Investigating Optic Nerve Sheath Diameter in Prone Position Spinal Surgery Patients: A Pilot Study.

Purpose: This study aimed to evaluate the effect of intraoperative positioning and ocular immobility on the amount of cerebrospinal fluid around the optic nerve in patients undergoing prone spinal surgery by measuring the optic nerve sheath diameter (ONSD) using ultrasound. Methods: Consecutive participants (n = 15 patients, 30 eyes) were scanned preoperatively, intraoperatively approximately 20 minutes before the end of the surgery, and postoperatively in the post-anesthesia care unit at least 10 min after the completion of the surgery at one academic hospital. Results: On average, patients who underwent prone spinal surgery had a 21% increase in ONSD intraoperatively, with a positive time-dependent relationship with the overall length of surgery (P < 0.001). ONSDs postoperatively returned to baseline and were not significantly different from preoperative measurements. Conclusion: Our findings suggest pooling and inadequate clearance of perioptic cerebrospinal fluid during prone spinal surgery that improves following termination of the procedure and return of the patient to an upright position.

Vitreopapillary Findings in Non-Arteritic Ischemic Optic Neuropathy versus Healthy Eyes: A Clinical and OCT Comparison.

PURPOSE: To study the vitreopapillary interface in non-arteritic ischemic optic neuropathy (NAION) for features that may predispose to optic nerve perfusion defects. DESIGN: Case-control study. PARTICIPANTS AND CONTROLS: Patients with NAION (Study group) were compared with healthy non-NAION patients with crowded discs (Control group I) and non-crowded optic discs (Control group II). METHODS: The vitreopapillary interface was studied in 32 eyes with NAION using high-resolution OCT scans. Results were compared with two control groups consisting of age, sex, and refraction-matched non-NAION individuals with crowded optic discs (Control Group I: 31 eyes) and non-crowded optic discs (Control Group II: 32 eyes). MAIN OUTCOME MEASURES: The incidence of total posterior vitreous detachment (PVD), vitreopapillary and vitreovascular attachments, and epipapillary membranes. RESULTS: The rate of PVD over the macula was similar among groups (NAION: 62.5%, Control I: 61.3%, and Control II: 65.6%, p=0.93) while the posterior hyaloid remained attached to the crowded discs at a significantly higher rate (NAION: 81.2%, Control I: 83.9% and Control II: 43.7%, p=0.0005). A higher rate of focal vitreopapillary attachments on crowded discs than on non-crowded discs was noted (NAION: 72.2%, crowded control I: 58.7%, and non-crowded control II: 19.1%, p=0.007). Vitreovascular attachments (NAION: 69%, crowded control I: 3% vs non-crowded control II: 6%, p=0.00001) and dense epipapillary membranes were observed in NAION eyes. CONCLUSIONS: Crowded discs may have stronger vitreopapillary attachments. A close relationship of these attachments with optic nerve vessels may lead to the transmission of strong tractional forces by a syneretic vitreous gel, especially after macular PVD. This transduced mechanical force may contort the vessel wall and disrupt the blood flow in NAION.

Longitudinal Evaluation of Circumpapillary Structure-Function and Vasculature-Function Relationships in Acute and Sub-acute Nonarteritic Anterior Ischemic Optic Neuropathy.

