Cataract

Subconjunctival injection of microcrystalline prodrug of dexamethasone for long-acting anti-inflammation after phacoemulsification surgery

Long-acting injectable formulations of dexamethasone with minimal invasiveness are highly desired to manage chronic ocular inflammatory conditions. Here, we applied microcrystals (MCs) of a hydrophobic acetone-based ketal-linked prodrug of dexamethasone (SKD) to treat postoperative ocular inflammation. We compared the efficacy and safety of SKD MCs through subconjunctival (SC) injection with that of Maxidex (a topical suspension of dexamethasone MCs) through SC injection and eye drops in the phacoemulsification combined with intraocular lens implantation (Phaco-IOL) rabbit model. In Phaco-IOL rabbit eyes, a single SC injection of SKD MCs (0.4 mg dexamethasone equiv.) showed anti-inflammatory effects comparable to Maxidex eye drops and completely alleviated the inflammation within 28 days, while an SC injection of Maxidex at the same dose only provided anti-inflammatory effects for 7 days. The study on the dose-dependent anti-inflammatory effects of SKD MCs showed no significant difference in anti-inflammatory effects for the high dosage (0.8 mg dexamethasone equiv.) and the low dosage (0.4 mg dexamethasone equiv.) in 28 days. Nevertheless, systematic drug distribution of SKD MCs and Maxidex in normal rabbits after SC injection demonstrates that the drug concentration in conjunctiva was higher for the high dosage and that a considerable amount of prodrug and dexamethasone could still be detected in the cornea and iris-ciliary body at least 84 days for SKD MCs at high dosage. Furthermore, no persistent elevated intraocular pressure and abnormality in retinal structure and thickness were observed, confirming the excellent safety of long-acting SKD MCs post-SC injection. Our findings provide valuable insights into using prodrug-based MCs for treating ocular postoperative inflammation, and the detailed drug distribution analysis would promote the clinical translation of these MCs in ocular diseases.

Spatial and morphologic features of lenses with different axial lengths in cataract patients: a swept-source optical coherence tomography-based study

BACKGROUND

To investigate the spatial and morphologic features of lenses with different axial length (ALs) in cataract patients using swept-source optical coherence tomography (SS-OCT).

METHODS

Totally 105 eyes of 105 patients scheduled to have cataract surgery were included. Eyes were divided into the control (AL < 24.5 mm), moderate myopia (MM, 24.5 ≤ AL < 26 mm) and high myopia (HM, AL ≥ 26 mm) groups. Spatial features including lens vault (LV) and iris-to-lens distance (ILD), and morphologic features including radii of curvature of anterior and posterior surface (Ra, Rp), lens diameter (LD) and lens thickness (LT) were measured in eight directions by SS-OCT.

RESULTS

Spatially, the HM group had larger LV and ILD than the control group (both P < .05). LV and ILD were negatively correlated with AL, respectively (LV: r = -.484, P < .0001; ILD: r = -.656, P < .0001). Morphologically, both MM and HM groups had greater Ra and Rp than the control group. Ra was positively correlated with AL (r = .622, P < .0001), while the relationship between Rp and AL was non-linear. Moreover, the MM and HM groups had larger LD than the control group (both P < .001). Anterior LT was thinner in the HM than in the MM group (P = .026), while posterior LT between these two groups was similar. When compared in eight directions, similar trends were seen in Ra, Rp and LD, and the HM group showed a greater difference in Ra between horizontal and vertical directions.

CONCLUSIONS

This SS-OCT-based study showed that longer axial length is associated with a flatter lens, which was mainly attributed to the increase of Ra and LD. Longitudinal studies would be necessary to establish a causal relationship and temporal progression.

Cataractous Eye Protein Isolate Stabilized Gold Nanoparticles Prevent Their Ethanol-Induced Aggregation

Due to their distinctive optical, electrical, and catalytic characteristics, gold nanoparticles (AuNPs) have found increasing use for a wide range of applications, including biomedicine and catalysis. Inherent agglomeration propensities impair their functional qualities, stability, and biocompatibility. This work investigates the potential applications of the cataractous eye protein isolate (CEPI), a waste product rich in proteins from cataract surgery, as a novel AuNP stabilizing agent. It was found that CEPI can successfully stabilize AuNPs under a variety of situations, preventing ethanol-induced aggregation and preserving their structural integrity. Using spectroscopic and analytical techniques, including UV-Vis spectroscopy, dynamic light scattering (DLS), circular dichroism (CD) spectroscopy, and fluorescence quenching studies, we confirmed the successful binding of CEPI to AuNPs and the enhanced stability of the conjugates. A shift in the localized surface plasmon resonance (LSPR) peak and modifications to the secondary structure of the CEPI were indicative of strong binding and protective effects between CEPI and AuNPs. These findings suggest that CEPI, an underutilized biomaterial, can serve as an effective and biocompatible stabilizer for AuNPs, with potential applications in biomedical and therapeutic fields.

Cascade catalytic multilayer modified intraocular lens for enhanced and safer posterior capsule opacification prevention

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. It is primarily caused by the proliferation, migration, and adhesion of residual lens epithelial cells within the capsular bag following phacoemulsification and intraocular lens (IOL) implantation. Although investigations of surface modification onto IOL have partially reduced PCO development in recent years, there are still challenges in long-term efficacy and intraocular biocompatibility. In this study, a cascade catalytic system is constructed using natural enzymes onto mesoporous silica nanoparticles (MSNs), which are subsequently fixed to the surface of IOL through layer-by-layer self-assemble of alternating positive and negative charges. The cascade catalytic reaction is trigged simply by glucose within the pouch to produce reactive oxygen species (ROS) without introducing any toxic drugs or external energy, attempting to minimize the possible toxic side effects to surrounding tissues. In vivo and in vitro experiments indicate the effective inhibition of PCO and favorable intraocular compatibility of the cascade catalytic platform modified IOL. More importantly, the modified IOL retains good optical performance and imaging quality, demonstrating promising prospects for application. This study provides a new possibility for enhanced and safer PCO prevention, playing great significance in clinical treatment. STATEMENT OF SIGNIFICANCE: Cascade catalytic nanoparticles-loaded multilayer modified IOL is obtained via LbL technique. The multilayer coating improves both the loading capacity and the activity of the cascade catalytic nanoparticles. The cascade catalytic reaction is trigged by glucose, producing ROS that efficiently induces apoptosis and death of remaining cells on IOL without introducing any toxic drugs or external energy. The innovative IOL provides a promising approach for enhanced and safer prevention of PCO.

Influence of Cataract Causing Mutations on αA-Crystallin: A Computational Approach

The αA-crystallin protein plays a vital role in maintaining the refractive index and transparency of the eye lens. Significant clinical studies have emerged as the αA-crystallin is prone to aggregation, resulting in the formation of cataracts with varied etiologies due to mutations. This work aims to comprehend the structural and functional role of cataract-causing mutations in αA-crystallin, particularly at N-Terminal and α-Crystallin Domains, using in-silico approaches including molecular dynamics simulation. About 19 mutants of αA-crystallin along with native structure were simulated for 100 ns and the post-simulations analyses reveal pronounced dynamics of αA-crystallin due to the enhanced structure flexibility as its native compactness was lost and is witnessed mainly by the mutants R12L, R21L, R21Q, R54L, R65Q, R116C and R116H. It is observed that αA-crystallin discloses the NTD motions as the dominant one and the same was endorsed by the linear variation between Rg and the center-of-mass of αA-crystallin. Interestingly, such enhanced dynamics of αA-crystallin mutants associated with the structure flexibility is internally modulated by the dynamic exchange of secondary structure elements β-sheets and coils (R2 = 0.619) during simulation. Besides, the observed pronounced dynamics of dimer interface region (β3-L6-β4 segment) of ACD along with CTD dynamics also gains importance. Particularly, the highly dynamic mutants are also characterized by enhanced non-covalent and hydrophobic interactions which renders detrimental effects towards its stability, and favours possible protein unfolding mechanisms. Overall, this study highlights the mutation-mediated structural distortions in αA-crystallin and demands the need for further potential development of inhibitors against cataract formation.

Identification of genes contributing to attenuation of rat model of galactose-induced cataract by pyruvate

Cataracts are a disease that reduces vision due to opacity formation of the lens. Diabetic cataracts occur at young age and progress relatively quickly, so the development of effective treatment has been awaited. Several studies have shown that pyruvate inhibits oxidative stress and glycation of lens proteins, which contribute to onset of diabetic cataracts. However, detailed molecular mechanisms have not been revealed. In this study, we attempted to reduce galactose-induced opacity by pyruvate with rat ex vivo model. Rat lenses were extracted and cultured in galactose-containing medium to induce lens opacity. After opacity had developed, continued culturing with pyruvate in the medium resulted in a reduction of lens opacity. Subsequently, we conducted microarray analysis to investigate the genes that contribute to the therapeutic effect. We performed quantitative expression measurements using RT-qPCR for extracted genes that were upregulated in cataract-induced lenses and downregulated in pyruvate-treated lenses, resulting in the identification of 34 candidate genes. Functional analysis using the STRING database suggests that metallothionein-related factors (Mt1a, Mt1m, and Mt2A) and epithelial-mesenchymal transition-related factors (Acta2, Anxa1, Cd81, Mki67, Timp1, and Tyms) contribute to the therapeutic effect of cataracts.

