Search Results (31)

Non-arteritic anterior ischemic optic neuropathy (NAION) leads to retinal ganglion cell (RGC) loss and visual impairment, with no effective treatment. This study investigated the neuroprotective effect of 670 nm photobiomodulation (PBM) in a rat NAION model (rNAION). Wistar rats received 670 nm light exposure (10-min, 3000 lux) twice daily for 3 days after rAION injury, followed by 4 days of light treatment once a day. This study evaluated the neuroprotective effects of 670 nm light in an rNAION model. Rats received 670 nm light therapy (10 min/day, 3000 lux) for seven days post-injury. Treatment improved visual function (a 3.36-fold increase in FVEP amplitude), enhanced RGC survival (1.55-fold), and reduced apoptosis (a 15.86-fold reduction in TUNEL-positive cells). Inflammatory cytokines and ED1+ macrophage infiltration were significantly decreased. Oxidative stress was attenuated, with increased ATP, Nrf2, and PGC-1α levels and improved mitochondrial dynamics. These findings support 670 nm light as a potential therapy for NAION. Full article

Mitochondria are vital organelles responsible for ATP production and metabolic regulation, essential for energy-intensive cells such as retinal ganglion cells. Dysfunction in mitochondrial oxidative phosphorylation or mitochondrial DNA (mtDNA) pathogenic variants can disrupt ATP synthesis, cause oxidative stress, and lead to cell death. This has profound implications for tissues such as the retina, optic nerve, and retinal pigment epithelium, which are dependent on robust mitochondrial function. In this review, we provide a comprehensive compilation of pathogenic variants in the mtDNA associated with various ophthalmic diseases, including Leber’s hereditary optic neuropathy, chronic progressive external ophthalmoplegia, Leigh syndrome, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, among others. We highlight the genetic variants implicated in these conditions, their pathogenic roles, and the phenotypic consequences of mitochondrial dysfunction in ocular tissues. In addition to well-established mutations, we also discuss the emerging evidence of the role of mtDNA’s variants in complex multifactorial diseases, such as non-arteritic anterior ischemic optic neuropathy, primary open-angle glaucoma, and age-related macular degeneration. The review aims to serve as a valuable resource for clinicians and researchers, providing a detailed overview of mtDNA pathogenic variants and their clinical significance in the context of mitochondrial-related eye diseases. Full article

Nonarteritic anterior ischemic optic neuropathy (NAION) is an ischemic lesion of the anterior optic nerve (ON), currently untreatable due to the length of time from symptom onset until treatment. We evaluated angiotensin-(1-7) (Ang-(1-7)): the MAS1-receptor ligand, as a possible NAION treatment using the rodent NAION model (rNAION). Long-Evans rats were unilaterally rNAION-induced. One-day post-induction, lesion severity was quantified via optic nerve head (ONH) edema using spectral domain optical coherence tomography. Animals meeting rNAION induction criteria were randomized into (1) Subcutaneous Ang-(1-7) infusion for 28 days and (2) Vehicle. Visual function was assessed using both visual acuity and flash visual evoked potentials (fVEP). Tissues were collected >30d and RGC neurons were quantified by stereology. ONs were histologically examined for inflammation. Ang-(1-7) improved post-rNAION visual function. Ang-(1-7)-treated animals showed improved visual acuity (ANCOVA: p = 0.0084) and improved fVEP amplitudes (ANCOVA: p = 0.0378) vs vehicle controls. The relative degree of improvement correlated with ONH edema severity. Treated animals showed trends towards increased RGC survival, and reduced optic nerve inflammatory cell infiltration. Ang-(1-7) is the first agent effective ≥1 day after rNAION induction. Ang-(1-7) type agonists may be useful in improving long-term function and neuronal survival in clinical NAION and other forms of white matter ischemia. Full article