PURPOSE: To investigate the global and regional correlations between longitudinal structure-function (S-F) and vasculature-function (V-F) using circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements, circumpapillary vessel density (cpVD) and the corresponding/final visual outcomes at different stages of nonarteritic anterior ischemic optic neuropathy (NAION). METHODS: Thirty eyes of 30 patients with acute NAION were included. LogMAR best-corrected visual acuity(BCVA), mean deviation (MD) and visual field index (VFI), cpRNFL thickness and cpVD across different retinal layers were examined at baseline, 2 weeks and 1 month after diagnosis. Potential correlations between the Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) parameters and visual outcomes were investigated in both acute and sub-acute NAION. RESULTS: Significant global and regional correlations in S-F relationship were identified exclusively in sub-acute stage (p<0.05). However, among the OCTA parameters for the acute NAION, the temporal cpVD in superficial vessel complex (SVC) and inner retinal layer (IRL) exhibited positive correlations with corresponding and final visual acuity and visual field outcomes. In the sub-acute stage of NAION, the cpVD of global or temporal section in radial peripapillary capillary (RPC), SVC and IRL were positively correlated with visual outcomes. CONCLUSION: Significant longitudinal V-F relationships exist both globally and regionally, in acute and sub-acute NAION. The cpVD parameters of the SVC and IRL are potentially valuable for evaluating corresponding and final visual outcomes and highlights the importance of monitoring cpVD over cpRNFL thickness in acute NAION.

Clinical outcomes of radial optic neurotomy versus pars plana vitrectomy in recent onset non-arteritic anterior ischemic optic neuropathy.

INTRODUCTION: This study investigated the effect of pars plana vitrectomy (VIT) versus pars plana vitrectomy combined with radial optic neurotomy (RON) on recent onset non-arteritic anterior ischemic optic neuropathy (NAION). METHODS: In this prospective interventional case series, individuals with recent-onset NAION, lower than one month and low vision (lower than 20/200) were recruited. Patients randomly underwent either VIT, or RON. RESULTS: 34 eyes of 34 patients were included in this study. 10, 9, and 15 eyes were randomly included in VIT, RON, and control groups, respectively. The BCVA of the VIT group improved significantly from 1.84 ± 0.5 logMAR at baseline to 1.29 ± 0.67, 0.93 ± 0.53, and 0.77 ± 0.47 logMAR at 1, 3, and 6 months, respectively (Ps < 0.05). The corresponding values for RON group were 1.73 ± 0.53 logMAR at baseline, which improved to 1.04 ± 0.65, 0.64 ± 0.28, and 0.61 ± 0.26 logMAR at the same follow-up visit times (P < 0.05).The corresponding values for the control group were 1.6 ± 0.58 log MAR at baseline, which improved to 1.03 ± 0.29, 1.00 ± 0.32, and 0.32 ± 0.83 log MAR at the same follow-up visit times. There was no significant statistical difference in BCVA between the three groups. However, both interventions resulted in statistically significant improvement in mean deviation (MD) of visual field (VF) compared with the control group at the end of 6 months (VIT P = 0.006, RON P = 0.043). RNFLT decreased from baseline 235.3 ± 44.01 to 75.6 ± 17.68 at 1 month in the VIT group (P < 0.001), from baseline 268.22 ± 65.9 to 76.67 ± 10.59 at 1 month in RON (P < 0.001), while it decreased from baseline 179.48 ± 39.02 to 112.92 ± 44.51 at 1 month in the control group. CONCLUSION: VIT and RON showed promising results in terms of MD of VF, and optic disc edema resolved faster in these groups compared to the control group in recent onset NAION. A larger sample size study is deemed necessary to generalize the results of this study.

New-onset of giant cell arteritis with ischemic optic neuropathy following the seventh-dose of COVID-19 mRNA vaccination: A case report and literature review.

Coronavirus disease (COVID-19) vaccines have demonstrated excellent efficacy in reducing the morbidity and severity of the disease. However, some patients have been reported to develop systemic rheumatic diseases, such as rheumatoid arthritis, myocarditis, Guillain-Barre syndrome, and giant cell arteritis (GCA) following COVID-19 vaccination. We present a case of GCA with ischemic optic neuropathy following COVID-19 mRNA vaccination. A 73-year-old woman developed headache, myalgia, scalp tenderness, and jaw claudication 4 days after her seventh dose of the vaccination; she also developed severe visual disturbances 1 month after the vaccination. The blood examination tests showed an increased serum C-reactive protein level and erythrocyte sedimentation rate. The echogram for the temporal artery showed a halo sign. Ophthalmic examination revealed ischemic optic neuropathy in both eyes. The patient was treated with a high-dose glucocorticoid and tocilizumab under the diagnosis of GCA with ischemic optic neuropathy, obtaining mild improvement of the symptoms. This report underscores the need for clinical vigilance and further data collection regarding GCA cases after COVID-19 vaccination.

