Optic Nerve Head Swelling Research Articles

Bilateral multifocal inner retinitis following a viral illness, likely Covid-19.

To describe a young female patient who presented with unilateral vision loss with multiple bilateral inner retinal lesions after a non-specific viral illness, likely Covid -19. Case Report: We reviewed the medical record, examined the retina, OCT images and fundus fluorescein angiogram of the patient along with the relevant medical literature. The patient presented to our Emergency Department at Moorfields Eye Hospital with a two-week history of new onset floaters and blurred vision in her right eye. On examination she was found to have a low grade bilateral vitritis, mild right optic nerve head swelling and multiple white inner retinal lesions in both eyes. Retinitis can be due to multiple infectious and non-infectious aetiologies. In this case report we discuss a case of rare multifocal inner retinitis from a non-specific viral illness - likely COVID -19.

Sympathetic Ophthalmia in Paediatric Post-Surgical Repair, A Case Report

Introduction : Sympathetic Ophthalmia (SO) is a rare and devastating complication of ocular trauma. Incidence reached 0.26% among cohort in paediatric open globe injury. We present a case report of pediatric Sympathetic Ophthalmia.
 Case Illustration : An 8-year-old boy is present in an outpatient clinic with a history of corneal lacerating injury on LE 1 month ago and had surgical repair 7 days after the injury. The patient complained of redness and blurry vision in both eyes. VA RE 0.5 and LE 0.05. RE revealed ciliary injection, flare/cell (f/s) +2/+2, and vitreous cell +1. LE revealed ciliary injection, corneal scars, f/s +2/+2, and vitreous cell +2 (Fig. 1). Fundus and OCT revealed macular oedema with exudative retinal detachment RE and bilateral optic nerve head swelling (Fig. 2). Patient was diagnosed with sympathetic ophthalmia and treated with prednisolone acetate 8x per day for RLE with high-dose oral steroid methylprednisolone 1 mg/kg body weight (32 mg). One week after treatment, clinical findings were improved, and the steroid was tapered. After 2 months f/s, macular oedema, exudative retinal detachment and optic nerve head swelling were resolved with VA RE 1.0 and LE 0.4.
 Discussion : Although the etiology of SO is currently unknown, it is believed that hypersensitivity following trauma to the fellow eye may be the trigger. The severity of SO's clinical presentation might range from mild to severe.
 Conclusion : Sympathetic ophthalmia is a serious complication that rarely occurs after trauma, especially in the pediatric population. Prompt treatment of oral and topical corticosteroids may lower the inflammatory response.

A novel Finding in the Diagnosis of Primary Vitreoretinal Lymphoma: A Case Report.

Introduce a unique case of primary vitreoretinal lymphoma with a new optical coherence tomography finding. A case report. A 67-year-old healthy man with complaints of blurry vision in his right eye. The patient's visual acuity was 20/60 and 20/20 in the right and left eyes, respectively. Anterior segment exam of the right eye demonstrated mild inflammation. Dilated fundoscopy revealed 2+ vitreous haze and 4+ disc edema. Optical coherence tomography of the macula in the right eye revealed optic nerve head swelling and thickening of the retina. Fluorescein angiography demonstrated mild leakage and staining of vessels along the inferotemporal arcade in the right eye. Labs were within normal limits except positive Herpes simplex virus 1 IgG. Initially, the patient was treated for herpetic panuveitis for three weeks with a favorable response. However, the clinical condition deteriorated as a new abnormality was identified in the macular region of the right eye through optical coherence tomography. Considering intraocular lymphoma as a potential diagnosis, the patient underwent a diagnostic vitrectomy. The vitreous sample analysis confirmed PVRL through immunohistochemistry and flow cytometry. The patient exhibited a rapid response following the initiation of intravenous and intravitreal methotrexate treatment. The presence of subretinal fluid accompanied by suspended hyperreflective lesions originating from the roof of the subretinal fluid pocket on the OCT of macula "stalactite sign" might serve as a characteristic sign indicative of primary vitreoretinal lymphoma; however, further investigation using robust studies is necessary to examine this hypothesis.

High diagnostic accuracy of T2FLAIR at 3 T in the detection of optic nerve head edema in acute optic neuritis.

