Cataract Research Articles

Effects of Gold Nanoparticles Phytoreduced with Rutin in an Early Rat Model of Diabetic Retinopathy and Cataracts.

Diabetic retinopathy (DR) and cataracts (CA) have an early onset in diabetes mellitus (DM) due to the redox imbalance and inflammation triggered by hyperglycaemia. Plant-based therapies are characterised by low tissue bioavailability. The study aimed to investigate the effect of gold nanoparticles phytoreduced with Rutin (AuNPsR), as a possible solution. Insulin, Rutin, and AuNPsR were administered to an early, six-week rat model of DR and CA. Oxidative stress (MDA, CAT, SOD) was assessed in serum and eye homogenates, and inflammatory cytokines (IL-1 beta, IL-6, TNF alpha) were quantified in ocular tissues. Eye fundus of retinal arterioles, transmission electron microscopy (TEM) of lenses, and histopathology of retinas were also performed. DM was linked to constricted retinal arterioles, reduced endogen antioxidants, and eye inflammation. Histologically, retinal wall thickness decreased. TEM showed increased lens opacity and fibre disorganisation. Rutin improved retinal arteriolar diameter, while reducing oxidative stress and inflammation. Retinas were moderately oedematous. Lens structure was preserved on TEM. Insulin restored retinal arteriolar diameter, while increasing MDA, and amplifying TEM lens opacity. The best outcomes were obtained for AuNPsR, as it improved fundus appearance of retinal arterioles, decreased MDA and increased antioxidant capacity. Retinal edema and disorganisation in lens fibres were still present.

Analysis of Age and Gender Factors on the Incidence Rate of Cataracts in the Ophthalmology Clinic

Cataracts are a cause of blindness which accounts for approximately half of all blindness in the world, especially in developing countries. The mechanism of cataract formation is highly multifactorial. Loss of transparency in the nucleus and cortex of the lens of the eye can occur as a result of oxidation of membrane lipids, structural or enzymatic proteins by peroxides or free radicals induced by UV light. Other factors that can cause cataract formation are degenerative processes and diabetes mellitus). Cataract therapy is a surgical procedure by removing the cloudy lens, because no medical therapy has been proven to remove cataracts in adults. There are many methods that can be done with surgery for cataract patients. One of them is phacoemulsification, which is a cataract surgery using a small incision method. In this technique, liquefaction of the lens is made using an ultrasound probe that is inserted through an incision in the cornea or anterior sclera. This study aims to determine the relationship between age and gender with the incidence of cataracts at the Eye Polyclinic Outpatient Installation in 2022. This is a retrospective analytic study by examining data in the Recamedics Department. The data is grouped by age, sex and type of cataracts. There were 197 patients who came to the eye polyclinic in July 2022. From the results of the study, 197 people suffered from cataracts with a percentage of 88 men (45%) and 109 women (55%) and the age group that suffered the most from cataracts was the age group 53-68 years and the most common cataracts were senile cataract. Analysis of the relationship between age and gender with the incidence of cataracts in the Outpatient Installation (Poly Eyes) for the period of July 2022 obtained a value for the relationship between age and the incidence of cataracts P = 0.846 and the relationship between sex and the incidence of cataracts P = 0.01. Conclusion: In this study there is a significant relationship between gender and the incidence of cataracts and there is no relationship between age and the incidence of cataracts.

Evaluation of a retinal oximetry image quality indicator in patients with cataract.

To evaluate a new automated retinal oximetry image quality indicator with cataract as a clinical model. Sixty-one eyes in 61 patients were imaged by the Oxymap T1 Retinal Oximeter at baseline and 25 eyes were also examined 3 weeks after cataract surgery. Image quality (0-10 on a continuous scale) was compared with standardized AREDS cataract grading and Pentacam lens densitometry. Associations with retinal oximetry measurements and visual acuity were examined. Image quality correlated with total, nuclear and posterior subcapsular cataract grades (ANOVA, p < 0.05), tended to be associated with lens densitometry and it improved from 4.3 ± 1.4 to 5.7 ± 1.0 (p < 0.05) after cataract surgery. Very low image quality, below 3, led to vessel detection failure in retinal oximetry images. Higher image qualities were linearly associated with higher measured retinal oxygen saturations (r = 0.52 in arteries and r = 0.46 in veins; p < 0.001). Retinal oximetry image quality deteriorated with increasing cataract density and improved after cataract surgery, supporting its use as a measure of optical clarity. The numerical quality indicator demonstrated a threshold below which images of poor optical quality should be discarded. Image quality affects the estimates of retinal oximetry parameters and should therefore be included in future analyses.

