The global burden of cataract

A Parallel Robot With Remote Centre-of-Motion for Eye Surgery: Design, Kinematics, Prototype, and Experiments

BACKGROUND

Millions of patients suffering from eye disease cannot receive proper treatment due to the lack of qualified surgeons. Medical robots have the potential to solve this problem and have attracted significant attention in the research community.

METHOD

This paper proposes a novel parallel robot with a remote centre of motion for minimally invasive eye surgery. Kinematics models, singularity and workspace analyses, and dimension optimisation are conducted. A prototype was developed, and experiments were conducted to test its mobility, accuracy, precision and stiffness.

RESULTS

The prototype robot can successfully perform the required motions, and has a precision ranging from 7 ± 2 μm to 30 ± 8 μm, accuracy from 21 ± 10 μm to 568 ± 374 μm, and stiffness ranging from 1.22 ± 0.39 N/mm to 10.53 ± 5.18 N/mm.

CONCLUSION

The prototype robot has a great potential for performing the minimally invasive surgery. Its stiffness meets the design requirement, but its accuracy and precision need to be further improved.

Assessing the cataract surgical rate and gender equity in cataract services in south-east Nigeria

BACKGROUND

In 2020, almost 100 million people were blind or visually impaired from cataract. Cataract surgery is a cost-effective treatment for cataracts. In Nigeria, twice as many women are cataract blind as men. Cataract surgical rate (CSR, the number of cataract operations per million population per year in a defined geographical location) is an output indicator of cataract surgical services. The recommended target CSR for sub-Saharan Africa is 1000/year. The aim of this study was to assess the CSR in men and women in Imo state, Nigeria.

METHODS

A retrospective review of cataract surgery undertaken in all eye health facilities in Imo State in 2019. Data collected included the type and location of facilities, patient demographics and the number and type of cataract operations performed in each facility. The CSR was calculated overall, in men and women, and in younger and older women.

RESULTS

The CSR overall was 330/million and was slightly higher in women (347/million) than in men (315/million) (p<0.001). More elderly women (≥65 years) accessed cataract surgery through outreach than men and younger women (OR 1.5 (95% CI 1.03 to 2.22, p=0.03) and 1.6 (95% CI 1.07 to 2.44, p=0.02)), respectively.

CONCLUSION

The overall CSR in Imo state was approximately one-third of that recommended for sub-Saharan Africa. Although the CSR was higher in women than in men, considerably higher CSRs are needed in women to address their higher burden of cataract blindness. Operational and intervention science research are needed, to identify and evaluate interventions which address demand and supply barriers to accessing cataract surgery, particularly for elderly women.

CircRNA HLCS regulates lens epithelial cell apoptosis via miR-338-3p/BPNT1 axis

PURPOSE

The purpose of this study was to investigate the effect of circ_HLCS on age-related cataract (ARC).

METHODS

Circ_HLCS, microRNA (miR)-338-3p, and bisphosphate 3'-nucleotidase 1 (BPNT1) were quantified by quantitative real-time polymerase chain reaction or western blot. Cell proliferation and cell viability were assessed by the 5-Ethynyl-2'-deoxyuridinr and cell counting kit-8 assays. Cell apoptosis was detected by flow cytometry. Targeted correlations among circ_HLCS, miR-338-3p, and BPNT1 were verified by the dual-luciferase reporter and RNA pull-down assays.

RESULTS

circ_HLCS was diminished in ARC tissues and UV-treated SRA01/04 cells. Elevated content of circ_HLCS undermined UV-induced cell proliferation inhibition and apoptosis. Mechanistically, circ_HLCS directly targeted miR-338-3p, and circ_HLCS regulated BPNT1 expression through miR-338-3p. Furthermore, reduction of miR-338-3p ameliorated UV-induced SRA01/04 cell damage by increasing BPNT1 expression.

CONCLUSION

Taken together, these data suggested that circ_HLCS inhibited apoptosis of UV-treated SRA01/04 cells by miR-338-3p/BPNT1 axis. Therefore, circ_HLCS might be a potential therapeutic target for ARC.

Fabrication of a 3D bioprinting model for posterior capsule opacification using GelMA and PLMA hydrogel-coated resin

Posterior capsule opacification (PCO) remains the predominant complication following cataract surgery, significantly impairing visual function restoration. In this study, we developed a PCO model that closely mimics the anatomical structure of the crystalline lens capsule post-surgery. The model incorporated a threaded structure for accurate positioning and observation, allowing for opening and closing. Utilizing 3D printing technology, a stable external support system was created using resin material consisting of a rigid, hollow base and cover. To replicate the lens capsule structure, a thin hydrogel coating was applied to the resin scaffold. The biocompatibility and impact on cellular functionality of various hydrogel compositions were assessed through an array of staining techniques, including calcein-AM/PI staining, rhodamine staining, BODIPY-C11 staining and EdU staining in conjunction with transwell assays. Additionally, the PCO model was utilized to investigate the effects of eight drugs with anti-inflammatory and anti-proliferative properties, including 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), THZ1, sorbinil, 4-octyl itaconate (4-OI), xanthohumol, zebularine, rapamycin and caffeic acid phenethyl ester, on human lens epithelial cells (HLECs). Confocal microscopy facilitated comprehensive imaging of the PCO model. The results demonstrated that the GelMA 60 5% + PLMA 2% composite hydrogel exhibited superior biocompatibility and minimal lipid peroxidation levels among the tested hydrogels. Moreover, compared to using hydrogel as the material for 3D printing the entire model, applying surface hydrogel spin coating with parameters of 2000 rpm × 2 on the resin-based 3D printed base yielded a more uniform cell distribution and reduced apoptosis. Furthermore, rapamycin, 4-OI and AICAR demonstrated potent antiproliferative effects in the drug intervention study. Confocal microscopy imaging revealed a uniform distribution of HLECs along the anatomical structure of the crystalline lens capsule within the PCO model, showcasing robust cell viability and regular morphology. In conclusion, the PCO model provides a valuable experimental platform for studying PCO pathogenesis and exploring potential therapeutic interventions.

Intraoperative complications and visual outcomes of cataract surgery in neovascular age-related macular degeneration

PURPOSE

To compare the rate of intraoperative complications and visual outcomes in patients with neovascular age-related macular degeneration (NvAMD) and control eyes without NvAMD undergoing phacoemulsification.

SETTING

Multicenter study.

DESIGN

Retrospective, nonrandomized comparative study.

METHODS

Eyes were classified based on the presence or absence of an NvAMD diagnosis. The main outcomes were (1) the rate of intraoperative complications, (2) the logMAR visual acuity (VA) at 4 to 12 weeks postoperatively in both groups, and (3) the reinjection rate of intravitreal antivascular endothelial growth factor after phacoemulsification.

RESULTS

Preoperative VA was worse in the NvAMD group (0.9 ± 0.5) compared with the reference group (0.6 ± 0.5). We observed no difference in the rate of posterior capsule rupture (PCR) (2.90% vs 2.77%; P = .889), dropped lens fragments (0.46% vs 0.29%; P = .618), or zonular dialysis (0.46% vs 0.58%, P = .749) between the 2 groups. Receiving ≥10 intravitreal injections before cataract surgery predicted the likelihood of PCR with an odds ratio of 2.86 (P = .027). Proportions of eyes achieving a visual gain of ≥0.3 logMAR (∼3 Snellen lines equivalent) was lower in NvAMD eyes (39.2% vs 63.7%; P < .0001). We observed 203 eyes (73%) in the active treatment group and 139 eyes (36%) in the inactive treatment group received >1 intravitreal injection after phacoemulsification (P < .0001).

CONCLUSIONS

The risk for PCR was higher for eyes receiving ≥10 intravitreal injections before phacoemulsification. Only 39% of eyes with NvAMD had visual improvement by ≥3 Snellen lines.

