Full thickness macular hole without necrosis in a case of viral retinitis

Case report

A 32-year-old woman presented with sudden painful visual loss associated with photophobia in both eyes. She denied any history of prior systemic or ocular disease. Best corrected visual acuity (BCVA) was counting fingers at 1 m in the right eye (RE) and 2/60 in left eye (LE). Slit lamp examination revealed severe anterior chamber reaction (white keratic precipitates, 4+ cells and 2+ flare), along with severe vitritis. There was grade 3 media haze in both eyes (Endophthalmitis Vitrectomy Study Group), though some yellowish patches suggestive of retinitis could be seen (Figure 1a, b). Macular details were hazy. Leading questions revealed a history of orogenital ulcers over the previous fortnight. Her husband also had similar lesions. OPEN IN VIEWER

With an empirical diagnosis of infective uveitis and retinitis, medical therapy with topical steroids and cycloplegia, together with oral valacyclovir (1 gm b.i.d.) and doxycycline (100 mg b.i.d.) were initiated with a plan to add oral steroids subsequently. Both husband and wife were found to be serologically positive for herpes simplex virus 2 (IgM-ELISA), but negative for HIV and syphilis. Our patient was therefore diagnosed as having acute retinal necrosis (ARN) and uveitis secondary to herpes simplex virus 2. The doxycycline was withdrawn, topical and anti-viral therapy continued, as well as oral prednisolone (1 mg/kg) which was added after three days. The orogenital ulcers of both partners were managed with oral valacyclovir.

At one-week follow-up, ocular inflammation had reduced and a macular lesion was vaguely visible in the RE. At three weeks, BCVA was 6/36 (RE) and 6/18 (LE). Clinical examination showed arterial thinning and macular ischaemia in both eyes (RE >> LE) with a full thickness macular hole (FTMH) in the RE (Figure 1c and d). Optical coherence tomography (OCT) scan revealed this to be a large macular hole without separation of the posterior vitreous cortex, while macular atrophy was seen in the LE. The hole measured a maximum of 240 µm in height and 1247 µm at its base. There was no evidence of traction or cystoid oedema, though the base of the hole had pigment clumps (Figure 2). Dosage of valacyclovir was tapered and stopped after six weeks; the same with prednisolone. The patient’s genital lesions resolved with therapy. Thereafter, the patient was unfortunately lost to follow-up, precluding evaluation of her macular ischaemia with fundus angiography. OPEN IN VIEWER

Informed consent was obtained from the patient.

Discussion

Viral retinitis is usually caused by herpes simplex and sometimes by herpes zoster. It can present acutely or non-acutely in immunocompetent patients, while in the latter necrosis may be absent. Progressive outer retinal necrosis is seen in immunosuppressed patients. Our case did not fulfil American Uveitis Society Criteria for diagnosing ARN, and hence we labelled it as non-necrotising viral retinitis. As opposed to the latter, ARN typically presents with peripheral lesions that develop necrotic holes and lead to retinal detachment with very poor visual prognosis. The initial clinical picture (Figure 1b) was similar to the ‘headlight in fog’ appearance of toxoplasmosis panuveitis. Toxoplamosis is a well-known cause of retino-choroiditis and should be included in the differential diagnosis of such cases. However, the presence of orogenital lesions in the couple, serological positivity for herpes virus and a good response to therapy indicated a viral aetiology in this case. A vitreous biopsy or an anterior chamber tap may be performed in cases where the diagnosis is doubtful or where therapeutic response is suboptimal.

Apart from macular damage, visual loss in cases with necrosis may be due to retinal detachment or atrophy and ischaemic optic atrophy. Aetiology of FTMH in viral retinitis is elusive and may be multi-factorial; necrotic retinal damage is common in ARN; tractional forces may be involved in FTMH. Our patient, however, had neither signs of an irregular necrotic macular hole nor of traction. A probable cause was macular oedema or ischaemia, though lamellar holes are expected in such cases. Non-necrotising viral retinitis does not usually produce FTMH, though macular ischaemia and macular oedema have been documented.^1–3

Clinical suspicion of infective conditions is paramount in the successful management of unexplained bilateral uveitis orretinitis. Ocular signs may be the presenting feature of an underlying sexually transmitted disease.