Aqueous Humor Research Articles

A case report of Penicillium chorioretinitis in a Border Collie dog

Systemic fungal pathogens typically gain entry through a single portal and disseminate to affect multiple body systems. Infections caused by fungal Penicillium species are rare in dogs, and these cases have a poor prognosis. An unknown Penicillium species was isolated from the right eye of a middle‐aged Border Collie without evidence of systemic disease. Due to financial limitations, an extensive diagnostic evaluation could not be performed. Histopathology alone failed to identify the specific causative agent; however, fungal culture on aqueous humor provided the definitive diagnosis. This case highlights the advantage of collecting ocular fluids after enucleation to diagnose atypical fungal infections.

Current trends and advancements in utilizing endoscopic cyclophotocoagulation for the Treatment of Glaucoma.

Glaucoma ranks as the second most prevalent cause of global blindness. Presently, the reduction of intraocular pressure (IOP) stands as the sole efficacious method for addressing this condition. Endoscopic cyclophotocoagulation (ECP) is designed to mitigate aqueous humor production by inducing coagulation or closure of the ciliary body. Since its inception in 1990s, ECP has emerged as a pivotal modality in the therapeutic armamentarium for glaucoma. This review primarily elucidates the instrumentation employed in ECP for the treatment of glaucoma, the mechanisms underlying its efficacy in glaucoma management, and a comparative analysis of ECP in relation to other modalities for anti-glaucoma treatment. Furthermore, it examines the contemporary clinical utilization of ECP in glaucoma therapy, as well as the prevalent postoperative complications and their preventive measures. We anticipate that the role of ECP in the treatment of glaucoma will persistently evolve alongside advancements in the field. Particularly noteworthy is its expanding applicability in glaucoma therapy and its increasingly vital role in personalized comprehensive treatment approaches.

Abstract A062: Insightful analysis: Harnessing aqueous humor ctDNA for retinoblastoma stratification

Abstract Retinoblastoma (RB) the most common intraocular malignancy in children poses a significant challenge as traditional tissue biopsies are not feasible. Due to its critical location within the eye and the high risk of tumor seeding, clinicians are limited in performing molecular analysis-based risk stratification prior to enucleation. In this study, we explored the potential of aqueous humor (AH) as a source for minimally invasive liquid biopsies, aiming to establish a molecular profiling methodology for circulating tumor DNA (ctDNA) for risk stratification. We analyzed AH samples and corresponding tumor tissues from 19 enucleated eyes of patients diagnosed with RB. The extracted ctDNA from AH underwent low-coverage whole-genome sequencing (lcWGS) and methylation profiling. These data were then compared with the genomic and methylation landscapes of the matched tumor DNA. Additionally, we assessed the ability of AH- derived ctDNA to predict retinoblastoma methylation cluster. Our findings demonstrate a high concordance between ctDNA from AH and the primary tumor DNA in both methylation patterns and genomic alterations detected by lcWGS allowing the correct prediction of the retinoblastoma molecular group. The shared aberrations underscore the potential of AH as a reliable surrogate for tumor tissue in retinoblastoma. Additionally, the methylation profiles revealed consistent epigenetic modifications, further supporting the accuracy of AH-derived ctDNA in reflecting the tumor’s molecular characteristics. This study highlights the feasibility and effectiveness of using AH for molecular ctDNA genetic analysis in retinoblastoma. The overall high concordance between ctDNA profiles with primary tumor DNA and the ability to accurately predict RB methylation classes, highlights the superiority of the liquid biopsy approach overcoming the limitations of traditional biopsies and transforming the potential for early molecular analysis and risk stratification. This revolutionary technique could redefine pre-enucleation diagnostics, offering unprecedented insights and paving the way for tailored, precision medicine in retinoblastoma care. Citation Format: Sophia H Montigel, Tatsiana Ryl, Stefanie Volz, Elena Afanasyeva, Tatjana Wedig, Nathalie Schwarz, Stefan M Pfister, Kristian W Pajtler, Petra Ketteler, Kendra K Maaß. Insightful analysis: Harnessing aqueous humor ctDNA for retinoblastoma stratification [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A062.

