Predictive value of computed tomography in visual outcome in indirect traumatic optic neuropathy complicated with periorbital facial bone fracture

The Association Between Craniofacial Fracture Patterns and Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) is a rare but potentially devastating complication of craniofacial trauma. Approximately half of patients with TON sustain permanent vision loss. In this study, we sought to identify the most common fracture patterns associated with TON. We performed a retrospective review of craniomaxillofacial CT scans of trauma patients who presented to the R Adams Cowley Shock Trauma Center from 2015 to 2017. Included were adult patients who had orbital fractures with or without other facial fractures. Patients diagnosed with TON by a formal ophthalmologic examination were analyzed. Craniofacial fracture patterns were identified. Bivariate analysis and multivariate logistic regression were performed to identify craniofacial fracture patterns most commonly associated with TON. A total of 574 patients with orbital fractures who met inclusion criteria [15 (2.6%)] were diagnosed with TON. The median [interquartile range (IQR)] age was 44 (28-59) years. Patients with optic canal fractures and sphenoid sinus fractures had greater odds of TON compared with patients who did not have these fracture types [adjusted odds ratio (aOR) 95% confidence interval (CI) 31.8 (2.6->100), 8.1 (2.7-24.4), respectively]. Patients who sustain optic canal and sphenoid sinus fractures in the setting of blunt facial trauma are at increased odds of having a TON. Surgeons and other physicians involved in the care of these patients should be aware of this association.

Factors predictive of poor visual outcome in indirect traumatic optic neuropathy: A retrospective cohort study

INTRODUCTION

The gold standard treatment for indirect traumatic optic neuropathy (ITON) has not yet been conclusively established, and it is essential to gain an understanding of visual prognosis and to counsel patients regarding the predictive risk factors of poor visual outcomes. Currently, there is limited information regarding ITON in Thai populations; therefore, this study aimed to determine the risk factors of poor visual outcome in patients with this condition.

METHODS

A retrospective review was conducted of all ITON cases diagnosed at Rajavithi Hospital and Sawanpracharak Hospital between January 2016 and December 2022 in order to determine clinical characteristics and evaluate associated risk factors of poor visual prognosis using binary logistic regression analysis.

RESULTS

The mean age of this cohort of 101 patients was 36.17 years, with a male predominance of 73.3 %. Motor vehicle accidents were the most common cause of ITON, with a statistically significant 79.2 % of cases. The patients were categorized into an "improved group" of 29 patients and an "unimproved group" of 72. The unimproved group had a significantly older mean age and poorer initial visual acuity of 20/200 (p-values 0.001 and p < 0.001 respectively). There was no significant difference between Computed Tomography (CT) findings in the two groups. The improved group had significantly better visual acuity (VA) at 1-month and final follow-up visit than the unimproved group (both p < 0.001). Differences between gender, Glasgow coma score, associated underlying diseases, and duration from trauma to intravenous glucocorticoids therapy in the two groups were not statistically significant. Multivariable logistic regression analysis identified patient age of 40 years or more (Odds ratio (OR) 3.447, 95 % CI, 1.085-10.955, p = 0.036) and poor baseline VA (OR 6.628, 95 % Confidence Interval (CI), 2.308-19.036, p < 0.001) as significant risk factors for poor visual outcome in ITON patients.

CONCLUSIONS

No clear benefit was found of intravenous glucocorticoids in treatment of ITON. Patients aged 40 years or more and/or with poor baseline visual status should be advised that they are at increased risk of poor final visual outcomes.

Traumatic Optic Neuropathy: Update on Management

Traumatic optic neuropathy is one of the causes of visual loss caused by blunt or penetrating head trauma and is classified as both direct and indirect. Clinical history and examination findings usually allow for the diagnosis of traumatic optic neuropathy. There is still controversy surrounding the management of traumatic optic neuropathy; some physicians advocate observation alone, while others recommend steroid therapy, surgery, or both. In this entry, we tried to highlight traumatic optic neuropathy's main pathophysiologic mechanisms with the most available updated treatment. Recent research suggests future therapies that may be helpful in traumatic optic neuropathy cases.