Association between systemic immune-inflammation index and cataract among outpatient US adults

Background

While several studies have noted a higher SII correlates with multiple diseases, research on the association between SII and cataract remains limited. Our cross-sectional study seeks to examine the association between SII and cataract among outpatient US adults.

Methods

This compensatory cross-sectional study utilized NHANES data from 1999 to 2008 cycles, conducting sample-weighted multivariate logistic regression and stratified analysis of subgroups.

Results

Among 11,205 adults included in this study (5,571 [46.2%] male; 5,634 [53.8%] female), 2,131 (15.2%) had cataract and 9,074 (84.8%) did not have cataract. A fully adjusted model showed that SII higher than 500 × 109/L was positively correlated with an increased risk of cataracts among women (OR, 1.27; 95% CI, 1.02-1.59) (p = 0.036). However, no difference was found in the men subgroup, and there was no significant interaction between SII and sex.

Conclusion

Our results indicated that a SII higher than 500 × 109/L was positively correlated with an increased risk of cataracts in women. This study is the first to specifically investigate the impact of a high SII on cataract risk in outpatient adults in the United States. By effectively addressing inflammation, it is possible to mitigate cataract progression and significantly enhance patient outcomes.

Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: A meta-analysis of randomized controlled trials

PURPOSE

The main purpose of our study is to compare the adverse events occurrence, complications, and postoperative outcomes of Femtosecond Laser-Assisted Cataract Surgery (FLACS) versus conventional phacoemulsification surgery (CPS) in adult patients undergoing cataract surgery.

METHODS

We conducted our research using PubMed, Scopus, and MEDLINE through EBSCOhost from 2012 to July 2022 with English and Spanish language restriction, including only Randomized Controlled Trials (RCTs). The PRISMA guidelines were observed for data abstraction, including a random-effects model for each outcome.

RESULTS

We analyzed 4844 eyes from 23 RCTs with some low risk of bias according to RoB 2 tool. We found statistically significant differences between the FLACS and CPS groups for the mean absolute error (MD = -0.12, 95% CI:-0.22-[-0.02], p = 0.01), the circularity of capsulorhexis (MD = 0.04, 95% CI: 0.04-0.05, p ≤ 0.00001), IOL centration (D = -0.07, 95% CI:-0.09-[-0.05], p ≤ 0.00001), CDE count (MD = -1.75, 95% CI: -2.75-[-0.74], p = 0.0006), mean phacoemulsification time (MD = -12.90, 95% CI:-20.89-[-4.92], p = 0.002), EPT (MD = -0.93, 95% CI: -1.68-[-0.019], p = 0.01) and endothelial cell density loss ((MD = -0.6, 95% CI: -1-[-0.19], p = 0.004). Also, the safety analysis showed a lower incidence of posterior capsule tear (PCT) in the FLACS group (OR =0.29, 95% CI: 0.09-1, p = 0.05).

CONCLUSIONS

Our results suggest that FLACS might be helpful for patients with relatively dense cataracts and low preoperative endothelial cell values.

Ferroptosis: a new perspective on the pathogenesis of radiation-induced cataracts

Ionizing radiation is a significant risk factor for cataracts, but the pathogenesis of radiation-induced cataracts remains incompletely understood. Ferroptosis, an iron-dependent form of programmed cell death discovered in recent years, has gained increasing attention for its role in various diseases. This article systematically reviews research progress on ionizing radiation, ferroptosis, age-related cataracts, and radiation-induced cataracts. It proposes the "ferroptosis hypothesis" for the pathogenesis of radiation-induced cataracts. Through ionization and oxidative stress effects, ionizing radiation leads to elevated free iron levels and exacerbated lipid peroxidation in lens cells, activating the ferroptosis pathway and resulting in lens opacity. The involvement of ferroptosis in the development of age-related cataracts suggests that it may also be an important pathogenic mechanism of radiation-induced cataracts. Targeting the ferroptosis pathway may be a novel strategy for preventing and treating radiation-induced cataracts. Furthermore, developing new ferroptosis-specific inhibitors with improved targeting and pharmacokinetic properties is also an essential direction for research on preventing and treating radiation-induced cataracts. The study of ferroptosis provides new insights into the mechanism and management of radiation-induced cataracts, potentially transforming radiation-induced cataracts from "inevitable" to "preventable and treatable."

Cumulative asparagine to aspartate deamidation fails to perturb γD-crystallin structure and stability

Deamidation frequently is invoked as an important driver of crystallin aggregation and cataract formation. Here, we characterized the structural and biophysical consequences of cumulative Asn to Asp changes in γD-crystallin. Using NMR spectroscopy, we demonstrate that N- or C-terminal domain-confined or fully Asn to Asp changed γD-crystallin exhibits essentially the same 1H-15N HSQC spectrum as the wild-type protein, implying that the overall structure is retained. Only a very small thermodynamic destabilization for the overall Asn to Asp γD-crystallin variants was noted by chaotropic unfolding, and assessment of the colloidal stability, by measuring diffusion interaction parameters, yielded no substantive differences in association propensities. Furthermore, using molecular dynamics simulations, no significant changes in dynamics for proteins with Asn to Asp or iso-Asp changes were detected. Our combined results demonstrate that substitution of all Asn by Asp residues, reflecting an extreme case of deamidation, did not affect the structure and biophysical properties of γD-crystallin. This suggests that these changes alone cannot be the major determinant in driving cataract formation.

The impact of music on anxiety, pain, and blood pressure in ophthalmic surgery: A systematic review and meta-analysis

OBJECTIVES

To evaluate the effectiveness of music therapy in reducing anxiety, pain, and vital sign changes in ophthalmic surgery patients.

METHODS

An extensive search of databases, including PubMed, Embase, Cochrane, Web of Science, and Google Scholar, identified relevant studies up to Jan 2024. Selection of studies was conducted based on the PICOS criteria. The quality of methodology was assessed using the Cochrane risk-of-bias assessment tool and Review Manager 5.4. Meta-analysis comparing the control group and the music therapy group was performed using R and Stata/SE 15.1 random or fixed effects model.

RESULTS

This meta-analysis included fifteen studies comprising 2098 participants. The analysis revealed that music therapy significantly reduced the risk of high anxiety levels as measured by Visual Analogue Scale (VAS) (I2 = 0 %, RR(95 %CI): 0.75(0.63, 0.88), p = 0.0006), indicating a substantial effect without heterogeneity. The Anxiety scores determined by State-Trait Anxiety Inventory-State (STAI-S) also showed a significant decrease (SMD(95 %CI): -0.75(-0.88, -0.61), p < 0.0001), albeit with moderate heterogeneity (I² = 36 %). Additionally, music therapy was associated with a reduction in intraoperative pain levels, with no observed heterogeneity (I2 = 0 %, SMD(95 %CI): -0.74(-0.93, -0.56), p < 0.0001). In contrast, music intervention did not significantly influence self-reported nervousness, relaxation, or satisfaction levels as determined by VAS. Regarding to physiological parameters, a marginal decrease in systolic blood pressure (SBP) was observed (SMD(95 %CI): -0.42(-0.79, -0.04), p = 0.0286), with considerable heterogeneity (I² = 92 %). Diastolic blood pressure (DBP) experienced a slight reduction (I² = 90 %, SMD(95 %CI): -0.45(-0.79, -0.11), p = 0.0088). However, no significant effect was observed on patients' heart rate (p = 0.0864).

CONCLUSION

Music therapy effectively reduced anxiety and pain, and moderately improved vital signs in patients undergoing ophthalmic surgery, highlighting its role in enhancing patient well-being. Further in-depth RCTs are needed to confirm its efficacy.

A 3D in vitro model for assessing the influence of intraocular lens: Posterior lens capsule interactions on lens epithelial cell responses

Posterior Capsule Opacification (PCO), the most frequent complication of cataract surgery, is caused by the infiltration and proliferation of lens epithelial cells (LECs) at the interface between the intraocular lens (IOL) and posterior lens capsule (PLC). According to the "no space, no cells, no PCO" theory, high affinity (or adhesion force) between the IOL and PLC would decrease the IOL: PLC interface space, hinder LEC migration, and thus reduce PCO formation. To test this hypothesis, an in vitro hemisphere-shaped simulated PLC (sPLC) was made to mimic the human IOL: PLC physical interactions and to assess their influence on LEC responses. Three commercially available IOLs with different affinities/adhesion forces toward the sPLC, including Acrylic foldable IOL, Silicone IOL, and PMMA IOL, were used in this investigation. Using the system, the physical interactions between IOLs and sPLC were quantified by measuring the adhesion force and interface space using an adhesion force apparatus and Optical Coherence Tomography, respectively. Our data shows that high adhesion force and tight binding between IOL and sPLC contribute to a small interface space (or "no space"). By introducing LECs into the in vitro system, we found that, with small interface space, among all IOLs, acrylic foldable IOLs permitted the least extent of LEC infiltration, proliferation, and differentiation (or "no cells"). Further statistical analyses using clinical data revealed that weak LEC responses are associated with low clinical PCO incidence rates (or "no PCO"). The findings support that the in vitro system could simulate IOL: PLC interplays and predict IOLs' PCO potential in support of the "no space, no cells, no PCO" hypothesis.

