ESCRS Guidelines on prevention, investigation and management of

1. Introduction
1.1 Endophthalmitis
Endophthalmitis is an inflammatory reaction occurring as a result of intraocular colonisation by bacteria,
fungi or rarely parasites. It can be exogenous (post-operative, post-traumatic) due to microbial contamination
spreading from the ocular surface or open incision (wound) or contaminated instruments, intraocular lenses
(IOLs) or intraocular foreign bodies or endogenous (septicaemia) in origin.
These guidelines on the prophylaxis and treatment of post-operative endophthalmitis are supported in detail
with literature references, which were classified according to the criteria of the Arbeitsgemeinschaft der
Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) [Association of the Scientific Medical
Societies in Germany] and the Ärztliches Zentrum für Qualität [Agency for Quality in Medicine] for evidencebased
medicine (EBM) (Table 1.1). This enables the reader to form an accurate opinion of the value of the
individual views stated. At the same time, he or she is able to form an opinion him/herself from the
extensive literature. Ultimately, it is apparent that there is a lack of well-founded prospective and controlled
studies of many procedures - an important task for the future. Results of the recently completed <strong>ESCRS</strong>
Study on the Antibiotic Prophylaxis of Post-operative Endophthalmitis (<strong>ESCRS</strong> Study) have been included in
these <strong>Guidelines</strong>.
Table 1.1 Classification of evidence type of studies
Stage Evidence based on:
I a meta-analysis of randomised controlled studies
I b at least one randomised controlled study
II a at least one well-designed controlled study without randomisation
II b at least one well-designed, quasi-experimental study
III well-designed, non-experimental descriptive studies
(e.g. comparative studies, correlative studies, case-control studies)
IV reports/opinions of expert circles, consensus conferences
and/or clinical experience of acknowledged authorities
1.2 Pathophysiology
The occurrence, severity and clinical course of endophthalmitis depends on the route of infection, the
virulence and number of inoculated pathogens as well as the patient's immune state and the time of
examination [205]. In 29 to 43 per cent of cataract operations, intraocular contamination occurs with
facultative pathogenic bacteria from the ocular surface without the development of endophthalmitis [41],
[68], [106]. Protective mechanisms, which have been summarised as the “immune privilege of the eye“
(anterior or posterior chamber-associated immune deviation, ACAID or POCAID) [205], are particularly
effective in the anterior part of the eye, act as a protective barrier and can limit the inflammatory reaction
[191], [198]. If this privilege is compromised, e.g. by an intra-operative capsular defect with vitreous loss,
the risk of endophthalmitis increases by a factor of 14 [98].
In microbial endophthalmitis, three phases of infection can be observed: an incubation phase, an
acceleration phase and a destructive phase [173]. A clinically inapparent incubation phase is observed
initially, which lasts at least 16 to 18 hours, even with virulent micro-organisms. Intraocular bacterial
inoculation above a critical level then leads to breakdown of the aqueous barrier with fibrin exudation and
cellular infiltration by neutrophilic granulocytes [24]. The incubation phase is determined mainly by the
generation time of the pathogen (e.g. Staphylococcus aureus and Pseudomonas aeruginosa up to 10 min,
Propionibacterium sp. > 5 h) and the specific characteristics of the pathogen such as toxin production. With
the commonest pathogens, Staphylococcus epidermidis (CNS) and Staphylococcus aureus, the greatest
infiltration is observed only three days after infection [24], [39].
In the case of primary infection of the posterior part of the eye, inflammation of the anterior chamber occurs
initially and this is accompanied within seven days by a specific immune response with macrophages and
lymphocytes in the vitreous cavity. Just three days after intraocular infection, pathogen-specific antibodies
can be detected, which contribute to pathogen elimination by opsonisation and phagocytosis within about
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