Isolated retinal cotton wool spot after coronary angiography.

Visual symptoms after coronary angiography are rarely encountered and mostly related to contrast induced transient cortical blindness or retinal artery occlusions. We report an intriguing case of a 50-year-old woman, who presented with vision deterioration in her right eye 12 h after coronary angiography for cardiac palpitation. Fundoscopy and optical coherence tomography scan revealed an isolated parafoveal cotton wool spot in her right eye that has totally resolved 6 weeks after initial presentation. This is the first case report of this rare post coronary angiography complication.

Introduction

Visual symptoms after coronary angiography are rarely encountered and mostly related to contrast induced transient cortical blindness, which is caused by neurotoxic effect of the contrast agent on the blood-brain barrier in the occipital lobe.[1]

Even less frequent is visual loss related to central or branch retinal artery occlusion after coronary angiography.[2]

We report an intriguing case of a 50-year-old woman, who presented with visual symptoms and a single cotton wool spot of her right macula 12 h after coronary angiography.

Case Report

A 50-year-old woman was referred to our clinic for acute onset of blurred vision in her right eye 12 h after coronary angiography for cardiac palpitation.

Her coronary angiography was uneventful and revealed coronary artery spasm. The procedure lasted 20 min during which the patient remained hemodynamically stable. Twelve hours after catheterization the patient complained of sudden blurred and patchy vision in the right eye.

Computed tomography scan of the patient’s brain was performed immediately to exclude a contrast induced transient cortical blindness, but it was unremarkable and the patient was referred to the department of ophthalmology.

On examination, the visual acuity (VA) was 6/6 in the right and 6/5 in the left eye. The patient had a history of hypertension and hypercholesterolemia and was not on any medications. Intraocular pressures were 14 mm Hg both sides and slit lamp examination showed a deep anterior chamber. Fundoscopy of the right eye revealed a tiny single parafoveal whitish patch in the right macula, suggestive of an isolated cotton wool spot. Amsler grid test showed a parafoveal scotoma corresponding to the area of the cotton wool spot. The left funduscopy findings were unremarkable [Figure 1].

Figure 1

Fundus photographs of a 50-year-old woman, who presented with blurry vision in her right eye 12 h after having coronary angiography. (a) Right eye showing a tiny single juxtafoveal whitish patch consistent with an isolated cotton wool spot. (b) Left eye fundoscopy was unremarkable

Optical coherence tomography (OCT) was performed and showed an isolated opacity in the level of the retinal nerve fiber layer corresponding to the cotton wool spot [Figure 2a].

Figure 2

Optical coherence tomography scan across the area of the cotton-wool spot: (a) At presentation showing a maximum overall retinal thickness of 350 μm with focal thickening of the retinal nerve fiber layer and (b) 6 weeks later showing a complete resolution of the cotton wool spot with normal foveola

Since the lady was under the care of cardiology, no further treatment was suggested from ophthalmological point of view, and she was started on diltiazem 120 mg daily for her coronary artery spasm by her cardiologist.

On review 6 weeks later, the symptoms had improved and VA was 6/6 in both eyes. Fundoscopy and Amsler grid test of the right eye were unremarkable. OCT scan showed a complete resolution of the cotton wool spot [Figure 2b].

Discussion

Coronary catheterization is a minimally invasive procedure and one of the commonest diagnostic tests performed for both diagnostic and interventional purposes in modern cardiology. Common complications include cardiac arrhythmia, myocardial infarct, transient ischemic attack, stroke and allergic reaction.[3]

The incidence of ophthalmic complications in diagnostic coronary angiography is extremely low, and differential diagnosis should always include contrast induced transient cortical blindness, retinal artery occlusion, amaurosis fugax and hysterical blindness.[4]

Few cases have been previously reported with transient cortical blindness and retinal artery occlusions presenting during or 24 h after coronary angiography.[5]

This is to our knowledge the first case of visual symptoms due to a single parafoveal cotton wool spot 12 h after coronary angiography. Cotton wool spots are thought to represent axoplasmic stasis at the level of retinal ganglion cell axons, resulting from axoplasmic flow interruption due to vascular or mechanical causes.

With regard to pathophysiology, a retinal artery occlusion after coronary catheterization can occur after complete or partial artery obstruction caused by atherosclerotic emboli at the time of coronary artery catheterization or later on.

In our case, we presume that non visible micro emboli caused the axoplasmic flow interruption and accumulation of axoplasmic material within the nerve fiber layer and resulted in an isolated parafoveal cotton wool spot that resolved 6 weeks after initial presentation.

Summarizing we present an intriguing case of a 50-year-old woman with an isolated cotton wool spot in her right macula 12 h after coronary angiography and emphasize this rare post cardiac catheterization complication for future cardiologists and ophthalmologists.