Effect of mutations on the folding and stability of γD-crystallin protein

Interprotein interactions between the partially unfolded states of γD-crystallin (γD-crys) protein are known to cause cataracts. Therefore, understanding the unfolding pathways of native γD-crys is extremely crucial to delineate their aggregation mechanism. In this study, we have performed extensive all-atom Molecular Dynamics simulations with explicit solvent to understand the role of the critical residues that drive the stability of the motifs and domains of γD-crys in its wild type and mutant forms. Our findings show that while the individual motifs of wild type are not stable in the native form, the individual domains remain structurally stable at 425K. This enhanced stability of the domain was attributed to the hydrophobic interactions between the motifs. Single and double point mutations of the domains with negatively charged aspartic and glutamic acid amino acid residues (I3E, W42D, W42E, I3D/W42D, I3E/W42E, and L92D/W157D) decreases the structural stability, leading to unfolding of individual domains of γD-crys. We believe that our study sheds light on the weakest links of γD-crys, along with the role of interactions stabilizing the domains. Further, this study bolsters and provides a better understanding of the domain swapping mechanism of aggregation of γD-crys.Communicated by Ramaswamy H. Sarma.

Deferring Postoperative Follow‑Up Visits up to 4 Weeks After Uneventful Cataract Surgery in a Tertiary Level Eye Hospital: Protocol for a Prospective, Quantitative, Experimental Control Study

BACKGROUND

Routine examination after cataract surgery, including a refraction test 4 to 6 weeks after surgery, is mandatory in most hospitals. In recent years, there has been growing interest in exploring alternative approaches to postoperative follow-up in cataract surgery patients due to the increasing number of cataract surgeries being performed, the limited availability of health care resources, and the need to optimize the use of health care services.

OBJECTIVE

We aim to compare postoperative visual outcomes after a day 0 examination in patients with 2 follow‑ups, one on day 7 and other on day 30, and patients with a single ophthalmic follow‑up between days 25 to 30.

METHODS

A prospective, quantitative, experimental control study will be carried out in Reiyukai Eiko Masunaga Eye Hospital, located in Banepa, Kavrepalanchok, Nepal. All patients undergoing cataract surgery meeting the inclusion and exclusion criteria irrespective of the type of surgery (small-incision cataract surgery or phacoemulsification) will be included in the study. The patients will be randomly assigned to 1 of 2 groups. Patients in group 1 will be examined on day 1, day 7, and day 30, whereas patients in group 2 will be examined on day 1 and once between days 25 to 30. The minimum clinically important difference (MCID) in our study will be set according to the improvement in the Snellen visual acuity chart.

RESULTS

The study is expected to be completed within 6 to 8 months from the start of the project. Data analysis and report writing will be carried out in a 2-month period. Best-corrected visual acuity will be compared between the 2 groups to determine if the MCID is achieved. The cost-effectiveness of the new approach will also be analyzed.

CONCLUSIONS

We aim to conclude that we can safely defer the 1-week postoperative follow-up visit in patients undergoing uncomplicated cataract surgery and that, moreover, we can reduce the patient load at the hospital and decrease patient expenses by decreasing the frequency of hospital visits.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/48616.

Ophthalmic surgery in New Zealand: analysis of 410,099 surgical procedures and nationwide surgical intervention rates from 2009 to 2018

BACKGROUND

Surgical intervention rates (SIR) provide a proxy measure of disease burden, surgical capacity, and the relative risk-benefit ratio of surgery. The current study assessed decade trends in ophthalmic surgery and calculated SIRs for all major classes of commonly performed ophthalmic procedures in New Zealand.

METHODS

Retrospective population-based analysis of all ophthalmic surgical procedures performed in New Zealand from 2009 to 2018. National and regional datasets from public and private health sectors and industry were analysed. SIRs were calculated for all major ophthalmic procedures, and subgrouped by patient demographics.

RESULTS

There were 410,099 ophthalmic surgical procedures completed with a 25.3% overall increase over 10 years. Procedures were mostly government-funded (51%, n = 210,830) with 71% of patients aged over 64 years. Cataract surgery (78%, n = 318,564) had the highest mean SIR (703/100,000/year) and increased by 25% during the study period, consistent with population growth in the over 64 years old age group. Vitrectomy surgery had the second highest mean SIR (67/100,000/year) and increased by 50%, well above national population growth during the study period. Other SIRs included conjunctival lesion-biopsy (38/100,000/year), glaucoma (33/100,000/year), strabismus (20/100,000/year), dacryocystorhinostomy (10/100,000/year), and keratoplasty surgery (4/100,000/year).

CONCLUSIONS

This comprehensive review of New Zealand ophthalmic surgery reports increasing SIRs that cannot be explained by population growth alone. Cataract surgery numbers increased year on year consistent with the increase in the over 64 years old population. Vitrectomy surgery growth exceeded that of the national population, including those over 64 years.

Evaluation of Systemic Medications Associated With Surgically Treated Cataract Among US Adults

PURPOSE

To comprehensively determine the associations between systemic medications and surgically treated cataract in the US population.

DESIGNS

Retrospective cross-sectional study.

METHODS

Participants aged ≥40 years from the 1999-2008 National Health and Nutrition Examination Survey (NHANES) were included. Surgically treated cataract was defined as cataract requiring a procedure. Data on prescription drug use over the past 30 days were collected via home interviews. Drug categories for ophthalmic indications and those prescribed in less than 0.5% of the participants were excluded from the analysis. Separate logistic regression models were used to explore associations between each drug category and surgically treated cataract. The Benjamin-Hochberg procedure was used to control the false discovery rate.

RESULTS

A total of 14,931 were included in the present analysis. The weighted prevalence of surgically treated cataract was 9.6% (n=2010). We identified 20 drug categories that had significant associations with surgically treated cataract, of which 8 associations remained statistically significant after further adjustment for pertinent comorbidities. The 3 drug categories with the highest odds ratio (OR) values were tricyclic antidepressants (OR, 2.21; 95% CI, 1.38-3.51; P = .001), insulin (OR, 2.13; 95% CI, 1.48-3.07; P = 9.41×10^-5) and group III antiarrhythmic agents (OR, 2.00; 95% CI, 1.25-3.19; P = .004). The use of sex hormone combinations among women reduced the risk of having surgically treated cataract (OR, 0.011; 95% CI, 0.001-0.089; P = 5.98×10^-5). Dose-response relationships were observed for all 8 drug categories.

CONCLUSIONS

Our comprehensive evaluation provides new knowledge on the complex relationships between systemic medications and surgically treated cataract.

A qualitative study on gender barriers to access cataract surgery in rural Gurugram, Haryana, India

This study aims to comprehend nuances of gender barriers to access cataract surgery in the rural population of Gurugram district, Haryana, India. Data from 100 male and 100 female cataract surgery patients who underwent surgery at the university-affiliated hospital’s department of ophthalmology were examined. Data on the patients’ ages, the better eye’s and operated eye’s visual acuity, the cataract’s maturity at the time of surgery and the type of cataract surgery chosen were examined. Visual impairment was defined when the better eye’s visual acuity was less than 6/18 (0.32). At the time of surgery, women had a serious visual impairment in the better eye and also opted for a less expensive surgery option. In-depth interviews and focus group discussions were planned to understand the attitude, social norms and nuances of women’s accessibility to cataract surgery. This essay includes a qualitative investigation on access restrictions based on gender.

Cataract Surgery in Low-Income Countries: A Good Deal!