Differentiating optic neuropathies using laser speckle flowgraphy: Evaluating blood flow patterns in the optic nerve head and peripapillary choroid.

PURPOSE: To compare blood flow (BF) impairment patterns in different optic neuropathies using laser speckle flowgraphy (LSFG). METHODS: This retrospective study enrolled 24 eyes of 24 patients with non-arteritic anterior ischemic optic neuropathy (NAAION), 59 eyes of 59 patients with optic neuritis (ON), 677 eyes of 677 patients with open-angle glaucoma (OAG), and 110 eyes of 110 controls. The patient backgrounds of all groups were compared. Ophthalmologic findings were evaluated, adjusting for age, sex, blood pressure, pulse rate, and underlying systemic diseases with 1:1 optimal propensity score matching. We used LSFG to obtain optic nerve head (ONH) vessel-area mean blur rate (MBR; ONH-MV), ONH tissue-area MBR (ONH-MT), and choroidal MBR. The NAAION and ON groups were compared with the control and OAG groups. RESULTS: Best-corrected visual acuity was worse in the NAAION, ON, and OAG groups than in controls (p < 0.001). Circumpapillary retinal nerve fibre layer thickness was higher in the NAAION and ON groups and lower in the OAG group than in controls (p < 0.001). Compared to controls, the NAAION and OAG groups had significantly lower ONH-MV, ONH-MT, and choroidal MBR (p < 0.05). Additionally, the NAAION group had lower ONH-MV and choroidal MBR than the OAG group (p = 0.003 and p < 0.001, respectively) but no difference in ONH-MT (p = 0.857). The ON group had significantly lower ONH-MV and choroidal MBR compared to the controls (p < 0.001 and p = 0.022, respectively) but no difference in ONH-MT (p = 0.773). CONCLUSION: Optic neuropathies showed different patterns of ocular BF impairment. Therefore, LSFG can be a useful tool for differentiating optic neuropathies.

Exploring the contribution of carotid artery disease to the onset of non-arteritic ischemic optic neuropathies: A systematic review.

PURPOSE: The role of carotid artery disease (CAD) in the development of various types of ocular arterial occlusive disorders has often been reported. This systematic review aims to evaluate and review the current evidence regarding the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of non-arteritic anterior (NA-AION) and posterior (NA-PION) ischemic optic neuropathy. METHODS: We systematically reviewed studies following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We systematically searched PubMed, Embase, and Scopus databases for relevant studies that clearly assessed the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of NA-AION and NA-PION. All studies that examined the associations between CAD and the development of NA-AION and NA-PION in adults aged 18 years or older were synthesized. Quality assessment using the Newcastle-Ottawa Scale (NOS), and Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports and Case-Series were also conducted. RESULTS: Our search identified 1933 manuscripts published in the English language. The number of participants with non-arteritic ischemic optic neuropathy (NA-ION) ranged from 1 to 191, with a total of 478 patients experiencing either NA-AION (410 out of 478), NA-PION (13 out of 478), or a combination of thereof (1 out of 478). The number of participants with NA-ION due to atherosclerosis ranged from 1 to 191, with a total of 376 patients. CONCLUSIONS: Although carotid artery disease may rarely contribute to the development of NA-ION, it should be considered as a possible cause of NA-ION.

Submacular and Intraretinal Fluid Associated with Arteritic Anterior Ischemic Optic Neuropathy.