Inhibition of fibril formation by polyphenols: molecular mechanisms, challenges, and prospective solutions

Fibril formation is a key feature in neurodegenerative diseases like Alzheimer's, Parkinson's, and systemic amyloidosis. Polyphenols, found in plant-based foods, show promise in inhibiting fibril formation and disrupting disease progression. The ability of polyphenols to break the amyloid fibrils of many disease-linked proteins has been tested in numerous studies. Polyphenols have their distinctive mechanism of action. They behave differently on various events in the aggregation pathway. Their action also differs for different proteins. Some polyphenols only inhibit the formation of fibrils whereas others break the preformed fibrils. Some break the fibrils into smaller species, and some change them to other morphologies. This article delves into the intricate molecular mechanisms underlying the inhibitory effects of polyphenols on fibrillogenesis, shedding light on their interactions with amyloidogenic proteins and the disruption of fibril assembly pathways. However, addressing the challenges associated with solubility, stability, and bioavailability of polyphenols is crucial. The current strategies involve nanotechnology to improve the solubility and bioavailability, thus showing the potential to enhance the efficacy of polyphenols as therapeutics. Advancements in structural biology, computational modeling, and biophysics have provided insights into polyphenol-fibril interactions, offering hope for novel therapies for neurodegenerative diseases and amyloidosis.

Compound electrolyte intraocular irrigating solution produces better effects on vision recovery of cataract patients after surgery than Ringer lactate solution

PURPOSE

Intraocular irrigating solution is extensively applied in cataract surgery. This paper explored the difference and relationship between optical coherence tomography (OCT) and optical quality analysis system (OQAS) parameters induced by compound electrolyte intraocular irrigating solution (CEIIS) or Ringer lactate (RL) solution during uncomplicated cataract surgery.

METHODS

Totally 200 senior cataract patients were randomly divided into the CEIIS and RL groups (N = 100 patients/group). The anterior chamber was irrigated by CEIIS or RL during phacoemulsification. Patients were subdivided into diabetes mellitus (DM)+ and DM- groups. The central macular thickness (CMT), hyper reflective foci (HF), modulation transfer function cutoff frequency (MTF cutoff), Strehl ratio (SR), objective scatter index (OSI), and OQAS values (OVs) at 100%, 20%, and 9% contrast levels were measured preoperatively and 1 day and 1 week after operation using spectral-domain optical coherence tomography and OQAS II, respectively. Best-corrected visual acuity (BCVA) was assessed using the Snellen scale, followed by statistical analysis of its logarithm of the minimal angle of resolution.

RESULTS

There were no significant differences in clinical characteristics between the CEIIS and RL groups. Both groups exhibited notably increased postoperative CMT, MTF cutoff, SR, OV at 100%, 20%, and 9% contrast levels, and reduced OSI, indicating CEIIS and RL improved postoperative visual quality. CEIIS surpassed RL solution in improving postoperative visual quality, decelerating the increase of macular HF numbers and CMT in DM+ patients and postoperative BCVA. There was no difference between CEIIS and RL in long-term vision improvement.

CONCLUSION

CEIIS surpasses RL in postoperative visual recovery and retards increases of macular HF numbers and CMT in senior DM+ cataract patients.

Efficacy of the efficacy between dexamethasone versus triamcinolone acetonide after cataract surgery: A systematic review and meta-analysis

PURPOSE

To evaluate the clinical effects between dexamethasone and triamcinolone acetonide (TA) after phacoemulsification and intraocular lens implantation among cataract patients.

METHODS

Pubmed, Embase, and the Cochrane Library were searched for studies published up to August 2020. The primary outcome was intraocular pressure. The secondary outcomes were the logarithm of the minimum angle of resolution (logMAR), anterior chamber cell, and anterior chamber flare. The pooled effect sizes were expressed as weighted mean differences (WMDs) or standardized mean differences (SMDs) of 95% confidence intervals (95% CIs). Cochrane Collaboration risk of bias tool and Newcastle-Ottawa scale criteria were used for the quality assessment of included studies.

RESULTS

Seven relevant studies met the inclusion criteria. For the primary outcome, there was no significant difference between TA injection and dexamethasone in comparing intraocular pressure (IOP) (SMD = 0.22, 95% confidence interval [CI] [-0.29, 0.73], P = .408; I² = 86.9%) in the first day after treatment and last day of assessment. For the secondary outcomes, the logMAR (WMD = 0.01, 95% CI [-0.06, 0.08]) and the anterior chamber flare (SMD = 0.08, 95% CI [-0.01, 0.18], P = .087; I² = 0%) showed no differences. However, the amount of anterior chamber cells (SMD = -0.21, 95% CI [-0.42, -0.01], P = .044; I² = 0%) in the TA injection on the first day postoperative was higher than for dexamethasone. After treatment, there was no difference between the 2 groups.

CONCLUSIONS

This study supports that there were no differences in IOP, logMAR, and anterior chamber flare between TA injection and dexamethasone among cataract patients. TA injection treatment on the first day showed higher amounts of anterior chamber cells than with dexamethasone.

Injectable hydrogels based on biopolymers for the treatment of ocular diseases

Injectable hydrogels based on biopolymers, fabricated utilizing diverse chemical and physical methodologies, exhibit exceptional physical, chemical, and biological properties. They have multifaceted applications encompassing wound healing, tissue regeneration, and across diverse scientific realms. This review critically evaluates their largely uncharted potential in ophthalmology, elucidating their diverse applications across an array of ocular diseases. These conditions include glaucoma, cataracts, corneal disorders (spanning from age-related degeneration to trauma, infections, and underlying chronic illnesses), retina-associated ailments (such as diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration (AMD)), eyelid abnormalities, and uveal melanoma (UM). This study provides a thorough analysis of applications of injectable hydrogels based on biopolymers across these ocular disorders. Injectable hydrogels based on biopolymers can be customized to have specific physical, chemical, and biological properties that make them suitable as drug delivery vehicles, tissue scaffolds, and sealants in the eye. For example, they can be engineered to have optimum viscosity to be injected intravitreally and sustain drug release to treat retinal diseases. Their porous structure and biocompatibility promote cellular infiltration to regenerate diseased corneal tissue. By accentuating their indispensable role in ocular disease treatment, this review strives to present innovative and targeted approaches in this domain, thereby advancing ocular therapeutics.

Role of C/EBP Homologous Protein (CHOP) and Nupr1 Interaction in Endoplasmic Reticulum Stress-Induced Apoptosis of Lens Epithelial Cells

Our study mainly analyzed the mechanism of C/EBP homologous protein (CHOP) and its interacting protein Nupr1 on endoplasmic reticulum stress (ERS) induced lens epithelial cells (LEC) apoptosis. Cell proliferation was detected by CCK-8. Apoptosis was detected by flow cytometry and TUNEL. Nupr1 expression was detected by RT-qPCR. The expressions of CHOP, Nupr1, apoptosis-related protein, and ERS-related protein were detected by Western blot. DCFH-DA probe was used to detect cell ROS. The SOD, GSH-PX, and MDA contents were detected by the kit. Co-IP was used to detect the interaction between CHOP and Nupr1. The morphology of the lens was detected by HE staining. The result shows that Tunicamycin (TU) can induce endoplasmic reticulum stress and apoptosis in LEC in a concentration-dependent manner. TU induction leads to the occurrence of CHOP nuclear translocation. Overexpression of CHOP can further enhance the inhibitory effect of TU on LEC proliferation and the promotion of apoptosis, while knockdown of CHOP has the opposite effect. CHOP and Nupr1 are interacting proteins, and knockdown of Nupr1 or addition of Nupr1 inhibitor ZZW-115 can reverse the effects of TU and overexpression of CHOP, respectively. It has been observed in animal experiments that treatment with oe-CHOP can further aggravate the pathological lesions of the rat lens, while ZZW-115 can reverse the effect of oe-CHOP to a certain extent and improve the lesions of the rat lens. Overall, CHOP interacts with Nupr1 to regulate apoptosis caused by ERS and mediate cataract progression in rats, and this study provides a new potential therapeutic target for the treatment of cataract.

Diversity in enrollment to clinical trials for cataract medicine and surgery: meta-analysis

PURPOSE

To investigate sex, racial, and ethnic disparities in patient enrollment across cataract trials registered in the United States.

SETTING

Participants enrolled in high-quality (reduced risk of bias), U.S.-registered (on ClinicalTrials.gov ), cataract-related randomized controlled trials (RCTs). RCTs must be completed, have used double or greater masking, and have published results through the registry or a scholarly journal.

DESIGN

Cross-sectional database study.