Infective Etiologies in Patients with Bilateral Congenital Cataract

Objective: To determine the frequency of positive Toxoplasma, Rubella, Cytomegalovirus, Herpes Simplex virus and Syphilis serology in patients with bilateral congenital cataract and their correlation with different type of cataracts and age groups.&#x0D; Study Design: Cross sectional study.&#x0D; Place and Duration of Study: Department of Pediatric Ophthalmology and Strabismus, Armed Forces Institute of Ophthalmology, Rawalpindi Pakistan, from May to Dec 2022.&#x0D; Methodology: Data was collected by a single investigator on Microsoft Excel sheet including patient’s age, gender, mode of delivery, consanguinity of parents, and type of congenital cataract, results of TORCH Screening and Presence or absence of amblyopia. TORCHS screening comprised of serum IgM and IgG levels for Toxoplasmosis, Rubella, Cytomegalovirus, Herpes Simplex virus and Syphilis. &#x0D; Results: A total of 134 patients reported to our institute with bilateral congenital cataract during the study period. Out of them 56 patients had positive results of TORCH screening (41.7%) Out of total 56 patients with bilateral congenital cataract testing positive for TORCH, 30(53.6%) were male while 26(46.4%) were female. Age range was from 1-17 months (9.2±4.2 months).Lamellar cataract was the most common cataract type in our study sample 16(28.6%).&#x0D; Conclusion: In patients with bilateral congenital cataract positive TORCHS serology was most frequent. Serum Rubella IgM followed by Rubella IgG was positive in most cases. Most common age of presentation in our study was from 4-7 months. Furthermore, lamellar cataract followed by nuclear cataract was the commonest cataract type.

Prevalence of pseudoexfoliation in diabetic patients with senile cataract: A hospital-based study in Kashmir, India.

: To study the prevalence of pseudoexfoliation syndrome (PEX) in diabetics with senile cataracts and compare it to the prevalence in nondiabetic control group. : Two hundred and fifty diabetics and 250 nondiabetics (age and sex matched) were evaluated for PEX deposition. : Chi-squared test was employed, and a P value < 0.05 was considered significant. In the PEX group, most patients belonged to the age group of 60-70 years (55.17%). Out of 18 patients with PEX, 11 (61.1%) showed bilaterality. There was a higher frequency of raised intraocular pressure (IOP; >20 mmHg) in PEX eyes (10.3%) than in the non-PEX eyes (5.9%). The PEX group had a higher number of eyes with cup-to-disc ratio (CDR) >0.6 (11.12%) than the non-PEX group (4.32%). Nuclear cataracts were more frequent in PEX eyes than non-PEX eyes, whereas PSC and mature cataracts were more prevalent in the non-PEX group. Most eyes had PEX deposition on the anterior lens capsule and pupillary margin. Of the 500 study eyes corresponding to the diabetic group, 418 had cataracts (rest pseudophakic), of which 28 had pseudoexfoliation, accounting for 6.7% of the total. In the nondiabetic control group comprising 500 eyes, 430 had senile cataracts (rest pseudophakic), of which 105 had PEX deposition, accounting for 24.4% of the total. : According to our findings, diabetics have a lower prevalence of PEX than nondiabetics. Few such studies have been conducted so far, and none have been conducted in the Indian population.

Lens Thickness in Atopic Cataract: A Case-Control Study.