Abstract B030: Advancing precision management in retinoblastoma via aqueous humor liquid biopsy: A case of TP53 and MDM4 alterations

Abstract Background: Precision medicine has revolutionized cancer treatment, but its application in retinoblastoma (RB) has been limited due to the risks associated with traditional tumor biopsies, which can lead to the spread of cancer outside the eye. Blood plasma has not been effective in intraocular RB management because the blood-brain barrier (BBB) prevents tumor-derived material from entering the bloodstream, and in cases of bilateral RB—occurring in over 40% of patients—each eye may harbor distinct genomic alterations, complicating the use of blood-based biomarkers. Given these challenges, the discovery of tumor-derived genomic material in the aqueous humor (AH) offers a promising and safer alternative—a liquid biopsy that provides localized and specific insights into the tumor's genetic makeup. Although AH liquid biopsies have been valuable in identifying genomic changes in RB, they have yet to guide treatment decisions. This is primarily due to the rarity of the disease, the heterogeneity of treatment modalities, and the unclear definition of in vivo RB subtype classifications. Consequently, translating these genomic insights into actionable, personalized treatment strategies has been challenging. Now, we present the first application of AH-monitored treatment in a 35-month-old male with unilateral RB, characterized by TP53 alteration and ecDNA-MDM4 amplification, highlighting a significant advancement in the precision management of RB. Methods: AH samples were obtained via clear corneal paracentesis and analyzed for copy number alterations and somatic variants using shallow whole-genome sequencing and targeted sequencing. The patient initially received systematic CEV, followed with intravitreal melphalan (IVM) monotherapy. Due to resistance, treatment was escalated to a combination of intravitreal melphalan and topotecan (IVM+IVT), monitored by the AH liquid biopsy genomic findings. Results:The patient initially showed resistance to monotherapy with intravitreal melphalan (IVM), but dual therapy with melphalan and topotecan (IVM+IVT) significantly reduced tumor fraction (TFx) from 81.61% to 26.63% and decreased tumor size. Continued dual therapy and subsequent topotecan monotherapy resulted in complete regression of vitreous seeds and stabilization of the disease, as indicated by a final AH TFx of 0%. At our institution, Children's Hospital Los Angeles (CHLA), the majority of RB cases are treated using IAC or IVM, with dual chemotherapy regimens rarely employed. Conclusions: This case underscores the importance of tailoring treatment protocols to genetic profiles identified through AH liquid biopsy in managing aggressive RB. The successful combination of genomic profiling and personalized therapy has potential to significantly improve clinical outcomes, marking a critical step toward real precision management of RB. Further clinical collaboration is essential to validate and refine protocols for TP53-altered and ecDNA-MDM4-driven RB. Citation Format: Liya Xu, Elaine Huang, Jesse Lee Berry. Advancing precision management in retinoblastoma via aqueous humor liquid biopsy: A case of TP53 and MDM4 alterations [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B030.

Ocular Pharmacokinetics of Faricimab Following Intravitreal Administration in Patients With Retinal Disease.

To characterize faricimab ocular and systemic pharmacokinetics (PK) in patients with neovascular age-related macular degeneration (nAMD) or diabetic macular edema (DME) and to assess the effect of faricimab ocular exposure on clinical endpoints. A population PK (popPK) model was developed using pooled data from phase 1 to 3 studies in patients with nAMD/DME. The dataset included 1095 faricimab aqueous humor (AH) concentrations from 284 patients and 8372 faricimab plasma concentrations from 2246 patients. Following intravitreal administration, faricimab PK was accurately described by a linear three-compartment model with sequential vitreous humor (VH), AH, and plasma compartments. Faricimab VH elimination to AH is the slowest process, with an estimated half-life (t1/2) of 7.5 days. Due to flip-flop kinetics, plasma, AH, and VH concentrations declined in parallel. Disease had no effect on faricimab PK. Plasma exposure was ∼6000-fold lower than VH exposure. Age, anti-drug antibodies, body weight, and sex statistically significantly influenced PK parameters but had no clinically meaningful effect on ocular and systemic exposure. VH t1/2 alone could not explain faricimab dosing frequency. Exposure-response analyses showed similar gains in best-corrected visual acuity across faricimab exposure ranges and dosing regimens. Faricimab ocular and systemic pharmacokinetics were quantified and accurately described by the popPK model, developed using a large dataset from patients with nAMD/DME. Exposure-response analyses suggest that faricimab phase 3 dosing algorithms are appropriate to select the most suitable dosing regimen. The popPK analysis suggested that faricimab dosing frequency was influenced by several factors and not by VH t1/2 alone.