Introduction: Anterior ischemic optic neuropathy (AION) is an ischemic disorder of the optic nerve and a common cause of acute, painless, permanent vision loss. It is divided into two types: arteritic AION (AAION) and non-arteritic anterior ischemic optic neuropathy (NAION). Although subretinal fluid associated with optic disc edema has been reported in cases of NAION, it is rarely described in AAION. Case Presentation: An 86-year-old female with a history of polymyalgia rheumatica presented with sudden vision loss in the left eye. Initial examination revealed left pallid optic disc edema with peripapillary hemorrhages. Optical coherence tomography (OCT) of the left macula showed intraretinal and submacular fluid. The patient was started on 50 mg of oral prednisone daily. The diagnosis of giant cell arteritis (GCA) was later confirmed with a positive temporal artery biopsy. Three weeks after presentation, an OCT was completed which demonstrated complete resolution of the intraretinal and submacular fluid. Although the presence of both intraretinal and subretinal fluid has been previously documented in cases of NAION, it is rarely reported in a patient with GCA. Conclusion: This is a newly described case of subretinal and intraretinal fluid in a patient with AAION. We postulate that the pathophysiology behind this is mediated by associated choroidal ischemia leading to altered permeability. OCT is an important imaging modality allowing for signs of GCA to be better characterized.

Bilateral Visual Impairment following Combination Chemotherapy with Carboplatin in Patients with Small Cell Lung Cancer: A Case Report.

Background: Platinum-based combination chemotherapy, including cisplatin and carboplatin, are important cytotoxic anti-cancer agents that are widely used to treat various solid tumors. Carboplatin has a similar effect on survival in small cell lung cancer, but generally has a milder toxicity profile when compared with cisplatin. Both may cause moderate or severe neurotoxicity, but ocular neurotoxicity from carboplatin is rarely reported. Case presentation: A 79-year-old man underwent intravenous polychemotherapy (atezolizumab, etoposide, and carboplatin) for small cell lung cancer. One week after the second cycle of chemotherapy, he reported bilateral visual loss as hand motion in both eyes. Dilated fundus examination showed retinal arterial narrowing without hemorrhage, and diffuse choroidal and retinal thinning was observed in an optical coherence tomography scan. Fluorescein angiography revealed significantly delayed circulation without evidence of obstructive lesions. 30-Flicker electroretinogram testing showed a complete absence of cone response in both eyes. The patient's visual acuity aggravated to no light perception in both eyes, even after the cessation of chemotherapy. Conclusions: Carboplatin combination chemotherapy administered at therapeutic doses can result in irreversible visual loss, a side effect that is not widely acknowledged. When using carboplatin, physicians should be aware of its potential ocular toxicity.

Peripapillary Retinal Nerve Fiber Layer Thickness as a Predictor of Visual Outcomes in Patients with Acute Nonarteritic Anterior Ischemic Optic Neuropathy.

Objective: To evaluate the utility of peripapillary retinal nerve fiber layer thickness (pRNFLT) for the prediction of visual outcomes, including visual acuity (VA) and visual field (VF), in subjects with acute nonarteritic anterior ischemic optic neuropathy (NAION). Materials and Methods: We performed a retrospective study of data relating to 60 eyes of 60 subjects with acute NAION. Of these, reliable VF values were obtained at both the initial and at 6-month follow-up visits for 30 eyes, which were included in the VF analysis. The pRNFLT was measured globally and separately in all four quadrants (superior, inferior, nasal, and temporal) using optical coherence tomography at the initial visit. Multivariate analysis and the area under the curve (AUC) were used to evaluate the utility of pRNFLT for the prediction of visual outcomes, including favorable VA (VA better than or equal to 20/25) and favorable VF (visual field index (VFI) ≥90%), at the 6-month follow-up visit. Results: The median VA and mean VFI at the initial visit were 0.40 (interquartile range (IQR): 0.40, 0.54; logarithm of the minimum angle of resolution (logMAR)) and 73.07% ± 6.73%, respectively. The median VA and mean VFI at the 6-month follow-up visit were 0.30 (IQR: 0.00, 0.70) logMAR and 69.27% ± 28.94%, respectively. Thinner temporal-quadrant pRNFLT was associated with favorable VA (odds ratio 0.98; p = 0.042) with a cut-off value of 128 µm (AUC 0.839, 95% CI: 0.732-0.947, sensitivity 77.27%, specificity 84.21%). Thinner nasal-quadrant pRNFLT was associated with favorable VF (odds ratio 0.97; p = 0.047) with a cut-off value of 105 µm (AUC 0.780, 95% CI: 0.612-0.948, sensitivity 90.00%, specificity 70.00%). Conclusions: The pRNFLT is clinically useful for the prediction of visual outcomes in patients with acute NAION. A temporal-quadrant pRNFLT ≤128 µm and a nasal-quadrant pRNFLT ≤105 µm predict favorable VA and VF at the 6-month follow-up visit, respectively.

