Purtscher Retinopathy and Purtscherlike Retinopathy
After acute compression injuries to the thorax or head, a patient may experience loss of vision associated with Purtscher retinopathy in 1 or both eyes. Cotton-wool spots, polygonal shaped areas of retinal whitening (Purtscher flecken), hemorrhages, and retinal edema are found most commonly surrounding the optic nerve head, and fluorescein angiography reveals evidence of arteriolar obstruction and leakage. Occasionally, patients present with optic nerve head edema and an afferent pupillary defect. Vision may be permanently lost from infarction, and optic atrophy may develop.
Purtscher retinopathy is thought to be a result of injury-induced complement activation, which causes granulocyte aggregation and leukoembolization. This process in turn can occlude small arterioles. When the occlusion of a precapillary arteriole affects the radial peripapillary capillary network, cotton-wool spots develop, which are foci of axoplasmic stasis in the nerve fiber layer; these areas of retinal whitening have indistinct borders and can obscure or partially overlie retinal blood vessels. When capillaries in lamina deeper than the radial peripapillary network are blocked, the funduscopic correlate is instead Purtscher flecken, which manifest as intraretinal whitening with a clear zone on either side of the retinal arterioles, venules, and precapillary arterioles.
Even in the absence of trauma, various other conditions may activate complement and produce a similar fundus appearance. Because Purtscher’s original description involved trauma, cases with similar fundus findings are termed Purtscherlike retinopathy (Fig 7-17; Table 7-3). For example, the retinopathy associated with acute pancreatitis, which appears identical to traumatic Purtscher retinopathy, is probably also caused by complement-mediated leukoembolization. Other conditions that may cause these changes include collagen-vascular diseases (such as systemic lupus erythematosus), childbirth, and amniotic fluid embolism.
Figure 7-17 Purtscherlike retinopathy. A, Fundus photos of a 20-year-old woman were taken 1 day after an uncomplicated delivery of a healthy baby. The patient had noted profound, persistent bilateral vision loss beginning 1 hour after parturition. Intraretinal hemorrhages (arrows) and bright superficial cotton-wool spots (arrowheads) were present, in addition to extensive areas of well demarcated Purtscher flecken (asterisk) with characteristic sparing of the perivascular retina. The flecken are likely the result of occlusion of the precapillary arterioles. B, Corresponding fundus photos taken 4 years later demonstrate optic atrophy and deep macular pigmentary atrophy. Visual acuity was 20/200 OD and 20/800 OS.
(Courtesy of Brian Leonard, MD.)
Table 7-3 Conditions Associated With Purtscher or Purtscherlike Retinopathy
Fat embolism following crushing injuries or long-bone fractures may cause similar retinal findings. Intraretinal hemorrhages are usually scattered in the paramacular area, and the cotton-wool spots of fat embolism are generally smaller and situated more peripherally in the retina than they are in Purtscher retinopathy.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.