METHODS

Trial (study sponsor country, study site location, trial initiation year, study phase, and study masking) and demographic data (sex, race, and ethnicity according to U.S. reporting guidelines) were collected. The Global Burden of Disease database provided sex-based cataract disease burdens. Pooled participation-to-prevalence ratios (PPRs) with 95% CIs were calculated for female sex, with values between 0.8 and 1.2 constituting sufficient study enrollment. Kruskal-Wallis tests (α = 0.05) with subsequent post hoc comparisons were used to evaluate demographic representations stratified by trial characteristics.

RESULTS

From 864 records, 100 clinical trials (N = 67 874) were identified, of which 97 (N = 67 697) reported sex demographics with a pooled female PPR of 0.89 (95% CI, 0.85-0.94). Of the 67 697 total participants, the absolute female enrollment was 19 062 (28.16%). Ethnicity and race were reported in 9 (N = 1792) and 26 trials (N = 23 181), respectively. Among trials that reported race, most were White (N = 19 574; 84.44%).

CONCLUSIONS

High-quality, U.S.-registered, cataract trials enrolled acceptable proportions of women. However, the absolute number of female and racialized participants was low. Race and ethnicity were underreported. Disparity trends predominately held across secondary variables. To promote generalizability, future trials should pursue equitable demographic enrollment.

Biodegradable Solid Polymer Electrolytes from the Discarded Cataractous Eye Protein Isolate

The protein extracted from the discarded eye lenses postcataract surgery, referred to as the cataractous eye protein isolate (CEPI), is employed as a polymer matrix for the construction of solid polymer electrolyte species (SPEs). SPEs are expected to be inexpensive, conductive, and mechanically stable in order to be economically and commercially viable. Environmentally, these materials should be biodegradable and nontoxic. Taking these factors into account, we investigated the possibility of using a discarded protein as a polymer matrix for SPEs. Natural compounds sorbitol and sinapic acid (SA) are used as the plasticizer and cross-linker, respectively, to tune the mechanical as well as electrochemical properties. The specific material formed is demonstrated to have high ionic conductivity ranging from ∼2 × 10-2 to ∼8 × 10-2 S cm-1. Without the addition of any salt, the ionic conductivity of sorbitol-plasticized non-cross-linked CEPI is ∼7.5 × 10-2 S cm-1. Upon the addition of NaCl, the conductivity is enhanced to ∼8 × 10-1 S cm-1. This study shows the possibility of utilizing a discarded protein CEPI as an alternative polymer matrix with further potential for the construction of tunable, flexible, recyclable, biocompatible, and biodegradable SPEs for flexible green electronics and biological devices.

Cell Penetrability of a γ-Crystallin Peptide Fragment from the Discarded Cataractous Eye Emulsion

The efficiency of the intracellular transport of medication and target specificity is frequently hampered by biological obstacles. The potential for therapeutic use of peptide fragments from naturally occurring proteins is promising, as peptides exhibit high selectivity due to several possibilities of interaction with their target. Certain peptide sequences, often referred to as cell-penetrating peptides (CPPs), are those that can penetrate cell membranes. Our goal is to find these sequences in the discarded postcataractery surgery emulsion known as the cataractous eye protein isolate (CEPI). One peptide fragment from this discarded protein has been identified to be a potential CPP based on the similarities with other well-known CPPs. Cell membrane penetrability and cytotoxicity of the peptide have been investigated. Fibroblast cells were incubated with the fluorescently labeled peptide and were observed under fluorescence as well as under confocal microscopy. It was found that the peptide possesses a cell-penetrating ability.

Crystalline lens nuclear age prediction as a new biomarker of nucleus degeneration

BACKGROUND

The crystalline lens is a transparent structure of the eye to focus light on the retina. It becomes muddy, hard and dense with increasing age, which makes the crystalline lens gradually lose its function. We aim to develop a nuclear age predictor to reflect the degeneration of the crystalline lens nucleus.

METHODS

First we trained and internally validated the nuclear age predictor with a deep-learning algorithm, using 12 904 anterior segment optical coherence tomography (AS-OCT) images from four diverse Asian and American cohorts: Zhongshan Ophthalmic Center with Machine0 (ZOM0), Tomey Corporation (TOMEY), University of California San Francisco and the Chinese University of Hong Kong. External testing was done on three independent datasets: Tokyo University (TU), ZOM1 and Shenzhen People's Hospital (SPH). We also demonstrate the possibility of detecting nuclear cataracts (NCs) from the nuclear age gap.

FINDINGS

In the internal validation dataset, the nuclear age could be predicted with a mean absolute error (MAE) of 2.570 years (95% CI 1.886 to 2.863). Across the three external testing datasets, the algorithm achieved MAEs of 4.261 years (95% CI 3.391 to 5.094) in TU, 3.920 years (95% CI 3.332 to 4.637) in ZOM1-NonCata and 4.380 years (95% CI 3.730 to 5.061) in SPH-NonCata. The MAEs for NC eyes were 8.490 years (95% CI 7.219 to 9.766) in ZOM1-NC and 9.998 years (95% CI 5.673 to 14.642) in SPH-NC. The nuclear age gap outperformed both ophthalmologists in detecting NCs, with areas under the receiver operating characteristic curves of 0.853 years (95% CI 0.787 to 0.917) in ZOM1 and 0.909 years (95% CI 0.828 to 0.978) in SPH.

INTERPRETATION

The nuclear age predictor shows good performance, validating the feasibility of using AS-OCT images as an effective screening tool for nucleus degeneration. Our work also demonstrates the potential use of the nuclear age gap to detect NCs.

Chitosan and Anionic Solubility Enhancer Sulfobutylether-β-Cyclodextrin-Based Nanoparticles as Dexamethasone Ophthalmic Delivery System for Anti-Inflammatory Therapy

Cataract surgery interventions are constantly increasing, particularly among adult and elderly patients. This type of surgery can lead to inflammatory states of the ocular anterior segment (AS), usually healed via postoperative treatment with dexamethasone (DEX)-containing eye drops. The application of eye drops is challenging due to the high number of daily administrations. In this study, mucoadhesive nanoparticles (NPs) were formulated to improve the residence time of DEX on the corneal mucosa, enhancing the drug's solubility and bioavailability. The NPs were generated using an ionotropic gelation technique, exploiting the interaction between the cationic group of chitosan (CS) and the anionic group of sulfobutylether-β-cyclodextrin (SBE-β-CD). The formation of the inclusion complex and its stoichiometry were studied through phase solubility studies, Job's plot method, and Bi-directional transport studies on MDCKII-MDR1. The obtained NPs showed good chemical and physical characteristics suitable for drug loading and subsequent testing on animal mucosa. The DEX-loaded CS/SBE-β-CD NPs exhibited a prolonged residence time on animal mucosa and demonstrated enhanced drug permeability through the corneal membrane, showing a sustained release profile. The developed NPs posed no irritation or toxicity concerns upon local administration, making them an optimal and innovative drug delivery system for inflammatory AS diseases treatment.

Fuch's Endothelial Corneal Dystrophy in Cataract Patients Is Associated with Elevated Levels of Inflammatory Chemokines, but Not Growth Factors, in the Aqueous Humor

The study investigated a profile of chemokines and growth factors in the aqueous humor (AH) of eyes with Fuch's endothelial corneal dystrophy (FECD) and cataracts in comparison with cataract patients as a control group. A total of 52 AH samples (26 FECD + cataract and 26 cataract/control) were collected before cataract surgery. None of the patients had any clinically apparent inflammation at the time of AH collection. The AH levels of MCP-1 (CCL2), MIP-1α (CCL3), MIP-1β(CCL4), RANTES (CCL5), eotaxin (CCL11), IP-10 (CXCL10), FGF basic, G-CSF, GM-CSF, PDGF-bb, and VEGF were compared between the groups. The analyses were performed using the Bio-Plex 200 System from Bio-Rad. Among the studied parameters, the AH levels of RANTES, eotaxin, and IP-10 significantly increased in the FECD + cataract eyes, compared with the cataract controls (p < 0.05). Elevated levels of the RANTES, Eotaxin, and IP-10 indicate more intense inflammation in the eyes of patients in the FECD + cataract group. Moreover, these factors exhibit potential as predictive biomarkers for early detection of FECD in cataract patients. The discovery of elevated concentrations of biochemical markers in a patient, who has not yet received a clinical diagnosis, may suggest the need for heightened observation of the other eye to monitor the potential development of FECD.

Individual-level socioeconomic status and cataract-induced visual disability among older adults in China: the overview and urban-rural difference

Objective

To investigate the prevalence of cataract-induced visual disability and its association with individual-level socioeconomic status (SES) among older adults in China.

Methods

Using the data of 354,743 older adults (60 years and older) from the Second China National Sample Survey on Disability in 2006. Cross-sectional study design was applied. The differences in visual disability prevalence of cataracts among sociodemographic subgroups were analyzed by the chi-square test, and the association between individual-level SES and cataract-induced visual disability was investigated by the multivariate logistic regression model.

