Investigative ophthalmology & visual science最新文献

Purpose: To quantify the value of using prior changes in spherical equivalent refractive error (SER) and axial length (AL) to predict future myopia progression.

Methods: For this post hoc analysis of a randomized controlled trial, we used data from children ages 5 to 12 years with SER -1.00 to -6.00 D who had been randomized 2:1 to 0.01% atropine or placebo eye drops for 24 months. Multivariable linear regression evaluated the association of baseline-to-12-month change in SER and AL versus 12-to-24-month change while controlling for age and SER or AL at 12 months. Treatment groups were pooled for analyses; sensitivity analyses were conducted using only the placebo group.

Results: Among 187 children, 136 (73%) with complete data were included. For predicting a 0.50-D-or-more SER increase of myopia in the second 12 months based on observing a 0.50-D-or-more increase of myopia in the first 12 months, the positive predictive value was 42% (19 of 45; 95% confidence interval [CI], 29%-57%). Greater baseline-to-12-month SER change was weakly associated with greater 12-to-24-month SER change (0.20 D per additional 1.00 D; 95% CI, 0.02 to 0.39; P = 0.03; partial R2 = 0.03). The 95% prediction interval half-width for 12-to-24-month change was ±0.66 D with prior change versus ±0.67 D without (difference = 0.01 D; 95% CI, -0.05 to 0.07). Analyses of AL and sensitivity analyses limited to the placebo group were qualitatively similar.

Conclusions: Changes in SER and AL of children in the prior 12 months were poor predictors of future myopia progression, limiting their usefulness for clinical decision-making or selecting participants for clinical trials.

Purpose: Emerging evidence implicates ferroptosis in trabecular meshwork (TM) injury during glaucoma pathogenesis. This study aims to systematically characterize ferroptosis-related gene signatures in primary open-angle glaucoma (POAG) and identify small-molecule therapeutics targeting this mechanism.

Methods: We performed Mendelian randomization (MR) analysis of East Asian genome-wide association study data to assess causal relationships between blood metals and POAG. Ferroptosis-related indicators (iron ions, MDA, GPX4, GSH) were measured in aqueous humor samples from patients with POAG using ELISA. Genome-wide expression of TM from patients with POAG was integrated with ferroptosis-related gene sets (FerrDb) to identify core regulatory genes. The CMap database and molecular docking were employed to screen therapeutic compounds, with subsequent validation in hydrogen peroxide (H2O2)-induced TM ferroptosis models. Digoxin was formulated as topical ophthalmic drops and administered twice daily to chronic ocular hypertension (COH) rat models to evaluate its IOP-lowering efficacy.

Results: MR analysis revealed that elevated serum iron levels causally increase POAG risk. Patients with POAG exhibited increased iron and MDA levels alongside decreased GPX4 and GSH. We identified 14 ferroptosis-related differentially expressed genes, with PPI analysis pinpointing SLC2A3, SCD, and HBA1 as hub genes linking ferroptosis to TM injury. Their dysregulation amplified lipid peroxidation cascades. CMap screening and molecular docking suggested ATPase inhibitor digoxin as a potential POAG therapeutic. Digoxin significantly attenuated H2O2-induced ferroptosis in HTMCs by reducing MDA and restoring GPX4, ultimately lowering IOP in COH eyes.

Conclusions: Our findings establish digoxin as a promising therapeutic agent that suppresses ferroptosis and reduces IOP via the SLC2A3/SCD/HBA1 pathway, providing a transformative strategy for POAG treatment.

Purpose: Photoreceptors are retinal cells with a high glucose metabolism and retinal degeneration, specifically retinitis pigmentosa (RP), affects glycolysis. We aimed to evaluate changes in the expression of genes related to glucose metabolism in rod photoreceptors at different stages of retinal degeneration in murine models and human retinal organoids.

Methods: RNA sequencing (RNA-seq) analysis was performed on a photoreceptor-like cell line induced to undergo degeneration and validated by real-time qPCR analysis of retinas from two murine models and one human organoid model of RP. Bioinformatic analysis was performed on published RNA-seq datasets from three murine RP models. Real-time qPCR analysis was also performed on retinas treated with an adeno-associated virus type 2 vector carrying the neurotrophic H105A peptide, derived from the pigment epithelium-derived factor.