Prognosticators of Visual Acuity After Indirect Traumatic Optic Neuropathy

BACKGROUND

The purpose of this study is to determine whether there are radiographic and systemic clinical characteristics that can predict final visual outcomes in patients with indirect traumatic optic neuropathy (iTON).

METHODS

This study is a retrospective, multicenter case series of adult patients with iTON treated initially at large, urban, and/or academic trauma centers with follow-up at an affiliated ophthalmology clinic. In addition to detailed cranial computed tomography characteristics, demographics, systemic comorbidities, coinjuries, blood products administered, and intracranial pressure, along with other factors, were gathered. LogMAR visual acuity (VA) at the initial presentation to the hospital and up to 12 months follow-up was collected.

RESULTS

Twenty patients met inclusion criteria; 16 (80%) were men with a mean age of 40.9 years (±20.9). Mean initial VA was 1.61 logMAR (∼20/800, ± 0.95), and final VA was 1.31 logMAR (∼20/400, ± 1.06). Three patients (4 eyes) had no light perception (NLP) VA at presentation and remained NLP at final follow-up. Of the predictors analyzed, only the initial VA was found to be a significant predictor of visual outcome. The presence of orbital fractures, intraconal and/or extraconal hemorrhage, as well as systemic comorbidities, were not found to significantly affect visual outcome.

CONCLUSIONS

After evaluating multiple factors, initial VA was the only factor associated with visual prognosis in iTON. This knowledge may better enable clinicians to predict visual prognosis and set reasonable expectations with patients and families at the time of injury.

Visual outcome of endogenous endophthalmitis in Thailand

To evaluate a 10-year visual outcome of endogenous endophthalmitis (EE) patients. A 10-year retrospective chart review of EE patients. Thirty-eight patients (40 eyes) were diagnosed with EE at the mean age of 42. Among the identifiable pathogens (71.1% culture positive), the causative agents were predominantly gram-negative bacteria (48.1%). The most common specie was Klebsiella pneumoniae (25.9%). About a quarter of the patients required surgical eye removal, and the remaining 45.7% had visual acuity (VA) worse than hand motion at one month after the infectious episode. The most common complication was ocular hypertension (52.5%). Poor initial VA was significantly associated with a worse visual outcome in the early post-treatment period (p 0.12, adjusted OR 10.20, 95% CI 1.65–62.96). Five patients continued to visit the clinic for at least ten years. One patient had gained his vision from hand motion to 6/7.5. Two patients had visual deterioration, one from corneal decompensation, and the other from chronic retinal re-detachment. Two patients developed phthisis bulbi, with either some VA perception of light or no light perception. Poor initial VA is the only prognostic factor of a poor early post-treatment visual outcome of EE.

Surgical Treatment and Visual Outcomes of Adult Orbital Roof Fractures

BACKGROUND

Fractures of the orbital roof require high-energy trauma and have been linked to high rates of neurologic and ocular complications. However, there is a paucity of literature exploring the association between injury, management, and visual prognosis.

METHODS

The authors performed a 3-year retrospective review of orbital roof fracture admissions to a Level I trauma center. Fracture displacement, comminution, and frontobasal type were ascertained from computed tomographic images. Pretreatment characteristics of operative orbital roof fractures were compared to those of nonoperative fractures. Risk factors for ophthalmologic complications were assessed using univariable/multivariable regression analyses.

RESULTS

In total, 225 patients fulfilled the inclusion criteria. Fractures were most commonly nondisplaced [n = 118 (52.4 percent)] and/or of type II frontobasal pattern (linear vault involving) [n = 100 (48.5 percent)]. Eight patients underwent open reduction and internal fixation of their orbital roof fractures (14.0 percent of displaced fractures). All repairs took place within 10 days from injury. Traumatic optic neuropathy [n = 19 (12.3 percent)] and retrobulbar hematoma [n = 11 (7.1 percent)] were the most common ophthalmologic complications, and led to long-term visual impairment in 51.6 percent of cases.

