A hypopyon is a sign of post-trabeculectomy endophthalmitis or not?

Sir, We read with interest the case reported by Tan et al in July 2003 issue of Eye. The author presented one of the first cases of late bleb-related endophthalmitis caused by group B Streptococcus.1 As the authors emphasized, delayed-onset endophthalmitis usually occurs in the leaking bleb and most of the cases were caused by Staphylococci or Streptococci.2, 3 and fewer cases by fungus.4 However, other forms of organisms occasionally causes hypopyon and mimic bacterial endophthalmitis. We present an atypical case of acute retinal necrosis syndrome (ARNS) mimicking bleb-related endophthalmitis after trabeculectomy. A 76-year-old woman complained of a visual disturbance in her right eye for the previous 7 days. She had suffered from shingles around the right eye. She had experienced chronic recurrent iridocyclitis with secondary open-angle glaucoma for the last 10 years and had received trabeculectomy 3 years ago in the right eye. Best-corrected visual acuity was light perception in the right eye. The right conjunctiva was severely injected. Marked cells and flare with angle hypopyon were present in the anterior chamber. A thin-walled bleb existed at the upper side of the conjunctiva. However, no opaque or leakage was seen in the bleb. The fundus was invisible because of extreme vitreous opacity. A pars plana vitrectomy was conducted with a tentative diagnosis of bleb-related endophthalmitis. The retina was mostly intact and several exudative lesions with white vessels were observed at the nasal and inferior mid-peripheries of the fundus (Figure 1). Suspecting of a viral infection, vitreous humour was sampled. Whereas the culture examination resulted in no bacterial growth, varicella-zoster virus (VZV)-specific DNA was detected by polymerase chain reaction (PCR). The patient was diagnosed as ARNS caused by VZV. Intravenous infusion of acyclovir of 750 mg/day and oral corticosteroid of 40 mg/day with topical corticosteroid were initiated. The white-exudative lesions gradually subsided and became necrotic degeneration. Visual acuity improved up to 160/200 in the right eye 2 months after vitrectomy. To our knowledge, this is the first description of ARNS mimicking bleb-related endophthalmitis. We should be aware that viral infection could masquerade clinical features resembling a bacterial endophthalmitis. Sponsoring organization: None.