Sir,

We read with high interest the case report by Dr Stead et al,1 who describe a patient with bilateral optic disc swelling associated with anterior and posterior scleritis, presumably related to localized Wegener's granulomatosis, despite the absence of biological or pathological evidence of the latter condition.

Although we perfectly agree with the general comment that B-scan is a key examination to diagnose posterior scleritis, we strongly feel that our recently reported patient2 had bilateral papillitis, rather than posterior scleritis. The patient, who presented with painless bilateral visual loss and no redness in the eye, had central scotomas and decreased colour perception. Except bilateral optic disc oedema, fundoscopy and fluorescein angiography disclosed no retinal or retinochoroidal involvement.

Pain, redness in the eye, anterior scleritis or uveitis, and retinal or retinochoroidal involvement (panuveitis, retinal folds, serous detachment, uveal effusion syndrome, etc) are the most important clinical signs indicating posterior scleritis.3, 4 None of those signs were detected in our case with confirmed toxoplasmosis, which is known to cause only rarely scleritis.5 In addition, an orbital MRI with contrast disclosed no posterior scleral thickening or retrobulbar oedema, which is often seen in posterior scleritis with orbital CT or MRI.6

In the complete absence of all these clinical and radiological signs, we felt that posterior scleritis was unlikely to be present in our patient, although we cannot formally rule out some scleral involvement, which was undetectable by a thorough orbital MRI. In conclusion, we agree with Dr Stead et al that a B-ultrasonography should be performed in patients with clinical signs indicating the possibility of posterior scleritis, although this was probably not the case in our patient.