To examine whether atopic cataracts are associated with thinner lenses. Department of Ophthalmology, Jikei University Hospital, Tokyo, Japan. Retrospective matched case-control study. A total of 31 eyes with atopic cataracts, 62 with non-atopic cataracts, and 31 without cataracts were analyzed. Each group was matched for age (± 4 years) and sex. The mean lens thickness (LT) was 3.76 ± 0.40, 3.94 ± 0.49, and 4.11 ± 0.40 mm in eyes with atopic cataracts, non-atopic cataracts, and normal lenses, respectively. Repeated-measures analysis of variance showed that the LT in the atopic cataract group was significantly thinner than that in the non-atopic cataract (P = 0.036) and normal lens (P < 0.001) groups. In multivariate logistic regression analysis, a thinner LT was negatively correlated with age (OR 0.91, 95% CI 0.86-0.96) and positively correlated with anterior subcapsular cataract (ASC) (OR 5.61, 95% CI 1.97-15.99). Atopy was not a significant factor. Twenty-four of the 62 eyes (38.7%) with non-atopic cataracts and 24 of the 31 eyes (77.4%) with atopic cataracts had ASC. The lenses of eyes with atopic cataracts were thinner than those of controls. Atopic cataracts frequently present with anterior subcapsular opacity, which is associated with lens thinning.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses.

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

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

BackgroundThe 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...

HUBUNGAN UMUR DAN JENIS KELAMIN DENGAN ANGKA KEJADIAN KATARAK SENILIS DI RS CAMATHA SAHIDYA

Background: Cataract is a disease with clouding of the lens, the cause of cataract is a multifactorial disease. The results of a data survey in 2020 at Camatha Sahidya Hospital, at least 42 people have had surgery for senile cataracts. Based on the survey data, researchers are interested in researching the relationship between age and gender with the incidence of senile cataracts at Camatha Sahidya Hospital, Batam City in 2021. &#x0D; Method: The method of this study was Observational Analytical with a Cross-Sectional approach carried out at Camatha Sahidya Hospital with a total sample of 65 people taken using a purposive sampling technique. The research results were analyzed by Chi-Square Test. &#x0D; Result: The results of the Chi-Square Test show that there is a relationship between age with the incidence of senile cataracts at Camatha Sahidya Hospital, Batam City in 2021 with a p value = (p≤0.05). Whereas for the gender variable, there is no relationship with the incidence of senile cataracts with a p value = (p&gt; 0.05). &#x0D; Conclusion: Based on the results of this study it can be concluded that there is a relationship between age with the incidence of senile cataracts and there is no significant relationship between gender and the incidence of senile cataracts at Camatha Sahidya Hospital, Batam City in 2021.

Change in macular thickness after uncomplicated phacoemulsification surgery using optical coherence tomography in a tertiary care hospital.

To determine the change in macular thickness after uncomplicated phacoemulsification surgery using optical coherence tomography in a tertiary care hospital. This study was conducted at Department of Ophthalmology Jinnah Postgraduate Medical Centre Karachi, for 6 months from 10th Dec 2019 to 10th June 2020. Sample size calculation of 52 eyes was done by using open epi software. Patients who fulfilled the inclusion criteria that is age ranging from 50 to 75 years, either gender with senile cataract having no preexisting ocular or systemic disease and those giving consent were included in this study. Patients with any comorbidity ocular trauma, having pre-existing ocular diseases such as active ocular infection, glaucoma, maculopathy or retinopathy were excluded from study. Patients with secondary cataract also excluded from study. After complete history, all patients underwent detailed ophthalmologic examination and Pre-surgery macular thickness recorded by using swept source OCT (DRI-OCT-2 Triton; Topcon). Surgery was performed and intraocular lens was implanted in all cases. Post procedure Macular thickness was measured using swept source OCT at 1st postoperative day, 1st month and 6th month after surgery. The mean age of patients was 62.06 ± 5.1 years. Total of 52 eyes diagnosed with senile cataract were included in this study. There were 30 (57.7%) males and 22(42.3%) females. The mean preoperative central foveal thickness was 201.3±24.8μm. The postoperative central foveal thickness was 200.3±25.2μm (153-265μm) at day 1st of surgery, 224.1 ± 53.8 μm (151-458 μm) at 1st month and 212.4±28.3μm (167-255μm) 6th month after surgery. The mean preoperative BCVA was 0.70 ± 0.43 (0.1-1.7) logMAR. The postoperative mean BCVA was 0.26 ± 0.42 (0.00-3.10) logMAR at 1st day, 0.07± 0.10 (0.000.7) logMAR at 1st month and 0.05 ± 0.10 (0.00-0.3) logMAR at 6th month. In our study we found an increase in macular thickness but there was no loss of BCVA from changes of macular thickness after surgery and the mean BCVA increased progressively in postoperative period.