Cataract is a major cause of blindness worldwide. In particular, in low-income countries, the burden of disease as well as its direct and indirect economic cost are a major challenge for the population and economy. In many cases, it would be possible to prevent or cure blindness with a comparably simple cataract surgery, but many countries lack the resources to strengthen healthcare systems and implement broad cataract surgery programs reaching, in particular, the rural poor. In this paper, we analyse whether such an intervention could be cost-effective or even cost-saving for the respective health systems. We calculate the net value of the lifelong costs of cataract with and without surgery. This calculation includes direct costs (e.g., treatment, glasses, surgery) as well as indirect cost of the caregiver and the patient. We total all costs from the year of onset of cataract until death and discount the respective values to the year of onset. We define the surgery as cost-saving if the net-value of costs with surgery is lower than without surgery. If the cost per quality adjusted life year is lower than one gross national product per capita, we define the intervention as highly cost-effective. We find that the cost-effectiveness of cataract surgery depends on the age of onset of the disease and the age of surgery. If the surgery is performed with the beginning of severe impairment, even surgery of a 78-year-old patient is still cost-saving. Almost all possible constellations are highly cost-effective, only for the very old it is questionable whether the surgery should be performed. The simulations show that cataract surgery is one of the most cost-effective interventions. However, millions of people in low-income countries still have no chance to prevent or cure blindness due to limited resources. The findings of this paper clearly call for a stronger effort to reach poor and rural populations with this cost-effective service.

The Diagnostic and Therapeutic Role of Circular RNA HIPK3 in Human Diseases

Circular RNAs (circRNAs) are a class of noncoding RNAs with closed-loop of single-stranded RNA structure. Although most of the circRNAs do not directly encode proteins, emerging evidence suggests that circRNAs play a pivotal and complex role in multiple biological processes by regulating gene expression. As one of the most popular circRNAs, circular homeodomain-interacting protein kinase 3 (circHIPK3) has frequently gained the interest of researchers in recent years. Accumulating studies have demonstrated the significant impacts on the occurrence and development of multiple human diseases including cancers, cardiovascular diseases, diabetes mellitus, inflammatory diseases, and others. The present review aims to provide a detailed description of the functions of circHIPK3 and comprehensively overview the diagnostic and therapeutic value of circHIPK3 in these certain diseases.

Inhibitory effect of lanosterol on cataractous lens of cynomolgus monkeys using a subconjunctival drug release system

Background

To evaluate the effect of lanosterol on cataractous lens of cynomolgus monkeys using a subconjunctival drug release system.

Methods

Nine elder cynomolgus monkeys were used, consisting of three monkeys without cataract as controls, three monkeys with naturally occurring cortical cataract, and three monkeys with nuclear cataract as intervention groups. Nanoparticulated thermogel with lanosterol and fluorescein was administered by subconjunctival injection in the monkeys with cataract. Fluorescence changes of injected thermogel and cataract progression were observed. Lanosterol concentration in aqueous humor, solubility changes in lens proteins, and oxidative stress levels were analyzed in the lenses of the control and intervention groups.

Results

Injected thermogel showed decreased fluorescence during follow up. Lanosterol concentration in aqueous humor increased in the first 2 weeks and then gradually decreased, which was in accordance with the changes in cortical lens clarity. However, lenses with nuclear opacification showed little change. In the cortical region of lenses with cortical cataract, solubility of α-crystallin was significantly increased after administration of lanosterol, as well as the reduction of oxidative stress.

Conclusions

We demonstrated the effect of lanosterol on cataract progression based on in vivo models of primates. Lanosterol showed a short-term and reliable reversal effect on reducing cataract severity in cortical cataract in the early stages, possibly due to the increase in the solubility of lens proteins and changes in the oxidative stress status. Lanosterol administration using subconjunctival drug release system could be a promising nonsurgical approach for future clinical studies of cataract prevention and treatment.

A longitudinal analysis of factors associated with age-related cataract among older Australian women: a cohort study of 7851 older Australian women 79-90 years

BACKGROUND

Age-related cataracts are a significant global health issue due to population ageing. More than 70% of older Australians aged 80 or above have clinically significant age-related cataracts.

AIM

The study aimed to identify factors associated with age-related cataracts among older Australian women 79-90 years.

METHOD

A 6-year longitudinal analysis of the Australian Longitudinal Study on Women's Health (ALSWH) was conducted on 7117 women from surveys four to six. The women were asked whether they had been diagnosed or treated for cataracts 3 years before each survey. We used generalised estimating equation (GEE) modelling to identify factors independently associated with age-related cataracts.

RESULTS

At baseline (79-84 years), 44.8% lived in metropolitan Australia, 67.9% had good general health, 26.5% had private health insurance, 30.6% had cataracts, 28.8% had undergone cataract surgery, 12.0% had diabetes, 24.9% had skin cancer, 56.2% had hypertension, 24.0% had a history of falls, 63.0% had visited general practitioner (GP) frequently, and 48.8% were driving themselves as their main means of transport. In the final model, poor general health [adjusted odds ratio (AOR) = 1.23, 95% CI = 1.14, 1.33)], not driving (AOR = 1.09, 95% CI = 1.01, 1.18), having private health insurance (AOR = 1.13, 95% CI = 1.04, 1.23), frequent GP visits (AOR = 1.16, 95% CI = 1.07, 1.25), skin cancer (AOR = 1.26, 95% CI = 1.16, 1.37), hypertension (AOR = 1.13, 95% CI = 1.05, 1.21), and fall (AOR = 1.12, 95% CI = 1.04, 1.22) were significantly associated with the age-related cataracts.

CONCLUSIONS

Systemic diseases, poor quality of life, driving cessation, and health service use were significantly associated with age-related cataracts in older women.

Governmental support for achieving "VISION 2020: the Right to Sight" in Iran: the cataract surgical rates

PURPOSE

The aim of this study was evaluate the effect of governmental support in the form of Health Transformation Plan (HTP) on increasing the cataract surgical rate.

METHODS

The number of cataract surgeries was collected from Iranian cataract surgery clinics during 2019. HTP was implemented in 2014. Forty-seven major and forty-five minor surgery centers were selected from all provinces. In each center, sampling was done from 2012, 2013, 2015, and 2016.

RESULTS

On average, 6202 and 7134 cataract surgery rate were performed before and after HTP, respectively. The cataract surgical rate rose by 15.03% after the HTP. After HTP, the proportion of cataract surgery increased by 21.32% in governmental centers and decreased by 17.56%, 24.45%, and 14.89% in private, insurance, and charity centers, respectively. The cataract surgical rate was 4093 and 6026 in the first economic quartile (the poorest), 3669 and 4595 in the second quartile, 5884 and 5928 in the third quartile, and 8427 and 9681 in the fourth quartile (the richest) before and after HTP, respectively. The highest growth in the cataract surgical rate was seen in the first quartile (47.24%) followed by the second (25.26%), fourth (14.88%), and third quartiles (0.74%).

CONCLUSION

The Health Transformation Plan has been successful in increasing the cataract surgical rate in the low-income group and identifying differences in the services as well as the economic groups within the population.

Proposed Role for Internal Lens Pressure as an Initiator of Age-Related Lens Protein Aggregation Diseases

The process that initiates lens stiffness evident in age-related lens protein aggregation diseases is thought to be mainly the result of oxidation. While oxidation is a major contributor, the exposure of lens proteins to physical stress over time increases susceptibility of lens proteins to oxidative damage, and this is believed to play a significant role in initiating these diseases. Accordingly, an overview of key physical stressors and molecular factors known to be implicated in the development of age-related lens protein aggregation diseases is presented, paying particular attention to the consequence of persistent increase in internal lens pressure.

The human lens: An antioxidant-dependent tissue revealed by the role of caffeine

Cataract is the leading cause of blindness worldwide and surgery is the only option to treat the disease. Although the surgery is considered to be relatively safe, complications may occur in a subset of patients and access to ophthalmic care may be limited. Due to a growing and ageing population, an increase in cataract prevalence is expected and its management will become a socioeconomic challenge. Hence, there is a need for an alternative to cataract surgery. It is well known that oxidative stress is one of the main pathological processes leading to the generation of the disease. Antioxidant supplementation may, therefore, be a strategy to delay or to prevent the progression of cataract. Caffeine is a widely consumed high-potency antioxidant and may be of interest for the prevention of the disease. This review aims to give an overview of the anatomy and function of the lens, its antioxidant and reactive oxygen species (ROS) composition, and the role of oxidative stress in cataractogenesis. Also, the pharmacokinetics and -dynamics of caffeine will be described and the literature will be reviewed to give an overview of its anti-cataract potential and its possible role in the prevention of the disease.