Optic nerve head edema (ONHE) detected by fundoscopy is observed in one-third of patients presenting optic neuritis (ON). While ONHE is an important semiological feature, the correlation between ONHE and optic nerve head MRI abnormalities (ONHMA), sometimes called "optic nerve head swelling," remains unknown. Our study aimed to assess the diagnostic accuracy of T2 fluid-attenuated inversion recovery (FLAIR) MRI sequence in detecting ONHE in patients with acute ON. In the present single-center study, data were extracted from two prospective cohort studies that consecutively included adults with a first episode of acute ON treated between 2015 and 2020. Two experienced readers blinded to study data independently analyzed imaging. A senior neuroradiologist resolved any discrepancies. The primary judgment criterion of ONHMA was assessed as optic nerve head high signal intensity on gadolinium-enhanced T2FLAIR MRI sequence. Its diagnostic accuracy was evaluated with both the gold standard of ONHE on fundus photography (FP) and peripapillary retinal nerve fiber layer thickening on optic coherence tomography (OCT). A total of 102 patients were included, providing 110 affected and 94 unaffected optic nerves. Agreement was high between the different modalities: 92% between MRI and FP (k= 0.77, 95% CI: 0.67-0.88) and 93% between MRI and OCT (k= 0.77, 95% CI: 0.67-0.87). MRI sensitivity was 0.84 (95% CI: 0.70-0.93) and specificity was 0.94 (95% CI: 0.89-0.97) when compared with the FP. Optic nerve head high T2FLAIR signal intensity corresponds indeed to the optic nerve head edema diagnosed by the ophthalmologists. MRI is a sensitive tool for detecting ONHE in patients presenting acute ON. In patients with optic neuritis the high T2FLAIR (fluid-attenuated inversion recovery) signal intensity of the optic nerve head corresponds indeed to optic nerve head edema, which is a useful feature in optic neuritis etiological evaluation and treatment. Optic nerve head edema is a prominent clinical feature of acute optic neuritis and is usually diagnosed during dilated or non-dilated eye fundus examination. Agreement was high between magnetic resonance imaging, fundus photography, and optical coherence tomography. Optic nerve head high T2 fluid attenuation inversion recovery signal intensity is a promising detection tool for optic nerve head edema in patients presenting acute optic neuritis.

Differences in optic nerve head structure between acute angle-closure glaucoma and open-angle glaucoma

This study aimed to compare the optic nerve head (ONH) structure in acute angle-closure glaucoma (AACG) and open-angle glaucoma (OAG) to investigate the differences in glaucomatous damage. The AACG and OAG eyes were matched with regard to global retinal nerve fiber layer thickness (RNFLT). AACG eyes were divided into two subgroups based on the presence of ONH swelling at the onset of AACG. RNFLT, Bruch’s membrane opening-minimum rim width (BMO-MRW), and Bruch’s membrane opening-minimum rim area (BMO-MRA) were analyzed. Global RNFLT values were similar in AACG and OAG groups, but lower than in the healthy group (P < 0.001). The global BMO-MRW and total BMO-MRA were significantly higher in AACG than in OAG group (P < 0.001, respectively). AACG showed similar global BMO-MRW and total BMO-MRA, irrespective of the presence or absence of ONH swelling, while AACG with ONH swelling was associated with significantly thinner global RNFLT compared to AACG without ONH swelling (P < 0.006). The result of differences in ONH structure between the OAG and AACG, especially the AACG with ONH swelling at the onset of AACG, suggests that the mechanisms of optic nerve damage in the two diseases are different.

Predicting Acute and Post-Recovery Outcomes in Cerebral Malaria and Other Comas by Optical Coherence Tomography (OCT in CM) - A protocol for an observational cohort study of Malawian children.

Cerebral malaria (CM) remains a significant global health challenge with high morbidity and mortality. Malarial retinopathy has been shown to be diagnostically and prognostically significant in the assessment of CM. The major mechanism of death in paediatric CM is brain swelling. Long term morbidity is typically characterised by neurological and neurodevelopmental sequelae. Optical coherence tomography can be used to quantify papilloedema and macular ischaemia, identified as hyperreflectivity. Here we describe a protocol to test the hypotheses that quantification of optic nerve head swelling using optical coherence tomography can identify severe brain swelling in CM, and that quantification of hyperreflectivity in the macula predicts neurodevelopmental outcomes post-recovery. Additionally, our protocol includes the development of a novel, low-cost, handheld optical coherence tomography machine and artificial intelligence tools to assist in image analysis.