Aldose reductase and glutathione in senile cataract nucleus of diabetics and non-diabetics

PurposeThe aim is to evaluate the aldose reductase (AR) and glutathione (GSH) activity in the nucleus of senile cataract in type 2 diabetes and non-diabetic group of patients.MethodsA total of 62 patients including 31 diabetics and 31 non- diabetics who were undergoing cataract surgery were included. Nucleus extracted was sent for analysis of AR and GSH activity while blood sample was taken for glycated haemoglobin (HbA1c) levels.Statistical analysisData were analysed using IBM SPSS 25. Comparison was carried out by unpaired T-test and correlations were established by Pearson’s correlation. The p value less than 0.05 was considered significant for all analyses.Study designThis is a prospective cross-sectional comparative study.ResultsIn this study, diabetic group patients showed earlier progression of cataract as compared to the non-diabetic group (p-value 0.0310). Mean HbA1c in the diabetic group was 7.34% compared to the non-diabetic group of 5.7% (p value < 0.001). AR in the diabetic patients was 2.07 mU/mg while the non-diabetic group was 0.22 mU/mg (p-value < 0.001). GSH in the diabetic group was 3.38 μMol/g and the non-diabetic group was 7.47 μMol/g (p value < 0.001). HbA1c showed positive correlation with AR among the diabetic group (p-value 0.028).ConclusionElevated oxidative stress can be strongly attributed to high AR and low GSH activity among the diabetic group as compared to the non-diabetic group and can lead to early cataract formation.

IOL Power Calculation in an Unusual Long Fellow Eye: A Case Report

Background: Intra-Ocular Lens (IOL) power calculation in long eyes remains challenging despite the availability of new formulas and biometers. This case report shows that optimization of the A-constant in the first eye can reduce postoperative refractive error in the second eye, even in the case of an IOL with negative power. This report aimed to describe a case in which this method was used to calculate IOL power to reduce postoperative refractive error in a long fellow eye. As far as we know, this is the first paper reporting the use of the optimized constant in the first eye to reduce postoperative error in the second eye in the case of a negative IOL. Case presentation: A highly myopic patient with nuclear cataracts underwent phacoemulsification cataract surgery (PCS) in both eyes. The axial length (AL) was 39.42 mm in the right eye and 37.45 mm in the left eye. All biometric data were obtained via low-coherence reflectometry using an OA-2000 biometer (Tomey, Nagoya, Japan). First, an IOL power calculation using the Barrett II formula and PCS was performed in the shorter eye. To evaluate the postoperative refractive error, the optimized A-constant in the left eye was estimated using the Camellin-Calossi formula. The new A-constant was then used for the right eye IOL power calculation using the same formula. The prediction error (PE) in the left eye was −0.23 D with the Barrett II formula. The optimized A-constant method using the Camellin-Calossi formula in the fellow eye gave −0.28 D of PE. Conclusions: The A-constant optimization for very long eyes, using data from the first operated eye, may be useful to reduce refractive prediction error in the second eye in very long eyes, as well as in the case of IOL power with negative values.

Carbon Monoxide Releasing Molecule-3 Alleviates Oxidative Stress and Apoptosis in Selenite-Induced Cataract in Rats via Activating Nrf2/HO-1 Pathway

