Endophthalmitis

Endophthalmitis is defined as an inflammation of the
inner structures of the eyeball i.e., uveal tissue and
retina associated with pouring of exudates in the
vitreous cavity, anterior chamber and posterior
chamber.
Etiology
Etiologically endophthalmitis may be infectious or
non-infectious (sterile).
A. Infective endophthalmitis
Modes of Infection
1. Exogenous infections. Purulent inflammations are
generally caused by exogenous infections
following perforating injuries, perforation of
infected corneal ulcers or as postoperative
infections following intraocular operations.

2. Endogenous or metastatic endophthalmitis. It
may occur rarely through blood stream from some
infected focus in the body such as caries teeth,
generalised septicaemia and puerperal sepsis.
3. Secondary infections from surrounding
structures. It is very rare. However, cases of
purulent intraocular inflammation have been
reported following extension of infection from
orbital cellulitis, thrombophlebitis and infected
corneal ulcers.
Causative organisms
1. Bacterial endophthalmitis. The most frequent
pathogens causing acute bacterial endophthalmitis
are gram positive cocci i.e., staphylococcus
epidermidis and staphylococcus aureus. Other
causative bacteria include streptococci, pseudomonas,
pneumococci and corynebacterium.
Propionio bacterium acnes and actinomyces are
gram-positive organisms capable of producing
slow grade endophthalmitis.
2. Fungal endophthalmitis is comparatively rare. It
is caused by aspergillus, fusarium, candida etc.
B. Non-infective (sterile) endophthalmitis
Sterile endophthalmitis refers to inflammation of inner
structures of eyeball caused by certain toxins/toxic
substances. It occurs in following situations.
1. Postoperative sterile endophthalmitis may occur
as toxic reaction to:
Chemicals adherent to intraocular lens (IOL) or
Chemicals adherent to instruments.
2. Post-traumatic sterile endophthalmitis may occur
as toxic reaction to retained intraocular foreign
body, e.g., pure copper.
3. Intraocular tumour necrosis may present as
sterile endophthalmitis (masquerade syndrome).
4. Phacoanaphylactic endophthalmitis may be
induced by lens proteins in patients with
Morgagnian cataract.
Note: Since postoperative acute bacterial
endophthalmitis is most important, so clinical features
and treatment described below pertain to this
condition.
Clinical picture of acute bacterial endophthalmitis
Acute postoperative endophthalmitis is a
catastrophic complication of intraocular surgery with
an incidence of about 0.1%. Source of infection in
most of the cases is thought to be patient’s own
periocular bacterial flora of the eyelids, conjunctiva,
and lacrimal sac. Other potential sources of infection
include contaminated solutions and instruments, and
environmental flora including that of surgeon and
operating room personnel.
Symptoms. Acute bacterial endophthalmitis usually
occurs within 7 days of operation and is characterized
by severe ocular pain, redness, lacrimation,
photophobia and marked loss of vision.
Signs are as follows (Fig. 7.18):
1. Lids become red and swollen.
2. Conjunctiva shows chemosis and marked
circumcorneal congestion.
Note: Conjunctival congestion, corneal oedema,
hypopyon and yellowish white exudates in the
vitreous seen in the pupillary area behind the IOL.
3. Cornea is oedematous, cloudy and ring infiltration
may be formed.
4. Edges of wound become yellow and necrotic and
wound may gape (Fig. 7.19) in exogenous form.
5. Anterior chamber shows hypopyon; soon it
becomes full of pus.
6. Iris, when visible, is oedematous and muddy.
7. Pupil shows yellow reflex due to purulent
exudation in vitreous. When anterior chamber
becomes full of pus, iris and pupil details are not
seen.
8. Vitreous exudation. In metastatic forms and in
cases with deep infections, vitreous cavity is
filled with exudation and pus. Soon a yellowish
white mass is seen through fixed dilated pupil.
This sign is called amaurotic cat’s-eye reflex.
9. Intraocular pressure is raised in early stages, but
in severe cases, the ciliary processes are
destroyed, and a fall in intraocular pressure may
ultimately result in shrinkage of the globe.

