Iris Abscess as A Presenting Feature of Endogenous Endophthalmitis

Abstract

Endogenous endophthalmitis is an uncommon cause of endophthalmitis, with chorioretinitis being the usual manifestation of the disease. Here, we highlight a rare case of endogenous endophthalmitis presenting with an iris abscess. A 35-year-old male was hospitalised for methicillin-resistant staphylococcus aureus (MRSA) septicaemia secondary to the right lower limb with multiple infected wounds and was referred for a complaint of right eye redness. Other than underlying hepatitis B, the patient was otherwise immunocompetent. The visual acuity was 6/12 and 6/9 on the right and left eye respectively. The right eye conjunctiva was red, with a yellowish iris nodule noted at 9 o’clock and hypopyon. The posterior segment revealed the presence of vitreous clumps inferiorly with choroiditis and pre-retinal haemorrhages at the inferotemporal quadrant. Endogenous endophthalmitis with iris abscess was suspected. A vitreous tap was performed with intravitreal injections of ceftazidime and vancomycin. Systemic and topical ceftazidime and vancomycin were also commenced. Vitreous tap cultures were negative for both bacterial and fungal species. Diagnostic and therapeutic pars plana vitrectomy was planned however was deferred as the patient was not fit for surgery. With pharmacological therapy, the size of the abscess gradually reduced with a resolution of the hypopyon. Visual acuity was maintained at 6/12 bilaterally. Unfortunately, the patient eventually succumbed to death due to widespread sepsis with multi-organ failure. Iris abscess is a rare occurrence. A review of the literature shows several reported cases of iris abscesses as manifestations of endophthalmitis, largely secondary to septicaemia, one after cataract extraction, and one of unknown aetiology. To our knowledge, this is the first reported case of iris abscess secondary to MRSA septicaemia. Given the relative rarity of this condition, specific treatment guidelines may vary given the relative paucity of large case series. This unusual presentation of endophthalmitis must be kept in mind to avoid missing a life and sight-threatening disease.