Binasal Quadrantanopia: A Rare Visual Field Defect Poses Challenges in Terms of Lesion Localization.

Binasal quadrantanopia is a rare type of visual field defect characteristic of vision loss in either the upper or lower quadrants of both nasal visual fields. The affected individuals often exhibit impairments in peripheral vision, leading to difficulties in various daily activities such as navigation, object recognition, and hazard avoidance. The consequences of binasal quadrantanopia can be profound, affecting the individual's quality of life and functional independence. However, due to its atypical presentation and overlapping clinical features with other visual field defects, accurately pinpointing the lesion's precise location for further management becomes a complex task. Here, we present an unusual case of binasal quadrantanopia caused by bilateral anterior ischemic optic neuropathy (AION) and aim to explore the unique characteristics, etiology, and diagnostic approaches associated with binasal quadrantanopia, shedding light on the challenges encountered in lesion localization.

The Relationship between Ischemic Optic Neuropathy and Internal Carotid Artery Dissection: A Systematic Review.

Background: To evaluate and review the current evidence regarding the association between ischemic optic neuropathy (ION) and internal carotid artery dissection (ICAD). Methods: We systematically reviewed studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines (PRISMA), searching three databases (Scopus, Pubmed, and Embase) for relevant articles that clearly described the correlation between ION and ICAD. All studies that examined the association between ICAD and the development of ION were synthesized. Quality assessment using the Newcastle-Ottawa Scale (NOS) and Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports and Case Series were conducted. Results: Our search yielded 198 manuscripts published in the English language. Following study screening, fourteen studies were selected. The number of participants with ION following ICAD ranged from one to four, with sixteen patients experiencing either anterior ION, posterior ION, or a combination of both. The anterior or posterior ischemic optic neuropathy (AION and PION) patients' ages were 48.75 ± 11.75 and 49.62 ± 12.85, respectively. Fourteen out of sixteen patients experienced spontaneous ICAD, whereas the traumatic etiology was ascertained in two patients. Conclusions: Hence, albeit rare, ophthalmologists should consider ICAD a potential cause of ION, especially in young adults with concomitant cephalic pain and vision reduction.

Evaluation and management of nonarteritic anterior ischemic optic neuropathy: a national survey.