Unilateral Papilledema as a Rare Manifestation of Cerebral Neurotoxoplasmosis in HIV Patient: Case Report

Introduction: Cerebral toxoplasmosis is one of the opportunistic diseases that present in patients with HIV/AIDS. One of the rare symptoms is unilateral papilledema due to cerebral toxoplasmosis. Case report: A 26-year-old male patient came with complaints blurred vision for 2 months. The patient had a history of pouting lips, and weakness face, arm, and legs on the left side of the body. The patient has been diagnosed with the observation of space occupying lesion Cerebri in November 2020. Patient with HIV stage IV (WHO) infection and CD4 14 cells/uL and viral load 5.43 x 105 copies /mL. Visual acuity left eye 6/18 PH 6/12, contrast sensitivity examination in both eyes 1.65, and the results of FD-15 are within normal limits, but the results of perimetry was enlargement of blind spot, relative afferent pupillary defect in the left eye, with optic nerve head swelling in the left eye. An MRI showed the presence of intracerebral neurotoxoplasmosis. Discussion: Papilledema is the manifestation of optic nerve abnormality due to an increase in intracranial pressure. Cerebral toxoplasmosis leads to asymmetric target lesion present with ring enhancement image on MRI with contrast which causes SOL and manifests as papilledema. Bilateral papilledema is a hallmark of increasing cerebrospinal fluid pressure, but unilateral papilledema is a rare case with a 2% of prevalence among papilledema cases. Two proposed mechanisms of atypical papilledema were anatomical nerve sheath anomalies and unilateral axoplasmic blockage of the lamina cribrosa. Conclusion: Early diagnosis and appropriate treatment have a very important role in determining the prognosis of patients with cerebral toxoplasmosis.

Upper Limit of Retinal Nerve Fibre Layer Thickness in Patients with Pseudopapilloedema

ABSTRACT An initial misdiagnosis of papilloedema in a patient with optic nerve head swelling can be anxiety-provoking and may result in unnecessary, invasive, and costly tests. Cirrus high definition, spectral domain-optical coherence tomography (Cirrus HD-OCT) may provide a rapid and non-invasive test. We sought to determine an upper limit of average retinal nerve fibre layer (RNFL) thickness in patients with pseudopapilloedema without visible drusen using Cirrus HD-OCT that could be utilised in conjunction with the clinical presentation and physical examination when managing patients with optic nerve head swelling. Inclusion criteria consisted of at least two neuro-ophthalmological visits and repeated imaging of the optic nerve head with Cirrus HD-OCT at least 6 months apart. Exclusion criteria included clinically visible drusen along with previous or concomitant diagnosis of retinal or other optic nerve pathology. Thirty-eight eyes from 19 patients with pseudopapilloedema were included in this study. The upper limit of average RNFL thickness was defined as two standard deviations above the mean of the average RNFL thickness and was calculated to be 158.65 µm for scans obtained with Cirrus HD-OCT devices. A patient with suspected optic nerve head swelling, an average RNFL thickness less than 158.65 µm, and no other evidence of papilloedema or neurological signs or symptoms can be managed with serial follow-ups with OCT imaging for at least 6 months. If the patient continues to have no clinical symptoms suggesting increased intracranial pressure and the average RNFL thickness is stable, the likelihood of papilloedema is minimal.

Acute uveitic phase of Vogt-Koyanagi-Harada disease: optic nerve head swelling, ocular blood flow and retinal oxygen metabolism.