Ocular Pharmacodynamics of Intravitreal Faricimab in Patients With Neovascular Age-Related Macular Degeneration or Diabetic Macular Edema.

Evaluate the ocular pharmacodynamics (PD) of intravitreal faricimab, a bispecific inhibitor of angiopoietin-2 (Ang-2) and vascular endothelial growth factor-A (VEGF-A), in patients with neovascular age-related macular degeneration (nAMD) or diabetic macular edema (DME). Aqueous humor (AH) samples (1025 free Ang-2 concentrations and 1345 free VEGF-A concentrations) were collected from approximately 300 faricimab-treated patients with nAMD or DME in phase2/3 trials. A population pharmacokinetic pharmacodynamic (popPKPD) model was developed to describe the dynamic effect of faricimab on free AH Ang-2 and VEGF-A. Mean baseline Ang-2 concentrations were 8.1 and 13.4pg/mL in patients with nAMD and DME, respectively. The corresponding mean baseline VEGF-A concentrations were 58 and 135pg/mL, respectively. Overall, approximately 79% of Ang-2 (84% within 8 weeks postdose and 55% beyond 12 weeks postdose) and 7% of VEGF-A postdose observations were below the lower limit of quantification. Model-derived Ang-2 and VEGF-A concentration-time profiles for patients on every 4-week/every 8-week dosing were predicted to maintain greater than 50% suppression of Ang-2 concentrations for the entire dosing period. Patients on every 12-week/16-week dosing were predicted to have greater than 50% Ang-2 suppression for 12 or more weeks, whereas 50% VEGF-A suppression was maintained for 9 to 10 weeks. At 8 weeks postdose, the median Ang-2 concentrations remained suppressed by approximately 80%. At 16 weeks postdose, the median VEGF-A concentrations returned to baseline, but median Ang-2 levels remained below baseline. A popPKPD analysis demonstrated faricimab's rapid and sustained suppression of AH Ang-2 and VEGF-A. A popPKPD analysis suggested that sustained suppression of ocular Ang-2 contributes to faricimab's extended durability, observed in clinical trials.

Abstract B059: Assessment of ctDNA analysis methods using high purity ctDNA from the aqueous humor of retinoblastoma eyes

Abstract Background: Whole-genome sequencing (WGS) of cell-free DNA (cfDNA) paired with methods like ichorCNA and DELFI has become a valuable approach for detecting circulating tumor DNA (ctDNA). However, the mixture of ctDNA with non-tumor cfDNA in plasma complicates accurate validation of ctDNA detection methods. In contrast, aqueous humor (AH) from treatment-free retinoblastoma (RB) eyes is uniquely enriched in ctDNA, providing an optimal source for generating reference samples. This study leverages AH-derived biological ctDNA to evaluate two established ctDNA analysis methods. Methods: Biologically derived cfDNA mixtures were created by combining WGS reads from two AH samples with pooled reads from non-tumor blood samples (N=20). One AH sample (RB_023_OS) showed >99% tumor fraction (TFx) with ichorCNA, while the other (RB_025_OD) had confirmed presence of ctDNA based on >99% variant allele frequency (VAF) for an RB1 variant, despite being somatic copy number alteration (SCNA)-negative. Mixtures were prepared across a range of TFx values (0.01-0.5) and unique sequencing coverages (0.1x, 0.5x, 1x, and 2x). TFx was calculated using ichorCNA with standard parameters and optimized parameters for low TFx levels. We also tested an enrichment strategy targeting shorter ctDNA fragments (≤150 base pairs) and generated genome-wide fragmentation profiles using the DELFI method to assess short-to-long (S:L) fragment ratios across 5-Mb bins. Results: We evaluated the impact of sequencing coverage, parameter selection, and fragment size selection on TFx estimation by ichorCNA. Standard ichorCNA parameters demonstrated limited sensitivity, detecting ctDNA only in samples with TFx of 5-6% or higher. Increasing sequencing coverage did not substantially improve the limit of detection (LoD) or the accuracy of TFx quantification. Optimized parameters reduced the LoD to 3% TFx, but only in samples with ≥0.5x coverage, indicating a dependence on sequencing depth for accurate ctDNA detection and quantification. In RB_025_OD, where no SCNAs were present, ichorCNA failed to estimate the TFx despite an RB1 VAF exceeding 99%, highlighting the platform's reliance on SCNAs for accurate TFx detection. Short fragment enrichment (≤150 base pairs) significantly increased TFx values across all samples but could be mapped back to the original TFx values accurately using polynomial curve fitting (R-squared=0.97). Genome- wide fragmentation profiles showed increasing deviation from non-tumor controls as TFx increased, with SCNA-positive samples exhibiting greater deviations than SCNA-negative samples. Conclusions: These findings demonstrate the dependence on sequencing coverage and the presence of SCNAs by current ctDNA analysis methods, highlighting their limitations for accurately detecting ctDNA in challenging scenarios. Citation Format: Nikki Higa, Peter Kuhn, Jesse L Berry, Liya Xu. Assessment of ctDNA analysis methods using high purity ctDNA from the aqueous humor of retinoblastoma eyes [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B059.

