Chapter 33

OCULAR MANIFESTATIONS OF NONOPHTHALMIC CONDITIONS

Wolfgang Schrader

Nonmechanical globe injuries may be caused by:

• chemicals (see Chapters 11 and 32);

• temperature;

• radiation (see Chapter 34); or

• mechanical impact elsewhere in the body.

Traumatic events not directly related to the eye rarely lead to ocular lesions; if they do, these are via:

• changes in rheologic conditions;

• hypoxia; or

• a sudden increase of the intravascular pressure.

Three mechanisms have been proposed to explain the resulting fundus findings:

• retinal vascular endothelial cell damage by increased intraluminal pressure;

• damage by emboli (e.g., air, blood products, fat); and

• mechanical forces acting at the vitreoretinal interface.

PURTSCHER’S RETINOPATHY

This is a retinopathy resulting from various etiologies and consisting of:

• marked macular and generalized retinal edema;

• multiple patches of peripapillary superficial retinal whitening;

• intraretinal hemorrhages around the optic disk; and

• disk edema (see Fig. 33–1).

The first case was described in 1868;¹ however, no epidemiological data are available.

FIGURE 33–1 Purtscher’s retinopathy (see the text for details).

Etiology

The most typical causes2–6 follow:

• severe head trauma;

• fracture of (long) bones; or

• chest compression (typically in an MVC);

the condition has also been described, however, after:

• concussions of the liver;

• blow to the orbit;

• carotid surgery/angiography; and

• thoracic/renal surgery.

Pathophysiology

Various suggestions have been made with regard to the pathophysiology, such as:

• extravasation from retinal vessels during a sudden increase in the intracranial pressure²;

• reflux venous shock waves produced from intra-thoracic chest compression⁷;

• fat emboli in retinal arterioles^8,9; and

• venous stasis.^9,10

The underlying systemic condition generates various intravascular microparticles that occlude small peripapillary arterioles,^5,11–14 with the following mechanisms/materials contributing:

• fat embolization from long bone fractures or acute pancreatitis (due to enzymatic digestion of omental fat)¹⁵;

• air emboli from compressive chest injuries¹⁵;

• retinal venous wall trauma from venous reflux with endothelial cell swelling and capillary engorgement in the upper body⁷;

• angiospastic response following a sudden increase in venous pressure^6,7;

• local retinal vascular coagulopathy or complement-induced granulocyte aggregation leading to multiple arteriolar occlusions¹⁶; and

• fibrin clots, aggregates of platelets and leukocytes.¹⁵

A Purtscher-like fundus picture may also occur in lupus erythematosus and at childbirth.^11,17

Evaluation

The symptoms^a are usually bilateral, although rarely symmetrical, and develop within 4 days.

• Unilateral cases have also been reported.^15,18

• Patients complain of decreased vision, often from 20/200 to counting fingers.

• IBO (the peripheral retina is commonly spared):

numerous white retinal patches or confluent cotton-wool spots around the disk;

superficial retinal hemorrhages;

serous macular detachments, dilated and tortuous vasculature, and

disk edema.

• FA:

focal areas of arteriolar obstruction;

patchy capillary nonperfusion;

disk edema;

dye leakage from retinal arterioles, capillaries, and venules;¹⁵

the choroidal filling may be normal in the acute stages with some blockage of background choroidal fluorescence;

late perivenous staining and/or partial vein obstruction; and

optic disk edema.

Management

Management is by observation.

Complications

Lesions similar to those in Purtscher’s retinopathy have been produced experimentally,^b resulting in the clinical picture of Purtscher’s retinopathy. It is thus obvious that the condition may be complicated by vascular occlusions in the retina and on the optic disk, leading to permanent functional impairment.

Prognosis and Outcome

The retinal lesions typically resolve in a few weeks to months. After resolution, the fundus may appear normal, but pigment migration and optic atrophy can occur.⁴

Fundus features in Purtscher-type retinopathy are similar and may appear in many other conditions. History, associated systemic disease, and the interval between injury and onset of visual signs/symptoms may help in the differential diagnosis. Common etiologies include the following.

