Chapter 157. Digital Globe Massage

Digital globe massage has been considered a heroic measure to salvage vision in cases of central retinal artery occlusion (CRAO), an ophthalmologic emergency.1–8 CRAO is one of several diagnoses to consider in the patient with acute painless loss of vision or a visual field. The typical patient is older, between the ages of 50 and 80 years of age, and with significant systemic illnesses. The CRAO is most likely an embolic event secondary to atherosclerotic disease. The vision loss is sudden, monocular, and painless. The outcome for CRAO is poor if treatment is delayed more than 2 hours. Spontaneous remission and recovery of visual function is rare. This condition requires an emergent consultation with an Ophthalmologist for medical management and the consideration of an anterior chamber paracentesis (Chapter 158). Digital globe massage can be used in an attempt to relieve the obstruction or break up the embolus so it moves distally to restore some blood flow to the retina.

The ophthalmic artery is a branch of the carotid artery (Figure 157-1). The first branch of the ophthalmic artery is the central retinal artery. This vessel runs along the optic nerve and enters the optic nerve. The central retinal artery is the main blood supply to the retina. The macula has an independent blood supply from other branches of the ophthalmic artery. An area between the macula and the optic nerve receives collateral circulation from the central retinal artery and the ciliary arteries in a small percentage of the population. This explains why a patient with a complete CRAO may have a normal appearing macula and occasionally an area of perfusing retina adjacent to the optic nerve area.

The individual etiology remains unclear in many cases. The main cause of retinal arterial occlusions is an embolic event lodging in the central retinal artery where it narrows to pass through the lamina cribrosa, or in a smaller distal branch arteriole. The embolism may be comprised of aggregated fibrin and platelets arising from an ulcerated vessel wall thrombus, cholesterol from an ulcerated carotid artery plaque, material from cardiac valvular disease, or thrombus formation from giant cell arteritis. The embolus may also result from an invasive procedure such as cardiac angioplasty, carotid angioplasty and stenting, or a carotid endarterectomy.

Abnormal cardiac rhythms are considered an etiology for intracardiac blood clot formation. These may embolize and lodge in the ophthalmic artery or distally in one of the branch arteries. Retrobulbar masses (e.g., a hematoma, neoplasm, or retrobulbar injection) may also lead to an optic nerve and central retinal artery compression.1

Physical Examination Findings

The patient may display vision compromise ranging from a small visual defect to a decreased ability to finger count or perceive light, and to complete blindness. Grossly, the eye appears normal. However, an afferent pupillary defect may be evident with little or no reaction to direct light and a normal reaction to consensual light. The initial fundoscopic examination may show a near-normal retinal appearance (Figure 157-2A). This soon progresses to a pale retina, bloodless or attenuated arterioles, and “boxcar” segmentation of the retinal veins (Figure 157-2B). The fundoscopic exam will then reveal a milky and edematous retina with a cherry-red macula if the entire central retinal artery is occluded. If the cilioretinal artery flow is not occluded, there will be an area of perfusion between the optic disc and the macula (Figure 157-2B). An embolus may be visible in the vasculature of the optic disc in rare cases. If a branch retinal artery is occluded, an embolus may be visible in the vessel with ischemia and infarction distal to the occlusion.

It has been shown experimentally that the retinal damage is irreversible after 100 minutes of nonperfusion.3 There is anecdotal evidence that heroic measures to salvage vision after a CRAO have sporadically resulted in the return of vision. A large study showed that the average final visual acuity in patients with a CRAO treated with heroic measures compared to those untreated was only a one-quarter line improvement in Snellen chart visual acuity. If the underlying cause of the CRAO is giant cell arteritis, up to 10% of the cases progress rapidly to bilateral vision loss if the arteritis is left untreated.