PURPOSE: The evaluation and management of Nonarteritic Anterior Ischemic Optic Neuropathy (NAION) lacks standardized guidelines. This study aimed to investigate the real-world practices of neuro-ophthalmologists in the evaluation and management of typical NAION cases. METHODS: A national survey, conducted between 2019 and 2021, involved all practicing neuro-ophthalmologists. A structured questionnaire assessed their approach to risk factor evaluation and treatment of NAION, with 19 questions about risk factors and six questions concerning treatment and prevention of fellow-eye involvement. RESULTS: Thirty-six out of 37 neuro-ophthalmologists participated. Most physicians referred patients for evaluation of the following risk factors: obstructive sleep apnea (83.3%), diabetes mellitus (83.3%), hypertension (77.7%), dyslipidemia (72.2%), and optic disc drusen (38.8%). However, there was considerable variation in the choice of diagnostic tests recommended. Furthermore, nearly 47% recommended an embolism workup. Regarding treatment, the majority (91%) did not recommend routine treatment for NAION, although in 16.7%, high-dose corticosteroids were occasionally prescribed. Secondary prevention with aspirin (80.6%), smoking cessation advice (86.1%), and advising against erectile dysfunction medications for men (80.6%) were common recommendations. CONCLUSION: While the risk factors associated with NAION are well-reported, there is a lack of uniformity on which tests should be ordered to evaluate these risk factors. Most neuro-ophthalmologists concur that routine treatment for NAION is not warranted, but not unanimously. Future studies to develop a consensus guideline for post-NAION work-up and management recommendations may assist in the detection and management of preventable risk factors.

Non-arteritic anterior ischemic optic neuropathy secondary to idiopathic intracranial hypertension.

Purpose: Patients with increased intracranial pressure and underlying hypertensive emergency may present with optic disc edema. Papilledema in this setting may be a predisposing risk factor for superimposed non-arteritic anterior ischemic optic neuropathy (NAION). We highlight the role of neuroimaging including diffusion-weighted imaging in magnetic resonance imaging that can help to differentiate visual loss from NAION versus papilledema in fulminant IIH with and without hypertension. Observations: A 46-year-old female presented with acute vision loss in the right eye and transient right hemiparesis. Neuro-ophthalmic examination revealed optic disc edema in both eyes. Magnetic resonance imaging (MRI) of the brain with diffusion-weighted imaging (DWI) sequences showed restricted diffusion in the optic nerve head of the affected eye. Lumbar puncture revealed an elevated opening pressure of 34.8 cm H2O confirming increased intracranial pressure. Additionally, literature searches were conducted in the PubMed, Google Scholar and Embase databases to uncover previous cases of patients with ischemic optic neuropathy and restricted diffusion on MRI. Conclusions and importance: We highlight the shared pathophysiology between optic disc edema related visual loss in NAION and papilledema in IIH. We review the overlapping clinical and radiographic findings in these two conditions which may occur simultaneously. The presence of restricted diffusion in the optic nerve head versus in the optic nerve parenchyma may support a diagnosis of superimposed NAION and might influence the decision to perform surgery in cases of IIH with fulminant visual loss. Although restricted diffusion on MRI DWI sequences is often used to define cytotoxic edema related to ischemic infarction in the brain, this radiographic finding alone should not be used to determine the indication for surgery for papilledema related visual loss in fulminant IIH.

Perinuclear Antineutrophil Cytoplasmic Antibody-Associated Ocular Manifestations: Case Series and Literature Review.

PURPOSE: To investigate the diversity of ocular manifestations in patients with positive perinuclear antineutrophil cytoplasmic antibody (p-ANCA). METHODS: The clinical records of five patients exhibiting ocular manifestations and testing positive for serum MPO-ANCA were retrospectively reviewed. RESULTS: Three out of five patients were female. The youngest patient was aged 26, whereas the eldest was 83 years old. 80% (n = 4) of them had purely anterior segment involvement, with the commonest manifestation being peripheral ulcerative keratitis and scleritis. Only one patient had posterior segment involvement, specifically posterior ischemic optic neuropathy. Two patients demonstrated unilateral involvement. There was only one patient diagnosed with systemic involvement, presenting as mixed nephrotic and nephritic syndrome, who required a course of intravenous methylprednisolone during the active stage. Three patients required second-line immunosuppressants throughout the course due to frequent relapse. CONCLUSION: Anterior segment ocular manifestations are not uncommon and can be the initial presentation of p-ANCA-associated vasculitis (AAV). Therefore, its evaluation should be considered in establishing the diagnosis of AAV, a life-threatening disease.

Clinical efficacy of dexamethasone parabulbar injection in patients with Nonarteritic anterior ischemic optic neuropathy.