Fat embolism20 is clinically recognized in up to 5% of patients with long bone fractures,^21,22 affects multiple organ systems,²³ and may be fatal in 20% of the severe cases.²⁴ Retinal lesions are present in 50–60% of patients, but they are more peripheral.^4,7

Acute pancreatitis occurs when digestive enzymes released from the inflamed pancreas degrade omental fat, liberating into the general circulation free fat emboli that may eventually lodge in the retinal circulation.¹⁵ A complement cascade may be activated by the release of pancreatic proteases, leading to leukoembolic retinal arteriolar occlusion.¹⁶

Compression cyanosis (or traumatic asphyxia) is accompanied by bluish discoloration of the chest, neck, face, and upper extremities.

Air embolization is a rare complication of chest/ jugular vein surgery/injury. Distinguishing fundus features include a uniformly gray appearance of the fundus, a pale optic nerve, and intra-arterial air.^d

Hydrostatic pressure syndrome occurs when a person is ejected from an aircraft traveling at very high speed. The high decelerating forces drive blood toward the head and create mental confusion, temporary loss of vision, periocular edema, ecchymosis of the lids, and subconjunctival and retinal hemorrhage.⁷

The nonophthalmologist should be aware of sight-threatening complications even in the absence of direct ocular involvement.

WHIPLASH SYNDROME

An energy transfer to the neck and head occurs via acceleration/deceleration; it is most common in rear-end collision MVCs²⁵ and may lead to a variety of clinical manifestations (whiplash-associated disorders). The predominant symptom is pain and discomfort, frequently in the absence of pathology on inspection or radiological investigation. There may be concussional injury to the brain.

Epidemiology and Prevention

In one study,²⁵ the driver-specific incidence rate was 96 per 100,000 licensed drivers per year. It varies with population density.^e

Pathophysiology

A violent flexion is immediately followed by an extension of the neck, which may cause a mechanical injury to the sympathetic nerves.

Evaluation

The patients may have a wide range of complaints.

• The most common presenting symptoms are neck pain (≤100%) and headache (54–66%).²⁵

• Horner’s syndrome^f may be the most common ocular manifestation.⁴

• Visual complaints are reported in 8 to 26%.^25,27

The reduction in visual acuity is rather acute but usually not worse than 20/30. The symptoms are bilateral and resolve over a period of a few days.

• On biomicroscopic examination, there is a gray swelling of the fovea. A crater-like depression less than 100 µm in diameter with slight RPE disturbance may remain unchanged even when the symptoms resolve.²⁶

• FA may be normal or may show a tiny focal area of hyperfluorescence.²⁶

Management

There is no known treatment.

Complications

An accompanying concussional injury to the brain may cause temporary palsy of the cranial nerves with diplopia.⁴

Prognosis and Outcome

The visual acuity usually, although not always, returns to normal. A similar clinical appearance and course may be seen after contusion and solar retinopathy (see Chapter 34).¹¹

The nonophthalmologist should be aware of sight-threatening complications even in the absence of direct ocular involvement. If the victim complains about visual loss after a whiplash injury, an ophthalmologist should be called for consultation. Accurate documentation is important.

SHAKEN BABY^g SYNDROME

The 15% mortality rate underscores the importance of recognizing this form of child abuse.²⁹

Epidemiology and Prevention

In central Europe, 3.5% of the parents confessed to having used so much violence on their children that it might have resulted in severe injury; 10% of traumatized children admitted to a hospital show evidence of physical violence.³⁰

In a single year, 1120 instances of child abuse were registered by the police in western Germany^h; the estimated number of cases was between 20,000 and 400,000.³⁰

• Two thirds of the abused children are babies.

• The typical victim is a male infant, younger than 6 months of age, who is alone with the perpetrator at the time of the injury.³¹

• The incidence is unrelated to race, gender, socioeconomic status, or education.³¹

• The presenting sign is eye related in 4 to 6% of the cases.

• Whereas after accidental head injuries nearly all babiesⁱ have normal funduscopic examinations, most babies with nonaccidental head injuries show varying degrees of retinal hemorrhages.

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