Reasons for delay in cataract surgery in patients with advanced cataracts during the COVID-19 pandemic

Purpose:

To analyze the reasons for delay in cataract surgery in patients with advanced cataracts during the COVID-19 pandemic.

Methods:

This was a prospective, cross-sectional, multicenter questionnaire study which included patients with mature cataract, nuclear sclerotic cataract grade IV, and cataracts with best corrected visual acuity (BCVA) <5/60, during the COVID-19 pandemic from December 2020 to April 2021. Reasons for delay in presentation to the hospital were analyzed.

Results:

One thousand four hundred seventy two patients were recruited with advanced cataracts. Absence of ophthalmic care nearby (44.2%), lack of awareness regarding elective surgeries (42.6%), lack of public transportation (37%), fear of contracting COVID-19 (23.4%), and waiting for outreach camps (20.4%) were found to be the reasons behind the delay in cataract surgery. 53.7% of the patients had worsening of defective vision and 55.3% of them had difficulty in carrying out activities of family living. 30.8% of the patients faced difficulty in commuting and 8.4% of the patients suffered a fall during this pandemic due to worsening of the visual acuity.

Conclusion:

The lockdown imposed during the pandemic has created a significant backlog of patients who are progressing to advanced cataracts due to lack of ophthalmic care nearby, lack of awareness regarding elective surgeries, lack of public transportation, and no outreach camps. Proactive measures to deal with this backlog are of utmost need to prevent blindness due to cataract.

Female gender: A significant barrier to access cataract surgery in rural Gurugram, Haryana, India

The goal of this study is to determine whether the female gender is a barrier for the access to cataract surgery in the rural population of Gurugram district, Haryana, India.

The data of consecutive 100 male and 100 female patients operated for cataract surgery at Department of Ophthalmology, University-affiliated hospital were studied. Data pertaining to age of the patients, visual acuity of the operated and better eye, maturity of the cataract at time of surgery, type of cataract surgery opted were analysed. Visual impairment was considered when visual acuity of the better eye was less than 6/18 (0.32).Two types of cataract surgery were offered to the patients: manual small-incision cataract surgery (SICS) and phacoemulsification. Independent t-tailed test was used to analyse data to ascertain female gender as a barrier to access cataract surgery.

The findings indicate that the difference in age at the time of surgery between men and women was not statistically significant ( p = .327). The analysis of visual impairment in the operated eye of men and women was also not statistically significant ( p = .173). However, the analysis of visual impairment in the better eye was strongly suggestive of gender bias with statistically significant results ( p = .001). In total, 71% male and 56% female patients opted for phacoemulsification surgery, whereas 44% women and 29% men chose less-expensive manual SICS surgery.

The study indicates that females had severe visual impairment in the better eye at the time of surgery and also opted for a less-expensive option indicating less financial freedom and decision-making power.

Essential function of adaptor protein Nck1 in platelet-derived growth factor receptor signaling in human lens epithelial cells

Binding of platelet-derived growth factor-BB (PDGF-BB) to its cognate receptor (PDGFR) promotes lens epithelial cell (LEC) proliferation and migration. After cataract surgery, these LEC behaviors have been proposed as an influential cause of posterior capsule opacification (PCO). Stimulated PDFGR undergoes dimerization and tyrosine phosphorylation providing docking sites for a SH2-domain-containing noncatalytic region of tyrosine kinase (Nck). Nck is an adaptor protein acting as a linker of the proximal and downstream signaling events. However, the functions of Nck1 protein in LEC have not been investigated so far. We reported here a crucial role of Nck1 protein in regulating PDGFR-mediated LEC activation using LEC with a silenced expression of Nck1 protein. The knockdown of Nck1 suppressed PDGF-BB-stimulated LEC proliferation and migration and disrupted the cell cycle progression especially G1/S transition. LEC lacking Nck1 protein failed to exhibit actin polymerization and membrane protrusions. The downregulation of Nck1 protein in LEC impaired PDGFR‐induced phosphorylation of intracellular signaling proteins, including Erk1/2, Akt, CREB and ATF1, which resulted in inhibition of LEC responses. Therefore, these data suggest that the loss of Nck1 expression may disturb LEC activation and Nck1 may potentially be a drug target to prevent PCO and lens-related disease.

Proteomic Analysis of Aqueous Humor Proteins in Association with Cataract Risks: Diabetes and Smoking

Cataracts are one of the most common eye diseases that can cause blindness. Discovering susceptibility factors in the proteome that contribute to cataract development would be helpful in gaining new insights in the molecular mechanisms of the cataract process. We used label-free nanoflow ultra-high-performance liquid chromatography–tandem mass spectrometry to compare aqueous humor protein expressions in cataract patients with different cataract risk factors such as diabetes mellitus (DM) and smoking and in controls (with cataract) without risk exposure. Eight patients with diabetes and who smoked (with double risk factors), five patients with diabetes and five patients who smoked (both with a single risk factor), and nine aged-matched cataract controls patients (non-risk exposure) were enrolled. In total, 136 aqueous humor proteins were identified, of which only alpha-2-Heremans–Schmid (HS)-glycoprotein was considered to be significantly risk-associated because it was differentially expressed in these three groups and exhibited increased expression with increasing risk factors. Significant changes in the aqueous humor level of alpha-2-HS-glycoprotein between DM and control samples and between smoking and control samples were confirmed using ELISA. The alpha-2-HS-glycoprotein, called fetuin-a, could be a potential aqueous biomarker associated with DM and smoking, which were cataract risk factors.

Impact of COVID-19 pandemic on cataract surgical volume: A North Indian experience

Purpose:

To analyze the impact of the pandemic on trends in cataract surgical volume in 2020 in a high-volume tertiary care academic center in North India.

Methods:

The monthly cataract surgical volume for a large, high-volume, tertiary care academic center in North India was obtained from January 2018 through December 2020. Based on historical trends, we used time-series forecasting, probability sensitivity analysis, and linear regression models to estimate what the expected monthly cataract volume should have been from March 2020 onward.

Results:

In 2020, we expected to perform 7500 cases (assuming historical trends) but performed only 2500 cases (33% of the expected volume). The remaining 5000 cases (67% cases) constituted the “fixed” backlog. Assuming the ramp-up in cataract surgical volume starts in January 2021, results of the Monte Carlo simulation revealed that for our system, it would take on average 5 months (May 2021) under the optimistic scenario and 10 months (October 2021) under the ambivalent scenario to reach pre-pandemic expected surgical volume. There would be a collective backlog of 5500 cases under the optimistic scenario (8.8 months’ worth of cases) and a collective backlog of 6900 cases under the ambivalent scenario (11 months’ worth of cases).

Conclusion:

An intuitive approach and out-of-the-box solutions are required by the government and private institutes’ collaborative efforts to help mitigate the disruptions caused by the pandemic and lessen the backlog without causing provider burnout.

Cataract and Associated Factors Among OPD Attendees in a Teaching Institute of North East India: A Baseline Observation

Background:

In India 66% of blindness among individuals aged 50 yrs and above is attributable to cataract. Cataract has multiple etiologies and many of them are modifiable. But data regarding burden and correlates of cataract among OPD attendees in Northeast India are insufficient.

Objectives:

To estimate the proportion of cataract among the attendees of ophthalmology OPD of a teaching hospital of Northeast India and to study the factors associated with it.

Methods:

This hospital based cross-sectional study was conducted during 7^th February to 6^th March 2020, using a pre-tested structured interview schedule, among 330 adults attending ophthalmology OPD of Agartala Government Medical College, chosen by consecutive sampling.

