How can we improve the quality of cataract services for all? A global scoping review

Predictors of time to recovery from cataract surgery among cataract patients at Menelik II Comprehensive Specialized Hospital: a retrospective follow up study

BACKGROUND

Cataracts are the leading cause of reversible blindness globally, disproportionately affecting populations in low- and middle-income countries. In Ethiopia, cataracts remain a significant public health concern. Despite the effectiveness of cataract surgery in restoring vision, information on recovery time and its predictors remain limited. The aim of this study was to assess time to recovery and its predictors among patients undergoing cataract.

METHODS

A retrospective cohort study was conducted on 459 cataract patients who underwent surgery between January 1 and December 31, 2023. Data were randomly extracted from their medical records between June 1 and August 15, 2024. The Kaplan-Meier method was used to estimate the survival probabilities and compare groups, with significant differences tested using the log-rank test. The Weibull regression with the inverse Gaussian frailty was applied following a goodness-of-fit test to identify predictors of time to recovery. Results are presented as adjusted hazard ratios (AHRs) with 95% confidence intervals (CIs). All statistical tests were declared significant at P-value < 0.05.

RESULTS

we reviewed 459 patient cards, and 368 (80.17%, 95% CI: 76.26-83.58%) had recovered from a cataract surgery over 7,919.28 person-weeks. The overall incidence rate of recovery was at 46.47 per 1,000 persons per week (95% CI: 41.95-51.47). The median recovery time was at 18.14 weeks (IQR: 12.29-24, 95% CI: 17.14-18.86). Age over 60 years (AHR = 0.25, 95% CI: 0.07-0.96), urban residence (AHR = 1.77, 95% CI: 1.15-2.70), preoperative visual acuity (medium: AHR = 1.98, 95% CI: 1.23-3.18; high: AHR = 5.83, 95% CI: 1.72-19.77), comorbidities (ocular: AHR = 0.30, 95% CI: 0.15-0.61; systemic: AHR = 0.41, 95% CI: 0.22-0.75), type of surgery (phacoemulsification: AHR = 1.98, 95% CI: 1.06-3.67; intracapsular cataract extraction: AHR = 0.14, 95% CI: 0.03-0.89), and complications (intraoperative: AHR = 0.29, 95% CI: 0.12-0.71; postoperative: AHR = 0.17, 95% CI: 0.06-0.47), and surgeries performed by an ophthalmologist (AHR = 3.44, 95% CI: 1.80-6.55) were statistically significant predictors of time to recovery from cataract surgery.

CONCLUSION

The median recovery time was shorter than in previous local studies but longer than in developed countries. Improved preoperative assessment, better comorbidity management, and minimizing complications may contribute to better recovery outcomes. The use of phacoemulsification and procedures performed by experienced ophthalmologists were associated with shorter recovery times, but further prospective studies are needed to confirm these findings. Personalized care approaches are recommended to optimize postoperative recovery.

Automated Imaging of Cataract Surgery Using Artificial Intelligence

Objectives: This study proposes a state-of-the-art technology to estimate a set of parameters to automatically display an optimized image on a screen during cataract surgery. Methods: We constructed an architecture comprising two stages to estimate the parameters for realizing the optimized image. The Pix2Pix approach was first introduced to generate fake images that mimic the optimal image. This part can be considered a preliminary step; it uses training datasets comprising both an original microscopy image as the input data and an optimally tuned image by ophthalmologists as the label data. The second part of the architecture was inspired by ensemble learning, in which two ResNet-50 models were trained in parallel using fake images obtained in the previous step and unprocessed images. Each set of features extracted by the ensemble-like scheme was exploited for the regression of the optimal parameters. Results: The fidelity of our method was confirmed through relevant quantitative assessments (NMSE 121.052 ± 181.227, PSNR 29.887 ± 4.682, SSIM 0.965 ± 0.047). Conclusions: Subsequently, surgeons reassured that the objects to be highlighted on the screen for cataract surgery were faithfully visualized by the automatically estimated parameters.

