Steroids for traumatic optic neuropathy

Traumatic optic neuropathy: a review of current studies

Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.

Gun-related eye injuries: A primer

Gun-related eye injuries are relatively common in the context of gunshot wounds to the head and neck. Many of the fundamental principles of gunshot wound management apply to the care of these patients, but the complex anatomy and functional relationships of the periocular region do pose special challenges. We provide a focused primer for physicians seeking a more in-depth understanding of gun-related eye injuries and present 3 representative cases outlining the spectrum of pathology, provide a focused review of the relevant ballistics concepts, and discuss the management of injuries to the periocular soft tissues, orbital structures, and globe. We found that good cosmetic and functional results can often be achieved with appropriate early intervention, but visual prognosis may remain guarded despite optimal treatment.

Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) refers to optic nerve injury resulting from direct and indirect head and facial trauma. The pathogenesis of indirect TON has not been fully elucidated, and the management of TON remains controversial. In this review article, I review the recent literature regarding TON and discuss how to manage indirect TON.

Trauma of the midface

Fractures of the midface pose a serious medical problem as for their complexity, frequency and their socio-economic impact. Interdisciplinary approaches and up-to-date diagnostic and surgical techniques provide favorable results in the majority of cases though. Traffic accidents are the leading cause and male adults in their thirties are affected most often. Treatment algorithms for nasal bone fractures, maxillary and zygomatic fractures are widely agreed upon whereas trauma to the frontal sinus and the orbital apex are matter of current debate. Advances in endoscopic surgery and limitations of evidence based gain of knowledge are matters that are focused on in the corresponding chapter. As for the fractures of the frontal sinus a strong tendency towards minimized approaches can be seen. Obliteration and cranialization seem to decrease in numbers. Some critical remarks in terms of high dose methylprednisolone therapy for traumatic optic nerve injury seem to be appropriate. Intraoperative cone beam radiographs and preshaped titanium mesh implants for orbital reconstruction are new techniques and essential aspects in midface traumatology. Fractures of the anterior skull base with cerebrospinal fluid leaks show very promising results in endonasal endoscopic repair.

Paediatric orbital fractures: the importance of regular thorough eye assessment and appropriate referral

The paediatric orbital fracture should always raise alarm bells to all clinicians working in an emergency department. A delay or failure in diagnosis and appropriate referral can result in rapidly developing and profound complications. We present a boy of childhood age who sustained trauma to his eye during a bicycle injury. Acceptance of the referral was based on no eye signs; however, on examination in our unit the eye had reduction in visual acuity, no pupillary reaction, and ophthalmoplegia. CT scan suggested bone impinging on the globe and the child was rushed to theatre for removal of the bony fragment. Postoperatively no improvement was noted and a diagnosis of traumatic optic neuropathy was made. An overview of factors complicating paediatric orbital injuries, their associated "red flags", and appropriate referral are discussed in this short paper.

[Traumatic optic nerve neuropathy. Longterm results following microsurgical optic nerve decompression]

BACKGROUND

Traumatic optic nerve neuropathy (TON) is defined as injury to the optic nerve with subsequent vision loss due to head or craniocerebral trauma. The treatment of this disease is the subject of controversial discussions. The purpose of the present study was to investigate pre- and immediate postoperative visual acuity in patients with unilateral TON and to compare the results with the time interval between trauma and surgical intervention.

PATIENTS AND METHODS

A total of 20 patients with unilateral TON and considerable vision loss were examined. All were treated with high dose corticoids and underwent microsurgical optic nerve decompression. Visual acuity was determined pre- and postoperatively. In long-term follow-up visual acuity was determined 3 months postoperatively.

RESULTS

Postoperatively, nine patients (45%) achieved an improvement in visual acuity of more than 0.4, and another three patients (15%) an improvement of ≥0.2. At 3 months postoperatively another four patients achieved a further improvement of their visual acuity of >0.2. A decrease in visual acuity was not observed in any case, nor were major surgical complications.