Result:

Proportion of cataract among the attendees was 36.7% and it was 51.5% among the subjects aged ≥50 years. Age, family type, literacy, diabetes mellitus and hypertension had significant associations with cataract (P < 0.05). Logistic regression model has identified age ≥ 50 yrs (OR: 5.57, 95% CI: 2.98-10.43) and illiteracy (OR: 2.67, 95% CI: 1.55-4.59) as the significant predictors for developing cataract (P < 0.05) in the study population.

Conclusion:

Proportion of cataract among OPD attendees is 36.7%, which is higher than the community prevalence of cataract in Tripura. Promoting literacy, reducing family size, blood sugar and blood pressure may bring down the proportion of cataract in this population.

Effects of Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser Capsulotomy on Visual Outcomes From a Lower-Middle Income Country

Objective

Neodymium-doped yttrium aluminium garnet (Nd: YAG) laser is a non-invasive and effective means to deal with posterior capsule opacification. Although it is safe, it may have some complications. The purpose of this study was to evaluate the efficacy of Nd: YAG laser capsulotomy in terms of visual outcomes.

Methodology

This retrospective study was carried out at the eye department of Shaheed Mohtarma Benazir Bhutto Medical College, Lyari and Sindh Government Lyari General Hospital, Karachi, by using a convenient sampling technique. The duration of the study was six months from 1^st January 2020 to 30^th June 2020. 50 eyes of patients older than 20 years of age of either gender with posterior capsule opacification after cataract surgery for more than 6 months of duration, capsular fibrosis, and visual distortion due to wrinkling were included in the study. 

Results

Our results show that in a total of 50 patients, the mean age was 59.08±5.84 years, of which, 20 (40%) were males. Out of 50 patients, 22 right while 28 left eyes were selected for Nd: YAG laser capsulotomy. None of the patients showed elevated intraocular pressure (IOP) after the 1^st week. Mean IOP was 16.84±3.63 mm of Hg on the 1^st day and mean IOP after 1^st week was 12.48±2.01 mm of Hg. Iritis was observed in 5 (10.0%) patients on the 1^st day and 4 (8.0%) patients on the 1^st week. Raised IOP was observed in 10 (20.0%) cases whereas cystoid macular edema was observed in only 1 (2%) patients on the 1^st day and 1^st week after laser therapy.

Conclusion

The study predicted that Nd: Yag laser posterior capsulotomy gives excellent results in terms of visual acuity. Complications that were associated with the Nd: Yag laser capsulotomy was a rise in intraocular pressure, cystoid macular edema, iritis, and IOL pitting.

Correlation of aqueous humor electrolytes with serum electrolytes in cataract patients

Purpose:

To correlate the aqueous humor electrolytes with serum electrolytes in patients with cataract.

Methods:

In this study, 348 eyes of patients undergoing cataract surgery, who had presented between 1^st January 2019 and 30^th June 2020, were included. Serum electrolytes were obtained and 0.15 ml of aqueous humor was obtained during surgery using an insulin syringe via the side port incision. Mean and standard deviation was used to analyze all the categorical and continuous data including all the electrolytes levels. Pearson’s correlation of coefficient was used to analyze the comparison between serum and aqueous humor electrolytes. Student T-test was used to compare electrolyte values between the serum and aqueous humor.

Results:

We observed a significant correlation of the aqueous humor electrolytes with their serum counterparts. The coefficient of correlation is 0.155, 0.44, and 0.405 for Na+, K+, and Cl−, respectively. There is also a significant increase in the aqueous humor electrolytes as compared to the serum levels.

Conclusion:

A significant increase in electrolytes levels in the aqueous humor of cataract patients possibly could have a role in the etiology of cataract.

Comparison of the Visual Outcomes of an Extended Depth-of-Focus Lens and a Trifocal Lens

Purpose

To compare the visual performance of the AcrySof IQ PanOptix trifocal intraocular lens and the TECNIS Symfony extended depth-of-focus lens at near and distance visual ranges.

Methods

A total of 146 patients (221 eyes) who underwent phacoemulsification and cataract extraction and received either a PanOptix or Symfony lens from January 2019 to July 2020 were included in the study (83 PanOptix non-toric, 30 PanOptix toric, 70 Symfony non-toric, and 38 Symfony toric). Uncorrected distance (UDVA), uncorrected near (UNVA), and corrected distance (CDVA) visual acuity were assessed at one-day, one-month, and three-months postoperatively. Averages of UDVA, UNVA, and CDVA were taken to evaluate which lens was superior at near and distance visual ranges. Secondary outcome measures including glare, halo, dryness, and problems with night vision were documented at each postoperative visit.

Results

At one month postoperatively, the average UNVA was 0.16 ± 0.14 logMAR in the PanOptix group and 0.21 ± 0.14 logMAR in the Symfony group (P=0.007); the average UDVA for the PanOptix group was 0.09 ± 0.13 logMAR compared to the Symfony group at 0.10 ± 0.14 logMAR (P=0.67); and the average CDVA was 0.02 ± 0.05 logMAR in the PanOptix group and 0.00 ± 0.04 logMAR in the Symfony group (P=0.11). At three months postoperatively, there were no statistically significant differences in UNVA, UDVA, or CDVA between the two groups (P=0.18, 0.79, 0.68 respectively). There was no statistically significant difference in secondary outcome measures at one- and three-months (P=0.49, 0.10 respectively).

Conclusion

The AcrySof IQ PanOptix trifocal intraocular lens appears to afford better UNVA compared to the TECNIS Symfony extended depth-of-focus intraocular lens at one-month postoperatively, though this difference was not seen at three months postoperatively. There is no statistically significant difference in UDVA and CDVA between the two groups at postoperative day one, one-month, and three-months.

Assessment of Knowledge and Attitude of Cataract and Their Associated Factors Among Adults in Arba Minch Zuria Woreda, Southern Ethiopia

Background

Cataract is the major cause of reversible blindness and visual impairment in developing countries. It has been assumed that there is poor access to information related to the cause, prevention, and treatment of cataract in developing countries. There is also a paucity of data on knowledge and attitude towards cataract in Ethiopia.

Purpose

This study aimed to assess the knowledge and attitude of cataract and their associated factors among adults in Arba Minch Zuria Woreda, Southern Ethiopia.

Patients and Methods

A community-based cross-sectional study was conducted among 623 adults from February 6 to April 16, 2020. The study participants were selected by the multi-stage sampling technique. Data were collected with a pre-tested structured questionnaire by using face-to-face interviews. The data were entered into Epi info version 7.2 and exported to SPSS version 23 for analysis. The level of statistical significance was set at a p-value less than 0.05 in multivariable logistic regression.

Results

Among 623 total participants, 54.9% of them had good knowledge about cataract, while 37.9% of them had favorable attitude about cataract. Inability to read and write (AOR=0.104, 95% CI: 0.042–0.258), primary school educational level (AOR=0.208, 95% CI: 0.091–0.478), secondary school educational level (AOR=0.199, 95% CI: 0.088–0.451), earning average monthly income 350–820 Ethiopian birr (AOR=2.364, 95% CI: 1.277–4.373), not having previous eye examination (AOR=0.605, 95% CI: 0.425–0.861) and unavailability of eye clinic (AOR=0.65, 95% CI: 0.446–0.945) were significantly associated with knowledge of cataract. No history of cataract (AOR=0.257, 95% CI: 0.157–0.418) was significantly associated with attitude towards cataract.

Conclusion

Significant portion of participants had poor knowledge and an unfavorable attitude towards a cataract. So, it is recommended that stakeholders in different hierarchies need to exert efforts on creating awareness about cataract by considering the education level of the community. Moreover, attention should be given to the availability and accessibility of the primary eye care unit.

