Retina Quiz
Blurred Road Ahead
For Injured Indy Driver
Mark T. Dunbar, O.D.
A 29-year-old racecar driver noted blurred vision in his right eye following a crash during the Indianapolis 500. He was hospitalized for a few days for various injuries. Upon his release, he was referred to an eye doctor for evaluation of the blurred vision.
On examination, his best-corrected visual acuities were 20/80 O.D., 20/20 O.S. Confrontation visual fields were full to careful finger counting O.U. The pupils were equally round and reactive without an afferent pupillary defect. Amsler grid testing of the right eye showed several small gray paracentral scotomas surrounding fixation and areas of metamorphopsia. Amsler grid testing of the left eye was normal. Anterior segment examination of both eyes was unremarkable.
On dilated fundus exam, the vitreous was clear. The optic nerves appeared
healthy with small cups and good rim coloration and perfusion O.U. Multiple
areas of retinal whitening, as seen in the photographs, radiated from the
optic nerve in the right eye. The areas of retinal whitening appeared superficial
and were associated with retinal edema. They did not extend to the macula.
These same changes were not present in the left eye. The remainder of the
retinal exam was normal in both eyes.
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| The right eye (left) shows areas of superficial retinal whitening surrounding the optic nerve head. The left eye is normal. | |
Discussion
This is an unusual condition referred to as Purtscher’s retinopathy, which develops as a result of severe compressive injury to the chest or head. Patients usually present with blurred vision and a peculiar retinopathy that involves one or both eyes. The typical findings include multiple patches of superficial retinal whitening, cotton wool spots and retinal hemorrhages that surround the optic nerve. It generally does not involve the macula, and the optic nerve is usually normal.Anatomically, the retinal whitening is superficial and will obscure the retinal vessels. It is generally accompanied by retinal swelling and superficial retinal hemorrhages.
The pathogenesis is controversial. The white patches likely represent focal areas of retinal ischemia, even though they have been commonly described as exudative. In severe cases, fluorescein angiography has shown areas of arterial obstruction. Also common is retinal arteriolar leakage, which can also be seen in Berlin’s edema. However, Berlin’s edema results from disruption of the photoreceptor outer segments following blunt trauma involving the macula. Purtscher’s retinopathy does not develop as a result of blunt trauma to the eye, but more likely from air embolism resulting from a compressive chest injury.
Other mechanisms that have been proposed include fat embolization in long-bone fractures and acute pancreatitis, venous reflux with endothelial cell swelling and capillary engorgement of the upper body, and severe angiospastic response following a sudden increase in venous pressure.
The long-term prognosis for Purtscher’s retinopathy is good. There is no treatment; only observation is recommended. The retinal hemorrhages will disappear, and the areas of retinal whitening will slowly fade, often resulting in localized areas of nerve fiber layer dropout. This, in turn, may lead to mild optic nerve pallor. The macula may show mild RPE mottling, although patients generally end up with fairly good acuity.
Our patient’s visual acuity returned to 20/25, but he continued to describe
subtle, well-defined gray areas on Amsler grid testing, even a year after
the initial incident. Still, this didn’t stop him from continuing to race
cars.
1. Gass JDM. Stereoscopic Atlas of Macular Disease: Diagnosis
and Treatment. 4th edition. St Louis: Mosby, 1997.
August 15, 2000