Background: Nonarteritic anterior ischemic optic neuropathy (NAAION) is a common optic neuropathy that often leads to significant visual acuity loss in patients. The present study evaluated the effects of parabulbar dexamethasone injection on visual outcomes in patients with NAAION. Methods: This retrospective case-control study included patients diagnosed with NAAION between January 2019 and December 2022. Thirty-four patients with NAAION (34 eyes) received dexamethasone parabulbar injections, while 39 patients with NAAION (39 eyes) received oral corticosteroid treatment (control group). Best-corrected visual acuity (BCVA), visual field (VF) defect, and retinal nerve fiber layer (RNFL) thickness of the affected eye were compared between groups at baseline and 2, 6, and 12 weeks post-treatment. Results: Mean BCVA significantly improved after 6 and 12 weeks in the injection groups compared with the control group (all P < 0.01). The visual field indices, mean deviation and pattern standard deviation significantly improved in the injection group compared with the control group after 2, 6, and 12 weeks (all P < 0.01). The RNFL showed a remarkable decrease in edema after 6 weeks (superior and nasal P values 0.005 and 0.013, respectively) in the injection group compared with the control group. Significant RNFL thinning was also observed in superior, inferior, temporal, and nasal quadrants in the control group after 12 weeks (all P values < 0.01). Also, fewer side effects were observed in the injection group compared to the control group. Conclusions: The results of this study suggested that dexamethasone parabulbar injection might be a safe and effective intervention for relieving visual acuity and VF in patients with NAAION.

Perivascular neurons instruct 3D vascular lattice formation via neurovascular contact.

The vasculature of the central nervous system is a 3D lattice composed of laminar vascular beds interconnected by penetrating vessels. The mechanisms controlling 3D lattice network formation remain largely unknown. Combining viral labeling, genetic marking, and single-cell profiling in the mouse retina, we discovered a perivascular neuronal subset, annotated as Fam19a4/Nts-positive retinal ganglion cells (Fam19a4/Nts-RGCs), directly contacting the vasculature with perisomatic endfeet. Developmental ablation of Fam19a4/Nts-RGCs led to disoriented growth of penetrating vessels near the ganglion cell layer (GCL), leading to a disorganized 3D vascular lattice. We identified enriched PIEZO2 expression in Fam19a4/Nts-RGCs. Piezo2 loss from all retinal neurons or Fam19a4/Nts-RGCs abolished the direct neurovascular contacts and phenocopied the Fam19a4/Nts-RGC ablation deficits. The defective vascular structure led to reduced capillary perfusion and sensitized the retina to ischemic insults. Furthermore, we uncovered a Piezo2-dependent perivascular granule cell subset for cerebellar vascular patterning, indicating neuronal Piezo2-dependent 3D vascular patterning in the brain.

An overview of neuro-ophthalmic disorders at Jenna Ophthalmic Center, Baghdad, Iraq (2021-2022).

Neuro-ophthalmic disorders are often documented individually for each illness, with little data available on their overall incidence and pattern. The overall incidence of neuro-ophthalmic illnesses in Iraq is still not recorded. This study aimed to evaluate the clinical, demographic, and etiological features of patients seeking consultation at an Iraqi neuro-ophthalmology clinic. A prospective cross-sectional observational research was conducted at the Janna Ophthalmic Center in Baghdad, Iraq. The center serves a diverse patient population from various governorates. All newly diagnosed patients with neuro-ophthalmic disorders who visited the neuro-ophthalmological clinic, regardless of gender or age group, were included. The neuro-ophthalmologist established a diagnosis for each case by reviewing the patient's medical history, doing physical examinations, administering specific tests, and, in certain cases, using neuroimaging methods. The duration of the study was extended from March 2021 to November 2022. Among the 6440 patients evaluated, 613 cases were confirmed at the neuro-ophthalmology clinic. Ischemic optic neuropathy (NAION, AION, and PION) was the most prevalent diagnosis, accounting for 17.61% of newly reported cases in the field of neuro-ophthalmology. This was followed by sixth nerve palsy. Diabetes mellitus affected 42.7% of the cases, followed by hypertension, which affected 39.3% of the participants. The incidence of neuro-ophthalmic diseases tended to be high. Ischemic optic neuropathy and sixth nerve palsy, traumatic/compressive optic neuropathy, and papilledema were the most common neuro-ophthalmic disorders reported.