The Better Operative Outcomes Software Tool (BOOST) Prospective Study: Improving the Quality of Cataract Surgery Outcomes in Low-Resource Settings

PURPOSE

Post-operative vision impairment is common among patients who have undergone cataract surgery in low-resource settings, impacting quality of clinical outcomes and patient experience. This prospective, multisite, single-armed, pragmatic validation study aimed to assess whether receiving tailored recommendations via the free Better Operative Outcomes Software Tool (BOOST) app improved surgical outcomes, as quantified by post-operative unaided distance visual acuity (UVA) measured 1-3 days after surgery.

METHODS

During the baseline data collection round, surgeons in low and middle-income countries recorded clinical characteristics of 60 consecutive cataract cases in BOOST. Additional data on the causes of poor outcomes from 20 consecutive cases with post-operative UVA of <6/60 (4-12 weeks post-surgery) were entered to automatically generate tailored recommendations for improvement, before 60 additional consecutive cases were recorded during the follow-up study round. Average UVA was compared between cases recorded in the baseline study round and those recorded during follow-up.

RESULTS

Among 4,233 cataract surgeries performed by 41 surgeons in 18 countries, only 2,002 (47.3%) had post-operative UVA 6/12 or better. Among the 14 surgeons (34.1%) who completed both rounds of the study (1,680 cases total), there was no clinically significant improvement in post-operative average UVA (logMAR units ±SD) between baseline (0.50 ± 0.37) and follow-up (0.47 ± 0.36) rounds (mean improvement 0.03, p = 0.486).

CONCLUSIONS

Receiving BOOST-generated recommendations did not result in improved UVA beyond what could be expected from prospective monitoring of surgical outcomes alone. Additional research is required to assess whether targeted support to implement changes could potentiate the uptake of app-generated recommendations and improve outcomes.

Strategies to address inequity of uncorrected refractive error in the Western Pacific: A modified Delphi process

PURPOSE

Uncorrected refractive error is the leading cause of vision impairment globally; however, little attention has been given to equity and access to services. This study aimed to identify and prioritise: (1) strategies to address inequity of access to refractive error services and (2) population groups to target with these strategies in five sub-regions within the Western Pacific.

METHODS

We invited eye care professionals to complete a two-round online prioritisation process. In round 1, panellists nominated population groups least able to access refractive error services, and strategies to improve access. Responses were summarised and presented in round 2, where panellists ranked the groups (by extent of difficulty and size) and strategies (in terms of reach, acceptability, sustainability, feasibility and equity). Groups and strategies were scored according to their rank within each sub-region.

RESULTS

Seventy five people from 17 countries completed both rounds (55% women). Regional differences were evident. Indigenous peoples were a priority group for improving access in Australasia and Southeast Asia, while East Asia identified refugees and Oceania identified rural/remote people. Across the five sub-regions, reducing out-of-pocket costs was a commonly prioritised strategy for refraction and spectacles. Australasia prioritised improving cultural safety, East Asia prioritised strengthening school eye health programmes and Oceania and Southeast Asia prioritised outreach to rural areas.

CONCLUSION

These results provide policy-makers, researchers and funders with a starting point for context-specific actions to improve access to refractive error services, particularly among underserved population groups who may be left behind in existing private sector-dominated models of care.

Assessment of eye health programme reach by comparison with rapid assessment of avoidable blindness (RAAB) survey data, Talagang, Pakistan

BACKGROUND

The purpose of this study was to quantify how much of the burden of visual impairment (VI) and unmet need in Talagang, identified by Rapid Assessment of Avoidable Blindness (RAAB) survey data, has been addressed by Community Eye Health (CEH) programme efforts.

METHODS

A RAAB survey was carried out in November 2018, with 2,824 participants in Talagang Tehsil, Punjab, Pakistan, aged 50 and over. Census data were used to extrapolate survey data to the population. Alongside this, a CEH programme was launched, consisting of community eye screening, and onward referral to rural health centres, secondary or tertiary ophthalmological services, as required. This health intervention aimed to address the eye care needs surfaced by the initial survey. From 2018 to 2022, 30,383 people aged 50 or over were screened; 14,054 needed referral to further steps of the treatment pathway and more detailed data collection. Programme data were compared to estimates of population unmet needs. Main outcome measures were prevalence of VI, and proportion of need met by CEH Programme, by cause and level of VI.