Cataract Surgical Services in Palestine

Purpose: Cataract surgery, quantity and quality, is an indicator of ophthalmic care. A comprehensive assessment of cataract surgical services has never been carried out in Palestine, including West Bank, Gaza Strip and East Jerusalem. The objective of this study was to estimate the cataract surgical rate in 2015 to and to explore the modes of payment and referral systems.Methods: A cross-sectional study conducted between June and August 2016. Medical Directors from Cataract Surgical Centres in Palestine were interviewed using a structured questionnaire to extract data on cataract output and surgical techniques. Additionally, data were collected on modes of payment for cataract services. The cataract surgical rate was calculated by dividing the total cataract output in 2015 by the estimated population of Palestine in millions.Results: In 2015, 9908 cataract surgeries were carried out in 22 centres. The cataract surgical rate was 2,117 operations per million population. Phacoemulsification was the most common technique (73.4%), however in government centres 67% were performed by extracapsular cataract extraction.In the Gaza Strip, 56.6% of cataract surgeries were operated at government centres, and 42.8% were operated at NGO centres while in West Bank, only 12% of cataract surgeries were operated at government centres, with two-thirds of cataracts diagnosed at governmental centres being referred to private and NGO centres. Seventy eight percent of cataract surgeries were funded by insurance, of which the government insurance scheme contributed 65%.Conclusion: The cataract surgical rate in Palestine falls short of the required WHO target. The majority of cataract surgeries are funded by insurance.

Cataract surgical reach: Falling short to catch white cataracts!

Purpose:

The aim of this study was to know proportion of white cataracts from among patients coming for cataract surgery, and to find causes delaying uptake of cataract surgery.

Methods:

A hospital-based, prospective study enrolled patients of senile cataract between April 2018 and March 2019. The proportion of white cataract was calculated and underlying causes delaying uptake of cataract surgery studied.

Results:

White cataracts constituted 13.5% of total 3634 senile cataract patients, with gender disparity disfavoring women. Bilateral white cataract was presentation in 39 (8%) patients and lens-related glaucoma in 24 (5%) patients. Pseudophakia in the other eye was single most common cause of delay.

Conclusion:

A large proportion of white cataracts suggest that penetration of cataract surgical services in not reaching to the most eligible individual.

Circular RNA circZNF292 regulates H2 O2 -induced injury in human lens epithelial HLE-B3 cells depending on the regulation of the miR-222-3p/E2F3 axis

Circular RNAs (circRNAs) play important roles in the pathogenesis of age-related cataract (ARC). CircRNA zinc finger protein 292 (circZNF292, hsa_circ_0004058) is downregulated in ARC lens capsules. Here, we focused on its precise roles in oxidative stress underlying the pathogenesis of ARC. CircZNF292, microRNA (miR)-222-3p, and E2F transcription factor 3 (E2F3) were quantified by quantitative real-time polymerase chain reaction or western blot. Cell viability was assessed by the cell counting kit-8 assay. Cell cycle distribution and apoptosis were detected by flow cytometry. The activities of superoxide dismutase, catalase, and malondialdehyde were measured using the corresponding assay kit. Targeted correlations among circZNF292, miR-222-3p, and E2F3 were verified by the dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays. Our data showed that circZNF292 was downregulated in ARC tissues and H₂ O₂ -treated human lens epithelial B3 (HLE-B3) cells. Increased expression of circZNF292 alleviated H₂ O₂ -induced cell viability suppression, apoptosis promotion, and oxidative stress enhancement. Mechanistically, circZNF292 directly targeted miR-222-3p, and circZNF292 regulated E2F3 expression through miR-222-3p. MiR-222-3p was a functional mediator of circZNF292 in modulating H₂ O₂ -induced injury in HLE-B3 cells. Furthermore, reduced level of miR-222-3p ameliorated H₂ O₂ -induced HLE-B3 cell damage by upregulating E2F3. Our present study demonstrated that increased expression of circZNF292 ameliorated H₂ O₂ -induced injury in HLE-B3 cells at least in part through the miR-222-3p/E2F3 axis, highlighting a novel insight into the involvement of circRNAs in the pathogenesis of ARC.

Simulating Outcomes of Cataract Surgery: Important Advances in Ophthalmology

As the human eye ages, the crystalline lens stiffens (presbyopia) and opacifies (cataract), requiring its replacement with an artificial lens [intraocular lens (IOL)]. Cataract surgery is the most frequently performed surgical procedure in the world. The increase in IOL designs has not been paralleled in practice by a sophistication in IOL selection methods, which rely on limited anatomical measurements of the eye and the surgeon's interpretation of the patient's needs and expectations. We propose that the future of IOL selection will be guided by 3D quantitative imaging of the crystalline lens to map lens opacities, anticipate IOL position, and develop fully customized eye models for ray-tracing-based IOL selection. Conversely, visual simulators (in which IOL designs are programmed in active elements) allow patients to experience prospective vision before surgery and to make more informed decisions about which IOL to choose. Quantitative imaging and optical and visual simulations of postsurgery outcomes will allow optimal treatments to be selected for a patient undergoing modern cataract surgery.

Time to recovery from cataract and its predictors among eye cataract patients treated with cataract surgery: A retrospective cohort study in Ethiopia

Background

Cataracts is the major global causes of blindness and a vision-affecting disease of the eye. Cataract surgery is a curative and cost-effective intervention. The number of people who undergo cataract surgery has increased rapidly. Hence, this study was aimed to determine predictors and the time of recovery of cataract patients after cataract surgery by using Simi parametric models of survival analysis.

Methods

A retrospective cohort study was conducted from January/01/2015 and January/30/2019. STATA version14.0 statistical software was used for analysis. The Kaplan-Meier survival method and log-rank test curves were applied. Weibull regression was used and adjusted hazard ratio 95% CI with a value of p less than 0.05 was used to identify a significant association.

Results

Two hundred twenty three cataract patients were recovered from cataract, 72.6% (95% CI 69.8%–75.9%). The overall median survival time was 23 weeks (IQR = 16 to 35) with (95% CI, 21%–25%). aged between 16 and 30year (AHR = 1.20 CI; 1.07–2.36), age 31 to 45 (AHR = 1.24 CI; 1.08–1.54), urban dwellers (AHR = 1.59; 95% CI, 1.18–2.14), medium visual acuity (AHR = 4.14 CI; 2.57–6.67), high visual acuity (AHR = 5.23 CI; 3.06–8.93), Secondary cataract (AHR = 2.59 CI; 1.01–3.02), traumatic cataract (AHR = 1.75 CI; 1.01–3.02), extra capsular cataract extraction surgery (AHR = 1.43 CI; 1.07–1.94),and diabetes mellitus (AHR = 0.75, CI; 0.41–0.96) were notably associated with time to recovery.

Conclusion

Time to recovery in the study area was slightly higher as compared with the global cut of time. Cataract patients with comorbidity of DM had lower recovery time.

•

A 72.6% cataract patients were recovered and 27.4% of were censored from cataract.

•

The overall median survival time was 23 weeks and the mean recovery time of the patients was 23.24 weeks.

•

A significant difference seen in the recovery rate among cataract patients with/out diabetes mellitus.

•

Time to recovery in the study area was slightly higher.

Safety and efficacy of fentanyl versus pethidine in cataract surgery under propofol- based sedation: A double-blind randomized controlled clinical trial

Background:

The study was aimed to evaluate the safety and efficacy of fentanyl and pethidine on the sedative quality of patients who underwent phacoemulsification cataract surgery with Propofol.

Materials and Methods:

In this double-blind randomized controlled clinical trial, patients who were candidates for elective phacoemulsification surgery with topical anesthesia were enrolled. The selected patients were randomly allocated into the two groups for receiving sedation with Propofol-Pethidine (PP) or propofol-fentanyl (PF) combinations. Demographic characteristics, hemodynamic parameters before, during, and after the operation, sedation and pain scores, and patients' and surgeons' satisfaction scores were compared in the two studied groups.

Results:

In this trial, 70 patients (35 patients in each group) have completed the study. Mean (standard deviation) operation time was 22.9 (6.8) and 25.46 (7.7) minutes in PF and PP groups (P = 0.118).Mean pain score in PF 0.46 (0.14) was significantly higher than PP groups 0.236 (0.06) (P = 0.011). The mean value of diastolic and systolic blood pressures, pulse rate, and mean arterial pressure dioxide were significantly decreased in both PF and PP groups (P_Time < 0.001), although there was no significant difference between groups.