CONCLUSIONS

Most orbital roof fractures can be managed conservatively, with no patients in this cohort incurring long-term fracture-related complications or returning for secondary treatment. Early fracture treatment is safe and may be beneficial in patients with vertical dysmotility, globe malposition, and/or a defect surface area larger than 4 cm2. Ophthalmologic prognosis is generally favorable; however, traumatic optic neuropathy is major cause of worse visual outcome in this population.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

A Systematic Literature Review on Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) is an uncommon vision-threatening disorder that can be caused by ocular or head trauma and is categorized into direct and indirect TON. The overall incidence of TON is 0.7-2.5%, and indirect TON has a higher prevalence than direct TON. Detection of an afferent pupillary defect in the presence of an intact globe in a patient with ocular or head trauma with decreased visual acuity strongly suggests TON. However, afferent pupillary defects may be difficult to detect in patients who have received narcotics that cause pupillary constriction and in those with bilateral TON. Mechanical shearing of the optic nerve axons and contusion necrosis due to immediate ischemia from damage to the optic nerve microcirculation and apoptosis of neurons is a probable mechanism. The proper management of TON is controversial. High-dose corticosteroid therapy and decompression of the optic nerve provide no additional benefit over observation alone. Intravenous erythropoietin may be a safe and efficient treatment for patients with TON.

The Biomechanics of Indirect Traumatic Optic Neuropathy Using a Computational Head Model With a Biofidelic Orbit

Indirect traumatic optic neuropathy (ITON) is an injury to the optic nerve due to head trauma and usually results in partial or complete loss of vision. In order to advance a mechanistic understanding of the injury to the optic nerve, we developed a head model with a biofidelic orbit. Head impacts were simulated under controlled conditions of impactor velocity. The locations of impact were varied to include frontal, lateral, and posterior parts of the head. Impact studies were conducted using two types of impactors that differed in their rigidity relative to the skull. The simulated results from both the impactors suggest that forehead impacts are those to which the optic nerve is most vulnerable. The mode and location of optic nerve injury is significantly different between the impacting conditions. Simulated results using a relatively rigid impactor (metal cylinder) suggest optic nerve injury initiates at the location of the intracranial end of the optic canal and spreads to the regions of the optic nerve in the vicinity of the optic canal. In this case, the deformation of the skull at the optic canal, resulting in deformation of the optic nerve, was the primary mode of injury. On the other hand, simulated results using a relatively compliant impactor (soccer ball) suggest that primary mode of injury comes from the brain tugging upon the optic nerve (from where it is affixed to the intracranial end of the optic canal) during coup countercoup motion of the brain. This study represents the first published effort to employ a biofidelic simulation of the full length of the optic nerve in which the orbit is integrated within the whole head.

Prognostic factors of trans-ethmosphenoid optic canal decompression for indirect traumatic optic neuropathy

AIM

To investigate a possible correlation between visual acuity (VA) prognosis and the presence at baseline of various orbital and ocular signs in patients affected by indirect traumatic optic neuropathy (ITON).

METHODS

From July 1^st, 2012 to July 1^st, 2015, 224 adults diagnosed with ITON who underwent endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) were reviewed. Visual outcome before and after treatment were taken into comparison.

RESULTS

Accompanied older in age, longer time to medical treatment and existence of optic canal fracture (OCF) were the independent predictors for poor postoperative VA and lower improvement degree of visual acuity (IDVA), while worse preoperative VA was predictive factor for poor postoperative VA only. Mean value of IDVA in patients with OCF was 0.19±0.30. Mean value of IDVA in patients without OCF was 0.29±0.35. IDVA in cases without OCF was significant higher than those with OCF (t=2.272, P<0.05).

CONCLUSION

Patients suffered from ITON without OCF before ETOCD have better surgical outcome than those with OCF. Older in age, longer time to medical treatment and existence of OCF are independent factors for poor VA prognosis and lower IDVA. Preoperative VA is independent factor for VA prognosis only.

Outcome of endoscopic trans-ethmosphenoid optic canal decompression for indirect traumatic optic neuropathy in children

Background

To evaluate the safety and outcomes of endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) for children with indirect traumatic optic neuropathy (ITON).