RESULTS

Among those aged 50 and over, 51.0% had VI in at least one eye. The leading causes were cataract (46.2%) and uncorrected refractive error (URE) (25.0%). In its first four years, the programme reached an estimated 18.3% of the unmet need from cataract, and 21.1% of URE, equally in both men and women.

CONCLUSIONS

Robustly collected survey and programme data can improve eye health planning, monitoring and evaluation, address inequities, and quantify the resources required for improving eye health. This study quantifies the time required to reach eye health needs at the community level.

Humanitarian missions and visual outcomes in cataract surgery: A literature review

The limited accessibility to ophthalmological services in remote regions of developing countries poses a significant challenge in visual healthcare. Cataracts and refractive errors are prominent causes of visual impairment, and surgery, despite being an efficient option, faces barriers in developing countries due to financial and geographical constraints. Humanitarian missions play a vital role in addressing this issue. The improvement in the accuracy of calculating IOL power through techniques such as keratometry and biometry is a fundamental step towards optimizing surgical outcomes and the quality of life for patients in these underserved regions. In this context, the consideration of keratometry and immersion ultrasound biometry as preoperative assessment standards in cataract surgeries in developing countries is presented as a pertinent and advisable strategy.

The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: Report 9, Risk factors for posterior capsule opacification

BACKGROUND/OBJECTIVES

Posterior Capsule Opacification (PCO) is the most common long-term post-operative adverse occurrence after cataract surgery often requiring treatment with YAG laser posterior capsulotomy. This study aimed to identify potential risk factors, known at the time of cataract surgery, that influence the development of PCO.

SUBJECT/METHODS

A retrospective study of publicly funded cataract surgery from The Royal College of Ophthalmologists' National Ophthalmology Database. Eligible for analysis were 500,872 cataract operations performed in 41 participating centres.

RESULTS

The 500,872 operations were performed on 243,167 (48.5%) left eyes and 257,705 (51.5%) right eyes from 373,579 patients by 2196 surgeons. Post-cataract PCO was recorded for 61,778 (12.3%) eyes and the six month, one, three, five and nine year observed rates of PCO were 2.3%, 4.4%, 19.7%, 34.0% and 46.9% respectively. Different PCO profiles were observed between IOL materials and the identified risk factors that increased the risk of developing PCO included hydrophilic IOL material, axial length >26 mm, the presence of high myopia and implantation of lower IOL powers and previous vitrectomy surgery, along with younger age and female gender.

CONCLUSIONS

Many factors influence the development of PCO relating to the patient, the eye, the lens and the surgery. Some factors are modifiable such as IOL material, therefore the opportunity exists to attempt to reduce PCO rates, benefitting patients and the UK NHS.

Ultraviolet B radiation induces oxidative stress and apoptosis in human lens epithelium cells by activating NF-κB signaling to down-regulate sodium vitamin C transporter 2 (SVCT2) expression

Ultraviolet B (UVB) exposure is reported to cause cataract formation by inducing excessive reactive oxygen species (ROS) and apoptosis in human lens epithelial cells (HLECs). Sodium-dependent Vitamin C transports-2 (SVCT2) is a ascorbic acid (AsA) transporter for that can protect cells and tissues from oxidative stress. Here, we focus on the functional characterization and mechanism analysis of SVCT2 in UVB-treated HLECs. The results showed a significant reduction of SVCT2 expression in HLECs treated with UVB. SVCT2 abated apoptosis and Bax expression and increased Bcl-2 expression. Moreover, SVCT2 decreased ROS accumulation and MDA level, but increased the activities of antioxidant enzymes (SOD and GSH-PX). NF-κB inhibitor (PDTC) alleviated ROS production and apoptosis, and promoted SVCT2 expression in UVB-treated HLECs. Additionally, ROS inhibitor (NAC) suppressed oxidative stress, apoptosis, and induced SVCT2 expression in UVB-treated HLECs, while these effects were significantly abated due to the activation of NF-κB signaling. Furthermore, SVCT2 facilitated 14C-AsA absorption in UVB-treated HLECs. Together, our findings demonstrated that UVB exposure-induced ROS generation, which further activated NF-κB signaling to down-regulate SVCT2 expression in HLECs. Then, downregulated SVCT2 promoted ROS accumulation and induced apoptosis by decreasing AsA uptake. Our data reveal a novel NF-κB/SVCT2/AsA regulatory pathway and suggest the therapeutic potential of SVCT2 in UVB-induced cataract.