Results

The weighted visual disability prevalence of cataracts was 4.84% in 2006. Older people with a higher household income per capita (OR = 0.83, 95% CI: 0.81-0.85), higher education level (primary school vs. illiteracy: OR = 0.80, 95% CI: 0.76-0.83; ≥undergraduate college vs. illiteracy: OR = 0.31, 95% CI: 0.25-0.39), and occupation (OR = 0.53, 95% CI: 0.50-0.56) were less likely to suffer from cataract-induced visual disability. Household income per capita and education level increase played a greater role in decreasing the risk of visual disability caused by cataracts in urban areas, while having occupation contributed more to reducing the risk of disability in rural areas.

Conclusion

The gap in individual-level SES is closely related to the visual health inequities among older Chinese people and there are two distinct mechanisms in rural and urban areas. Strategies to promote collaborative healthcare development regionally, strengthen safeguards for disadvantaged groups, and increase public awareness of visual disability prevention are warranted.

Dysregulation of histone deacetylases in ocular diseases

Ocular diseases are a growing global concern and have a significant impact on the quality of life. Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the most prevalent ocular diseases. Their prevalence and the global market size are also increasing. However, the available pharmacotherapy is currently limited. These diseases share common pathophysiological features, including neovascularization, inflammation, and/or neurodegeneration. Histone deacetylases (HDACs) are a class of enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. HDACs are crucial for regulating various cellular processes, such as gene expression, protein stability, localization, and function. They have also been studied in various research fields, including cancer, inflammatory diseases, neurological disorders, and vascular diseases. Our study aimed to investigate the relationship between HDACs and ocular diseases, to identify a new strategy for pharmacotherapy. This review article explores the role of HDACs in ocular diseases, specifically focusing on diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity, as well as optic nerve disorders, such as glaucoma and optic neuropathy. Additionally, we explore the interplay between HDACs and key regulators of fibrosis and angiogenesis, such as TGF-β and VEGF, highlighting the potential of targeting HDAC as novel therapeutic strategies for ocular diseases.

Prevalence of cataract and its contributing factors in Iranian elderly population: the Gilan eye study

PURPOSE

To report the prevalence and the associated factors leading to cataract among the Iranian population living in Gilan Province, Iran.

METHODS

This population-based cross-sectional study was performed from June to November 2014 on 2,975 residents aged ≥ 50 years old living in urban and rural regions of the Gilan Province in Iran. A representative sample of residents in the province was recruited into the study through door-to-door visiting, and baseline data were collected by questionnaire. All participants were referred to the medical center for comprehensive ophthalmic examination, laboratory tests, and blood pressure measurement.

RESULTS

Among the population, 2,588 (86.99%) subjects were eligible to be included in this study, categorized either into the cataract or the non-cataract group. The mean age of participants was 62.59 ± 8.92 years, and 57.5% were female. Higher prevalence of cataract was found in individuals of older ages (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.10 to 1.16; P < 0.001) and a history of previous ocular surgery (OR = 5.78; 95% CI = 2.28 to 14.63; P < 0.001). At the same time, a lower prevalence of cataract was seen in patients exposed to sunlight for more than 4 h per day (OR = 0.49; 95% CI = 0.32 to 0.73; P = 0.001).

CONCLUSION

Cataract affects 50.50% of the study population, especially those over 80. The mildest form of cataract, grade zero, is the most common. Surgery for cataract has good outcomes. The risk of cataract is higher for those older or who have had eye surgeries. People not affected by cataract tend to be exposed to more sunlight.

Effect of motion-graphic video-based training on the performance of operating room nurse students in cataract surgery in Iran: a randomized controlled study

PURPOSE

The present study was conducted to determine the effect of motion-graphic video-based training on the performance of operating room nurse students in cataract surgery using phacoemulsification at Kermanshah University of Medical Sciences in Iran.

METHODS

This was a randomized controlled study conducted among 36 students training to become operating room nurses. The control group only received routine training, and the intervention group received motion-graphic video-based training on the scrub nurse’s performance in cataract surgery in addition to the educator’s training. The performance of the students in both groups as scrub nurses was measured through a researcher-made checklist in a pre-test and a post-test.

RESULTS

The mean scores for performance in the pre-test and post-test were 17.83 and 26.44 in the control group and 18.33 and 50.94 in the intervention group, respectively, and a significant difference was identified between the mean scores of the pre- and post-test in both groups (P=0.001). The intervention also led to a significant increase in the mean performance score in the intervention group compared to the control group (P=0.001).

CONCLUSION

Considering the significant difference in the performance score of the intervention group compared to the control group, motion-graphic video-based training had a positive effect on the performance of operating room nurse students, and such training can be used to improve clinical training.

Adenosine Triphosphate (ATP) and Protein Aggregation in Age-Related Vision-Threatening Ocular Diseases

Protein aggregation is the etiopathogenesis of the three most profound vision-threatening eye diseases: age-related cataract, presbyopia, and age-related macular degeneration. This perspective organizes known information on ATP and protein aggregation with a fundamental unrecognized function of ATP. With recognition that maintenance of protein solubility is related to the high intracellular concentration of ATP in cells, tissues, and organs, we hypothesize that (1) ATP serves a critical molecular function for organismal homeostasis of proteins and (2) the hydrotropic feature of ATP prevents pathological protein aggregation while assisting in the maintenance of protein solubility and cellular, tissue, and organismal function. As such, the metabolite ATP plays an extraordinarily important role in the prevention of protein aggregation in the leading causes of vision loss or blindness worldwide.

Aging, oxidative stress and degenerative diseases: mechanisms, complications and emerging therapeutic strategies

Aging accompanied by several age-related complications, is a multifaceted inevitable biological progression involving various genetic, environmental, and lifestyle factors. The major factor in this process is oxidative stress, caused by an abundance of reactive oxygen species (ROS) generated in the mitochondria and endoplasmic reticulum (ER). ROS and RNS pose a threat by disrupting signaling mechanisms and causing oxidative damage to cellular components. This oxidative stress affects both the ER and mitochondria, causing proteopathies (abnormal protein aggregation), initiation of unfolded protein response, mitochondrial dysfunction, abnormal cellular senescence, ultimately leading to inflammaging (chronic inflammation associated with aging) and, in rare cases, metastasis. RONS during oxidative stress dysregulate multiple metabolic pathways like NF-κB, MAPK, Nrf-2/Keap-1/ARE and PI3K/Akt which may lead to inappropriate cell death through apoptosis and necrosis. Inflammaging contributes to the development of inflammatory and degenerative diseases such as neurodegenerative diseases, diabetes, cardiovascular disease, chronic kidney disease, and retinopathy. The body's antioxidant systems, sirtuins, autophagy, apoptosis, and biogenesis play a role in maintaining homeostasis, but they have limitations and cannot achieve an ideal state of balance. Certain interventions, such as calorie restriction, intermittent fasting, dietary habits, and regular exercise, have shown beneficial effects in counteracting the aging process. In addition, interventions like senotherapy (targeting senescent cells) and sirtuin-activating compounds (STACs) enhance autophagy and apoptosis for efficient removal of damaged oxidative products and organelles. Further, STACs enhance biogenesis for the regeneration of required organelles to maintain homeostasis. This review article explores the various aspects of oxidative damage, the associated complications, and potential strategies to mitigate these effects.

Ocular development after highly effective modulator treatment early in life

Highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulator therapies (HEMT), including elexacaftor-tezacaftor-ivacaftor, correct the underlying molecular defect causing CF. HEMT decreases general symptom burden by improving clinical metrics and quality of life for most people with CF (PwCF) with eligible CFTR variants. This has resulted in more pregnancies in women living with CF. All HEMT are known to be able pass through the placenta and into breast milk in mothers who continue on this therapy while pregnant and breast feeding. Toxicity studies of HEMT in young rats demonstrated infant cataracts, and case reports have reported the presence of congenital cataracts in early life exposure to HEMT. This article reviews the evidence for how HEMT influences the dynamic and interdependent processes of healthy and abnormal lens development in the context of HEMT exposure during pregnancy and breastfeeding, and raises questions that remain unanswered.

NIR-triggered thermosensitive polymer brush coating modified intraocular lens for smart prevention of posterior capsular opacification

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. Drug-eluting intraocular lens (IOLs) is a promising concept of PCO treatment in modern cataract surgery. However, the large dose of drugs in IOL leads to uncontrollable and unpredictable drug release, which inevitably brings risks of overtreatment and ocular toxicity. Herein, a low-power NIR-triggered thermosensitive IOL named IDG@P(NIPAM-co-AA)-IOL is proposed to improve security and prevent PCO by synergetic controlled drug therapy and simultaneous photo-therapy. Thermosensitive polymer brushes Poly(N-isopropylacrylamide-co-Acrylic acid) (P(NIPAM-co-AA)) is prepared on IOL via surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization. Then, Doxorubicin (DOX) and Indocyanine green (ICG) co-loaded Gelatin NPs (IDG NPs) are loaded in P(NIPAM-co-AA) by temperature control. The IDG NPs perform in suit photodynamic & photothermal therapy (PTT&PDT), and the produced heat also provides a trigger for controllable drug therapy with a cascade effect. Such functional IOL shows excellent synergistic drug-phototherapy effect and NIR-triggered drug release behavior. And there is no obvious PCO occurrence in IDG@P(NIPAM-co-AA) IOL under NIR irradiation compared with control group. This proposed IDG@P(NIPAM-co-AA)-IOL serves as a promising platform that combines phototherapy and drug-therapy to enhance the therapeutic potential and medication safety for future clinical application of PCO treatment.