Results: The aerobic glycolysis genes, Hk2, Pkm1, Pkm2, Ldha, and Slc6a6 and other glucose metabolism genes were found downregulated in the in vitro model of photoreceptor degeneration and in the in vivo RhoP23H/+, rd1, and rd10 models at early stages of the disease. The decreased expression of the aerobic glycolysis genes, except for PKM2, was confirmed in human organoids with mutations in the USH2A gene associated with RP. Expression was partially recovered in RhoP23H/+ retinas after treatment with the adeno-associated virus type 2 vector expressing the neurotrophic H105A peptide.

Conclusions: Glucose metabolism gene expression was found altered during the progression of RP in murine and human models of the disease. Expression was partially recovered in a molecular response to the treatment with the neurotrophic factor H105A.

Purpose: Compromise in trabecular meshwork (TM) function due to extracellular matrix (ECM) accumulation contributes to increased intraocular pressure (IOP) in primary open-angle glaucoma (POAG). Our previous study demonstrated the role of cathepsin K (CTSK), a potent collagenase, on ECM homeostasis, actin bundling in TM, and IOP regulation. This study was designed to understand the response of TM cells to the loss of CTSK function.

Methods: Normal primary human TM (HTM) cells transfected with either small interfering RNA (siRNA) against CTSK (siCTSK) or scrambled siRNA (siScr) as a control were screened using mass spectrometry-based quantitative proteomics for changes in protein levels. Immunofluorescence imaging was used to identify changes in the distribution of differentially expressed proteins. Flow cytometry analysis provided evidence for the cell death mechanism resulting from the loss of CTSK function. Biochemical analysis was performed to quantify filamentous actin, assess BMP1 activity, and measure calcium levels.

Results: CTSK loss significantly disrupted collagen biogenesis and ECM remodeling and increased intracellular calcium levels and the expression of calcium-regulatory proteins. Actin polymerization was increased due to protein kinase D1 (PRKD1) activation through the slingshot phosphatase 1 (SSH1)/cofilin pathway, promoting focal adhesion maturation. Despite increased apoptotic markers (CASP3, CASP7, TRADD, PPM1F), caspase-3/-7 activation was not induced, suggesting apoptosis-independent cellular remodeling. Notably, RhoQ and myosin motor proteins were significantly downregulated, indicating altered mechanotransduction.

Conclusions: Our findings underscore the multifaceted role of CTSK in maintaining critical cellular processes within the TM. Specifically, we have shown that CTSK is closely involved in regulating ECM homeostasis, influencing calcium signaling, and governing cytoskeletal dynamics and TM cellularity.

Purpose: The SIX6 gene is a major susceptibility gene for human glaucoma, and its variants have been implicated in structural and functional alterations of the retina, such as nerve fiber layer thinning and retinal ganglion cell degeneration, which contribute to glaucoma development. This study investigated whether SIX6 polymorphisms are associated with glaucoma in dogs, focusing on the Shiba-Inu and Shih-Tzu breeds.

Methods: We genotyped 19 single nucleotide polymorphisms within the SIX6 gene region in 109 Shiba-Inus (49 cases and 60 controls) and 57 Shih-Tzus (18 cases and 39 controls), followed by association analyses. Comparative sequence analysis of canine and human SIX6 was performed to assess evolutionary conservation.

Results: In Shiba-Inus, rs851962234, located in the 3'-untranslated region of SIX6, was significantly associated with glaucoma (P = 0.0047; Pc = 0.038), with the minor A allele showing a frequency of 17.3% in cases and 4.2% in controls, and conferring an increased risk (odds ratio, 3.56). In contrast, rs851962234 showed no association in Shih-Tzus, likely owing to the rarity of the A allele in this breed. No other single nucleotide polymorphisms were associated with glaucoma in either breed. A comparative analysis showed a 98.4% amino acid identity between canine and human SIX6 across the coding regions.

Conclusions: This study identifies rs851962234 in canine SIX6 as being significantly associated with glaucoma in Shiba-Inus, suggesting its potential role in modulating SIX6 expression and retinal ganglion cell vulnerability. These findings offer new insight into the genetic basis of canine glaucoma and highlight parallels and distinctions with human disease.