Purpose This study investigated the protective effect of carbon monoxide releasing molecule-3 (CORM-3), the classical donor of carbon monoxide, on selenite-induced cataract in rats and explore its possible mechanism. Methods Sprague-Dawley rat pups treated with sodium selenite (Na2SeO3) were chosen as the cataract model. Fifty rat pups were randomly divided into 5 groups: Control group, Na2SeO3 (3.46 mg/kg) group, low-dose CORM-3 (8 mg/kg/d) + Na2SeO3 group, high-dose CORM-3 (16 mg/kg/d) + Na2SeO3 group, and inactivated CORM-3 (iCORM-3) (8 mg/kg/d) + Na2SeO3 group. The protective effect of CORM-3 was tested by lens opacity scores, hematoxylin and eosin staining, TdT-mediated dUTP nick-end labeling assay, and enzyme-linked immunosorbent assay. Besides, quantitative real-time PCR and western blotting were used for mechanism validation. Results Na2SeO3 induced nuclear cataract rapidly and stably, and the achievement ratio of Na2SeO3 group was 100%. CORM-3 alleviated lens opacity of selenite-induced cataract and attenuated the morphological changes of the rat lens. The levels of antioxidant enzymes GSH and SOD in rat lens were also increased by CORM-3 treatment. CORM-3 significantly reduced the ratio of apoptotic lens epithelial cells, besides, CORM-3 decreased the expression of Cleaved Caspase-3 and Bax induced by selenite and increased the expression of Bcl-2 in rat lens inhibited by selenite. Moreover, Nrf-2 and HO-1 were upregulated and Keap1 was downregulated after CORM-3 treatment. While iCORM-3 did not exert the same effect as CORM-3. Conclusions Exogenous CO released from CORM-3 alleviates oxidative stress and apoptosis in selenite-induced rat cataract via activating Nrf2/HO-1 pathway. CORM-3 may serve as a promising preventive and therapeutic strategy for cataract.

Unveiling endothelial resilience: Comparative analysis of phacoemulsification and manual small-incision cataract surgery with 6-month postoperative surveillance

Abstract Purpose: The purpose is to find out changes in endothelial cell density (ECD) in eyes undergoing phacoemulsification (Phaco) versus manual small-incision cataract surgery (MSICS) or small-incision cataract surgery (SICS) with 6-month postoperative follow-up. Methods: An observational prospective study of 200 eyes of 200 patients was conducted over 13 months (December 2016–December 2017). Patients with senile cataracts undergoing surgery by any of the two methods (SICS and Phaco) were included in this study. After preoperative examinations, patients underwent surgery by either Phaco or SICS according to patients’ preferences and affordability. All intra- and postoperative data were collected prospectively, and the minimum follow-up was 6 months. Data were entered into an Excel file format and subsequently analyzed with SPSS (Statistical Package for the Social Sciences), unpaired t-test, paired test, ANOVA test, and Pearson correlation coefficient. P &lt;0.05 was considered statistically significant. Results: The mean ECD during the preoperative period in the SICS group was 2537.789 cells/mm2 (range = 2004.3–3564.7) and in the Phaco group 2592.878 cells/mm2 (range = 2020.0–3434.3). There was significantly more cell loss in SICS at 1 week than in Phaco (P = 0.0001). On 1-month and 3-month follow-up, gain and stabilization in ECD were noted in both the groups which was significantly more in the SICS group than in the Phaco group (P = 0.001 and P = 0.004, respectively). However, at 6 months, ECD loss was stabilized for both the groups, and there was statistically no significant difference between both groups (P = 0.108). Conclusion: While there is an initial difference in EC loss between MSICS and Phaco, there is a significant stabilization observed over the 6-month postoperative period, resulting in comparable EC loss between the two methods.

Blood inflammatory biomarkers in participants with idiopathic epiretinal membrane: A retrospective case series study.

The objective was to evaluate the levels of monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in patients with idiopathic epiretinal membrane (iERM). This retrospective case series study comprised of participants with iERM and participants with cataract. The values of MLR, NLR, PLR and from participants' peripheral blood were assessed among groups. The best cutoff value of MLR, NLR, and PLR in iERM was found by performing a receiver operating characteristic curve analysis and determining the optimum cutoff value for each variable. In total, 95 participants with iERM were included in the study group, and 61 participants with senile cataract were included as controls. The lymphocyte count in the iERM group was significantly lower than the control group (1.69 ± 0.63 vs. 1.95 ± 0.53, P = .003). The monocyte count in the iERM group was significantly higher than the control group (0.39 ± 0.11 vs. 0.31 ± 0.10, P < .001). The area under the curve of MLR, NLR, and PLR in differentiating patients with IERM and controls was 0.782, 0.645, and 0.657, respectively, according to receiver operating characteristic. The best cutoff value of MLR was > 0.18, with sensitivity and specificity of 74.7% and 75.4%, respectively. The NLR was > 2.06, with a sensitivity and specificity of 50.5% and 83.6%, respectively. The PLR was > 95.89, with a sensitivity and specificity of 86.3% and 41.0%, respectively. The findings of this study suggest that systemic inflammation may be associated with iERM. IERM patients may be prone to have high MLR, NLR, and PLR values.