Methods

From July 1st, 2008 to July 1st, 2015, 62 children diagnosed with ITON who underwent ETOCD were reviewed. Main outcome measure was improvement in visual acuity after treatment.

Results

Altogether 62 children (62 eyes) with a mean age of 11.26 ± 4.14 years were included. Thirty-three (53.2%) of them had residual vision before surgery while 29 (46.8%) had no light perception (NLP). The overall visual acuity improvement rate after surgery was 54.84%. The improvement rate of patients with residual vision (69.70%) was significant higher than that of patients with no light perception (NLP) (37.9%) (P = 0.012). However, no significant difference was shown among patients with different residual vision (P = 0.630). Presence of orbital and/ or optic canal fracture and hemorrhage within the post-ethmoid and/or sphenoid sinus resulted in poor postoperative visual acuity, duration of presenting complaints did not affect final visual acuity or did not effect outcomes. Intervention performed in children presenting even after 7 days from the injury did not influence the final visual outcome. Three patients developed cerebrospinal fluid rhinorrhea and one encountered cavernous sinus hemorrhage during surgery. No other severe complications were observed.

Conclusion

Children with residual vision had better postoperative visual prognosis and benefited more from ETOCD than children with NLP. Intervention performed in children presenting even after 7 days from the injury did not influence the final visual outcome, however, this needs to be reassessed in children presenting long after the injury.Treatment should still be recommended even for cases of delayed presentation to hospital.

Facial Fracture Patterns Associated with Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) is rare. The heterogeneity of injury patterns and patient condition on presentation makes diagnosis difficult. Fracture patterns associated with TON have never been evaluated. Retrospective review of 42 patients diagnosed with TON at the R. Adams Cowley Shock Trauma Center from May 1998 to August 2010 was performed. Thirty-three patients met criteria for study inclusion of fracture patterns. Additional variables measured included patient demographics and mechanism. Cluster analysis was used to form homogenous groups of patients based on different fracture patterns. Fracture frequency was analyzed by group and study population. Visual depiction of fracture patterns was created for each group. Cluster analysis of fracture patterns yielded five common "groups" or fracture patterns among the study population. Group 1 ( n  = 3, 9%) revealed contralateral lateral orbital wall (100%), zygoma (67%), and nasal bone (67%) fractures. Group 2 ( n  = 7, 21%) demonstrated fractures of the frontal bone (86%), nasal bones (71%), and ipsilateral orbital roof (57%). Group 3 ( n  = 14, 43%) involved fractures of the ipsilateral zygoma (100%), lateral orbital wall (29%), as well as frontal and nasal bones (21% each). Group 4 ( n  = 5, 15%) consisted of mid- and upper-face fractures; 100% fractured the ipsilateral orbital floor, medial and lateral walls, maxilla, and zygoma; 80% fractured the orbital roof and bilateral zygoma. Group 5 ( n  = 4, 12%) was characterized by fractures of the ipsilateral orbital floor, medial and lateral orbital walls (75% each), and orbital roof (50%). A notably high 15 of 33 patients (45%) sustained penetrating trauma. Our study demonstrates five fracture pattern groups associated with TON. Zygomatic, frontal, nasal, and orbital fractures were the most common. Fractures with a combination of frontal, nasal, and orbital fractures are particularly concerning and warrant close attention to the eye.

Risk factors affecting the visual outcome in patients with indirect traumatic optic neuropathy

PURPOSE

To evaluate the etiology and possible prognostic factors affecting the visual outcome in patients with indirect traumatic optic neuropathy (TON).

METHODS

The records of patients with indirect TON were reviewed and compared the results of treatment with high doses of corticosteroids (Group 1) and simple observation without treatment (Group 2).

