The luxation of a globe results when the globe’s equator bulges out anteriorly past the eyelid aperture. The contraction of the orbicularis muscle further displaces the globe anteriorly, causing it to be trapped outside the eyelid aperture, which further limits spontaneous reduction and extraocular movement. 1–4 The most common risk factor associated with spontaneous globe luxation (SGL) is proptosis from having shallow orbits or space-invading retrobulbar lesions.3 Other reported predisposing factors linked with SGL are structural anomalies such as having relaxed supporting fascia, orbital septum, or laxed extraocular muscles.5,6 In one study, malar hypoplasia is reported as the most common predisposing factor for SGL.7 In malar hypoplasia, the apex of the cornea is often present anterior to the malar prominence predisposing anterior globe luxation. In 2002, Kunesh and Katz described exophthalmos secondary to Graves’ orbitopathy as the most common predisposing factor in globe luxation.1 Though infrequently reported, exophthalmos secondary to orbital fat hypertrophy is also noted as a predisposing factor in obese patients.7
SGL can be caused by non-traumatic eye manipulations, as in the case presented. It can also be caused by forceful Valsalva or eyelid maneuvering during contact lens insertion, as users push the eyelids past their natural threshold.1,3 In the case of voluntary globe luxation (VGL), participants initially experience SGL and later learn to sublux their globes without manipulation just by using their extraocular muscles.8,9 A small number of cases have also been reported of self-enucleation of the globe by “gouging” in patients with mental illness.10–13 Though rare, traumatic globe subluxation (TGS) occurs secondary to significant traumatic events that damage the orbit and push the globe anteriorly. In the ED, TGS may present following high energy motor vehicle accidents and can also be seen when someone grips the eyeballs during a fight, or secondary to birth trauma with compression of the cranium.14–22
The pathogenesis of SGL is not fully elucidated. However, different pathological processes and risk factors have been reported. Graves' ophthalmopathy is the most common cause of space-occupying disease leading to SGL. SGL has been linked with floppy eyelid syndrome (FES).2,5,13 FES is described as saggy eyelids accompanying punctate epithelial keratopathy, ptosis of lateral eyelashes, and characteristic conjunctival changes. Hashimoto’s disease2 and hyperemesis gravidarum, which causes shallow ocular space secondary to extraocular contusion (is contusion the right word?) and Valsalva pressure, are also linked to causing SGL.3 Other disease processes implicated to cause SGL include arteriovenous malformations, Engelmann’s disease, histiocytosis X, orbital tumors, and unusually large globes.3,23,24 In 2012, Kumar et al. reported the first case of SGL associated with chronic obstructive pulmonary disease.6 They hypothesized that the raised intrathoracic pressure and a subsequent increase in intraorbital pressure might have instigated the luxation. In 2015 Ortega-Evangelio et al. reported SGL secondary to iatrogenic Cushing syndrome.25 A case of globe luxation was also reported on a patient under otherwise uneventful general anesthesia. 26
The occurrence of globe luxation has been noted at higher frequency in African American individuals due to a higher likelihood of these populations having shallow orbits.3,26 Obesity is an important risk factor that causes exophthalmos and is also associated in with FES in patients.7,13,26 However, other reports have also shown that FES could occur in individuals with normal BMI.27 In the case presented, the patient was African American and obese. Additionally, the patient had a history of uncontrolled hypertension, another risk factor for FES.27 This patient had some etiologies that were felt to be more likely than others. It was hypothesized that the patient may have undiagnosed Grave’s disease given the bilateral proptosis seen on exam and CT. A revisiting of the CT imaging with a radiologist demonstrates dilated optic nerve sheaths, tortuosity of the optic nerve, and empty Sella, which are the most common imaging findings in a patient with idiopathic intracranial hypertension.28,29 In addition to these imaging findings, the patient’s body habitus, female gender, and presented visual disturbance make a high differential diagnosis of mild IIH. As far as we know, there has not been a reported case of IIH associated SGL. Other etiologies as a cause for SGL in our patient include undiagnosed FES, exophthalmos in the context of fat hypertrophy or another undiagnosed medical condition that could have predisposed her to SGL.
In addition to causing distress and severe anxiety, SGL poses numerous immediate as well as long-term complications. In this case, the patient had reported pain, photophobia, and blurry vision. Globe exposure may result in keratitis and blepharospasm. Traction of the optic nerve and retinal vasculature may potentially cause retinal venous congestion and loss of visual acuity with potential vision loss.1,3,9,13 Hence, timely reduction of the globe may help reduce the likelihood of optic nerve complications. There has been a case report of bilateral optic neuropathy linked with floppy eye syndrome and voluntary globe luxation.13 An additional report discusses SGL-induced optic neuropathy as a subsequent complication as well.30
Uncomplicated globe subluxation can be reduced relatively easily. Before any attempt to reduce the globe, an ocular exam including acuity, pupillary reflex, and extraocular movement at minimum is warranted. A successful globe reduction can be facilitated by encouraging the patient to relax. The use of anxiolytics, analgesics and topical ocular anesthetic agents further eases the reduction process.3 In the case presented, no anxiolytic, analgesic, or anesthetic agents were used before reduction, which could have helped the patient’s level of anxiety and pain. If the eyelids are retracted behind the displaced globe, advise the patient to look down before retracting the eyelids. Simultaneously, apply moderate and continuous pressure posteriorly and downward direction of the sclera.26,31 In the case presented, the patient’s eyelid was not retracted behind the subluxated globe, making the reduction easier. It is crucial to consider infiltrative diseases and orbital tumors in patients with SGL. If an attempt to reduce the globe fails, urgent ophthalmologist consultation is indicated.
Globe luxation can also be managed surgically by performing lateral tarsorrhaphy. However, this procedure has been reported to predispose subsequent luxation because it creates a tighter orbit and elevated intraorbital pressure. Furthermore, if subluxation reoccurs, the reduced palpebral aperture will make performing another reduction very challenging.24 An alternative surgical procedure is orbital decompression. Lumbreras-Fernández et al. reported the superiority of orbital decompression to tarsorrhaphy in managing patients with SGL and exophthalmos.7 Luckily, most cases of SGL require no surgical intervention.
Following the reduction of the globe, treating the underlying condition and advising patients to lose weight may help prevent future subluxation.3,7,25 If no reported risk factors or identifiable triggering medical or psychiatric illnesses present, orbital imaging or serological studies for thyroid ophthalmopathy should be considered. Post-reduction outpatient follow up with an ophthalmologist and primary care provider can aid uncover the underlying etiology and predisposing factors.
Globe subluxation generates anxiety, both to the patients and to unfamiliar providers in the ED. Mainly because, unsurprisingly, many ED nurses and doctors will not have treated it before. Globe subluxation is diagnosed clinically as the luxation is observable to the naked eye. Safeguarding visual function should be the primary target, and immediate diagnosis and action are essential to protecting patient vision. Hence, providers must familiarize themselves with the risk factors and associated disease processes. Knowledge of pre-reduction eye examination, globe reduction procedure, and post-reduction management are critical elements in SGL treatment and prevention of reoccurrence.