The treatment of arteritic anterior ischemic optic neuropathy (AAION), non-arteritic ischemic optic neuropathy (NAAION), and posterior ischemic optic neuropathy (PION) is a topic of ongoing research with mixed evidence on some pharmacotherapies and a need for more consensus. This manuscript provides an overview of these conditions’ current, potential future, and attempted pharmacotherapies. AAION’s current treatment regimen consists of high-dose steroids, with methotrexate, tocilizumab, and abatacept, being the most viable steroid-sparing therapy candidates. As for NAAION, the treatments being tried are vast, with mixed evidence supporting each modality. Similarly, despite the various treatment options explored, there still needs to be a universally effective therapy for PION. More research is needed to formulate an agreed-upon treatment regimen for these conditions. Full article

Purpose: While patients with cardiovascular comorbidities are at a higher risk for the occurrence of non-arteritic anterior ischemic optic neuropathy (NAION), it is unclear whether adherence to medication results in risk reduction. The purpose of this study was to investigate whether nonadherence to medical therapy for cardiovascular morbidity correlates with a higher risk for NAION when compared to patients with strict adherence. Methods: A retrospective case-control study was conducted among members of Clalit Health Services in Israel from 2001 to 2022. For each of the 757 NAION cases, three controls (totaling 2271 patients) were matched based on birth year and sex, with a propensity score analysis employed to adjust for a range of comorbidities. A patient was deemed nonadherent with medical treatment if their purchased quantity of medication was less than 60% of the prescribed annual dosage. Mixed models were used to evaluate exposure differences, and conditional logistic regression was applied, incorporating adjustments for socioeconomic status and ethnicity, to examine the impact of medication nonadherence on NAION risk. Results: A total of 3028 patients were included in the study; 757 patients with the diagnosis of NAION and 2271 in the matched control group. The average age of NAION patients was 69 ± 9 years and 55% were male. After adjustments for socioeconomic status and ethnicity, nonadherence to calcium channel blockers (CCBs) (odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.03–1.71) and anti-arrhythmic (OR: 5.67, 95% CI: 1.89–21.2) medications emerged as significant risk factors. Similarly, nonadherence to cardioprotective medications (OR: 1.46, 95% CI: 1.23–1.74) was also identified as a significant risk factor. Conclusions: Nonadherence to treatments for cardiovascular disease, specifically to medications known to improve prognosis, is associated with a higher risk for NAION. Full article

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. Full article

We evaluated whether inhibiting sterile alpha and (Toll/interleukin receptor (TIR)) motif-containing 1 (SARM1) activity protects retinal ganglion cells (RGCs) following ischemic axonopathy (rodent nonarteritic anterior ischemic optic neuropathy: rNAION) by itself and combined with ciliary neurotrophic factor (CNTF). Genetically modified SARM1(−) rats were rNAION-induced in one eye and compared against equivalently induced wild-type animals of the same background. Optic nerve (ON) diameters were quantified using optical coherence tomography (SD-OCT). RGCs were quantified 30 d post-induction using retinal stereology for Brn3a(+) nuclei. ON sections were analyzed by TEM and immunohistochemistry. SARM1(−)(−) and WT animals were then bilaterally sequentially rNAION-induced. One eye received intravitreal vehicle injection following induction; the contralateral side received CNTF and was analyzed 30 d post-induction. Inhibiting SARM1 activity suppressed axonal collapse following ischemic axonopathy. SARM1(−) animals significantly reduced RGC loss, compared with WT animals (49.4 ± 6.8% RGC loss in SARM1(−) vs. 63.6 ± 3.2% sem RGC loss in WT; Mann–Whitney one-tailed U-test, (p = 0.049)). IVT-CNTF treatment vs. IVT-vehicle in SARM1(−) animals further reduced RGC loss by 24% at 30 d post-induction, but CNTF did not, by itself, improve long-term RGC survival in WT animals compared with vehicle (Mann–Whitney one-tailed t-test; p = 0.033). While inhibiting SARM1 activity is itself neuroprotective, combining SARM1 inhibition and CNTF treatment generated a long-term, synergistic neuroprotective effect in ischemic neuropathy. Combinatorial treatments for NAION utilizing independent neuroprotective mechanisms may thus provide a greater effect than individual treatment modalities. Full article

