An unusual case of retinitis

Abstract

A 35-year-old HIV positive man presented to casualty at Moorfields Eye Hospital in July, 1999, with a 10 day history of redness in the right eye and 3 days of reduced visual acuity and floaters. A diagnosis of conjunctivitis had been made and he was using topical chloramphenicol. He had been diagnosed as HIV positive in 1989 and developed Kaposi’s sarcoma of the hard palate in 1991, which was treated with radiotherapy and interferon. His medications were didanosine (400 mg per day), nevirapine (200 mg twice daily), delavirdine (600 mg twice daily), saquinavir (800 mg per day) and cotrimoxazole (960 mg thrice weekly+). His viral load was 91 000 copies/mL with a CD4 count of 320/ L. His lowest recorded CD4 count was 190/ L. Examination showed him to be myopic with corrected visual acuity of 6/9 on the right. His eye was injected, with moderate anterior chamber and vitreous inflammation. Retinal examination showed a large area of pallor superiorly with thin, finely pigmented retina peripherally (figure). The left eye was normal. Atypical viral retinitis was the provisional diagnosis. He had a biopsy sample of his vitreous taken, which was sent for culture, histology, and PCR of viral DNA. He was admitted and treated with 2 mg intravitreal gangiclovir and intravenous foscarnet (60 mg/kg thrice daily) to treat herpes viruses Cytomegalovirus (CMV), Varicella zoster virus (VZV), herpes simplex virus (HSV) which are the commonest causes of retinitis in patients with AIDS. Over the following days the edge of the retinal lesion advanced, however the periphery became atrophic. The results of viral DNA PCR were available 5 days later and were negative for HSV-1, HSV-2, CMV, VZV and Epstein Barr virus. Syphilis screening showed a positive TPHA and positive VDRL (1/256). IgG was detected, however IgM was not, suggestive of past treponemal infection, and the patient remembered having had treatment for syphilis 10 years previously with intramuscular procaine penicillin, but he had been lost to follow-up. With his optic nerve and macula under threat from spread of retinitis, he was treated with amoxycillin 3 mg twice daily and probenicid 1 g twice daily for 5 days, by which time the retinitis had stopped advancing and showed signs of healing with a return of visual acuity to 6/6. Further investigation of his clinical state and syphilitic status was then undertaken. When last seen in October, 1999, his eye was quiet with acuity of 6/6. CASE REPORT