Conclusion:

Our findings indicated the equivalence effects on hemodynamic parameters for both pethidine and fentanyl in combination with propofol in which they could provide appropriate sedation and safe anesthesia with lower complications and acceptable patients' and surgeons' satisfaction.

Survey report on keratoplasty in China: A 5-year review from 2014 to 2018

To provide the general information on corneal transplantation (CT) in China, China Cornea Society designed a questionnaire on CT from 2014 to 2018 and entrusted it to 31 committee members for implementation of the survey nationwide. This article presents the results of the survey and compares the indicators used in the survey and those in the annual statistical report released by the Eye Bank Association of America (EBAA). The number of corneal transplantations completed by the 64 hospitals from 2014 to 2018 was respectively 5377, 6394, 7595, 8270 and 8980, totally 36,616 (22,959 male and 13,657 female). The five largest hospitals by the number of corneal transplantations completed 15,994 surgeries in total, accounting for 43.68% of all the surgeries performed in the 64 hospitals. The most common indication for corneal transplantations was corneal leukoma (7683, 20.98%), followed by bacterial keratitis (4209, 11.49%), corneal dystrophies (4189, 11.44%), keratoconus (3578, 9.77%) and corneal perforation (2839, 7.75%). The main surgical techniques were penetrating keratoplasty (PK) (19,896, 54.34%), anterior lamellar keratoplasty (ALK) (13,869, 37.88%). The proportion of PK decreased from 57.97% in 2014 to 52.88% in 2018 while the proportion of ALK increased from 36.04% in 2014 to 37.92% in 2018. The geographical distribution of keratoplasties performed in China is unbalanced. PK and ALK were the main techniques of CT and corneal leukoma, bacterial keratitis and corneal dystrophies were the main indications for CT in China.

A Perspective on Biophysical Studies of Crystallin Aggregation and Implications for Cataract Formation

Lens crystallins are subject to various types of damage during their lifetime which triggers protein misfolding and aggregation, ultimately causing cataracts. There are several models for crystallin aggregation, but a comprehensive picture of the mechanism of cataract is still underway. The complex biomolecular interactions underlying crystallin aggregation have motivated major efforts to resolve the structural details and mechanism of aggregation using multiple biophysical techniques at different resolutions. Together, experimental and computational approaches identify and characterize both amyloidogenic and amorphous aggregates leading to an improved understanding of crystallin aggregation. A rigorous characterization of the aggregation-prone intermediates is crucial in cataract-mediated drug discovery. This Perspective summarizes recent biophysical studies on lens crystallin aggregation. We evaluate the outstanding challenges, future outlook, and rewards in this fertile field of research. With lessons learned from protein folding and multiple pathways of aggregation, we highlight the differences in the overall mechanisms of age-related and congenital cataracts. We expect that a correlation between the existing and developing biophysical techniques would provide a platform to study amyloid architecture in the eye lens and reduce the existing gaps in our understanding of crystallin biophysics.

CircRNA Is a Rising Star in Researches of Ocular Diseases

A newly rediscovered subclass of noncoding RNAs, circular RNAs (circRNAs), is produced by a back-splicing mechanism with a covalently closed loop structure. They not only serve as the sponge for microRNAs (miRNAs) and proteins but also regulate gene expression and epigenetic modification, translate into peptides, and generate pseudogenes. Dysregulation of circRNA expression has opened a new chapter in the etiology of various human disorders, including cancer and cardiovascular, neurodegenerative, and ocular diseases. Recent studies recognized the vital roles that circRNAs played in the pathogenesis of various eye diseases, highlighting circRNAs as promising biomarkers for diagnosis and assessment of progression and prognosis. Interventions targeting circRNAs provide insights for developing novel treatments for these ocular diseases. This review summarizes our current perception of the properties, biogenesis, and functions of circRNAs and the development of circRNA researches related to ophthalmologic diseases, including diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, glaucoma, corneal neovascularization, cataract, pterygium, proliferative vitreoretinopathy, retinoblastoma, and ocular melanoma.

Intraocular pressure variation after conventional extracapsular cataract extraction, manual small incision cataract surgery and phacoemulsification in an indigenous black population

Introduction

intraocular pressure changes have been reported following the various cataract surgical technique. This study aims to compare the intra-ocular pressure (IOP) variation following conventional extra-capsular cataract extraction (ECCE), manual small incision cataract surgery (MSICS) and phacoemulsification in an indigenous black population.

Methods

a comparative cross-sectional study of adult patients aged 40 years and above who had pressure was measured with Goldman’s applanation tonometer pre-operatively and 1^st day, 1^st week, 1^st month as well as 3^rd month post-operative periods and recorded. Data was analyzed using SPSS version 21. Mean IOP changes between study groups were compared using ANOVA. P-value of < 0.05 was taken as statistically significant.

Results

total of 82 patients consisting of 20(24.4%) ECCE, 32(39%) MSICS and 30(36.6%) phacoemulsification with mean preoperative 13.4mmHg, 13.5mmHg and 14.1 mmHg (p = 0.657) respectively was studied. Mean IOP increased from baseline at 1st day post-operative period in the ECCE and MSICS groups (13.4 ± 3.0mmHg to 13.7 ± 4.5mmHg (p = 0.84) and 13.5 ± 3.1mmHg to 15.3 ± 5.1mmHg (P = 0.48) respectively), and decrease in the phacoemulsification group (14.1 ± 2.6mmHg to 13.9 ± 3.5mmHg (p = 0.378). There was a decline in IOP in all the 3 study groups by one week post-operative period; the difference was significant only in the ECCE group (p = 0.032). By 3^rd month postoperatively, there was a reduction in mean IOP when compared with pre-operative IOP the difference being greatest in the ECCE group.

Conclusion

ECCE, MSICS, and Phacoemulsification cause a decline in IOP below preoperative levels at 3^rd month postoperatively in the MSICS group.

The Tudor-domain protein TDRD7, mutated in congenital cataract, controls the heat shock protein HSPB1 (HSP27) and lens fiber cell morphology

Mutations of the RNA granule component TDRD7 (OMIM: 611258) cause pediatric cataract. We applied an integrated approach to uncover the molecular pathology of cataract in Tdrd7-/- mice. Early postnatal Tdrd7-/- animals precipitously develop cataract suggesting a global-level breakdown/misregulation of key cellular processes. High-throughput RNA sequencing integrated with iSyTE-bioinformatics analysis identified the molecular chaperone and cytoskeletal modulator, HSPB1, among high-priority downregulated candidates in Tdrd7-/- lens. A protein fluorescence two-dimensional difference in-gel electrophoresis (2D-DIGE)-coupled mass spectrometry screen also identified HSPB1 downregulation, offering independent support for its importance to Tdrd7-/- cataractogenesis. Lens fiber cells normally undergo nuclear degradation for transparency, posing a challenge: how is their cell morphology, also critical for transparency, controlled post-nuclear degradation? HSPB1 functions in cytoskeletal maintenance, and its reduction in Tdrd7-/- lens precedes cataract, suggesting cytoskeletal defects may contribute to Tdrd7-/- cataract. In agreement, scanning electron microscopy (SEM) revealed abnormal fiber cell morphology in Tdrd7-/- lenses. Further, abnormal phalloidin and wheat germ agglutinin (WGA) staining of Tdrd7-/- fiber cells, particularly those exhibiting nuclear degradation, reveals distinct regulatory mechanisms control F-actin cytoskeletal and/or membrane maintenance in post-organelle degradation maturation stage fiber cells. Indeed, RNA immunoprecipitation identified Hspb1 mRNA in wild-type lens lysate TDRD7-pulldowns, and single-molecule RNA imaging showed co-localization of TDRD7 protein with cytoplasmic Hspb1 mRNA in differentiating fiber cells, suggesting that TDRD7-ribonucleoprotein complexes may be involved in optimal buildup of key factors. Finally, Hspb1 knockdown in Xenopus causes eye/lens defects. Together, these data uncover TDRD7's novel upstream role in elevation of stress-responsive chaperones for cytoskeletal maintenance in post-nuclear degradation lens fiber cells, perturbation of which causes early-onset cataracts.