Liquid biopsy in retinoblastomas

The liquid biopsy is playing an increasingly more important role in the diagnosis and treatment of retinoblastomas. The possibility of safe and uncomplicated retrieval and examination of aqueous humour from the anterior chamber contributes significantly to the differential diagnosis and to abetter understanding of the disease. It helps with the prognosis both in terms of eye-preserving treatment and in estimating the risk of metastatic disease and helps with genetic uncertainties in unilateral disease. It is expected that the further development of liquid biopsy methods will form the basis for a personalized diagnosis and treatment of children with a retinoblastoma in the future.

The impact of vitreomacular traction on vitreous vascular endothelial growth factor and placental growth factor levels in neovascular age-related macular degeneration patients.

To investigate the effect of vitreomacular traction (VMT) on vitreous vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) levels in patients with active neovascular age-related macular degeneration (nAMD). A prospective, interventional, case-control study. The study included a total of 70 patients from whom vitreous samples were obtained. The patients were categorized into four group: 10 patients with active nAMD accompanying VMT, 17 patients with VMT, 24 patients with active nAMD and 19 healthy patients without any diagnosis other than cataract. VEGF and PlGF levels were measured. The mean vitreous VEGF level was 34.7 ± 4.98 pg/ml in the nAMD and VMT group, 32.36 ± 4.55 pg/ml in the VMT group, 34.02 ± 3.79 pg/ml in the nAMD group, and 32.33 ± 2.4 pg/ml in the healthy control group. The mean vitreous PlGF level was 58.92 ± 20.83 pg/ml in the nAMD and VMT group, 46.29 ± 3.45 pg/ml in the VMT group, 54.64 ± 16.88 pg/ml in the nAMD group, and 53.66 ± 19.35 pg/ml in the healthy control group. No significant differences were observed in terms of vitreous VEGF and PlGF concentrations among the groups (p > 0.05 and p > 0.05, respectively). Aqueous humour VEGF and PlGF levels were significantly higher than vitreous levels in nAMD patients (p = 0.005 and p = 0.005, respectively). The present study found no increases in vitreous VEGF and PlGF levels in both VMT + nAMD and VMT cases. Furthermore, patients with nAMD had significantly higher levels of PlGF and VEGF in aqueous humour compared to vitreous levels.

Ocular Tissue Distribution of Omidenepag Isopropyl in Rabbits and Cynomolgus Monkeys.