Medical Management

Various methods have been employed to reduce intraocular pressure or to dilate the artery in an attempt to facilitate dislodgement of the embolus.1–8 None of these have been proven to be of benefit in the management of a CRAO.6 On the other hand, none of these have been proven to be harmful. Thus, they may prove to be useful in saving the patients vision. The following interventions should be considered as coadjuvants to digital globe masses. Oral nitrates (0.5 or 0.4 mg nitroglycerin pills or spray) may vasodilate the retinal artery. Instruct the patient to breathe into a paper bag to increase blood carbon dioxide levels and induce vasodilation. If available, administer carbogen (95% oxygen and 5% carbon dioxide) by face mask instead of using the paper bag. Oral and intravenous carbonic anhydrase inhibitors (500 mg Diamox or acetazolamide) will reduce intraocular pressure and decrease ophthalmic arterial vascular resistance to forward flow. Intravenous mannitol (1 g/kg of a 20% solution) may cause intraocular fluid to exit the eye and decrease intraocular pressure. Hyperbaric oxygenation treatment can compensate to prevent retinal hypoxemia and ischemia in some cases while awaiting the restoration of arterial flow.3 Intra-arterial fibrinolysis with urokinase or recombinant tissue plasminogen activator (rTPA) can be successful in improving vision and shows promise.1,5

Digital globe massage can be performed in cases of CRAO where medical management is contraindicated or not successful. It can also be performed simultaneously with medical management. Treat the patient if they present to the Emergency Department within 24 hours of symptom onset.7 It should be performed ideally within 90 minutes of the CRAO.

Digital globe massage is contraindicated if the patient has had ocular surgery. Consult an Ophthalmologist in these cases before performing the procedure. Digital globe massage is contraindicated if there is the possibility of a perforated globe. There are otherwise no contraindications to digital globe massage in a nontraumatic CRAO.

No special equipment is required to perform a digital globe massage.

Perform a fundoscopic examination and visual acuity testing. Document these results in the medical record. Explain the procedure, its risks, and benefits to the patient and/or their representative. This potentially vision-saving procedure should not be delayed. Verbal consent is adequate and the conversation documented in the medical record. Place the patient supine or in a reclining position.

Stand next to the patient's torso and facing them. Instruct the patient to tightly close the eyelids of the affected eye. Place the dominant thumb over the patient's eyelids. Apply firm and steady pressure with the thumb for approximately 5 seconds. Abruptly release pressure by quickly lifting the thumb of the eyelids. Repeat the procedure several more times.2

Immediately perform a repeat fundoscopic examination and visual acuity testing. Document and compare these to the preprocedural evaluations. It should be noted that the fundoscopic examination may show improvement while the visual acuity has changed very little or not at all. Depending on the ischemic time, visual acuity may never improve. Repeat the digital globe massage if there is little or no improvement in the fundoscopic examination. If significant improvement is noted, the procedure may be repeated in the hope of further improvement.

All patients must be evaluated by an Ophthalmologist in the Emergency Department. If one is not available, consider transferring the patient to another facility to be evaluated by an Ophthalmologist. These patients require inpatient admission for further evaluation and management.

Patients with a CRAO usually have significant comorbidities such as hypertension, atherosclerosis, or diabetes. These patients are at risk for additional morbidity and require prompt medical referral to determine the etiology of the CRAO. Medical testing should include blood pressure evaluation, electrocardiography, echocardiography, blood glucose management, lipid and cholesterol testing, and hyperviscosity studies. Any irregularities or abnormal studies will require further evaluation. Patients over the age of 60 need an immediate erythrocyte sedimentation rate (ESR) test in consideration of the possibility of giant cell arteritis.

If properly performed, digital globe massage has few immediate complications. Over vigorous digital globe massage can result in a lens dislocation or a ruptured globe.4 Mechanical trauma can result in injury to the cornea, retinal detachments, and intraocular hemorrhage (e.g., hyphema and intravitreal hemorrhage).

A central retinal artery occlusion is a true ophthalmologic emergency. The patient will present with sudden, painless, and unilateral loss of vision. Immediate management is required in an attempt to restore the patient's vision. This includes medical management, anterior chamber paracentesis, and digital globe massage. These techniques attempt to reduce intraocular pressure or break up the embolus in order to allow the embolus to move downstream and restore at least partial blood flow to the retina. Despite these interventions, the patient's vision may not recover.