To investigate the association of optic nerve head (ONH) swelling in the acute uveitic phase of Vogt-Koyanagi-Harada (VKH) disease with blood flow velocity in the choroid and ONH and oxygen saturation and diameter of retinal vessels. In this prospective study, 25 patients (50 eyes) were studied. Thirteen patients (26 eyes) had ONH swelling and 12 patients (24 eyes) had no ONH swelling. Laser speckle flowgraphy (LSFG) and retinal oximetry measurements were performed at presentation. In the ONH, mean blur rate (MBR)-vessel, representing blood flow velocity in retinal vessels, was significantly lower in the eyes affected by ONH swelling, while choroidal MBR was not significantly different. Eyes with ONH swelling had a significantly lower oxygen saturation in retinal venules, a significantly higher arteriovenous oxygen saturation difference and a significantly smaller calibre of retinal arterioles compared with eyes without ONH swelling. There were significant positive correlations between the MBR-vessel of the ONH and venular oxygen saturation and calibre of retinal arterioles. In addition, MBR-vessel of the ONH had a significant negative correlation with arteriovenous oxygen saturation difference. The occurrence of ONH swelling in the acute uveitic phase of VKH disease is associated with lower retinal blood flow velocity and smaller calibre of retinal arterioles as well as lower oxygen saturation in retinal venules and higher arteriovenous difference in oxygen saturation.

Differences in Neuropathic Pain and Radiological Features Between AQP4-ON, MOG-ON, and IDON

PurposeThe purpose of this study was to investigate pain and radiological features of different types of first-episode demyelinating optic neuritis (ON).MethodsEighty-three patients presenting with first-episode aquaporin-4 (AQP4) antibody-associated ON (AQP4-ON; n = 28), myelin oligodendrocyte glycoprotein (MOG) antibody-associated ON (MOG-ON; n = 26) and idiopathic demyelinating optic neuritis (IDON, n = 29) were included in this retrospective case-control study. We assessed optic nerve lesions on magnetic resonance imaging (MRI), acute pain associated with onset of optic neuritis and clinical characteristics of those ON patients with different serum autoantibody status.Results24 AQP4-ON patients (85.75%), 23 MOG-ON patients (88.5%) and 24 IDON patients (82.8%) suffered from ON-associated pain. MOG-ON had mostly retro-orbital pain; AQP4-ON and IDON had mostly neuropathic pain. In addition, pain was more severe in AQP4ON patients than in other ON patients. In MRI, bilateral involvement was more common in AQP4-ON than IDON (26.9 and 3.7%); radiological optic nerve head swelling was more common in MOG-ON than in AQP4-ON and IDON (68.0 vs. 23.1 vs. 25.9%). MRI lesion in peri-optic nerve sheath was more common in AQP4-ON (53.8 vs. 16.0 vs. 3.7%). In 70 patients with ON-associated pain, gadolinium enhancement of orbital optic nerve was most common in MOG-ON patients (82.4 vs. 55.0 vs. 33.3%, P = 0.018), and enhancement of optic chiasma was most common in AQP4-ON patients (40.0 vs. 5.9 vs. 6.7%, P = 0.015). Perineural and orbital enhancement was observed only in patients with MOG-ON (P < 0.001). The length of enhancement was longer in AQP4-ON patients than in MOG-ON and IDON patients.ConclusionPain is a common symptom in patients with all types of demyelinating ON. AQP4-ON is frequently associated with severe ON-associated pain and longitudinally extensive optic nerve inflammatory lesions. Intra-orbital and peri-optic inflammation were more frequently observed in patients with MOG-ON, which was closely related to optic disc swelling and retro-orbital pain provoked by eye movements.

Optic Disc Edema in Syphilis.

Syphilis is an uncommon cause of optic nerve head edema; however, differentiating syphilis from other etiologies of optic nerve head swelling may be challenging. We describe 4 cases of ocular syphilis presenting with swollen optic nerve head(s) without overt signs of intraocular inflammation to better define the phenotypic presentation of this condition to allow its early recognition and treatment and discuss potential pathophysiological mechanisms of syphilitic optic neuropathy. Retrospective case series of patients presenting to a tertiary neuro-ophthalmology practice with a swollen optic nerve head(s) but no overt signs of intraocular inflammation, which was eventually determined to be secondary to syphilis. Four patients were included in the study. The mean age was 43 years, 2 were women and 2 had bilateral involvement. Two patients had a recent history of skin rash, and one patient was investigated for abdominal pain and elevated liver enzymes. Two patients presented with photopsias and preserved visual function, whereas 2 presented with vision loss. Although chorioretinitis was present in all cases, it was very subtle in all and was only appreciated on fundus autofluorescence (FA) in 3 of 4 cases. Three patients demonstrated evidence of optic perineuritis on neuro-imaging. All patients were treated with a course of intravenous penicillin with a variable degree of visual recovery. Systemic symptoms are common in patients with syphilic optic neuropathy. Optic disc edema as a manifestation of syphilis is usually accompanied by subtle chorioretinitis, which is best appreciated on FA. Optic perineuritis is common in patients with syphilitic optic neuropathy, with its pathophysiology likely similar to meningitis seen in neurosyphilis.