To evaluate the ocular distribution of omidenepag isopropyl (OMDI) and its active form omidenepag (OMD), an EP2 receptor agonist, after topical administration of OMDI into rabbit and monkey eyes, and to determine whether OMDI and OMD interact with target receptors or enzymes of other antiglaucoma agents. Both eyes of six rabbits and of 14 monkeys were topically instilled with 0.03% [14C]-OMDI. Rabbits were sacrificed after one to four hours, and ocular tissues were collected. Monkeys were sacrificed after 0.25 to 24 hours, and blood and ocular tissues were collected. Radioactivity was measured in each sample. The interactions of OMDI and OMD with the receptors and enzymes associated with the mechanisms of action of other antiglaucoma agents were evaluated. Most radioactivity applied to rabbit eyes was recovered as OMD from the cornea, aqueous humor, and iris-ciliary body. Similarly, high concentrations of radioactivity were observed in monkey cornea, bulbar/palpebral conjunctiva, and trabecular meshwork. OMD bound to EP2 receptors, but neither OMD nor OMDI bound to α2A, β1, and β2 adrenergic receptors or inhibited enzymatic activities of CA1 and CA2. OMD and OMDI had little or no effect on ROCK1 and ROCK2. OMDI rapidly permeates rabbit and monkey corneas and is converted to OMD, which distributes into anterior ocular tissues. Neither OMD nor OMDI interacted with the target receptors or enzymes of other antiglaucoma agents, suggesting that OMD interacts highly selectively with EP2 receptors. OMDI is a specific antiglaucoma agent that interacts selectively with ocular EP2 receptors.

Kinin B1- and B2-Receptor Subtypes Contract Isolated Bovine Ciliary Muscle: Their Role in Ocular Lens Function and Intraocular Pressure Reduction

Background: Bradykinin is an endogenously produced nonapeptide with many physiological and pathological functions that are mediated by two pharmacologically defined receptor subtypes, B1- and B2-receptors. Current studies sought to characterize the functional bradykinin (BK) receptors present in freshly isolated bovine ciliary muscle (BCM) using an organ-bath tissue contraction system. Methods: Cumulative longitudinal isometric tension responses of BCM strips (4–5 mm) were recorded before and after the addition of test compounds to BCM strips hooked up to an isometric strain gauge transducer system. Results: BK and its analogs (7–11 concentrations) contracted BCM in a biphasic concentration-dependent manner. The first high affinity/potency phase accounted for 40–60% of the maximal contraction by each of BK (potency, EC50 = 0.9 ± 0.3 nM), Lys-BK (EC50 = 0.7 ± 0.1 nM), Met-Lys-BK (EC50 = 1 ± 0.1 nM), Hyp3-BK (EC50 = 1 ± 0.2 nM), RMP-7 (EC50 = 3.5 ± 0.5 nM), and Des-Arg9-BK (EC50 = 10 ± 0.4nM) (mean ± SEM, n = 3–8). The second lower activity phase of contraction potency values for these peptides ranged between 100 nM and 3 µM. In the presence of a selective B1-receptor antagonist (R715; 0.1–10 µM), the concentration–response curves to Des-Arg9-BK (B1-receptor agonist) were still observed, indicating activation of B2-receptors by this kinin. Likewise, when B2-receptors were completely blocked by using a B2-selective antagonist (WIN-64338; 1–10 µM), BK still induced BCM contraction, now by stimulating B1-receptors. Conclusions: This agonist/antagonist profile of BCM receptors indicated the presence of both B1- and B2-receptor subtypes, both being responsible for contracting this smooth muscle. The BCM kinin receptors may be involved in changing the shape of the ocular lens to influence accommodation, and since the ciliary muscle is attached to the trabecular meshwork through which aqueous humor drains, endogenously released kinins may regulate intraocular pressure.

Preclinical and Clinical Pharmacokinetics of a New Preservative-Free Bimatoprost 0.01% Ophthalmic Gel to Treat Glaucoma and Ocular Hypertension.

Purpose: Pharmacokinetic evaluation of ocular penetration and systemic accumulation of preservative-free bimatoprost 0.01% ophthalmic gel (PFB 0.01% gel). Methods: In a preclinical study, pigmented rabbits received a single ocular administration of PFB 0.01% gel (N = 15) or preserved bimatoprost 0.01% or 0.03% ophthalmic solution [PB 0.01% (N = 15) or PB 0.03% (N = 15)]. The aqueous humor, iris, and ciliary body were analyzed for bimatoprost+bimatoprost free acid. In a Phase 1, randomized, open-label clinical study, healthy participants received PFB 0.01% gel (N = 20) or PB 0.01% (N = 20) daily in each eye (Days 1-15). Bimatoprost levels in human plasma were analyzed on Days 1 and 15. All serological analyses used validated methods. Adverse events were collected throughout and ocular assessments were performed on Days 1 and 15. Results: In the preclinical study, Cmax (bimatoprost+bimatoprost free acid) for PFB 0.01% gel, PB 0.01%, and PB 0.03% was 50.2, 26.3, and 59.9 ng/mL; AUC0.5-8 h was 134.0 ng·h/mL, 67.0 ng·h/mL, and 148.0 ng·h/mL. In the clinical study, systemic exposure to bimatoprost (AUC0-last) on Days 1 and 15 was lower for PFB 0.01% gel (0.5248 and 0.5645 ng·min/mL) than PB 0.01% (0.8461 and 0.7551 ng·min/mL), with no systemic accumulation of bimatoprost in either group. There were no clinically important differences between groups in ocular or systemic tolerability in the clinical study and no serious adverse events. Conclusions: PFB 0.01% gel showed improved ocular penetration compared with PB 0.01%. Systemic absorption was comparable, with a favorable clinical safety profile, supporting PFB 0.01% gel as a potential treatment for glaucoma and ocular hypertension.