Treatment
An early diagnosis and vigorous therapy is the
hallmark of the treatment of endophthalmitis.
Following therapeutic regime is recommended for
suspected bacterial endophthalmitis.
A. Antibiotic therapy
1. Intravitreal antibiotics and diagnostic tap should
be made as early as possible. It is performed
transconjunctivally under topical anaesthesia from
the area of pars plana (4-5 mm from the limbus). The
vitreous tap is made using 23-gauge needle followed
by the intravitreal injection using a disposable
tuberculin syringe and 30-gauge needle.
The main stay of treatment of acute bacterial
endophthalmitis is intravitreal injection of antibiotics
at the earliest possible. Usually a combination of two
antibiotics – one effective against gram positive
coagulase negative staphylococci and the other
against gram-negative bacilli is used as below :
First choice: Vancomycin 1 mg in 0.1 ml plus
ceftazidime 2.25 mg in 0.1 ml.
Second choice: Vancomycin 1 mg in 0.1 ml plus
Amikacin 0.4 mg in 0.1 ml.
Third choice: Vancomycin 1 mg in 0.1 ml plus
gentamycin 0.2 mg in 0.1 ml.
Note:
Some surgeons prefer to add dexamethasone 0.4
mg in 0.1 ml to limit post-inflammatory consequences.
Gentamycin is 4 times more retinotoxic (causes
macular infarction) than amikacin. Preferably the
aminoglycosides should be avoided.
The aspirated fluid sample should be used for
bacterial culture and smear examination. If vitreous
aspirate is collected in an emergency when
immediate facilities for culture are not available, it
should be stored promptly in refrigerator at 4°C.
If there is no improvement, a repeat intravitreal
injection should be given after 48 hours taking
into consideration the reports of bacteriological
examination.
2. Subconjunctival injections of antibiotics should
be given daily for 5-7 days to maintain therapeutic
intraocular concentration :
First choice : Vancomycin 25 mg in 0.5 ml plus.
Ceftazidime 100 mg in 0.5 ml
Second choice : Vancomycin 25 mg in 0.5 ml plus
Cefuroxime 125 mg in 0.5 ml
3. Topical concentrated antibiotics should be
started immediately and used frequently (every 30
minute to 1 hourly). To begin with a combination of
two drugs should be preferred, one having a
predominant effect on the gram-positive organisms
and the other against gram-negative organisms as
below:
Vancomycin (50 mg/ml) or cefazoline (50mg/ml)
plus.
Amikacin (20 mg/ml) or tobramycin (15 mg%).
4. Systemic antibiotics have limited role in the
management of endophthalmitis, but most of the
surgeons do use them.
Ciprofloxacin intravenous infusion 200 mg BD
for 3-4 days followed by orally 500 mg BD for
6-7 days, or
Vancomycin 1 gm IV BD and ceftazidime 2 g IV
8 hourly, or
Cefazoline 1.5 gm IV 6 hourly and amikacin 1 gm
IV three times a day.
B. Steroid therapy
Steroids limit the tissue damage caused by
inflammatory process. Most surgeons recommend
their use after 24 to 48 hours of control of infection
by intensive antibiotic therapy. However, some
surgeons recommend their immediate use

(controversial). Routes of administration and doses
are:
Intravitreal injection of dexamethasone 0.4 mg in
0.1ml.
Subconjunctival injection of dexamethasone 4
mg (1ml) OD for 5-7 days.
Topical dexamethasone (0.1%) or predacetate
(1%) used frequently.
Systemic steroids. Oral corticosteroids should
preferably be started after 24 hours of intensive
antibiotic therapy. A daily therapy regime with 60
mg prednisolone to be followed by 50, 40, 30, 20
and 10 mg for 2 days each may be adopted.
C. Supportive therapy
1. Cycloplegics. Preferably 1% atropine or
alternatively 2% homatropine eyedrops should
be instilled TDS or QID.
2. Antiglaucoma drugs.In patients with raised
intraocular pressure drugs such a oral
acetazolamide (250 mg TDS) and timolol (0.5%
BD) may be prescribed.
D. Vitrectomy operation should be performed if the
patient does not improve with the above intensive
therapy for 48 to 72 hours or when the patient presents
with severe infection with visual acuity reduced to
light perception. Vitrectomy helps in removal of
infecting organisms, toxins and enzymes present in
the infected vitreous mass.