Purpose: To examine melanin changes in the RPE and choroid during the acute phase of Vogt-Koyanagi-Harada (VKH) disease using polarization-sensitive optical coherence tomography (PS-OCT).

Methods: This study included 15 eyes of 8 patients with new-onset VKH disease and 5 eyes of 3 patients with posterior scleritis. PS-OCT captured a 12 × 12 mm area centered on the fovea, and en face images were created for the RPE and choroid. Polarimetric entropy within a 6-mm diameter circle centered on the fovea was calculated and compared between groups.

Results: Choroidal polarimetric entropy was significantly lower in eyes with VKH disease than in those with posterior scleritis at baseline (0.296 ± 0.047 vs. 0.392 ± 0.050; P = 0.005; r = 0.64; 95% confidence interval, 0.42-0.74). One month after starting treatment, eyes with VKH disease showed a significant increase in choroidal polarimetric entropy (0.296 ± 0.047 to 0.350 ± 0.075; P = 0.001; r = 0.85; 95% confidence interval, 0.61-0.95), whereas no significant change was observed in eyes with posterior scleritis. RPE polarimetric entropy showed no significant changes between baseline and 1 month, with no differences between groups.

Conclusions: PS-OCT revealed that choroidal melanin density decreased during the acute phase of VKH disease and significantly increased after treatment. PS-OCT provides a noninvasive method for observing melanin dynamics in VKH disease and aids in differentiating it from posterior scleritis. PS-OCT could offer valuable insights into the pathology of VKH disease and its potential implications for management.

Purpose: Ocular rosacea (OR) is a chronic inflammatory and vision-threatening disease of the ocular surface often associated with Meibomian gland dysfunction (MGD). Despite its clinical impact, OR remains underdiagnosed and incurable. The pathogenesis of OR and MGD is poorly understood, partly due to a lack of reliable models. This study aimed to develop a rat model of MGD and OR, and validate its relevance by comparing with the human pathology.

Methods: Rat upper eyelids were exposed to UVB (300 mJ/cm2/day) for 5 days. Clinical signs, Meibomian gland (MG) morphology, and function were assessed and compared with human OR samples. Transcriptomics and lipidomics were performed to investigate UVB-induced changes.

Results: UVB caused acute damage to eyelid skin and MGs with increased oxidative stress, mitochondrial dysfunction, apoptosis, inflammation, and elevated lipid production. Whereas inflammation and lipid hyperproduction decreased during the 2-week healing process, MG duct hyperkeratinization and meibocyte stem cell depletion persisted, leading to MGD and corneal epithelial defects. Progressive fibrosis in rat MGs was similar to that observed in human patients with OR, suggesting chronic and irreversible damage to MGs. Transcriptomic analysis showed shared gene regulation patterns between UVB-induced rat MGs and human rosacea and MGD. Lipidomic analysis revealed UVB-induced changes in MG lipid composition.

Conclusions: This model is a valuable tool for studying the pathophysiology of MGD in OR and evaluating new treatments. The transcriptomic and lipidomic similarities between rat model and human disease provide insights into shared molecular pathways and lipid composition, offering potential biomarkers for diagnosis and therapeutic targets.

Purpose: Clinical proteomics enhances our understanding of biological functions and pathological processes. Since the localization of various protein clusters within the cornea is still unknown, a spatial model of the human corneal proteome was established.

Methods: In this study, successive layers of corneal tissue from five human corneas were ablated using a nanosecond mid-infrared laser, with ablation depth verified by optical coherence tomography. Each layer was analyzed by LC-MS/MS-based quantitative proteomics to generate a spatial map of the corneal proteome.

Results: A total of 4,454 proteins were identified. A clear distinction between proteome clusters reflecting the tissue layers within the cornea was observed. Various biological processes were localized in the individual segments of the cornea. Increased abundances of metabolic proteins in the epithelium reflected high metabolic activity and regeneration processes. The endothelium was characterized by high energy demand and increased levels of transmembrane proteins. Notably, the stroma exhibited significantly higher abundances of immune-related proteins. A distinct proteomic profile was also observed in the subepithelial region, which is clinically involved in corneal wound healing.