Genetic Insights and Epidemiological Models in Understanding Primary Open Angle Glaucoma

Primary open-angle glaucoma (POAG) is a multifactorial chronic optic neuropathy with significant genetic heterogeneity. The pathogenesis of POAG involves an imbalance between the production and drainage of aqueous humor (AH). Genetic theories suggest that transgenic mice demonstrating the GLU50LYS mutation in optineurin (OPTN) experience retinal ganglion cell apoptosis, while mutant myocilin (MYOC) proteins induce endoplasmic reticulum (ER) stress, leading to an unfolded protein response (UPR) and subsequent apoptosis of trabecular meshwork cells (TMC). Furthermore, the interaction between MYOC and mitochondria in the trabecular meshwork (TM) and astrocytes may lead to mitochondrial membrane depolarization and calcium channel dysregulation, contributing to POAG. Overexpression of MYOC variants (P370L, Q368X) is also implicated, as are epigenetic modifications and signaling pathways such as histone and DNA modification. POAG has been associated with autosomal dominant inheritance, with mutations in MYOC and OPTN being prominent causative factors, although many cases involve multiple genetic loci. Currently, over 20 genetic loci have been linked to POAG, with 14 chromosomal loci (GLC1A to GLC1N) identified, 5 of which contribute to juvenile-onset open-angle glaucoma (JOAG). Of these loci, MYOC, OPTN, WD repeat domain 36 (WDR36), and neurotrophin-4 (NTF4) are the most studied causative genes. The ongoing study of molecular genetics offers potential pathways for future therapeutic advances in the treatment of POAG.

Pigment epithelium-derived factor exerts neuroprotection in oxygen-induced retinopathy by targeting endoplasmic reticulum stress and oxidative stress

Endoplasmic reticulum (ER) stress and oxidative stress have been involved in the occurrence of neuronal apoptosis in ischemic retinopathy. Pigment epitheliu-derived factor (PEDF) is well known for its multifunctional properties, including neuroprotection, anti-inflammation and antioxidant. However, the association between PEDF and ER stress or oxidative stress in ischemic retinopathy remain incompletely understood. In this study, the concentration of the key factor of ER stress C/EBP homologous protein (CHOP) in aqueous humor (AqH) and vitreous samples of proliferative diabetic retinopathy (PDR) patients were measured by ELISA assays. Oxygen-induced retinopathy (OIR) mice model was established and PEDF intravitreal injections were conducted. Primary bone marrow derived macrophages (BMDMs) were isolated and cultured under hypoxic conditions in vitro. Western blotting, real-time RT-PCR, immunofluorescence, transmission electron microscopy (TEM), TUNEL assays were performed to explore roles of PEDF on ER stress and oxidative stress, as well as subsequently neuronal apoptosis under hypoxic conditions in vivo and in vitro. The results revealed that ER stress and oxidative stress were notably activated under hypoxic conditions. We also observed that hypoxia evoked ultrastructural damage of ER and mitochondrion in the retina. However, PEDF significantly prevented ER stress and oxidative stress, as well as the damage of ultrastructure, resulting in diminution of photoreceptor apoptosis in OIR retinas. These results indicate that PEDF may play its neuroprotection role through inhibiting ER stress and oxidative stress in ischemic retinopathy, which is a novel molecular mechanism of PEDF protecting photoreceptors from ischemic damage, thereby suggesting that PEDF is an effective therapeutic agent for the treatment of neuron damage in ischemic retinal diseases.