Retinal Vein Changes as a Biomarker to Guide Diagnosis and Management of Elevated Intracranial Pressure.

Retinal vein changes, which can be observed on clinical exam or ophthalmic imaging, are promising non-invasive biomarkers for elevated intracranial pressure (ICP) as a complement to other markers of high ICP including optic nerve head swelling. Animal and human studies have demonstrated increase in retinal vein pressure associated with elevated ICP mediated by increase in cerebral venous pressure, compression of venous outflow by elevated cerebral spinal fluid pressure in the optic nerve sheath, and compression of venous outflow by optic nerve head swelling. Retinal vein pressure can be estimated using ophthalmodynamometry. Correlates of retinal vein pressure include spontaneous retinal venous pulsations, retinal vein diameter, and retinal vein tortuosity. All of these have potential for clinical use to diagnose and monitor elevated ICP. Challenges include diagnostic prediction based on single clinical measurements and accurate assessment of retinal vein parameters in cases where optic nerve head swelling limits visualization of the retinal veins.

Distinct patterns of MRI lesions in MOG antibody disease and AQP4 NMOSD: a systematic review and meta-analysis

Backgroundthe distinct MRI features of MOG-antibody disease (MOG-AD) and AQP4-NMOSD are still poorly defined. We performed a systematic review and meta-analysis to identify specific patterns of MRI abnormalities able to discriminate between MOG-AD and AQP4-NMOSD. Methodsfourteen case-series (1028 patients) were included. Outcomes were MRI lesion patterns in optic nerve (ON), brain and spinal cord (SC) that were selected after a systematic literature review and analysed separately as the event rate for individual MRI lesions in MOG-AD (experimental group) and AQP4-NMOSD (control group) by using a random effect model. ResultsMOG-AD showed a higher number of MRI lesions than AQP4-NMOSD patients in the retrobulbar ON (OR=5.67; 95%CI=2.11–15.24; p=0.0006) with ON head swelling (OR=8.20; 95%CI=4.13–16.28; p<0.00001), corpus callosum (OR=2.30; 95%CI=1.11–4.76; p=0.02), pons (OR=2.87; 95%CI=1.45–5.67; p=0.002), and lumbar/conus SC (OR=3.47; 95%CI=1.66–7.24; p=0.0009). Conversely, lesions in the canalicular (OR=0.42; 95%CI=0.18–0.98; p=0.05) and intracranial ON (OR=0.30; 95%CI=0.11=0.84; p=0.02), area postrema (OR=0.12; 95%CI=0.02–0.61; p=0.01), medulla (OR=0.40; 95%CI=0.20–0.78; p=0.007), and cervical SC (OR=0.29; 95%CI=0.09–0.92; p=0.04) were prominent in patients with AQP4-NMOSD. Participants’ age was found to be a source of heterogeneity across studies. Conclusionour study provides further evidence that MOG-AD and AQP4-NMOSD have distinct MRI features that may help clinicians for an early differential diagnosis.

A tearfully painful darkness

A 70-year-old woman presented with new onset of left eye and facial pain. Ophthalmic and neurological examinations, magnetic resonance imaging brain, erythrocyte sedimentation rate, and C-reactive protein were unrevealing. A few days later, she developed vision loss in her left eye. Examination revealed decreased visual acuity with a relative afferent pupillary defect in the left eye and a diffuse mild swelling of the left optic nerve head. Repeat magnetic resonance imaging showed T2 hyperintensity and enhancement of the intraorbital optic nerve and surrounding tissues with no other intracranial abnormalities. Serum studies showed elevated myelin oligodendrocyte glycoprotein IgG titer. She was treated with IV methylprednisolone 1000 mg daily for 3 days and was discharged on prolonged prednisone taper with return of vision to baseline.

Optic disc drusen: a systematic review : Up-to-date and future perspective.

