Sir,

Early diagnosis and treatment of giant cell arteritis (GCA) is important to prevent blindness in one or both eyes.1 Occult giant cell arteritis, now a well-established entity, is defined as ocular involvement of GCA without any systemic symptoms and signs of giant cell arteritis.1 The ocular symptoms and ischaemic lesions can be seen in a variety of combinations. We describe a case of occult GCA who presented with history of transient visual loss and bilateral cotton wool spots (CWSs).

Case report

A 59-year-old male Caucasian, who was otherwise fit, sought consultation complaining of a history of transient bilateral visual blur lasting for a few hours followed by complete resolution. Questioning specifically for systemic signs and symptoms associated with GCA at or before the onset of visual symptoms proved negative. His past medical history was unremarkable.

Visual acuities in both eyes were 6/6. His colour vision, visual fields, pupillary exam and anterior segment examination were normal. Fundus examination showed numerous elevated, whitish CWSs in both eyes with normal looking optic discs and maculae (Figure 1). The patient's superficial temporal arteries were nontender and pulsatile on both sides. His cardiovascular exam including carotid auscultation was normal.

Figure 1
figure 1

Fundus photograph showing CWSs, normal looking disc, and macula.

Full size image

ESR was elevated at 112 mm/h and CRP was 85 units. Fluorescein angiography showed poor and reduced filling of the retinal circulation with normal choroidal circulation and no disc oedema. He was not started on any treatment but underwent an urgent temporal artery biopsy. Histopathology showed mononuclear cell infiltration of the vessel wall, fragmentation of the internal elastic lamina, and multinucleated giant cells thus confirming the diagnosis of GCA. While awaiting his biopsy results, he re-presented with vision in his right eye having reduced to counting fingers with no obvious disc swelling. He was commenced on high-dose oral steroids and his vision improved to 6/6 with some constriction of peripheral visual field.

Comment

Occult GCA, a potential cause of blindness, is defined as ocular involvement of GCA without any systemic symptoms and signs of GCA.1 The ocular symptoms include visual loss, amaurosis fugax, diplopia and eye pain.1 Ocular ischaemic lesions described are anterior ischaemic optic neuropathy, posterior ischaemic optic neuropathy, central retinal artery occlusion, cilioretinal artery occlusion and CWSs.1 The symptoms and signs can be seen in a variety of combinations.

CWS is an important clinical sign of associated systemic disease. It is widely held to reflect focal inner retinal ischaemic lesions; however recent perspective2 suggest CWSs to comprise localised accumulation of axoplasmic debris within adjacent bundles of unmyelinated ganglion cell axons.

Hayreh et al1 describes CWSs in up to one third of eyes with visual loss during the early stages of occult GCA. In a recent study, Asensio et al3 describes two patients who were presented with single isolated CWS as the only clinical manifestation. They suggest CWSs can be an early ophthalmoscopic finding in GCA and can precede an important visual loss.

In our patient, transient visual blur was the only presenting symptom and CWSs were sole manifestation of temporal artery biopsy positive occult GCA. Although he developed reduction in vision related to poor central retinal artery perfusion, prompt systemic steroid treatment resulted in him regaining his central vision at its previous level.

We are not aware of any publication in which bilateral CWSs are the only presenting sign of occult GCA. In conclusion, the sole finding of CWSs and nonspecific visual symptoms in a patient aged >55 years needs to be investigated further to exclude the possibility of occult GCA.