Non-arteritic anterior ischemic optic neuropathy (NA-AION) represents one of the most important causes of blindness or severely impaired vision in middle-aged and elderly people. Unilateral optic disc edema and abrupt, painless vision loss are its defining features. It is commonly assumed that NA-AION is caused by an ischemic infarction of the optic nerve head, and, although the exact pathogenesis is still unknown, several risk factors and comorbidities associated with its development have been found. NA-AION occurs generally in patients older than 50 years who have small optic discs and vasculopathy risk factors. Even though numerous treatment options have been proposed, no available effective medical or surgical therapy or prophylactic measure for NA-AION currently exists. The purpose of present-day therapeutic strategies is therefore to identify and possibly control any underlying modifiable risk factors, aiming to prevent the development of new NA-AION episodes in the affected and fellow eye. A thorough assessment of NAION, including its history, epidemiology, etiology, pathophysiology, risk factors, associated comorbidities, clinical findings, diagnostic tests, treatment choices, prognosis, and future research, is the goal of this work. Full article

Purpose: This study aimed to investigate whether intravitreal aflibercept was safe and effective in patients with acute nonarteritic anterior ischemic optic neuropathy (NAION). Methods: This was a chart study of 25 individuals with acute NAION (25 eyes). An intravitreal injection of 2 mg/0.05 mL of aflibercept was administered to fifteen participants. The remaining ten patients in the control group were given standard care. The researchers measured the initial visual acuity, retinal nerve fiber layer thickness (RNFLT), and automated perimetry. During the follow-up period, the researchers measured the final visual acuity, RNFLT, automated perimetry, and side effects. Results: Visual acuity and visual field assessment were significantly improved in the study group, and optical coherence tomography testing demonstrated significant disc edema resolution. The therapy results differed significantly between the two groups regarding visual outcomes (F = 0.027, p = 0.039) and RNFLT decrease (F = 5.507, p = 0.003). However, the difference in visual field alterations was not significant (F = 0.724, p = 0.387). Conclusions: Intravitreal injection of aflibercept can significantly improve visual acuity and resolve disc edema in patients with acute NAION. Intravitreal aflibercept may be an alternative treatment for acute NAION. However, a large series investigation is needed to assess the long-term therapeutic benefit and safety of intravitreal aflibercept in patients with acute NAION. Full article

Purpose: to assess the vasculature and thickness of the macula using OCT-A in patients who had experienced a previous episode of Leber hereditary optic neuropathy (LHON) or non-arteritic anterior ischemic optic neuropathy (NA-AION). Methods: twelve eyes with chronic LHON and ten eyes with chronic NA-AION and eight NA-AION fellow eyes were examined using OCT-A. The vessel density was measured in the superficial and deep plexus of the retina. Moreover, the full and inner thicknesses of the retina were assessed. Results: There were significant differences in all sectors between the groups in regard to the superficial vessel density and the inner and full thicknesses of the retina. The nasal sector of the macular superficial vessel density was affected more in LHON than in NA-AION; the same with the temporal sector of the retinal thickness. There were no significant differences between the groups in the deep vessel plexus. There were no significant differences between the vasculature of the inferior and superior hemifields of the macula in all groups and no correlation with the visual function. Conclusions: The superficial perfusion and structure of the macula assessed with OCT-A are affected both in chronic LHON and NA-AION, but more in LHON eyes, especially in the nasal and temporal sectors. Full article

Ocular neurodegenerative diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration are common retinal diseases responsible for most of the blindness causes in the working-age and elderly populations in developed countries. Many of the current treatments used in these pathologies fail to stop or slow the progression of the disease. Therefore, other types of treatments with neuroprotective characteristics may be necessary to allow a more satisfactory management of the disease. Citicoline and coenzyme Q10 are molecules that have neuroprotective, antioxidant, and anti-inflammatory properties, and their use could have a beneficial effect in ocular neurodegenerative pathologies. This review provides a compilation, mainly from the last 10 years, of the main studies that have been published on the use of these drugs in these neurodegenerative diseases of the retina, analyzing the usefulness of these drugs in these pathologies. Full article

