Giant cell arteritis is characterized primarily by inflammation in certain large and medium-sized arteries. The major risk factors are age, female gender and Northern European descent.

In this report we describe two cases of acute vision loss due to giant cell arteritis. In both cases the erythrocyte sedimentation rate (ESR) was below 50 mm/hr and the presenting complaint was foggy vision followed by acute blindness. The cases are to some extent different, for example in the former case the patient reported jaw claudication and ophthalmologic evaluation was consistent with anterior ischemic optic neuropathy. In the latter case there was narrowing and box-carring of blood cells in retinal arterioles, consistent with occlusion of the central retinal artery. This patient had recently finished a 2-year long treatment with glucocorticosteroids for polymyalgia rheumatica.

The retina and the optic nerve do not survive for long without perfusion. If giant cell arteritis causes blindness in one eye there is significant risk for the other eye to go blind if no treatment is given. Corticosteroids can spare the other eye and suppress the underlying inflammatory disease process as well. It is vital to confirm the diagnosis of giant cell arteritis with a biopsy and start corticosteroid treatment as soon as possible, even before the biopsy is taken.

Table I
International criteria for the diagnosis of giant cell arteritis. The patient must meet at least three of the five criteria.

Figure 1a and 1b
Figure 1a shows a patient´s occluded temporal artery (case 1), with typical changes of giant cell arteritis. Intimal hyperplasia and a blood clot obliterate the lumen. Localized inflammation, with lymphocytes/plasma cells and multi-nucleated white blood cells, is present (Haematoxylin and eosin stain (H&E); low power).

Figure 1b is from the same biopsy but in higher magnification. The arrow points to where the internal elastic lamina becomes fragmented. Phagocytes have cleared the fragments. Multi-nucleated giant cells are often seen and the disease takes it´s name from them. No giant cells can be seen with certainty on this image (H&E; high power).

 

Figure 2a and 2b
Retinal photographs, taken at patient´s arrival (case 2), show a "cherry red spot" that is produced by ichaemic edema of the retina all around the fovea. Figure 2b is the same image, only cropped, and shows "box carring", produced by obstructed blood flow in the arterioles.

 

Figure 3a and 3b
This retinal photograph (from the patient in case 2) was taken three days later and shows continuing pallor of the retina in spite of unobstructed blood flow. Figure 3b is cropped from figure 3a.