Effect of Modified Peristaltic Phacoemulsification Device on Efficiency and Post-Occlusion Pressure Surge

Purpose

To evaluate efficiency of grooving, nuclear fragment removal, and changes in pressure control in the Oertli Faros using traditional peristaltic and Speed and Precision (SPEEP) features. The SPEEP mode uses novel peristaltic technology permitting independent control of flow and vacuum.

Methods

A porcine lens model was used with an enclosed chamber simulating the anterior segment. Grooving efficiency is evaluated with flow rates of 10, 30, and 50 mL/min using whole lenses. Lens cubes were emulsified at 20, 40, 60, 80, and 100% power with both SPEEP and non-SPEEP modes. Surge was evaluated with pressure gauges placed on the irrigation tubing and aspiration tubing. Pressure readings were recorded per the following: fluid and vacuum were initiated for 15 seconds, vacuum tubing was occluded for 5 seconds, tubing patency was then re-introduced for 15 seconds. Differences between sensors were recorded.

Results

No significant increase in efficiency was seen with increasing flow rate from 30 to 50 mL/min using SPEEP. No significant differences were shown in lens fragment removal in SPEEP and non-SPEEP modes at any power tested. Pressure difference measurements were not significantly different with SPEEP and non-SPEEP modes.

Conclusion

We showed that lower flow rates show comparable efficiency of grooving when using the SPEEP mode. The SPEEP function did not show increased efficiency in nuclear fragment removal when compared to traditional mode. Surge control was also comparable with both SPEEP and non-SPEEP modes. We suggest that the SPEEP function included in the Oertli Faros may have some advantages.

Deep learning for detecting visually impaired cataracts using fundus images

Purpose: To develop a visual function-based deep learning system (DLS) using fundus images to screen for visually impaired cataracts. Materials and methods: A total of 8,395 fundus images (5,245 subjects) with corresponding visual function parameters collected from three clinical centers were used to develop and evaluate a DLS for classifying non-cataracts, mild cataracts, and visually impaired cataracts. Three deep learning algorithms (DenseNet121, Inception V3, and ResNet50) were leveraged to train models to obtain the best one for the system. The performance of the system was evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results: The AUC of the best algorithm (DenseNet121) on the internal test dataset and the two external test datasets were 0.998 (95% CI, 0.996-0.999) to 0.999 (95% CI, 0.998-1.000),0.938 (95% CI, 0.924-0.951) to 0.966 (95% CI, 0.946-0.983) and 0.937 (95% CI, 0.918-0.953) to 0.977 (95% CI, 0.962-0.989), respectively. In the comparison between the system and cataract specialists, better performance was observed in the system for detecting visually impaired cataracts (p < 0.05). Conclusion: Our study shows the potential of a function-focused screening tool to identify visually impaired cataracts from fundus images, enabling timely patient referral to tertiary eye hospitals.

ATCUN-like Copper Site in βB2-Crystallin Plays a Protective Role in Cataract-Associated Aggregation

Cataract is the leading cause of blindness worldwide, and it is caused by crystallin damage and aggregation. Senile cataractous lenses have relatively high levels of metals, while some metal ions can directly induce the aggregation of human γ-crystallins. Here, we evaluated the impact of divalent metal ions in the aggregation of human βB2-crystallin, one of the most abundant crystallins in the lens. Turbidity assays showed that Pb2+, Hg2+, Cu2+, and Zn2+ ions induce the aggregation of βB2-crystallin. Metal-induced aggregation is partially reverted by a chelating agent, indicating the formation of metal-bridged species. Our study focused on the mechanism of copper-induced aggregation of βB2-crystallin, finding that it involves metal-bridging, disulfide-bridging, and loss of protein stability. Circular dichroism and electron paramagnetic resonance (EPR) revealed the presence of at least three Cu2+ binding sites in βB2-crystallin, one of them with spectroscopic features typical for Cu2+ bound to an amino-terminal copper and nickel (ATCUN) binding motif, which is found in Cu transport proteins. The ATCUN-like Cu binding site is located at the unstructured N-terminus of βB2-crystallin, and it could be modeled by a peptide with the first six residues in the protein sequence (NH2-ASDHQF-). Isothermal titration calorimetry indicates a nanomolar Cu2+ binding affinity for the ATCUN-like site. An N-truncated form of βB2-crystallin is more susceptible to Cu-induced aggregation and is less thermally stable, indicating a protective role for the ATCUN-like site. EPR and X-ray absorption spectroscopy studies reveal the presence of a copper redox active site in βB2-crystallin that is associated with metal-induced aggregation and formation of disulfide-bridged oligomers. Our study demonstrates metal-induced aggregation of βB2-crystallin and the presence of putative copper binding sites in the protein. Whether the copper-transport ATCUN-like site in βB2-crystallin plays a functional/protective role or constitutes a vestige from its evolution as a lens structural protein remains to be elucidated.

Successful Use of Low-Dose Combination Propofol and Fentanyl in Cataract Surgery Phacoemulsification

Background

The combination between sedatives and opioids is one of the recommended anesthetic options in ophthalmic procedures and regimens are more advantageous as smaller amounts of each drug can be administered to reduce side effects and have proper outcomes due to the synergistic effects. This study aims to observe the use of low-dose propofol and fentanyl for patients undergoing phacoemulsification surgery.

Material and Methods

This observational study involves a sample of 125 adult patients who underwent elective cataract procedures using the phacoemulsification technique and had an American Society of Anesthesiologists (ASA) physical status of 1 to 3. Dose amount of fentanyl and propofol, Ramsay score, hemodynamic parameter, side effects, and patient satisfaction were evaluated, recorded, and analyzed using a 5-point Likert scale.

Results

The result showed the mean absolute dose of propofol was 12.46±4.376 mg, with a range between 10 and 30 mg, while the mean per body weight was 0.21±0.075 mg. Similarly, the mean absolute dose for fentanyl was 25.04±3.012 mcg within the range of 10-50 mcg, and the per-body weight dose was 0.43±0.080 mcg. About 90.4% and 9.6% of the patients reached Ramsay 2 and 3, respectively. The analysis of systolic, diastolic blood pressure, mean arterial pressure, and pulse rate showed that the combination of low-dose fentanyl and propofol was significantly lower than before therapy administration in all four values (p < 0.05).

Conclusion

The combination of low-dose propofol and fentanyl in cataract surgery using phacoemulsification successfully reached the targeted sedation level and a significant decrease in blood pressure, MAP, pulse rate, minimal side effects, and high satisfaction rate.

Involvement of IGF1 in endoplasmic reticulum stress contributes to cataract formation through regulating Nrf2/NF-κB signaling

Endoplasmic reticulum (ER) stress is reportedly involved in the development of ophthalmic diseases. This study aimed to investigate the role and potential mechanism of insulin-like growth factor 1 (IGF1) in ER stress. A mouse cataract model was constructed by subcutaneous injection of sodium selenite, and sh-IGF1 was used to evaluate the effect of silencing IGF1 on cataract progression. Slit-lamp and histological examination of the lens were performed to examine lens damage. The regulatory effects of IGF1 on inflammatory responses, oxidative stress, and ER stress were evaluated using ELISA, reverse transcription-quantitative PCR (RT-qPCR), and immunoblotting analysis. Tunicamycin was used to induce ER stress in the lens of epithelial cells. The NF-E2 related factor-2 (Nrf2) inhibitor ML385 and nuclear factor-κB (NF-κB) agonist diprovocim were used to confirm whether IGF1 regulates inflammation and ER stress through Nrf2/NF-κB signaling. Silencing IGF1 alleviated lens damage and reduced lens turbidity in the cataract mice. Silencing IGF1 inhibited inflammatory response, oxidative stress and ER stress response. Meanwhile, IGF1 was highly expressed in sodium selenite-treated lens epithelial cells. The ER stress agonist tunicamycin suppressed cell viability as well as induced ER stress, oxidative stress and inflammation. Silencing IGF1 increased cell viability, EdU-positive rate and migration. Also, silencing of IGF1 reduced inflammation and ER stress via regulating Nrf2/NF-κB pathway. This study reveals silencing IGF1 attenuated cataract through regulating Nrf2/NF-κB signaling, which shares novel insights into the underlying mechanism of cataract and provides potential therapeutic target for cataract.

Cost Utility and Value of Information Analysis of Femtosecond Laser-Assisted Cataract Surgery

Importance

The efficacy and safety of femtosecond laser-assisted cataract surgery is well documented. An important requirement for decision makers is the evaluation of the cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) over a sufficiently long horizon. Evaluating the cost-effectiveness of this treatment was a preplanned secondary objective of the Economic Evaluation of Femtosecond Laser Assisted Cataract Surgery (FEMCAT) trial.

