Endophthalmitis (post-operative) (Exogenous endophthalmitis)

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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Endophthalmitis (post-operative)







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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. Pooled estimates of incidence range from 1.09-2.65 per 1,000 cataract operations                                                

A Cochrane systematic review has provided limited 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 2.1% at an average 18 months following glaucoma drainage surgery
Pooled estimate of endophthalmitis following anti-VEGF treatment is 3 per 10,000 injections
Organisms (examples only, 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


  • increased operative time
  • posterior capsular rupture
  • wound leakage

Sources of contamination:

  • 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, HIV infection


Acute presentation:

  • visual loss
  • pain
  • redness
  • photophobia

Chronic presentation: similar, usually milder, delayed


Acute presentation:

  • 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

Chronic presentation: similar, usually milder, delayed

Differential diagnosis

Post-operative inflammation without infection
Other causes of acute red eye, for example acute anterior uveitis
Vitreous haemorrhage

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Non pharmacological




Management Category

A1: emergency referral to ophthalmologist, no intervention. Telephone oncall ophthalmologist

Possible management by ophthalmologist

Admission to hospital
Ultrasound scan
Anterior chamber/vitreous tap, or vitrectomy, followed by microbiology of specimen
Antibiotics: topical, subconjunctival, intravitreal, systemic (including intravenous) as indicated
Steroids: topical, intravitreal, systemic as indicated

Evidence base

Sources of evidence

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

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

Plain language summary

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 three 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.

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 the vitreous (the jelly inside the eye) is removed. Antibiotics may also be given as eye drops, injections beneath the skin of the eye, and by mouth or by infusion into a vein.

Endophthalmitis (post-operative) Exogenous endophthalmitis
Version 12
Date of search 24.05.19
Date of revision 24.10.19
Date of publication 22.03.21
Date for review 23.05.21
© College of Optometrists 

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