Optic disc drusen (ODD) are acellular deposits in the prelaminar optic nerve head. The most accredited theory is that they are secondary to abnormalities in axonal metabolism and degeneration, but the pathogenesis is not clear to date. Although ODD are often considered a benign condition, the great majority of patients with ODD show visual field defects and are at higher risk for developing anterior ischemic optic neuropathy. ODD are classified as superficial or buried, with the latter being often misdiagnosed as papilledema with optic nerve head swelling, leading to an unnecessary investigation for causes of increased intracranial pressure. The recent technological improvements in OCT imaging which allowed an earlier and more certain diagnosis even of the smallest ODD, renovated the interest around this pathology. However, an updated systematic review is still missing. Therefore, the aim of this work is to provide a concise yet comprehensive overview of the current state of art, focusing on pathophysiology, clinical presentation, diagnostic methods, treatment modalities and potential future perspectives of this condition.

Optic Nerve Head Volumetry by Optical Coherence Tomography in Papilledema Related to Idiopathic Intracranial Hypertension.

PurposeIdiopathic intracranial hypertension (IIH) leads to optic nerve head swelling and optic atrophy if left untreated. We wanted to assess an easy to perform volumetric algorithm to detect and quantify papilledema in comparison to retinal nerve fiber layer (RNFL) analysis using optical coherence tomography (OCT).MethodsParticipants with and without IIH underwent visual acuity testing at different contrast levels and static perimetry. Spectralis-OCT measurements comprised standard imaging of the peripapillary RNFL and macular ganglion cell layer (GCL). The optic nerve head volume (ONHV) was determined using the standard segmentation software and the 3.45 mm early treatment diabetic retinopathy study (ETDRS) grid, necessitating manual correction within Bruch membrane opening. Three neuro-ophthalmologists graded fundus images according to the Frisén scale. A mixed linear model (MLM) was used to determine differences between study groups. Sensitivity and specificity was evaluated using the area under the receiver-operating characteristic (ROC).ResultsTwenty-one patients with IIH had an increased ONHV of 6.46 ± 2.36 mm3 as compared to 25 controls with 3.20 ± 0.25 mm3 (P < 0.001). The ONHV cutoff distinguishing IIH from controls was 3.97 mm3 (i.e. no patient with IIH had an ONHV below and no healthy individual above this value). The area under the curve (AUC) for ONHV was 0.99 and for the RNFL at 3.5 mm 0.90. The Frisén scale grading correlated higher with the ONHV (r = 0.90) than with the RNFL thickness (r = 0.68). ONHV measurements were highly reproducible in both groups (coefficient of variation <0.01%).ConclusionsOCT-based volumetry of the optic nerve head discriminates very accurately between individuals with and without IIH. It may serve as a useful adjunct to the rating with the subjective and ordinal Frisén scale.Translational RelevanceA simple OCT protocol run on the proprietary software of a commercial OCT device can reliably discriminate between normal optic nerve heads or pseudo-papilledema and true papilledema while being highly reproducible. Our normative data and OCT preset may be used in further clinical studies.

From international ophthalmology to space ophthalmology: the threats to vision on the way to Moon and Mars colonization.

To report the ophthalmological risks of space travel. The literature about the effect of microgravity and cosmic radiation on the human eye has been reviewed, focusing on the so-called "spaceflight related neuro-ocular syndrome (SANS)", and possible remedies. The eye is the major candidate to suffer from the adverse space conditions, so much so that SANS is the main concern of the National Aeronautics and Space Administration (NASA). SANS, that affects astronauts engaged in long-duration spaceflights, is characterized by optic nerve head swelling, flattening of the posterior region of the scleral shell, choroidal folds, retinal cotton wool spots, and hyperopic shift. Even if it seems related to an increased volume of the cerebrospinal fluid in the brain and the optic nerve sheaths, its pathogenesis is still unclear. In addition, cataract is related to the effect of galactic cosmic rays on the lens. Centrifuges, pressurizing chambers, and mechanical counter-pressure suits have been advanced to counteract the upward fluid shift responsible for the SANS syndrome. Shields with a high content of hydrogen, magnetic shielding systems, and wearable radiation shielding devices are under study to mitigate the exposure to galactic cosmic rays. Since 1961, the year of the first manned mission outside the Earth, history has shown that the human being may venture in space. Yet, visual impairment is the top health risk for long-duration spaceflight. Effective remediation is mandatory in anticipation of long space missions and Moon and Mars colonization.

