Tetrahedral framework nucleic acids-based delivery of MicroRNA-22 inhibits pathological neovascularization and vaso-obliteration by regulating the Wnt pathway

The objective of this study was to investigate the effects and molecular mechanisms of tetrahedral framework nucleic acids-microRNA22 (tFNAs-miR22) on inhibiting pathological retinal neovascularization (RNV) and restoring physiological retinal vessels. A novel DNA nanocomplex (tFNAs-miR22) was synthesised by modifying microRNA-22 (miR22) through attachment onto tetrahedral frame nucleic acids (tFNAs), which possess diverse biological functions. Cell proliferation, wound healing, and tube formation were employed for in vitro assays to investigate the angiogenic function of cells. Oxygen-induced retinopathy (OIR) model was utilised to examine the effects of reducing pathological neovascularization (RNV) and inhibiting vascular occlusion in vivo. In vitro, tFNAs-miR22 demonstrated the ability to penetrate endothelial cells and effectively suppress cell proliferation, tube formation, and migration in a hypoxic environment. In vivo, tFNAs-miR22 exhibited promising results in reducing RNV and promoting the restoration of normal retinal blood vessels in OIR model through modulation of the Wnt pathway. This study provided a theoretical basis for the further understanding of RNV, and highlighted the innovative and potential of tFNAs-miR22 as a therapeutic option for ischemic retinal diseases.

Real-world visual outcomes of cataract surgery based on population-based studies: a systematic review

BACKGROUND/AIMS

Quantity of cataract surgery has long been an important public health indicator to assess health accessibility, however the quality of care has been less investigated. We aimed to summarise the up-to-date evidences to assess the real-world visual outcomes after cataract surgery in different settings.

METHODS

A systematic review was undertaken in October 2021. Population-based cross-sectional and longitudinal studies reporting vision-related outcomes after cataract surgery published from 2006 onward were included. A meta-analysis was not planned.

RESULTS

Twenty-six cross-sectional studies from low-income and middle-income countries (LMICs) and five cross-sectional studies from high-income countries (HICs) were included. The proportions of participants with postoperative presenting visual acuity (VA) ≥0.32 (20/60) were all over 70% in all HICS studies, but mostly below 70% in LMICS studies, ranging from 29.9% to 80.5%. Significant difference in postoperative VA was also observed within countries. The leading causes for postoperative visual impairment (defined mostly as presenting VA <20/60) mainly included refractive error, ocular comorbidities and surgical complications including posterior capsule opacification, except for one study in Nigeria wherein the leading cause was aphakia. Only four population-based cohort studies were included with 5-20 years of follow-up time, generally demonstrating no significant changes in postoperative visual outcomes during the follow-up.

CONCLUSIONS

We observed large inequality in the visual outcomes and principal causes of visual impairment after cataract surgery among different countries and regions. Structured quality control and enhancement programmes are needed to improve the outcomes of cataract surgery and reduce inequality.

Safety and efficacy in pediatric secondary intraocular lens implantation, in-the-bag versus sulcus implantation: a multicenter, single-blinded randomized controlled trial

BACKGROUND

Treatment of pediatric cataract remains challenging because of the extremely high incidence of postoperative adverse events (AEs), especially the AEs related to the locations of secondary implanted intraocular lens (IOL). There are two common locations for secondary IOL implantation in pediatric aphakic eyes: ciliary sulcus or in-the-bag implantation. However, there are currently no large, prospective studies comparing complication rates and visual prognosis of in-the-bag versus ciliarysulcus secondary IOL implantation in pediatric patients. Whether or how much secondary in-the-bag IOL implantation benefits the pediatric patients more than sulcus implantation and deserves to be performed routinely by surgeons remains to be elucidated. Here, we describe the protocol of a randomized controlled trial (RCT) designed to evaluate the safety and efficacy of two approaches of IOL implantation in pediatric aphakia.

METHODS

The study is a multicenter, single-blinded RCT with 10 years of follow-up. Overall, a minimum of 286 eyes (approximately 228 participants assuming 75% have two study eyes) will be recruited. This study will be carried out in four eye clinics across China. Consecutive eligible patients are randomized to undergo either secondary in-the-bag IOL implantation or secondary sulcus IOL implantation. Participants with two eyes eligible will receive the same treatment. The primary outcomes are IOL decentration and the incidence of glaucoma-related AEs. The secondary outcomes include the incidence of other AEs, IOL tilt, visual acuity, and ocular refractive power. Analysis of the primary and secondary outcomes is to be based on the intention-to-treat and per-protocol analysis. Statistical analyses will include the χ² test or Fisher's exact test for the primary outcome, mixed model and generalized estimated equation (GEE) model for the secondary outcome, Kaplan-Meier survival curves for the cumulative probability of glaucoma-related AEs over time in each group.

DISCUSSION

To the best of our knowledge, this study is the first RCT to evaluate the safety and efficacy of secondary IOL implantation in pediatric aphakia. The results will provide high-quality evidence for the clinical guidelines for the treatment of pediatric aphakia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05136950. Registered on 1 November 2021.