RESULTS

The mean age at the time of injury was 34.7 ± 11.4 (18-58) years in Group 1 and 37.5 ± 17.7 (8-73) years in Group 2 (p = 0.513). The mean value for the first referral of the patient to the ophthalmology clinic following trauma was 2.4 ± 2.4 (1-10) days in Group 1 and 16.7 ± 13.9 (1-30) days in Group 2 (p = 0.004). The most common causes of trauma were road traffic collision (57.1 and 68%) in the Group 1 and 2, respectively (p = 0.606). The mean initial visual acuity was 0.03 ± 0.07 (0.00-0.30) in Group 1 and 0.17 ± 0.21 (0.00-0.80) decimal in Group 2 patients (p = 0.001). The mean visual acuity at the final follow-up was 0.21 ± 0.35 (0.00-1.00) and 0.46 ± 0.42 (0.00-1.00) in Group 1 and Group 2, respectively, indicating better initial and final visual acuity values in Group 2 (p = 0.022), and also a statistically significant recovery of visual acuity between initial and final values in both groups (p < 0.05). The most important determinant of the final visual acuity was initial visual acuity (p < 0.001; 95.0% CI: 0.792-2.096).

CONCLUSIONS

Our study demonstrated that road traffic collision is the leading cause of indirect traumatic optic neuropathy, and the best predictor of final visual acuity outcome is the initial visual acuity.

Treatment Outcomes following Traumatic Optic Neuropathy

BACKGROUND

Traumatic optic neuropathy is characterized by sudden loss of vision following facial trauma leading to variable visual deficits. The purpose of this study was to evaluate recent institutional trends in the treatment of traumatic optic neuropathy, evaluate the outcomes of different treatment strategies, and identify factors associated with improved vision.

METHODS

Institutional review board approval was obtained to retrospectively review patients diagnosed with traumatic optic neuropathy at a high-volume trauma center from 2004 to 2012. Pretreatment and posttreatment visual acuity was compared using quantitative analysis of standard ophthalmologic conversion.

RESULTS

A total of 109 patients met inclusion criteria (74.3 percent male patients), with a mean age of 38.0 ± 17.5 years (range, 8 to 82 years). Management of traumatic optic neuropathy involved intravenous corticosteroids alone in 8.3 percent of patients (n = 9), 56.9 percent (n = 62) underwent observation, 28.4 percent (n = 31) had surgical intervention, and 6.4 percent (n = 7) underwent surgery and corticosteroid administration. Only 19.3 percent of patients returned for follow-up. Vision improved in 47.6 percent of patients, with a mean follow-up of 12.9 weeks. Patients younger than 50 years had a trend toward higher rates of visual improvement, 60 percent versus 16.7 percent (p = 0.15).

CONCLUSIONS

The majority of traumatic optic neuropathy patients are unlikely to return for a follow-up examination. Optic nerve decompression has fallen out of favor in the authors' institution, and observation is the most common management strategy. Outcomes following corticosteroid administration and observation are comparable.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Indirect traumatic optic neuropathy

Indirect traumatic optic neuropathy (ITON) refers to optic nerve injury resulting from impact remote to the optic nerve. The mechanism of injury is not understood, and there are no confirmed protocols for prevention, mitigation or treatment. Most data concerning this condition comes from case series of civilian patients suffering blunt injury, such as from sports- or motor vehicle-related concussion, rather than military-related ballistic or blast damage. Research in this field will likely require the development of robust databases to identify patients with ITON and follow related outcomes, in addition to both in-vivo animal and virtual human models to study the mechanisms of damage and potential therapies.

Orbit fractures: Identifying patient factors indicating high risk for ocular and periocular injury

OBJECTIVES/HYPOTHESIS

Maxillofacial trauma frequently involves the bony orbit that surrounds the ocular globe. Concomitant globe injury is a concern whenever orbit trauma occurs and in severe cases can occasionally result in vision loss. The mechanism of injury, physical exam findings, and radiographic imaging can provide useful information concerning the severity of the injury and concerns for vision loss. Using these three tools, it is hypothesized that the patient's history, physical exam, and radiographic findings can identify high-risk maxillofacial trauma patients with concomitant ocular injury. Identification of high risk patients who require comprehensive ophthalmologic evaluation may alter management and possibly preserve or restore vision.

