OBJECTIVETo establish an animal model of traumatic optic neuropathy (TON) that resemble to clinical state and study the mechanical principle and change of pathophysiology of its nerve injury for clinical diagnosis and treatment.

METHODSNew Zealand white rabbits were used as the research objects. The method introduced by Wang Yi was repeated and improved. Mild and severe animal models of TON were established by reformed Wang Yi operation separately. After the spring gun struck, all animals were observed on pupils and direct light reflex and received the examinations of pattern reversal visual evoked potentials (PR-VEP). The pathophysiology of normal and injury optic nerve was observed.

RESULTSAfter recovery from anesthesia, the mydriasis and disappearance or dullness of direct light reflex happened in all injured eyes. No brain contusion, infection, orbital fracture and death were found. One optic nerve was broken with complete tunica vaginalis. The latency and amplitude of injured eyes deteriorated gradually. In group B, the waves became flat rapidly. After injury, the optic nerve underwent 3 stages: edema, hyperplasia and atrophy. The pathomorphological changes of injured eyes in group B were more serious than that in group A in any time.

CONCLUSIONSThe reformed operation can establish constant nerve injury with high success rate. In mildly injured eyes, the injury deteriorated gradually. However, part visual function remained. In severely injured eyes, the pathomorphological changes were irreversible sooner after struck, and the visual function lost completely. There is a good correlation between PR-VEP and pathomorphology. PR-VEP can guide the clinical diagnosis and treatment.

Animals ; Evoked Potentials, Visual ; Male ; Models, Animal ; Optic Nerve ; physiopathology ; Optic Nerve Injuries ; physiopathology ; Rabbits

OBJECTIVETo establish the animal model of traumatic optic neuropathy similar to clinical feature by injuring the optic nerve of the pipeline through the ethmoid and sphenoid sinus. The electrophysiology and morphology were observed.

METHODSThe optic nerve in 2 cats was anatomically observed. Thirty healthy adult cats were divided into 1 h, 1 d, 3 d, 1 w, 2 w, 4 w injury groups. The right eye was selected as the experiment eye, and the left as the control. The optic canals were damaged by the injury instrument. The changes of optic nerve were observed using light and electron microscope. The pattern reversal visual evoked potential (PR-VEP) was used to determine the succeed model and pupil was monitored. PR-VEP and neural tissue morphology were examined at intervals of 1 h, 1 d, 3 d, 1 w, 2 w, 4 w after trauma.

RESULTSEight cats had Marcus-Gunn's pupil, and 22 cats did not have after injury. Neural tissue was physaliphorous degeneration in light microscope. The neural fibers swelled gradually and fibers physaliphorous degeneration in the first day after damage. At the seventh day, the bubble enlarged to be a big flat. After two weeks, the big flat bubble came out to be a bigger bubble. Under the electronic microscope, axons were physaliphorous degeneration, crack emerged between axon membrane and myelin sheath and myelin sheath were loose in the first day. At the third day, axon swelled, physaliphorous degeneration rose and myelin sheath were loose obviously. At the seventh day, axon and myelin sheath appeared loop in half cycle and bubble-like broke up. A lot of pieces came out and axon became physaliphorous and uniform. Microtubule and microfilament disappeared. After two weeks, myelin sheath became onion-like. On fourth week, myelin sheaths enlarged and squeezed to center. Axoplasm disappeared and neural tissues collapsed.

CONCLUSIONSThis animal model was similar to clinical optic nerve decompression through ethmoid and sphenoid sinus. The change of PR-VEP and neuromorphology were distinct before and after trauma. The pathological changes of optic nerve catching vibrated injury are mainly degeneration, so earlier decompression of optic nerve may improve the visual function.

Animals ; Cats ; Disease Models, Animal ; Evoked Potentials, Visual ; Optic Nerve ; pathology ; physiopathology ; Optic Nerve Injuries ; pathology ; physiopathology

PURPOSE: To investigate the clinical manifestations and diagnoses of optic disc swelling. METHODS: The medical records of 49 patients who experienced optic disc swelling between March 2008 and June 2009 were retrospectively reviewed. The characteristics of non-arteritic anterior ischemic optic neuropathy (NA-AION) and optic neuritis (ON), which showed optic disc swelling most commonly, were compared. RESULTS: NA-AION was the most common disorder (34.7%) that presented with optic disc swelling. ON was identified in 15 patients (30.6%). Seven out of 49 patients (14.3%) had intracranially associated diseases, such as papilledema and compressive optic neuropathy. Pseudopapilledema was noted in four patients (8.2%). Other diseases (e.g., papillophlebitis, neuroretinitis, and diabetic papillopathy) were seen in six patients (12.2%). Ocular pain was observed more commonly in patients with ON (p = 0.001). Patients with ON expected a better visual prognosis than patients with NA-AION (0.12 +/- 0.32 vs. 0.49 +/- 0.35, p = 0.001). CONCLUSIONS: NA-AION and ON should be considered in the differential diagnosis when patients with optic disc swelling present to the neuro-ophthalmology clinic. Detailed history taking and supportive examinations, such as visual field, color-vision and imaging tests, should also be performed as indicated. Regular follow-up of such exams is necessary for the differential diagnosis of these diseases.
Adult ; Female ; Humans ; Male ; Middle Aged ; Optic Nerve Diseases/complications/etiology ; Optic Neuritis/complications/physiopathology ; Optic Neuropathy, Ischemic/complications/physiopathology ; Papilledema/*etiology ; Retrospective Studies ; Visual Fields