A new normal with cataract surgery during COVID-19 pandemic

Cataract is the second leading cause of preventable blindness on the globe. Several programs across the country have been running efficiently to increase the cataract surgical rates and decrease blindness due to cataract. The current COVID-19 pandemic has led to a complete halt of these programs and thus accumulating all the elective cataract procedures. At present with the better understanding of the safety precautions among the health care workers and general population the Government of India (GoI) has given clearance for functioning of eye care facilities. In order to facilitate smooth functioning of every clinic, in this paper, we prepared preferred practice pattern based on consensus discussions between leading ophthalmologists in India including representatives from major governmental and private institutions as well as the All India Ophthalmological Society leadership. These guidelines will be applicable to all practice settings including tertiary institutions, corporate and group practices and individual eye clinics. The guidelines include triage, use of personal protective equipment, precautions to be taken in the OPD and operating room as well for elective cataract screening and surgery. These guidelines have been prepared based on current situation but are expected to evolve over a period of time based on the ongoing pandemic and guidelines from GoI.

Up-Regulation of GATA4 Regulates Human Lens Epithelial Cell Function in Age-Related Cataract

PURPOSE

GATA4 has emerged as a novel regulator that plays a critical role in mediating senescence. However, the role of GATA4 in age-related cataract (ARC), the leading cause of visual impairment, requires further elucidation.

METHODS

GATA4 expression was measured by quantitative RT-PCR and capillary Western immunoassay (WES). The MTT assay, EdU assay, and rhodamine-123/Hoechst and calcein-AM/propidium iodide double staining were used to investigate the role of GATA4 in the viability, proliferation, and apoptosis of cultured human lens epithelial cells (HLECs).

RESULTS

HLECs were subjected to 3 different treatment models, including prolonged exposure to low-dose H2O2, UVB irradiation, and mild heating, to simulate senescence and apoptosis. GATA4 expression was significantly increased in these models in a time- and dose-dependent manner. Overexpression of GATA4 reduced cell viability, accelerated apoptosis development, and reduced the proliferation of HLECs. Furthermore, the expression of GATA4 from ARC was up-regulated at both mRNA and at protein level compared with clear lenses.

CONCLUSION

GATA4 is up-regulated in all 3 models of HLECs in vitro and the cells from ARC lenses in vivo. Up-regulation of GATA4 mediates HLEC dysfunction. GATA4-mediated effects in HLECs would provide a novel insight into the pathogenesis of ARC.

Prevalence and risk factors on age-related cataract and surgery in adults over 50 years old in Binhu District, Wuxi, China

AIM

To investigate the prevalence and risk factors of age-related cataract (ARC), ARC surgery procedures, and postoperative vision results among adults over 50 years old in the Binhu District of Wuxi City, China.

METHODS

Thirty basic sampling units were analyzed via a cluster random sampling method. Detailed medical histories were collected and eye examinations were performed. Cataract prevalence and surgical procedures were quantified.

RESULTS

Among the 6150 participants, 1421 cataract cases were diagnosed and prevalence was 23.1%. The prevalence of cortical, nuclear, and posterior subcapsular cataracts increased with age (P<0.001). Cataract prevalence was significantly higher among elderly, female, or illiterate individuals and people with hypertension, diabetes, and a history of smoking and drinking (all P<0.05). As participant age increased and education level decreased, the frequency of cataract blindness surgeries gradually decreased, but without statistical significance within groups (P>0.05). The odds ratio of cataract patients who had or did not have cataract surgery was 3.15 (87/28) and the frequency of cataract blindness surgery was 75.7% (87/115). Poor visual outcomes was in 107 eyes (40.7%) after cataract surgery. Poor vision was mostly caused by uncorrected reflective errors (30.9%) and ocular comorbidities (41.1%). The prevalence of cataract surgery complications was 5.7% (15/263). Surgical complications and posterior capsular opacification were avoidable factors facilitating poor vision.

CONCLUSION

ARC, especially in females and illiterate individuals, presents a public health problem in this district. Poor visual outcomes after cataract surgery are frequent. High-quality cataract surgeries and treatment of ocular comorbidities are vital.

The Impact of Sociodemographic and Socioeconomic Factors on the Burden of Cataract in Small Island Developing States (SIDS) in the Caribbean from 1990 to 2016

Purpose: To study the impact of sociodemographic and socioeconomic factors on the cataract burden in Caribbean small island developing states (SIDS) using disability-adjusted life-years (DALYs).Methods: National and regional age and sex specific cataract DALY numbers and rates from 1990 to 2016 for Caribbean SIDS, were extracted from the Global Burden of Disease Study 2016. The human development index (HDI), healthcare access and quality (HAQ) index, and the World Bank's classification of economies were used as socioeconomic status indicators. The Gini coefficient, Atkinson, Theil and concentration indices were used to measure health inequality. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the sociodemographic and socioeconomic factors associated with differences in cataract burden.Results: Men had higher age-standardized DALY rates than women (P < .001) with median rates of 90.72 (Interquartile range [IQR], 87.8-94.2) and 83.94(IQR, 80.9-86.5), respectively. The burden of cataract increased with age. Upper-middle income countries had higher age-standardized DALY rates than high income countries (P < .001), with median rates of 90.1 (IQR, 86.8-93.4) and 79.8 (IQR, 77.5-81.8), respectively. Age-standardized DALY rates were inversely correlated with HDI (r = - 0.61, β = - 51.56 [P < .05]) and HAQ (r = - 0.68, β = - 0.46 [P < .01). Between-country inequality was negligible, and the burden of cataract is greater among the poor.Conclusion: Global trends of socioeconomic factors were confirmed. Significantly, men had higher age-standardized DALY rates than women. This is an area for further research.

Association of Sex With the Global Burden of Cataract

Importance

Eye disease burden could help guide health policy making. Differences in cataract burden by sex is a major concern of reducing avoidable blindness caused by cataract.

Objective

To investigate the association of sex with the global burden of cataract by year, age, and socioeconomic status using disability-adjusted life-years (DALYs).

Design, Setting, and Participants

This international, comparative burden-of-disease study extracted the global, regional, and national sex-specific DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataract by year and age from the Global Burden of Disease Study 2015. The DALY data were collected from January 1, 1990, through December 31, 2015, for ever 5 years. The human development index (HDI) in 2015 was extracted as an indicator of national socioeconomic status from the Human Development Report.

Main Outcomes and Measures

Comparisons of sex-specific DALY estimates due to cataract by year, age, and socioeconomic status at the global level. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the socioeconomic-associated sex differences in cataract burden.

Results

Differences in rates of cataract by sex were similar between 1990 and 2015, with age-standardized DALY rates of 54.5 among men vs 65.0 among women in 1990 and 52.3 among men vs 67.0 among women in 2015. Women had higher rates than men of the same age, and sexual differences increased with age. Paired Wilcoxon signed rank test revealed that age-standardized DALY rates among women were higher than those among men for each HDI-based country group (z range, -4.236 to -6.093; P < .001). The difference (female minus male) in age-standardized DALY rates (r = -0.610 [P < .001]; standardized β = -0.610 [P < .001]) and the female to male age-standardized DALY rate ratios (r = -0.180 [P = .02]; standardized β = -0.180 [P = .02]) were inversely correlated with HDI.

Conclusions and Relevance

Although global cataract health care is progressing, sexual differences in cataract burden showed little improvement in the past few decades. Worldwide, women have a higher cataract burden than men. Older age and lower socioeconomic status are associated with greater differences in rates of cataract by sex. Our findings may enhance public awareness of sexual differences in global cataract burden and emphasize the importance of making sex-sensitive health policy to manage global vision loss caused by cataract.