Cyclodialysis Cleft After Intravitreal Injection

Introduction: A cyclodialysis cleft, separating the ciliary body muscle from the scleral spur, can cause ocular hypotony by creating an abnormal aqueous humor drainage pathway. Though rare, this can occur post-intravitreal injection. Case presentation: A 53-year-old man with diabetic retinopathy presented with persistent hypotony in his right eye after receiving an aflibercept intravitreal injection. On presentation, his visual acuity was 20/200, and intraocular pressure (IOP) was 2 mmHg. Examination revealed a cyclodialysis cleft in the right eye. Despite initial treatment with steroids and atropine, the hypotony persisted, leading to surgical repair via ab-interno cyclopexy. Post-surgery, IOP normalized, and vision slightly improved. At three months post-operation, IOP was stable at 16 mmHg without glaucoma medication, and no signs of hypotony were present, with vision improving to 20/150. Conclusion: Misplaced intravitreal injections can lead to cyclodialysis cleft formation. Ophthalmologists should be aware of this possible complication. Meticulous gonioscopy and the adjunctive use of ocular imaging are crucial for the proper diagnosis of these cases. Ab-interno direct cyclopexy is an effective surgical approach for cyclodialysis clefts non- responsive to medical or laser treatment.

A 32-Year-Old Male with Corneal Hydrops

Case Presentation: A 32-year-old male with a history of left eye keratoconus presented to the emergency department with left eye pain and blurry vision for two days. Out of concern for corneal hydrops, ophthalmology was consulted, and the diagnosis was confirmed. Per ophthalmology recommendations, the patient was started on hypertonic saline and prednisolone eye drops and referred to a corneal specialist. Discussion: Corneal hydrops is characterized by stromal edema caused by leakage of aqueous humor due to rupture of Descemet membrane. This case describes a patient with a keratoconus deformity who developed corneal hydrops.

Role of angiopoietin-like 4 in neovascularization associated with retinopathy of prematurity

To elucidate the mechanisms of angiopoietin-like 4 (ANGTPL4) in neovascularization (NV) in retinopathy of prematurity (ROP). We compared ANGPTL4 expression levels of aqueous humor and vitreous fluid samples in infants with acute-phase ROP and control group. ANGPTL4-/- mice and WT mice were used to constructed oxygen-induced retinopathy (OIR) mouse models, with retinal tissues collected on postnatal days 12 (P12), 15 (P15) and 17 (P17). Analysis of retinal vessels and transcriptomics were performed to explore the role of ANGTPL4 in NV. The results showed ANGPTL4 level was significantly higher in the aqueous humour and vitreous fluid of children with ROP than that of control group. At P15 and P17, the vascular indices in the ANGPTL4-/--CON group were lower than those in the WT-CON group. The central non-perfused area of the retina and number of neovascular nuclei were also smaller in the ANGPTL4-/--OIR group than in the WT-OIR group. Immunofluorescence results showed the overexpression of ANGPTL4 protein in the WT-OIR group than in the WT-CON group, especially at P17. Furthermore, extracellular matrix (ECM) organisation was one of the key involved pathways based on gene ontology (GO) enrichment analyses. ANGPTL4 was one of the core genes involved in ECM organization, and neuralized E3 ubiquitin protein ligase 1B (NEURL1B), cd36 Molecule (CD36), matrix metallopeptidase 3 (MMP3) and collagen type III alpha 1 chain (COL3A1) were the first nodes interacting with ANGPTL4.In conclusion, ANGPTL4 is involved in the pathological NV by regulating NEURL1B, CD36, MMP3, and COL3A1. Thus, ANGPTL4 is a potential therapeutic target for ROP.