BACKGROUNDIndirect traumatic optic neuropathy (TON) is an acute injury of the optic nerve associated with severe visual dysfunction, which may be a result of secondary mechanical injury and vascular disorder of the optic nerve due to trauma. We analyzed the natural course of axonal loss and blood flow disturbances in patients with indirect TON to find a possible therapeutic window.

METHODSA cohort of 54 patients with indirect TON recruited between October 2008 and October 2010 at Beijing Tongren Hospital was retrospectively analyzed. The patients were divided into no light perception group (NLP) and better than NLP (btNLP) group. Specifically, the thickness of the retinal nerve fiber layer (RNFL) measured by spectral domain optical coherence tomography (SD-OCT), and hemodynamic parameters of the ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary artery (PCA) were determined.

RESULTSTwo weeks after injury, there was a statistically significant decrease in the thickness of RNFL in the btNLP group as compared with the fellow control eyes (P < 0.05). In contrast, in the NLP group, RNFL thickness slightly increased for 2 weeks following injury, then overtly reduced after 4 weeks (P < 0.05). Peak systolic velocity (PSV) of CRA was significantly decreased 4 weeks after injury (P < 0.05) in both the NLP group and btNLP group (P < 0.05). The thickness of RNFL in the NLP group was negatively correlated with PSV of CRA after 1 week of injury (P < 0.05, r = -0.962).

CONCLUSIONSSD-OCT is a useful supplement in detecting the axonal loss in TON. The dynamic change of the thickness of RNFL appears to correlate with the hemodynamic disturbances in the natural course of TON. The first 2 weeks following an injury is critical and should be considered as the therapeutic window for TON patients.

Adult ; Female ; Humans ; Male ; Middle Aged ; Nerve Fibers ; physiology ; Optic Nerve ; physiology ; Optic Nerve Injuries ; physiopathology ; Retinal Neurons ; physiology ; Retrospective Studies ; Tomography, Optical Coherence

OBJECTIVETo investigate the progression of visual field loss and to explore the prognosis of glaucomatous optic neuropathy in patients with chronic angle-closure glaucoma (CACG) after their intraocular pressures were well controlled under 21 mmHg.

METHODSForty-seven eyes of 29 patients in the Department of Ophthalmology in PUMC Hospital were included. All the patients had at least two separate tests of visual fields using the 24-2 program of the Humphery Visual Field Analyzer after their intraocular pressure were well controlled under 21 mmHg after sugery. The visual fields of patients were followed routinely for at least 1 year. In addition, all patients were divided into 2 groups according to follow-up period: 1-2 years group and over 2 years group. Visual field scores were calculated with the Advanced Glaucoma Intervention Study (AGIS) method. The visual fields were divided 5 sections and the sensitivity and defect depth of each section were calculated.

RESULTNo statistically significant differences were found in terms of AGIS scores, localized sensitivities and localized defects within the time interval of the observation.

CONCLUSIONGlaucomatous optic neuropathy is not likely to progressively deteriorate in CACG cases once their intraocular pressure are well controlled under 21 mmHg.

Aged ; Female ; Follow-Up Studies ; Glaucoma, Angle-Closure ; physiopathology ; surgery ; Humans ; Intraocular Pressure ; Male ; Middle Aged ; Optic Disk ; physiopathology ; Optic Nerve Diseases ; physiopathology ; Retrospective Studies ; Visual Fields

Acupuncture Therapy ; Adolescent ; Craniocerebral Trauma ; complications ; Humans ; Male ; Optic Nerve Injuries ; etiology ; physiopathology ; therapy ; Vision, Ocular

