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.

Figure 1
figure 1

Fundus photograph of the right eye at 2 days after pars plana vitrectomy. Several exudative lesions with white vessels were observed at the nasal and inferior midperipheries of the fundus.

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.