STUDY DESIGN

A retrospective clinical chart review was performed at a tertiary academic medical center.

METHODS

Subjects were identified using the institutional trauma registry. Data collected included subject demographics, patient medical records and notes, ophthalmologic testing, and radiographic imaging. The incidence of orbit fracture and concomitant ocular injury associated with the mechanism of injury, physical exam findings, and radiographic imaging was determined. Statistical analysis was performed using a chi-square and Fisher exact test.

RESULTS

In this study, 279 subjects with orbit fractures were identified and the incidence of concomitant ocular injury was 27.6% (77 of 279). Mechanism of injury was statistically associated with an increased risk of ocular injury (P = 0.0340), with penetrating trauma being the most likely etiology. The physical exam findings of visual acuity and an afferent pupillary defect were statistically associated with ocular injury (P = 0.0029 and 0.0001, respectively). Depth of orbit fracture on radiographic imaging was statistically associated with ocular injury (P = 0.0024), with fractures extending to the posterior third of the orbit being most likely to have associated ocular injury.

CONCLUSION

Maxillofacial trauma patients with orbit fractures and concomitant ocular injury occur in more than one in four patients. Comprehensive ophthalmologic evaluation is recommended for all patients who sustain an orbit fracture. Subjects with a penetrating trauma mechanism of injury, physical exam findings of visual acuity deficits and an afferent pupillary defect, and radiographic imaging demonstrating fracture depth involvement of the posterior orbit are at highest risk for vision loss and warrant specific concern for ocular injury assessment.

LEVEL OF EVIDENCE

IV.

Traumatic optic neuropathy: facial CT findings affecting visual acuity

The purpose of this study was to determine the relationship between admission visual acuity (VA) and facial computed tomographic (CT) findings of traumatic optic neuropathy (TON). We retrospectively evaluated CT findings in 44 patients with TON. Mid-facial fractures, extraconal and intraconal hematomas, hematomas along the optic nerve and the posterior globe, optic canal fracture, nerve impingement by optic canal fracture fragment, and extraconal and intraconal emphysema were evaluated. CT variables of patients with and without available VA were compared. VA was converted into logarithm of the minimum angle of resolution (logMAR) to provide a numeric scale for the purpose of statistical analysis. The risk factors related to poor VA on univariate analysis were as follows: intraconal hematoma [median logMAR -4.7 versus -1.15, p = 0.016] and hematoma along the optic nerve [median -4.7 versus -1.3, p = 0.029]. Intraconal hematoma was the best predictor of poor VA (coefficient, 1.01; SE, 0.34; and p = 0.008). Receiver operating characteristic (ROC) curve analysis showed that the presence of intraconal hematoma and hematoma along the optic nerve predicted poor VA (logMAR of -3.7 or lower) with an area under the curve of 0.8 and 0.85, respectively. TON patients at higher risk of severe visual impairment may be identified based on admission facial CT.

Multidetector computed tomography of maxillofacial fractures: the key to high-impact radiological reporting

Maxillofacial fractures are very common. Recognizing patterns of facial fractures is helpful in assessing maxillofacial injury and accurately characterizing all fractures that may be present. Facial fractures are grouped into the following categories: nasal bone, naso-orbito-ethmoid, orbital, zygomatic, maxillary (including Le Fort-type fractures), mandibular, and frontal sinus fractures. Within each subgroup of facial fractures, there are key findings, whether of the fracture itself or of potential associated injuries, that are important factors in determining whether the patient is managed conservatively or with surgery. This article highlights the features of facial fractures that are the most important to the surgeons and provides a framework for effective radiological reporting.