CONCLUSIONS

Factors which predict good prognosis for vision recovery include a short time interval between trauma and intervention, edema, and/or hematoma of the optic nerve sheath. Factors which predict a worse prognosis are a fracture line directly through the nerve canal, a time period between trauma and intervention of more than 24 h, and initial complete amaurosis.

Traumatic optic neuropathy after maxillofacial trauma: a review of 8 cases

PURPOSE

To study the incidence and prognostic factors of traumatic optic neuropathy in maxillofacial trauma cases.

MATERIAL AND METHOD

Eight patients diagnosed with traumatic optic neuropathy among 354 cases of maxillofacial trauma treated from December 2008 through May 2011 were included in this retrospective study. Factors at the time of trauma, clinical findings, computed tomographic findings, and interventional modalities were studied for any improvement in vision.

RESULTS

Of 354 maxillofacial trauma cases, 8 cases (2.25%) were diagnosed with traumatic optic neuropathy. Patients' ages ranged from 21 to 60 years. The causes of trauma were road traffic accidents in 7 patients and surgery for zygomaticomaxillary complex (ZMC) fractures in 1 patient. All patients had ZMC fracture; 1 patient had Le Fort II, mandible condyle, and ramus fractures and 2 had associated cranial bone fracture. Six patients were administered steroid therapy; 1 patient showed improvement in visual acuity. Two patients underwent decompression by a lateral orbital approach; 1 patient showed an improvement in visual acuity. In 2 other patients, a spontaneous recovery was observed. Four of the 8 patients underwent open reduction and fixation of the maxillofacial fractures. Of the remaining patients, 1 patient had a nondisplaced ZMC fracture that was treated without surgical intervention and the other 3 patients refused any surgical intervention.

CONCLUSIONS

The present findings showed the occurrence of traumatic optic neuropathy in association with ZMC, Le Fort II, and cranial bone fractures. Additional risk factors such as a history of a loss of consciousness, injury to the superolateral orbital region, fracture of the optic canal, evidence of orbital hemorrhage, and evidence of blood within the posterior ethmoidal cells should be considered during the evaluation.

Steroids for traumatic optic neuropathy

BACKGROUND

Traumatic optic neuropathy (TON) is an important cause of severe visual loss following blunt or penetrating head trauma. Following the initial injury, optic nerve swelling within the optic nerve canal can result in secondary retinal ganglion cell loss. Optic nerve decompression with steroids or surgical interventions or both has therefore been advocated as a means of improving visual prognosis in TON.

OBJECTIVES

The aim of this review was to examine the effectiveness and safety of using steroids in TON.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 11), MEDLINE (January 1950 to November 2010), EMBASE (January 1980 to November 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (http://clinicaltrials.gov) and Web of Science Conference Proceedings Citation Index- Science (CPCI-S). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 23 November 2010. We also searched the reference lists of included studies, other reviews and book chapters on TON to find references to additional trials. The Science Citation Index was used to look for papers that cited the studies included in this review. We did not manually search any journals or conference proceedings. We contacted trial investigators and experts in the field to identify additional published and unpublished studies.

SELECTION CRITERIA

We planned to include only randomised controlled trials (RCTs) of TON in which any steroid regime, either on its own or in combination with surgical optic nerve decompression, was compared to surgery alone or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the titles and abstracts identified from the electronic searches.

MAIN RESULTS

We included one study that met our selection criteria; a double-masked, placebo-controlled, randomised trial of high dose intravenous steroids in patients with indirect TON diagnosed within seven days of the initial injury. A total of 31 eligible participants were randomised to receive either high dose intravenous steroids (n = 16) or placebo (n = 15), and they were all followed-up for three months. Mean final best corrected visual acuity (BCVA) was 1.78±1.23 Logarithm of the Minimum Angle of Resolution (LogMAR) in the placebo group, and 1.11±1.14 LogMAR in the steroid group. The mean difference in BCVA between the placebo and steroid groups was 0.67 LogMAR (95% confidence interval -1.54 to 0.20), and this difference was not statistically significant (P = 0.13). At three months follow-up, an improvement in BCVA of 0.40 LogMAR occurred in eight eyes (8/15, 53.3%) in the placebo group, and in 11 eyes (11/16, 68.8%) in the treatment group. This difference was not statistically significant (P = 0.38).