Efficacy and safety of platelet-rich plasma for acute nonarteritic anterior ischemic optic neuropathy: a prospective cohort study.

Background: As the most common acute optic neuropathy in older patients, nonarteritic anterior ischemic optic neuropathy (NAION) presents with varying degrees of visual acuity loss and visual field defect. However, there is no generally accepted treatment for NAION. Objectives: To evaluate the efficacy and safety of platelet-rich plasma (PRP) for patients with acute NAION within 2 months. Design: A prospective, nonrandomized controlled trial. Methods: Twenty-five eyes of 25 patients were enrolled. Of them, 13 received anisodine hydrobromide and butylphthalide-sodium chloride injection continuously for 10 days as basic treatment in the control group, and 12 received two tenon capsule injections of PRP on a 10 days interval as an additional treatment in the PRP group. We compared the best-corrected visual acuity (BCVA) and capillary perfusion density (CPD) of radial peripapillary capillaries and the moth-eaten eara of the peripapillary superficial capillary plexus and deep capillary plexus at 1 day (D1) before the first PRP treatment and 7 days (D7), 14 days (D14), and 30 days (D30) after the first PRP injection. Ocular and systemic adverse effects were assessed. Results: In the PRP group, a better BCVA occurred at D30 (adjusted p = 0.005, compared with D1, recovered from 0.67 ± 0.59 to 0.43 ± 0.59), and a significant improvement in CPD was observed at D30 (adjusted p < 0.001, p = 0.027, p = 0.027, compared with D1, D7, D14, in sequence, the value was 35.97 ± 4.65, 38.73 ± 4.61, 39.05 ± 5.26, 42.71 ± 4.72, respectively). CPD at D7 in the PRP group was better than that in the control group (p = 0.043). However, neither BCVA nor the moth-eaten area index were significantly different (all p > 0.5) between the two groups. The main adverse effect was local discomfort resolved within 1 week, and no other systemic adverse events occurred. Conclusion: Tenon capsule injection of PRP was a safe treatment for AION and could improve capillary perfusion of the optic nerve head and might be helpful in increasing short-term vision in patients with acute NAION.

A rare case of simultaneous occurrence of non-arteritic anterior ischemic optic neuropathy and corpus callosum ischemia.

PURPOSE: To report a case of non-arteritic anterior ischemic optic neuropathy (NAION) in an elderly patient with ischemia of the left splenium of the corpus callosum, providing details of the diagnostic work-up and subsequent follow-up. METHODS SECTION: Case report. RESULTS: A pseudophakic 80 years-old woman referred complaining sudden visual impairment in the left eye (LE) in concomitance with episode of hypertensive crisis. Fundus examination showed diffuse swelling of optic disc associated with flame peripapillary hemorrhages in LE and small crowded disc in right eye (RE). A superior altitudinal defect with arcuate defect including the blind spot were detected at the visual field in the LE. The patient was diagnosed with NAION. Five days later the patient complained a further vision loss and a pathological area within the left splenium of corpus callosum, consistent ischemia, was depicted at magnetic resonance imaging of brain. Corpus callosum infarction was completely asymptomatic and neurological evaluation was normal. At 45 days follow-up fundus examination showed white ischemic nerve while visual field was irreversibly constricted with tubular defect in LE. CONCLUSION: In case of NAION linked with corpus callosum ischemia multimodal imaging and systemic work-up play a pivotal role for an early diagnosis.