate red reflex and preclude view of fundus

Delayed presentation: similar, usually milder.

Differential diagnosis

Endogenous endophthalmitis (due to haematological spread of various pathogens)
Post-operative inflammation without infection
Other causes of acute red eye, for example acute anterior uveitis
Vitreous haemorrhage

Management by optometrist

Practitioners should work within their scope of practice, and where necessary seek further advice or refer the patient elsewhere

Non pharmacological




Management category

A1: emergency referral to ophthalmologist, no intervention. Emphasise to the patient the urgency of the condition and instruct them to attend the local hospital eye department or hospital A&E the same day, explaining that you will leave a message so that they are expected. Telephone the department to explain what you have done, preferably leaving your message with a doctor or other health care professional.

Possible management in secondary care or local primary/community pathways where available

Additional guidance may be available

Aim to initiate treatment within one hour of diagnosis
Admission to hospital
Ultrasound scan
Anterior chamber/vitreous tap, or vitrectomy, followed by microbiology of specimen
Broad-spectrum intravitreal antibiotics (e.g. ceftazidime and vancomycin)
Adjunctive intra-vitreal corticosteroids/oral antibiotics 
Pars plana vitrectomy (severe cases)

Evidence base

Sources of evidence

Ang GS, Varga Z, Shaarawy T. Postoperative infection in penetrating versus non-penetrating glaucoma surgery. Br J Ophthalmol. 2010;94(12):1571-6

Emami S, Kitayama K, Coleman AL. Adjunctive steroid therapy versus antibiotics alone for acute endophthalmitis after intraocular procedure. Cochrane Database Syst Rev. 2022;6(6):CD012131

Fabiani C, Agarwal M, Dogra M, Tosi GM, Davis JL. Exogenous Endophthalmitis. Ocul Immunol Inflamm. 2022:1-10

Gentile RC, Shukla S, Shah M, Ritterband DC, Engelbert M, Davis A, Hu DN. Microbiological spectrum and antibiotic sensitivity in endophthalmitis: a 25-year review. Ophthalmology 2014;121(8):1634-42

Gower EW, Lindsley K, Nanji AA, Leyngold I, McDonnell PJ. Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery. Cochrane Database Syst Rev. 2017;2:CD006364

Jackson TL, Paraskevopoulos T, Georgalas I. Systematic review of 342 cases of endogenous bacterial endophthalmitis. Surv Ophthalmol 2014;59(6):627-35

Low L, Shah V, Norridge CF, Donachie PH, Buchan JC. RCOphth NOD, Report 10: Risk factors for post-cataract surgery endophthalmitis. Ophthalmology. 2023: S0161-6420(23)00517-1. doi: 10.1016/j.ophtha.2023.07.021. Online ahead of print

Menchini F, Toneatto G, Miele A, Donati S, Lanzetta P, Virgili G. Antibiotic prophylaxis for preventing endophthalmitis after intravitreal injection: a systematic review. Eye (Lond). 2018;32(9):1423-31

Muqit MM, Mehat M, Bunce C, Bainbridge JW. Early vitrectomy for exogenous endophthalmitis following surgery. Cochrane Database Syst Rev. 2022;11(11):CD013760

Peck TJ, Patel SN, Ho AC. Endophthalmitis after cataract surgery: an update on recent advances. Curr Opin Ophthalmol. 2021;32(1):62-68. 


What is Endophthalmitis?

The most frequently performed eye operation is cataract surgery and it is normally highly successful in restoring vision. However, in a very small proportion of cases (fewer than one per thousand) it is complicated by infection (endophthalmitis), usually caused by common bacteria such as those on the patient’s own skin. Endophthalmitis (which means inflammation inside the eye) can also occasionally be caused by retained surgical material (e.g. cotton fibres). It is called ‘acute’ if it occurs within the first week after surgery and ‘chronic’ if it occurs up to a month after surgery. It occurs more often in patients who are diabetic or who have an infection or drug treatment that suppresses the immune system.

Endophthalmitis causes pain, redness, undue light sensitivity and blurred vision when it is acute; symptoms are less severe when it is chronic. The signs seen by the optometrist or the ophthalmologist are typical of inflammation within the eye.

How is Endophthalmitis managed?

If the optometrist suspects endophthalmitis, the recommendation is emergency (same day) referral to an ophthalmologist, who will usually admit the patient to hospital. A specimen is taken from within the eye so that the infecting organism can be identified and antibiotic is placed directly inside the eye. Sometimes surgery is required to remove the vitreous (the jelly inside the eye).

Endophthalmitis (post-operative) Exogenous endophthalmitis
Version 14
Date of search 25.07.23
Date of revision 26.10.23
Date of publication 23.01.24
Date for review 24.07.25
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