Conclusions: These results highlight the proteomic differentiation and functional specialization of individual corneal layers and provide insights into key biological processes, including immune responses, wound healing, and corneal homeostasis. Additionally, these findings hold the potential to be contrasted with pathological conditions and to trace the morphological localization of pharmacological target molecules.

Purpose: The purpose of this study was to investigate the effects of repeated red laser irradiation at a supraclinical dose on histology and apoptosis-related molecular markers in guinea pig ocular tissues.

Methods: Guinea pigs (1 month old) were randomized into two groups: the repeated irradiation group and the control group. After pupil dilation, the repeated irradiation group received binocular red laser (650 nm, 10 mW) exposure for 3 minutes per session, 6 sessions daily, over 8 days. Ocular surface morphology was examined using slit lamp microscopy. Retinal histopathology was assessed by hematoxylin and eosin (H&E) staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, immunohistochemistry, and immunofluorescence. Protein and mRNA expression of apoptosis-related markers (Caspase-3, Caspase-9, Bax, and Bcl-2) were quantified by Western blotting and quantitative polymerase chain reaction.

Results: Repeated red laser exposure-induced lesions localized to the retina temporal to optic nerve, characterized by outer nuclear layer (ONL) pyknosis, photoreceptor inner/outer segments degeneration, and retinal pigment epithelium (RPE) disruption. TUNEL staining revealed a significant increase in apoptotic cells within the ONL of irradiated eyes compared with controls (84.33 ± 54.32 vs. 5.06 ± 2.99 cells/section, P = 0.002). Analysis of apoptosis-related proteins revealed upregulation of Bax protein (P < 0.05), downregulation of Bcl-2 mRNA (P < 0.05), and an increased Bax/Bcl-2 mRNA ratio (P < 0.01). Pro-Caspase-9 protein levels decreased (P < 0.05), whereas Caspase-3 gene expression was elevated (P < 0.001). The RPE layer showed disrupted continuity with RPE65 expression reduced within 1000 µm of the optic nerve (1.00 ± 0.13 vs. 0.69 ± 0.07, P < 0.001).

Conclusions: Through repeated red laser irradiation at supraclinical dose and frequencies, this study identified the vulnerable targets of red laser in the fundus, demonstrating damage to the ONL, photoreceptor inner/outer segments, and RPE, whereas no adverse effects were observed on anterior segment structures including the cornea and lens.

Purpose: The purpose of this study was to determine which baseline factors, including ultra-widefield fluorescein angiography (UWF-FA) nonperfusion and macular optical coherence tomography angiography (OCTA) metrics, predict 2-year progression of retinal nonperfusion on UWF-FA in diabetic retinopathy (DR).

Methods: This prospective observational study included 73 patients (110 eyes) with diabetes across the spectrum of DR severity, followed for 2 years. Retinal nonperfusion was manually quantified as ischemic index, and progression was calculated as the 2-year minus baseline ischemic index for gradable retina. For receiver operating characteristic (ROC) analyses, progression was further defined as a binary event when the 2-year ischemic index increase exceeded two standard deviations (SDs) above the mean progression observed in non-referable DR. Linear mixed-effects models evaluated baseline predictors, and ROC analyses assessed the discriminative performance of significant predictors.

Results: Mean 2-year ischemic index progression was 0.45 ± 0.90%, with greater progression in moderate and severe nonproliferative DR than in non-referable DR. In multivariate models, greater baseline ischemic index (standardized β = 0.27, P = 0.002), higher deep capillary plexus (DCP) geometric perfusion deficit (β = 0.36, P = 0.006), and lower DCP vessel density (β = -0.22, P = 0.012) independently predicted total nonperfusion progression. Baseline ischemic index, DCP geometric perfusion deficit, and DCP vessel density yielded areas under the curve of 0.84, 0.77, and 0.70, respectively, for detecting binary nonperfusion progression.

Conclusions: In this cohort, baseline UWF-FA nonperfusion was the strongest predictor of retinal nonperfusion progression, whereas macular DCP OCTA metrics provided independent, noninvasive prognostic information. Macular DCP OCTA parameters may serve as adjunctive biomarkers to refine DR risk stratification, particularly when UWF-FA is unavailable.