A 32-year-old man with blurred vision in the right eye and headache presented with anterior uveitis, an intraocular pressure (IOP) of 60 mmHg, an open angle, no visual field defects, and normal optic nerve. He had a history of five previous similar attacks. In each of the previous instances, his anterior uveitis and high IOP were controlled with antiglaucoma medications and topical steroids. However, at the fifth attack, his optic disc was pale and a superior paracentral visual field defect was shown. Brain magnetic resonance image studies were normal. This case represents that a recurrent Posner-Schlossman syndrome (PSS)-induced optic disc atrophy likely due to ocular ischemia caused by a recurrent, high IOP. Although PSS is a self-limiting syndrome, we should manage high IOP and prevent ischemia of the optic nerve head by treating with ocular antihypertensive medications.
Atrophy/diagnosis/etiology ; Diagnosis, Differential ; Glaucoma, Open-Angle/*complications/diagnosis/physiopathology ; Humans ; *Intraocular Pressure ; Male ; Optic Disk/*pathology ; Optic Nerve Diseases/diagnosis/*etiology/physiopathology ; Syndrome ; Young Adult

PURPOSE: We analyzed the effect of the changes of the optic disc area (ODA) caused by the axial length and the refractive error, and the consequent changes of the distance from the optic disc margin to the circular scan (OD-CS) of Optical coherence tomography (OCT) on the measurement of the retinal nerve fiber layer thickness(RNFLT) were examined. METHODS: One hundred two eyes of 51 children (age range 4 to 15 years) were measured using OCT including the RNFLT. For the ODA and the OD-CS, the relative area formed by the ODA and the circular scan was obtained. In addition, the correlation of the refractive error and the axial length to the optic disc factors was assessed. RESULTS: As hyperopia progresses to myopia, the axial length became longer, the ODA became smaller (r=-0.442, p=0.000) and the OD-CS showed a tendency to increase (r=0.471, p=0.000). As the OD-CS became longer, the measured average RNFLT decreased significantly (r=-0.248, p=0.012), and the ODA and the OD-CS showed a significant correlation to the RNFL thickness that was measured in the nasal and inferior areas, the S2, N2 and N3 areas and the I1 area. CONCLUSIONS: As ODA becomes smaller and the OD-CS becomes longer, the RNFLT measured in the nasal and inferior areas, the S2, N2, N3, I1 area has a tendency to be thinner. Hence, consideration of the disc area is required when interpreting the RNFLT of these eyes.
Adolescent ; Aging/physiology ; Child ; Child, Preschool ; Female ; Glaucoma/diagnosis ; Humans ; Male ; Nerve Fibers/*pathology ; Optic Disk/*pathology ; Optic Nerve Diseases/*physiopathology ; Refraction, Ocular ; Refractive Errors/*physiopathology ; Retinal Ganglion Cells/*pathology ; Tomography, Optical Coherence ; Visual Acuity

In order to study the underlying electrode-nerve functional mechanism, optimize the electrode design and guide the prosthesis application, we applied finite element method to analyze the spatial distribution of electric field generated by optic nerve electrical stimulation with spiral cuff electrode. A macroscopic cylindrical model of optic nerve was elaborated, taking into account of electrode contact configurations and possible variations of the thickness of cerebrospinal fluid (CSF). By building an appropriate mesh on this model and under some boundary conditions, the finite element method was applied to compute the 3D electric field generated by the electrode with finite element software COMSOL Multiphysics. The stimulation results indicated that, under the same conditions of stimulation, the longitudinal tripolar electrode structure could generate larger current density than that of biopolar electrode structure (located in the opposite of nerve trunk). However biopolar electrode structure requirs less leads, and is more easily implanted. By means of parametric sweep, the results suggest that, with the increase of the CSF thickness and a higher conductivity of CSF than those of other tissues, the distribution of electric field generated by electrodes is extended but scattered, and the diffuse current distribution makes nerve stimulation less effective.
Electric Stimulation ; Electrodes, Implanted ; Electromagnetic Fields ; Extracellular Space ; Finite Element Analysis ; Humans ; Optic Nerve ; cytology ; physiopathology ; Visual Prosthesis

PURPOSE: To compare the glaucomatous optic nerve damage in primary angle-closure glaucoma (PACG) with acute attack (acute PACG; AACG) and PACG without acute attack (chronic PACG; CACG). METHODS: The study subjects were 84 normal individuals, 130 AACG patients, and 86 CACG patients. Color optic disc photographs were evaluated for the presence or absence of 10 qualitative signs to differentiate between normal and glaucomatous optic discs. RESULTS: Abnormally shaped rim width (alteration of ISN'T rule), bared circumlinear vessel, vessel bayonetting, rim width narrower than the temporal sector, and zone beta (nasal and superotemporal sectors) were detected more frequently in the CACG group than in the AACG group (P< 0.05). The most accurate qualitative sign was abnormally shaped rim width in both groups. The specificity and sensitivity of abnormally shaped rim width were 71.4% and 60.8% for AACG, and 71.4% and 81.4% for CACG, respectively. CONCLUSIONS: The optic disc damage is greater in CACG than in AACG.
Optic Nerve/*pathology ; Middle Aged ; Male ; Intraocular Pressure ; Humans ; Glaucoma, Angle-Closure/*pathology/physiopathology ; Female ; Chronic Disease ; Aged ; Acute Disease