Introduction. Glaucoma and non-arteritic anterior ischemic optic neuropathy (NAION) are optic neuropathies that can both lead to irreversible blindness. Several studies have compared optical coherence tomography angiography (OCTA) findings in glaucoma and NAION in the presence of similar functional and structural damages with contradictory results. The goal of this study was to use a deep learning system to differentiate OCTA in glaucoma and NAION. Material and methods. Sixty eyes with glaucoma (including primary open angle glaucoma, angle-closure glaucoma, normal tension glaucoma, pigmentary glaucoma, pseudoexfoliative glaucoma and juvenile glaucoma), thirty eyes with atrophic NAION and forty control eyes (NC) were included. All patients underwent OCTA imaging and automatic segmentation was used to analyze the macular superficial capillary plexus (SCP) and the radial peripapillary capillary (RPC) plexus. We used the classic convolutional neural network (CNN) architecture of ResNet50. Attribution maps were obtained using the “Integrated Gradients” method. Results. The best performances were obtained with the SCP + RPC model achieving a mean area under the receiver operating characteristics curve (ROC AUC) of 0.94 (95% CI 0.92–0.96) for glaucoma, 0.90 (95% CI 0.86–0.94) for NAION and 0.96 (95% CI 0.96–0.97) for NC. Conclusion. This study shows that deep learning architecture can classify NAION, glaucoma and normal OCTA images with a good diagnostic performance and may outperform the specialist assessment. Full article

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common cause of sudden optic nerve (ON)-related vision loss in humans. Study of this disease has been limited by the lack of available tissue and difficulties in evaluating both treatments and the window of effectiveness after symptom onset. The rodent nonarteritic anterior ischemic optic neuropathy model (rNAION) closely resembles clinical NAION in its pathophysiological changes and physiological responses. The rNAION model enables analysis of the specific responses to sudden ischemic axonopathy and effectiveness of potential treatments. However, there are anatomic and genetic differences between human and rodent ON, and the inducing factors for the disease and the model are different. These variables can result in marked differences in lesion development between the two species, as well as in the possible responses to various treatments. These caveats are discussed in the current article, as well as some of the species-associated differences that may be related to ischemic lesion severity and responses. Full article

Supplementing with vitamin B3 has been reported to protect against retinal ganglion cell (RGC) damage events and exhibit multiple neuroprotective properties in a mouse model of optic nerve injury. In this study, a rat model of anterior ischemic optic neuropathy was used to assess the neuroprotective benefits of vitamin B3 (rAION). Vitamin B3 (500 mg/kg/day) or phosphate-buffered saline (PBS) was administered to the rAION-induced rats every day for 28 days. The vitamin B3-treated group had significantly higher first positive and second negative peak (P1-N2) amplitudes of flash visual-evoked potentials and RGC densities than the PBS-treated group (p < 0.05). A terminal deoxynucleotidyl transferase dUTP nick end labeling assay conducted on vitamin B3-treated rats revealed a significant reduction in apoptotic cells (p < 0.05). Superoxide dismutase and thiobarbituric acid reactive substance activity showed that vitamin B3 treatment decreased reactive oxygen species (p < 0.05). Therefore, vitamin B3 supplementation preserves vision in rAION-induced rats by reducing oxidative stress, neuroinflammation, and mitochondrial apoptosis. Full article

Amiodarone-associated optic neuropathy (AAON) is a complex clinical diagnosis, requiring distinction from non-arteritic ischemic optic neuropathy (NAION) due to a shared at-risk patient population. Diagnosis of AAON is complicated by a varied clinical presentation and incomplete pathophysiologic mechanisms. This article reviews pertinent literature for describing and clinically delineating AAON from NAION, as well as newly reported protective mechanisms of insulin-like growth factor 1 (IGF-1) and PI3K/Akt against amiodarone-induced oxidative and apoptotic injury in retinal ganglion and pigment epithelial cells. These studies offer a basis for exploring mechanisms of amiodarone toxicity in the optic nerve. Full article