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Editor,—The coexistence of endophthalmitis and orbital cellulitis in one individual is often a result of endogenous complications, such as metastatic septicaemia or infiltration from a neighbouring orbital infection.1-3 However, the coexistence of both these diseases as complications following intraocular or extraocular surgery is very rarely recognised and has only been reported previously in two patients who underwent radial keratotomy and penetrating keratoplasty.34 We report a patient who underwent uncomplicated phacoemulsification surgery under sub-Tenon anaesthesia and presented with an acute endophthalmitis and orbital cellulitis, leading to phthisis bulbi despite a good response to prompt treatment.
A 77 year old woman with high myopia and left aphakia underwent uncomplicated elective phacoemulsification surgery of the right eye under sub-Tenon anaesthesia, without intraocular lens implantation. Postoperative ocular examination was satisfactory but on the second day after surgery, she developed headache, vomiting, and ocular pain, with decreased vision in the operated eye to hand movements.
Examination revealed a proptotic right eye with erythematous lid swelling, purulent discharge, and some restriction in all extraocular movements. There were generalised corneal oedema, severe fibrinous uveitis, and vitritis. Postoperative endophthalmitis with orbital cellulitis was diagnosed (Fig 1). The patient was admitted for emergency aqueous and vitreous biopsy with intravitreal antibiotic injection. Oral prednisolone 40 mg once daily and standard intensive topical antibiotics were commenced and changed accordingly when bacteriology cultures confirmed the growth ofStreptococcus pneumoniae.
She suffered from bronchial asthma with a productive cough. She was febrile since her second admission, but both sputum and urinary cultures were negative. Diabetes and dacryocystitis were also excluded. Computed tomography (CT) orbital scan had revealed no retrobulbar or orbital abscess. As the isolated pathogen was Strep pneumoniae, endogenous spread from her chronic respiratory disease to the eye was still a possibility. Her ocular infections had eventually resolved into phthisis bulbi with no perception of light 2 months after the surgery.
The cause of postoperative endophthalmitis is often a result of inoculation of pathogens directly into the ocular cavity during surgery or indirectly into periocular tissues with subsequent access gained via an open wound. However, the precise mechanism leading to orbital cellulitis from endophthalmitis is less clear.
In our patient, sub-Tenon anaesthesia was applied and this could potentially have served as an access for the pathogen into the orbital cavity. One of two reported cases of postoperative endophthalmitis and orbital cellulitis received only topical anaesthesia at the primary procedure4; orbital cellulitis developed following vitreous biopsy and intravitreal antibiotic injection, and the type of anaesthesia was not mentioned. Sub-Tenon anaesthesia is an increasingly popular procedure for intraocular surgery, and when performed by the anaesthetist, skin preparation is usually undertaken using Betadine (Seton), but conjunctival lavage with antiseptic is not usually practised and periocular tissues are not draped. We recommend fastidious preparation of the lids and conjunctiva with 5% povidone iodine before sub-Tenon anaesthesia together with appropriate draping in addition to the standard procedure before intraocular surgery which has been shown to reduce the incidence of postoperative infection.5
There is a general assumption that orbital cellulitis is an infective consequence of endophthalmitis, where the orbit was infected with the causative pathogen. On the other hand, orbital cellulitis could simply be an inflammatory response to the severe infection of the globe. The patient we describe presented with coexisting orbital cellulitis and endophthalmitis, probably resulting from simultaneous inoculation of the infecting organism into orbital tissues and the eye from the conjunctiva. This is supported by the findings of periorbital soft tissue swelling on the CT scan. In addition, the degree of orbital involvement could simply reflect the virulence of the particular organism.3 Phthisis bulbi within 2 months of the initial infection was also the result of the reported case of post-radial keratotomy, even though the causative pathogen differed from the present case. As the prognosis of both coexisting diseases is far worse than endophthalmitis or orbital cellulitis alone, early recognition and the initiation of aggressive treatment are vital.