Traumatology of the optic nerve and contribution of crystallins to axonal regeneration

Within a few decades, the repair of long neuronal pathways such as spinal cord tracts, the optic nerve or intracerebral tracts has gone from being strongly contested to being recognized as a potential clinical challenge. Cut axonal stumps within the optic nerve were originally thought to retract and become irreversibly necrotic within the injury zone. Optic nerve astrocytes were assumed to form a gliotic scar and remodelling of the extracellular matrix to result in a forbidden environment for re-growth of axons. Retrograde signals to the ganglion cell bodies were considered to prevent anabolism, thus also initiating apoptotic death and gliotic repair within the retina. However, increasing evidence suggests the reversibility of these regressive processes, as shown by the analysis of molecular events at the site of injury and within ganglion cells. We review optic nerve repair from the perspective of the proximal axon stump being a major player in determining the successful formation of a growth cone. The axonal stump and consequently the prospective growth cone, communicates with astrocytes, microglial cells and the extracellular matrix via a panoply of molecular tools. We initially highlight these aspects on the basis of recent data from numerous laboratories. Then, we examine the mechanisms by which an injury-induced growth cone can sense its surroundings within the area distal to the injury. Based on requirements for successful axonal elongation within the optic nerve, we explore the models employed to instigate successful growth cone formation by ganglion cell stimulation and optic nerve remodelling, which in turn accelerate growth. Ultimately, with regard to the proteomics of regenerating retinal tissue, we discuss the discovery of isoforms of crystallins, with crystallin beta-b2 (crybb2) being clearly upregulated in the regenerating retina. Crystallins are produced and used to promote the elongation of growth cones. In vivo and in vitro, crystallins beta and gamma additionally promote the growth of axons by enhancing the production of ciliary neurotrophic factor (CNTF), indicating that they also act on astrocytes to promote axonal regrowth synergistically. These are the first data showing that axonal regeneration is related to crybb2 movement within neurons and to additional stimulation of CNTF. We demonstrate that neuronal crystallins constitute a novel class of neurite-promoting factors that probably operate through an autocrine and paracrine mechanism and that they can be used in neurodegenerative diseases. Thus, the post-injury fate of neurons cannot be seen merely as inevitable but, instead, must be regarded as a challenge to shape conditions for initiating growth cone formation to repair the damaged optic nerve.

Predictive value of visual evoked potentials, relative afferent pupillary defect, and orbital fractures in patients with traumatic optic neuropathy

BACKGROUND

The purpose of this study was to determine the predictive value of flash visual-evoked potentials (VEP), relative afferent pupillary defect, and presence of orbital fractures in patients with traumatic optic neuropathy.

METHODS

A prospective study was conducted in 15 patients with indirect traumatic optic neuropathy. All patients underwent a thorough ophthalmic examination. Initial visual acuity, final visual acuity, and relative afferent pupillary defect were determined, and visual acuity was converted into logMAR units. We performed flash VEP and an orbital computed tomography scan in all patients.

RESULTS

There was a good correlation between relative afferent pupillary defect and final visual acuity (r = -0.83), and better initial visual acuity could predict better final visual acuity (r = 0.92). According to findings from flash VEP parameters, there was a relationship between final visual acuity and amplitude ratio of the wave (r = 0.59) and latency ratio of the wave (r = -0.61). Neither primary visual acuity nor final visual acuity was related to the presence of orbital fractures in the orbital CT scan.

CONCLUSION

Patients with traumatic optic neuropathy often present with severe vision loss. Flash VEP, poor initial visual acuity, and higher grade of relative afferent pupillary defect could predict final visual acuity in these patients. Presence of orbital fracture was not a predictive factor for primary visual acuity or final visual acuity.

Orbital Fracture: Significance of lateral wall

The lateral orbital wall is the strongest among other orbital walls. However, it is commonly fractured in the setting of severe facial trauma. The fracture usually occurs at the sphenozygomatic suture line. In general, patients with lateral wall fractures are commonly young male who may present with mid facial swelling and some degree of deformity. In some cases, lateral orbital wall fracture may be associated with visual loss or change in mental status due to associated intracranial injury. Imaging studies with computed tomography is important in the proper diagnosis and planning of the surgical intervention. Management of intracranial or eye injuries should be undertaken on emergent basis. Thereafter, significantly displaced lateral wall fractures need to be repaired on timely basis. Proper realignment of the plane of the lateral orbital wall at the sphenozygomatic suture along with the other complex articulations of the zygomatic bone is necessary for proper functional and aesthetic outcome.