Objective

To estimate the cost utility of FLACS compared with phacoemulsification cataract surgery (PCS) on a 12-month time horizon.

Design, Setting, and Participants

This multicenter randomized clinical trial compared FLACS with PCS in parallel groups. All FLACS procedures were performed using the CATALYS precision system. Participants were recruited and treated in ambulatory surgery settings in 5 university-hospital centers in France. All consecutive patients eligible for a unilateral or bilateral cataract surgery 22 years or older with written informed consent were included. Data were collected from October 2013 to October 2018, and data were analyzed from January 2020 to June 2022.

Interventions

FLACS or PCS.

Main Outcomes and Measures

Utility was measured through the Health Utility Index questionnaire. Costs of cataract surgery were estimated by microcosting. All inpatient and outpatient costs were collected from the French National Health Data System.

Results

Of 870 randomized patients, 543 (62.4%) were female, and the mean (SD) age at surgery was 72.3 (8.6) years. A total of 440 patients were randomized to receive FLACS and 430 to receive PCS; the rate of bilateral surgery was 63.3% (551 of 870). The mean (SD) costs of cataract surgery were €1124.0 (€162.2; US $1235) for FLACS and €565.5 (€61.4; US $621) for PCS. The total mean (SD) cost of care at 12 months was €7085 (€6700; US $7787) in participants treated with FLACS and €6502 (€7323; US $7146) in participants treated with PCS. FLACS yielded a mean (SD) of 0.788 (0.009) quality-adjusted life-years (QALYs), and PCS yielded 0.792 (0.009) QALYs. The difference in mean costs was €545.9 (95% CI, -434.1 to 1525.8; US $600), and the difference in QALYs was -0.004 (95% CI, -0.028 to 0.021). The incremental cost-effectiveness ratio (ICER) was -€136 476 (US $150 000) per QALY. The cost-effectiveness probability of FLACS compared with PCS was 15.7% for a cost-effectiveness threshold of €30 000 (US $32 973) per QALY. At this threshold, the expected value of perfect information was €246 139 079 (US $270 530 231).

Conclusions and Relevance

The ICER of FLACS compared with PCS was not within the $50 000 to $100 000 per QALY range frequently cited as cost-effective. Additional research and development on FLACS is needed to improve its effectiveness and lower its price.

Trial Registration

ClinicalTrials.gov Identifier: NCT01982006.

Swab Pressing vs Stromal Hydration to Prevent Incision Leakage and Transient Collapse of Anterior Chamber in Phacoemulsification: A Randomized Clinical Trial

Importance

During phacoemulsification, incision leakage and the subsequent anterior chamber collapse often occur after the withdrawal of the handpiece, which cannot be prevented by current sealing techniques. A new technique called swab pressing is proposed here to apply pressure with a cotton swab to seal the incision immediately, but efficacy remains unknown.

Objective

To determine if swab pressing is noninferior to stromal hydration, the current practice, in sealing incisions in phacoemulsification for age-related cataract.

Design, Setting, and Participants

This noninferiority randomized controlled clinical trial was conducted between February 2022 and September 2022 at the Zhongshan Ophthalmic Center, Guangzhou, China. Patients aged 60 to 90 years with age-related cataract were enrolled.

Interventions

Participants were randomly assigned (1:1) to receive swab pressing or stromal hydration. All surgeries were performed by a single experienced surgeon who was unmasked to the assignment.

Main Outcomes and Measures

The proportion of closed clear corneal incisions evaluated using intraoperative optical coherence tomography.

Results

A total of 126 eyes of 126 participants were randomized into the swab pressing group (63 [50%]) and stromal hydration group (63 [50%]). The mean (SD) age of participants was 69.2 (6.14) years and 70.1 (7.67) years in the pressing and stromal hydration groups, respectively. A total of 39 participants (61.9%) in the pressing group and 35 (55.6%) in the modified group were female. The proportion of closed incisions was 96.8% (61 of 63) in the swab pressing group and 93.7% (59 of 63) in the stromal hydration group. Noninferiority was met, as the lower 95% CI of -5.83 percentage points was greater than the prescribed noninferiority margin of -6.60 percentage points (difference, 3.17 percentage points; 95% CI, -5.83 to 12.18 percentage points). The rate of anterior chamber collapse (pressing: 0 of 63 vs stromal hydration: 35 of 63 [55.6%]; P < .001) was lower in the swab pressing group. There were no differences between the 2 groups in the proportion of closed incisions and central anterior chamber depth at postoperative hour 1 and day 1.

Conclusions and Relevance

In this study, swab pressing was noninferior to stromal hydration in sealing clear corneal incisions in phacoemulsification for age-related cataract. While this trial involved only 1 surgeon who was not masked to the interventions, the results suggest that swab pressing is feasible and further investigations would be warranted to determine if it prevents the intraoperative transient collapse of anterior chamber or affects visual acuity outcomes.

Trial Registration

ClinicalTrials.gov Identifier: NCT05242653.

Meandered and muddled: a systematic review on the impact of air pollution on ocular health

From the years 1970-2023, a systematic overview of the diverse consequences of particulate matter on eye health and a disease classification according to acute, chronic, and genetic are presented using the PubMed, Research Gate, Google Scholar, and Science Direct databases. Various studies on medical aspects correlate with the eye and health. However, from an application perspective, there is limited research on the ocular surface and air pollution. The main objective of the study is to uncover the relationship between eye health and air pollution, particularly particulate matter, along with other external factors acting as aggravators. The secondary goal of the work is to examine the existing models for mimicking human eyes. The study is followed by a questionnaire survey in a workshop, in which the exposure-based investigation was tagged based on their activity. This paper establishes a relationship between particulate matter and its influence on human health, leading to numerous eye diseases like dry eyes, conjunctivitis, myopia, glaucoma, and trachoma. The results of the questionnaire survey indicate that about 68% of the people working in the workshop are symptomatic with tears, blurred vision, and mood swings, while 32% of the people were asymptomatic. Although there are approaches for conducting experiments, the evaluation is not well defined; empirical and numerical solutions for particle deposition on the eye are needed. There prevails a broad gap in the arena of ocular deposition modeling.

Vitamin K and the Visual System-A Narrative Review

Vitamin K occupies a unique and often obscured place among its fellow fat-soluble vitamins. Evidence is mounting, however, that vitamin K (VK) may play an important role in the visual system apart from the hepatic carboxylation of hemostatic-related proteins. However, to our knowledge, no review covering the topic has appeared in the medical literature. Recent studies have confirmed that matrix Gla protein (MGP), a vitamin K-dependent protein (VKDP), is essential for the regulation of intraocular pressure in mice. The PREDIMED (Prevención con Dieta Mediterránea) study, a randomized trial involving 5860 adults at risk for cardiovascular disease, demonstrated a 29% reduction in the risk of cataract surgery in participants with the highest tertile of dietary vitamin K1 (PK) intake compared with those with the lowest tertile. However, the specific requirements of the eye and visual system (EVS) for VK, and what might constitute an optimized VK status, is currently unknown and largely unexplored. It is, therefore, the intention of this narrative review to provide an introduction concerning VK and the visual system, review ocular VK biology, and provide some historical context for recent discoveries. Potential opportunities and gaps in current research efforts will be touched upon in the hope of raising awareness and encouraging continued VK-related investigations in this important and highly specialized sensory system.

The regulatory role of microRNAs in common eye diseases: A brief review

MicroRNAs (miRNAs) are highly conserved, small non-coding RNA molecules (∼21 nucleotides) that regulate numerous biological processes, including developmental timing, hematopoiesis, organogenesis, apoptosis, cell differentiation, and proliferation either by mRNA degradation or translation repression. Since eye physiology requires a perfect orchestration of complex regulatory networks, an altered expression of key regulatory molecules such as miRNAs potentially leads to numerous eye disorders. In recent years, comprehensive progress has been made in demonstrating the precise roles of miRNAs, emphasizing their potential use in diagnostic and therapeutic purposes of chronic human diseases. Thus, this review explicitly illustrates the regulatory roles of miRNAs in four common eye disorders, such as cataract, glaucoma, macular degeneration, and uveitis, and their application in disease management.

The essential role of N6-methyladenosine RNA methylation in complex eye diseases

There are many complex eye diseases which are the leading causes of blindness, however, the pathogenesis of the complex eye diseases is not fully understood, especially the underlying molecular mechanisms of N6-methyladenosine (m6A) RNA methylation in the eye diseases have not been extensive clarified. Our review summarizes the latest advances in the studies of m6A modification in the pathogenesis of the complex eye diseases, including cornea disease, cataract, diabetic retinopathy, age-related macular degeneration, proliferative vitreoretinopathy, Graves' disease, uveal melanoma, retinoblastoma, and traumatic optic neuropathy. We further discuss the possibility of developing m6A modification signatures as biomarkers for the diagnosis of the eye diseases, as well as potential therapeutic approaches.