Optic nerve head width and retinal nerve fiber layer changes are proper indexes for validating the successful induction of experimental anterior ischemic optic neuropathy

Reproducible skills are essential for successful induction of a rat model of anterior ischemic optic neuropathy (rAION). We established an in vivo validation index by measuring the natural course of optic nerve head (ONH) width and retinal nerve fiber layer (RNFL) thickness in the rAION model using optical coherence tomography (OCT). The rAION model was induced by photodynamic operations. We measured the ONH width, RNFL, Inner Plexiform layer (IPL) and Ganglion cell complex (GCC) thickness in the acute stage (<3 days), subacute stage (day-7 to day-14) and later stage (day-14 to day-28) post-infarct by OCT. Retinal layers were measured by hematoxylin and eosin stain (HE) to confirm the OCT findings. The RGCs survival rate was determined by retrograde Fluoro-gold labeling, and the visual function was assessed with flash visual-evoked potentials (FVEPs) 4 weeks post-infarct. We observed significant thinning in GCC, IPL, and RNFL at day-14 and day-28 but only RNFL showed significant thinning between day-14 and day-28. The ONH showed significant swelling in the acute stage which correlated at a greater extent with RNFL than GCC and IPL. Further RNFL correlated at a greater extent at with GCC than IPL. HE-stained retina cross sections also showed IPL and RNFL thinning, which further confirmed our OCT findings. The RGC density and P1-N2 amplitude were significantly reduced in rAION. Our data suggest that Swelling, reduction of swelling, and atrophy of RNFL in acute, sub-acute, and later stage, respectively and ONH swelling in the acute stage are essential events for confirming the successful induction of rAION.

Update on Perioperative Ischemic Optic Neuropathy Associated With Non-ophthalmic Surgery.

Perioperative visual loss (POVL) is a rare, serious complication of non-ophthalmic surgeries. Ischemic optic neuropathy (ION), and retinal arterial occlusion (RAO) are the main causes (1, 2). Less frequent are cortical blindness (3), acute glaucoma (4), and choroidal and vitreous hemorrhage (5). ION is the most common cause for which the neurologist or neuro-ophthalmologist is consulted as it is associated either with a normal ophthalmic exam (posterior ION, PION), or less often, with optic nerve (ON) head swelling (anterior ION, AION). The presumed cause is impaired blood supply to the optic nerve (Figure 1). The most common surgical procedures complicated by ION are cardiac surgery and spinal fusion. Retrospective studies, surveys, and case reports are the basis of most knowledge regarding peri-operative ION (poION), with cohort and case-control studies helping to identify candidate risk factors (6, 7). Animal models have provided insight regarding mechanisms (8). This mini-review is an update on the latest advancements regarding poION in non-ophthalmic surgeries in epidemiological, clinical, and animal studies.

Optic disc drusen: understanding an old problem from a new perspective.

Optic disc drusen (ODD) are acellular deposits located in the optic nerve head of up to 2.4% of the population. They may develop as by-products of impaired axonal metabolism in genetically predisposed individuals, in whom a narrow scleral canal is hypothesized to play a role. Although ODD are often considered as benign innocent bystanders, recognized as part of a routine ophthalmological examination, the vast majority of patients with ODD have visual field defects. Optic disc drusen (ODD)-associated complications with severe visual loss, most often due to anterior ischaemic optic neuropathy, are also known to occur. There are no treatments available to prevent or ameliorate the vision loss caused by ODD. In children, the ODD are usually uncalcified and buried within the optic nerve head tissue. In these cases, the condition can be difficult to diagnose, as it often resembles a papilloedema with optic nerve head swelling caused by raised intracranial pressure. During the teenage years, the ODD progressively become more calcified and probably also larger, which allow them to be visible on ophthalmoscopy. With the advent and proper utilization of high-resolution modalities of optical coherence tomography (OCT), it has now become possible to detect even the smallest and most deeply located ODD. This allows for ODD detection at a much earlier developmental stage than has previously been possible and enhances the possibilities of research in underlying mechanisms. A review of the literature on ODD was conducted using the PUBMED database. The review focuses on the current knowledge regarding pathogenesis, diagnostics, clinical disease-tracking methodologies, structure-function relationships and treatment strategies of ODD.