AUTHORS' CONCLUSIONS

There is a relatively high rate of spontaneous visual recovery in TON and there is no convincing data that steroids provide any additional visual benefit over observation alone. Recent evidence also suggests a possible detrimental effect of steroids in TON and further studies are urgently needed to clarify this important issue. Each case therefore needs to be assessed on an individual basis and proper informed consent is paramount.

Lack of protective effect of local administration of triamcinolone or systemic treatment with methylprednisolone against damages caused by optic nerve crush in rats

The purpose of the present study was to investigate the effects of administrations of triamcinolone acetonide and systemic methylprednisolone sodium succinate on optic nerves (ON) and retinal ganglion cells (RGC) in a rat model of optic nerve crush. The treated groups either received triamcinolone immediately in the form of two pieces of soaked-gelform surrounding retrobulbar optic nerves (0.5 mg/per gelform) or methylprednisolone via peritoneal injection, and control group received intra-peritoneal injection with phosphate-buffered saline (PBS) after crush experiments. RGC density was counted by retrograde labeling with Fluorogold, and visual function was assessed by flash visual-evoked potentials. Terminal transferase dUTP nick end-labeling (TUNEL) assays, Western blot analysis of serine/threonine kinase (p-Akt), extracellular signal-regulated kinases (p-ERK) and signal transducer and activator of transcription 3 (p-STAT3) and immunohistochemistry of ED1, marker of macrophage/microglia in the optic nerve were conducted. Two and four weeks after optic nerve crush experiments, neither triamcinolone nor methylprednisolone treatment rescued the RGC from death in the central and mid-peripheral retinas compared with those of the corresponding optic nerve-crushed and PBS-treated rats. Visual-evoked potentials measurements showed a prolonged latency of the P(1) wave in all treated groups (triamcinolone-treated: 123 ± 23 ms, methylprednisolone-treated: 133 ± 25 ms and PBS-treated: 151 ± 55 ms) after two weeks. TUNEL assays showed that there was no decrease in apoptotic cells in the RGC layers of both triamcinolone treated and methylprednisolone-treated retinas. Western blot analysis showed that p-AKT, p-ERK and p-Stat3 were not up-regulated in either retina of the triamcinolone or methylprednisolone treated rats. In addition, the number of ED1-positive cells was not attenuated at the lesion sites of the ON in either treatment group. Based upon these results, we conclude that neither retrobulbar administration of triamcinolone nor systemic administration of methylprednisolone has any neuroprotective effects in a rat model of optic nerve crush.

Optic nerve trauma with unilateral edema as a result of head injury

We encountered a patient who suffered a head injury that translated to the optic nerves, leading to dramatic unilateral right optic nerve edema. The decedent was a 20-year-old unsecured passenger in a convertible. The car collided with a pickup truck. The patient survived for 8 h. At autopsy, a comminuted skull fracture involving the right frontal bone including the right orbital plate was found. The right optic nerve measured 1.2 cm in diameter, compared to only 0.4 cm for the left optic nerve. Microscopically, the right optic nerve was markedly edematous, but the nerve fibers and nuclei were viable and intact. The dramatic difference in size between the right and left optic nerves can be attributed to several mechanisms. The survival interval was essential for the asymmetrical swelling to take place. Optic nerve trauma is relatively rare in head injuries, reported to be present in 0.5% of automobile accidents and assaults. Other causes of optic nerve trauma and edema include tumors, osteopetrosis, or reaction to a peripheral hemodialysis shunt.