Cataract Surgery following Corneal Allogenic Intrastromal Ring Segments and Implantable Collamer Lens

The management of cataracts in keratoconus patients poses a challenge due to the irregular corneal shape and variability in corneal topography, which may lead to errors in determining corneal power. In this report, we present a case of a 48-year-old male with a history of keratoconus and prior Visian Implantable Collamer lenses and Corneal Allogenic Intrastromal Ring Segments procedures, who presented with a nuclear cataract in his right eye. To address this patient’s complex case, he underwent ICL explantation, cataract extraction, and intraocular lens (IOL) implantation, utilizing the Johnson &amp; Johnson Sensar AR40 monofocal 3-piece lens with a power of −9.5. The Barrett True K formula predicted a spherical equivalent of −1.76, and at the post-operative one-month follow-up, the uncorrected distance visual acuity (UDVA) was 20/60, with pinhole improvement to 20/50. The manifest refraction was −2.50–3.25 × 145, and the best corrected visual acuity was 20/25. This case report highlights the unique challenges encountered in managing keratoconus patients with a history of prior ICL and CAIRS procedures, followed by cataract extraction. Our findings underscore the importance of a comprehensive approach in the management of progressive keratoconus and cataracts to ensure optimal outcomes.

Lens Thickness and Associated Factors among Age-Related Cataracts Patients in Chattogram, Bangladesh

Background: Lens Thickness (LT) is one of the important parameters in ocular biometry. The observation of LT among cataract patients is of great importance from clinical and pathophysiological perspectives. The study aimed to investigate the relationship between the LT and lens density changes concerning age, types and densities of agerelated cataracts in a sample of the Bangladeshi population. Materials and methods: It is a prospective observational case control study. A total of 2066 (n = 2066) participants were included in the study from an Eye Hospital in Chattogram, Bangladesh. All participants underwent standard vision testing. LT was evaluated using the immersion technique with A-scan ultrasound. The types and density of cataracts were identified with a slit-lamp attached to a video camera. Cataract was classified morphologically into cortical, nuclear, and posterior sub-capsular types. Nuclear cataract was observed under oblique illumination, and retro-illumination was used to assess cortical and posterior sub-capsular cataracts. The density of the lens nucleus was graded as Emery and Little classification. Results: Ages of the study population ranged from 40-95 years, with a mean age of 62.76 ± 9.43 years. Of the participants, 937 (45.4%) were males and 1129 (54.6%) were females. The mean LT was 4.15±0.86mm. The LT was greater in older (³60 years) patients than in the younger (41-59 years) (4.21±0.85mm versus 4.01±0.86mm, p &lt; 0.001). The mean LT in male and female patients were, respectively, 4.18±0.89mm and 4.12±0.84mm with any statistical significance (p&lt;0.097). The mean LT was the highest in nuclear cataracts (4.79 ± 0.39mm), followed by cortical (3.9 ± 0.73mm) and posterior sub-capsular cataracts (4.16 ± 0.93mm). The relation between LT and the Grade of cataract was insignificant (p&lt;0.078). Conclusion: In this large Bangladeshi age-related cataractous population, we found that thicker lenses are associated with older age and nuclear cataracts. IAHS Medical Journal Vol 5(2), Dec 2022; 58-61

Glycolysis Aids in Human Lens Epithelial Cells' Adaptation to Hypoxia.