Evaluation of Ocular Biometric Parameters Following Cataract Surgery

Background: The aim of this study was to highlight the structural changes in patients with cataract following surgery and the repercussions on the anterior pole. Methods: A total of 83 patients diagnosed with cataract who underwent uneventful phacoemulsification was included. Every patient was examined one week prior to and two weeks after the surgery. Pre- and postoperative assessment included examination of the anterior and posterior segment, keratometry, and optical biometry. Results: The pre- vs. postoperative axial length (AL) mean difference was 0.07 ± 0.18 mm (p < 0.001).The mean difference of the postoperative anterior chamber depth (ACD) vs. preoperative ACD values (1.11 ± 0.50 mm) was also statistically significant (p < 0.001). The linear regression function postoperative central corneal thickness (CCT) = 0.9004 × (preoperative CCT) + 0.0668, where it characterized a reduced positive correlation (R2) of 68.89% between the postoperative CCT and preoperative CCT. The mean pre-/post-operative differences in the K1 values were 0.08 ± 0.38 D, with a statistically significant difference between the two datasets (p = 0.0152). The mean pre/postoperative difference in the K2 values was 0.002 ± 0.58 D (p = 0.4854). Conclusions: ACD deepened significantly postoperatively. Regarding AL, there was a decrease after surgery, and a very good positive correlation between the post and preoperative values. The CCT values decreased with age. The 2.2-mm corneal incision during cataract surgery resulted in a relatively small postoperative residual astigmatism.

Histone acetyltransferase inhibition reverses opacity in rat galactose-induced cataract

Cataract, a disease that causes opacity of the lens, is the leading cause of blindness worldwide. Cataracts secondary to diabetes are common, even in young patients, so they are of significant clinical importance. Here, we used an ex vivo model of galactose-induced cataracts in the rat lens to investigate the therapeutic effects of histone acetyltransferase (HAT) inhibitors. Among the tested HAT inhibitors, TH1834 was the only one that could reverse most of the opacity once it had formed in the lens. Combination treatment with C646/CPTH2 and CBP30/CPTH2 also had therapeutic effects. In lens cross-sections, vacuoles were present in the tissue of the cortical equatorial region of untreated cataract samples. In treated cataract samples, lens tissue regenerated to fill the vacuoles. To identify the genes regulated by HAT inhibitors, qRT-PCR was performed on treated and untreated cataract samples to determine candidate genes. Expression of Acta1 and Stmn4, both of which are involved in the cytoskeleton, were altered significantly in C646+CPTH2 samples. Expression of Emd, a nuclear membrane protein, and Prtfdc1, which is involved in cancer cell proliferation, were altered significantly in CBP30+CPTH2 samples. Acta1, Acta2, Arrdc3, Hebp2, Hist2h2ab, Pmf1, Ppdpf, Rbm3, RGD1561694, Slc16a6, Slfn13, Tagln, Tgfb1i1, and Tuba1c in TH1834 samples were significantly altered. These genes were primarily related to regulation of cell proliferation, the cytoskeleton, and cell differentiation. Expression levels increased with the onset of cataracts and was suppressed in samples treated with HAT inhibitors.

Atm inhibition decreases lens opacity in a rat model of galactose-induced cataract

Cataract causes vision loss and blindness due to formation of opacities of the lens. The regulatory mechanisms of cataract formation and progression remain unclear, and no effective drug treatments are clinically available. In the present study, we tested the effect of ataxia telangiectasia mutated (Atm) inhibitors using an ex vivo model in which rat lenses were cultured in galactose-containing medium to induce opacity formation. After lens opacities were induced by galactose, the lenses were further incubated with the Atm inhibitors AZD0156 or KU55933, which decreased lens opacity. Subsequently, we used microarray analysis to investigate the underlying molecular mechanisms of action, and extracted genes that were upregulated by galactose-induced opacity, but not by inhibitor treatment. Quantitative measurement of mRNA levels and subsequent STRING analysis revealed that a functional network consisting primarily of actin family and actin-binding proteins was upregulated by galactose treatment and downregulated by both Atm inhibitors. In particular, Acta2 is a known marker of epithelial-mesenchymal transition (EMT) in epithelial cells, and other genes connected in this functional network (Actn1, Tagln, Thbs1, and Angptl4) also suggested involvement of EMT. Abnormal differentiation of lens epithelial cells via EMT could contribute to formation of opacities; therefore, suppression of these genes by Atm inhibition is a potential therapeutic target for reducing opacities and alleviating cataract-related visual impairment.

Survey of Ophthalmology Training Experiences Among Young Ophthalmologists in the Asia-Pacific

PURPOSE

To describe ophthalmology training experiences across the Asia-Pacific (APAC).

DESIGN

Survey study.

METHODS

We utilized an anonymous online survey, which was previously validated and conducted in Europe, through Young Ophthalmologist leaders from the national member societies of the Asia-Pacific Academy of Ophthalmology (APAO) from September 2019 to July 2021. Responses were based on a 5-point Likert scale (where applicable) and data were analyzed using Microsoft Excel. Our main outcome measures were differences between regions, that is, Southeast Asia (SEA) and Western Pacific (WP); and seniority, that is, trainees/junior ophthalmologists and senior ophthalmologists.

RESULTS

We collated 130 responses representing 20 regions in the APAC region. The year of completion of ophthalmic training ranged from 1999 to 2024. The mean duration of training was 3.7±1.0 years. Most (98/130, 75%) indicated an interest for a common training standard across the APAC. Comparing SEA and WP trainees, both regions had similar working environments, but those in SEA reported significantly lower remuneration than their counterparts in WP ($600 vs $3000, P <0.05). WP trainees performed more phacoemulsification surgeries (76 WP vs 19 SEA), while SEA trainees conducted more manual small incision cataract surgeries (157 WP vs 1.5 SEA per duration of training). Senior ophthalmologists performed more cataract surgeries (210.9 senior ophthalmologists vs 40.1 junior ophthalmologists). Trainees had less confidence in medical competency areas such as interpreting an electroretinogram/visual evoked potential/electrooculogram (SEA=1.8, WP=2.1) and conducting an angiography (SEA=2.8, WP=3.4).

CONCLUSIONS

Our study highlighted heterogeneity among ophthalmology training experiences in the APAC region, with the majority indicating an interest in a common training standard.

Polygenic Risk Score Improves Cataract Prediction in East Asian Population

Cataracts, characterized by crystalline lens opacities in human eyes, is the leading cause of blindness globally. Due to its multifactorial complexity, the molecular mechanisms remain poorly understood. Larger cohorts of genome-wide association studies (GWAS) are needed to investigate cataracts’ genetic basis. In this study, a GWAS was performed on the largest Han population to date, analyzing a total of 7079 patients and 13,256 controls from the Taiwan Biobank (TWB) 2.0 cohort. Two cataract-associated SNPs with an adjustment of p < 1 × 10−7 in the older groups and nine SNPs with an adjustment of p < 1 × 10−6 in the younger group were identified. Except for the reported AGMO in animal models, most variations, including rs74774546 in GJA1 and rs237885 in OXTR, were not identified before this study. Furthermore, a polygenic risk score (PRS) was created for the young and old populations to identify high-risk cataract individuals, with areas under the receiver operating curve (AUROCs) of 0.829 and 0.785, respectively, after covariate adjustments. Younger individuals had 17.45 times the risk while older people had 10.97 times the risk when comparing individuals in the highest and lowest PRS quantiles. Validation analysis on an independent TWB1.0 cohort revealed AUROCs of 0.744 and 0.659.

Delays in Seeking Medical Services in Elderly Patients With Senile Cataract

Delay in seeking medical services is common in elderly populations, which leads to disease progression and life difficulty. This study aims to assess the prevalence of delay in medical visits and treatment and define associated effects and factors in patients with senile cataract, which may help obtain a better understanding of late-life psychopathology and provide the basis for interventions. Patients aged more than 60 years were prospectively recruited in Zhongshan Ophthalmic Center (ZOC). All participants were diagnosed with binocular senile cataract and decided to have primary surgery in ZOC. The distributions of the popularity of delaying outpatient visits and treatment, the degrees of visual impairment, the influences on quality of life, and the reasons for delaying treatment among participants were accessed by the descriptive statistics. Factors associated with the perceptions of cataract treatment were accessed using a binary logistic regression model. A total of 400 senile patients aged from 60 to 94 years were enrolled. At diagnosis, 82 (20.5%) participants had a low vision with monocular acuity of both eyes below 0.05. All participants have felt that their normal lives were affected, and 64 (16%) participants felt that their lives were affected severely. Only 17 (4.25%) participants have sought for medical services immediately after feeling vision loss, and 294 (73.50%) participants have felt vision loss since a year ago before seeking medical help. A total of 298 (74.50%) participants have delayed the surgery time, and 229 (57.25%) patients delayed it for more than 12 months. There were 147 (36.75%) participants delaying surgery on account of no knowledge about it and 114 (28.50%) participants delaying surgery because of fear. There are a high proportion of elderly patients with senile cataract delaying their outpatient visits and surgery treatment, whose normal lives were severely affected. Increasing medical service propaganda about cataract and other common diseases in elderly populations would probably be helpful for improving perceptions of diseases and decreasing medical delays. Public needs to draw more attention to the healthy and medical status of the elderly ocular patients.