Clinical Evaluation of a Novel CRISPR-Cas12a-Based RID-MyC Assay for the Diagnosis of Fungal Endophthalmitis

ObjectiveThis study evaluates the RID-MyC (Rapid Identification of Mycoses using CRISPR) assay, a CRISPR/Cas12a-based diagnostic tool, for its efficacy in diagnosing fungal endophthalmitis (FE), comparing it with panfungal PCR and culture methods. DesignA comparative cross-sectional study assessing the performance of the RID-MyC assay against established diagnostic modalities for FE. SubjectsThe study included 133 intraocular samples from 117 patients with suspected microbial endophthalmitis. MethodsThe study compared the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the RID-MyC assay against panfungal PCR and culture. The Limit of Detection (LoD) for Aspergillus flavus and Candida albicans was determined for both RID-MyC and panfungal PCR across three different media: nuclease-free water (NFW), aqueous humor (AH), and vitreous humor (VH). Discrepancy analysis was conducted for discordant results, incorporating clinical outcomes and responses to antifungal treatment. Main Outcome MeasuresThe study primarily assessed the sensitivity, specificity, PPV, and NPV for clinical samples. Time to diagnosis was also evaluated. ResultsThe RID-MyC assay demonstrated a sensitivity of 88.24% (CI: 63.56% to 98.54%) and specificity of 93.1% (CI: 86.86% to 96.98%), with PPV and NPV of 65.22% (CI: 48.45% to 78.91%) and 98.18% (CI: 93.62% to 99.50%), respectively. Discrepancy analysis enhanced sensitivity to 90.48% (CI: 69.62% to 98.83%) and specificity to 96.43% (CI: 91.11% to 99.02%). The RID-MyC assay was 10 to 1000-fold more sensitive than panfungal PCR in detecting Aspergillus flavus and Candida albicans in intraocular specimens. The time to diagnosis with the RID-MyC assay was consistently under two hours. ConclusionsThe RID-MyC assay may advance the rapid and precise diagnosis of FE, with possible relevance to other invasive fungal conditions.

Physiological activation of liver X receptor provides protection against ocular inflammation in uveitic glaucoma.

Virus-induced trabeculitis is considered a significant cause of uveitic glaucoma, being marked by a sudden increase in intraocular pressure and relatively mild inflammation in the anterior chamber of the eye. In previous proteome analyses of aqueous humor (AH) derived from Cytomegalovirus (CMV) uveitic glaucoma patients, we observed the liver X receptor (LXR) pathway to be among the most prominently activated canonical pathways. In the present study, we explored the role of the LXR pathway in the etiology of glaucoma in association with ocular inflammation. LXRα/β and ABCA1, the downstream targets of LXR, were distributed throughout the conventional AH outflow pathway of the human eye, and their increased levels in human trabecular meshwork cells in response to CMV infection and Lipopolysaccharide treatment. Treatment with an LXR agonist (T091317) suppressed LPS-induced inflammation and this response was reversed under the deficiency of LXRα/LXRβ. Furthermore, in the rat endotoxin uveitis model, the LXR agonist significantly reduced infiltrating cells and expression of proinflammatory cytokines in the iris and retina. These results reveal upregulation of LXR-ABCA1 under inflammatory insult in the conventional AH outflow pathway, and activation of LXR exhibiting an anti-inflammatory effect, implying its essential physiological protective role in glaucoma associated with ocular inflammation.

Phenotypic Biomarkers of Aqueous Extracellular Vesicles from Retinoblastoma Eyes.

Recent advancements in aqueous humor (AH) cell-free DNA (cfDNA) genomics have opened new avenues for ex vivo molecular profiling of retinoblastoma (RB), the most common pediatric intraocular malignancy, where biopsy is typically prohibited. While these insights offer a genetic blueprint of the tumor, they lack multi-omic molecular phenotyping, which is essential for understanding the functional state. Extracellular vesicles (EVs), naturally present in AH, are promising by offering time-resolved phenotypic information. We employed multiplex bead-based flow cytometry and Single Extracellular Vesicle Nanoscopy (SEVEN) to analyze EV phenotypes in AH from a cohort of five RB, with three uveal melanoma (UM) and two age-matched glaucoma (GLC) samples serving as controls. The studies identified CD133-enriched EVs uniquely in RB AH, absent in both GLC and UM AH. This was corroborated by further analysis of five RB cell lines, including two commercial (Y79, Weri) and three in-house developed lines, confirming CD133 enrichment and supporting its role as an RB-specific EV marker. Single-vesicle analysis demonstrated a strong association of CD133 with CD81 and CD63, with minimal CD9 presence. These results, validated through complementary techniques, position CD133 as a critical marker in RB-derived EVs, paving the way for enhanced multi-omic RB characterization and potential advancements in clinical diagnostics.