Hypoxic environments are known to trigger pathological damage in multiple cellular subtypes. Interestingly, the lens is a naturally hypoxic tissue, with glycolysis serving as its main source of energy. Hypoxia is essential for maintaining the long-term transparency of the lens in addition to avoiding nuclear cataracts. Herein, we explore the complex mechanisms by which lens epithelial cells adapt to hypoxic conditions while maintaining their normal growth and metabolic activity. Our data show that the glycolysis pathway is significantly upregulated during human lens epithelial (HLE) cells exposure to hypoxia. The inhibition of glycolysis under hypoxic conditions incited endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production in HLE cells, leading to cellular apoptosis. After ATP was replenished, the damage to the cells was not completely recovered, and ER stress, ROS production, and cell apoptosis still occurred. These results suggest that glycolysis not only performs energy metabolism in the process of HLE cells adapting to hypoxia, but also helps them continuously resist cell apoptosis caused by ER stress and ROS production. Furthermore, our proteomic atlas provides possible rescue mechanisms for cellular damage caused by hypoxia.

The Long Noncoding RNA H19 Promotes Fibrotic Processes in Lens Epithelial Cells.

The purpose of this study was to investigate the role of lncRNA H19 in epithelial-mesenchymal transition (EMT) and its molecular mechanism in fibrotic cataracts. TGF-β2-induced EMT was induced in human lens epithelial cell line (HLECs) and rat lens explants to mimic posterior capsular opacification (PCO) in vitro and in vivo. Anterior subcapsular cataract (ASC) was induced in C57BL/6J mice. The long noncoding RNA (lncRNA) H19 (H19) expression was detected by RT-qPCR. Whole-mount staining of lens anterior capsule was used to detect α-SMA and vimentin. Lentiviruses carrying shRNA or H19 vector were transfected in HLECs to knockdown or overexpress H19. Cell migration and proliferation were characterized by EdU, Transwell, and scratch assay. EMT level was detected by Western blotting and immunofluorescence. The rAAV2 carrying mouse H19 shRNA was injected into ASC model mouse anterior chambers as a gene therapy to determine its therapeutic potential. PCO and ASC models were built successfully. We found H19 upregulation in PCO and ASC models in vivo and in vitro. Overexpression of H19 by lentivirus transfection increased cell migration, proliferation, and EMT. In addition, H19 knockdown by lentivirus suppressed cell migration, proliferation, and EMT levels in HLECs. Moreover, transfection of rAAV2 H19 shRNA alleviated fibrotic area in ASC mouse lens anterior capsules. Excessive H19 participates in lens fibrosis. Overexpression of H19 increases, whereas knockdown of H19 ameliorates HLECs migration, proliferation, and EMT. These results demonstrate H19 might be a potential target for fibrotic cataracts.

Characterization of a Novel Gja8 (Cx50) Mutation in a New Cataract Rat Model.

To describe a novel spontaneous cataract inbred strain isolated from large-scale breeding SD rats, identify the responsible gene mutation, and understand how this mutation affects lens function. Exome sequencing of 12 cataract-associated genes was performed in the affected and healthy relatives. Sequences of rat wild-type or mutant gap junction protein alpha 8 gene (Gja8) were transfected into cells. The expression level of protein was assayed by Western blot analysis. Subcellular localization of connexin 50 (Cx50) was analyzed in confocal fluorescent images. Wound-healing, 5-ethynyl-2'-deoxyuridine incorporation, and attachment assay were performed to characterize the cell migration, proliferation and adhesion. The abnormality was found to be inheritable in an autosomal semi-dominant pattern through different mating patterns. We found a G to T transversion at codon 655 in Gja8, leading to a substitution of valine by phenylalanine (p.V219F). Gja8V219F/+ heterozygotes expressed nuclear cataract while Gja8V219F/V219F homozygotes manifested microphthalmia in addition to cataract. Histology revealed fiber disorders and loss of organelle-free zone in the mutant lens. Cx50V219F altered its location in HeLa cells and inhibited the proliferation, migration and adhesion abilities of HLEB3 cells. The mutation also reduced the expression of focal adhesion kinase and its phosphorylation. The c.655G>T mutation (p.V219F) is a novel mutation in Gja8, inducing semi-dominant nuclear cataracts in a new spontaneous cataract rat model. The p.V219F mutation altered Cx50 distribution, inhibited lens epithelial cell proliferation, migration, and adhesion, and disrupted fiber cell differentiation. As a consequence, the nuclear cataract and small lens formed.