Logistics description of a high yield cataract surgery non-profitable expedition

PURPOSE

To describe the logistics and methodology of a high yield surgical non-profitable campaign.

METHODS

A descriptive study based on previous non-profitable campaigns dedicated to cataract surgery.

RESULTS

The method is based on planification, finance acquisition, volunteer support, foreign affairs with the collaborating country where the surgeries are going to be performed, team organization, and overall, summoning all the stated items to materialize a global humanitarian campaign to eradicate cataracts by clinical and surgical procedures.

CONCLUSIONS

Blindness due to cataracts can be over-ruled. We consider that through our planification and methodology, other organizations may acquire some knowledge to improve their methodology and carry out similar volunteering surgical campaigns. Planification, coordination, financial aid, determination, and a strong will power are altogether compulsory for a successful non-profitable surgical campaign.

Comparison of dynamic defocus curve on cataract patients implanting extended depth of focus and monofocal intraocular lens

BACKGROUND

The aim of the study was to compare the dynamic defocus curve on patients post-implantation of the extended depth-of-focus (EDOF) and monofocal intraocular lens (IOL).

METHODS

A total of 62 age-related cataract patients receiving phacoemulsification with implantation of TECNIS Symfony (ZXR00) or monofocal IOLs were enrolled. The binocular static and dynamic defocus curves with corrected distance visual acuity were evaluated at one month postoperatively.

RESULTS

The ZXR00 group achieved significantly better intermediate (P = 0.044) and near (P = 0.017) visual acuity (VA) than the monofocal group. Two groups had similar uncorrected and corrected distance VA (P > 0.05, respectively). The dynamic defocus curve revealed a smoother decline from 0.0 D to - 2.0 D in the ZXR00 group. Defocused dynamic VA in the ZXR00 group was significantly better (P < 0.05) except at 0.0 D (P = 0.724) and - 0.5 D (P = 0.176). The area under the curve (P = 0.002) and corrected dynamic vision accommodation (P = 0.001) derived from the dynamic defocus curves were better in the ZXR00 group. A positive correlation was observed between defocused dynamic and static VA in both groups (P < 0.001). Multiple linear regression analysis indicated that defocused static VA and corrected dynamic vision accommodation were significant influential factors for the defocused dynamic VA from - 1.0 D to - 3.0 D (P < 0.05).

CONCLUSIONS

The EDOF IOL provided similar distance vision, better intermediate and near vision, and a better overall dynamic defocus curve than the monofocal IOL. The dynamic defocus curve may be comprehensively applied to evaluate the all-distance dynamic visual performance post-cataract surgery.

Effective cataract surgical coverage in adults aged 50 years and older: estimates from population-based surveys in 55 countries

BACKGROUND

Cataract is the leading cause of blindness globally. Effective cataract surgical coverage (eCSC) measures the number of people in a population who have been operated on for cataract, and had a good outcome, as a proportion of all people operated on or requiring surgery. Therefore, eCSC describes service access (ie, cataract surgical coverage, [CSC]) adjusted for quality. The 74th World Health Assembly endorsed a global target for eCSC of a 30-percentage point increase by 2030. To enable monitoring of progress towards this target, we analysed Rapid Assessment of Avoidable Blindness (RAAB) survey data to establish baseline estimates of eCSC and CSC.

METHODS

In this secondary analysis, we used data from 148 RAAB surveys undertaken in 55 countries (2003-21) to calculate eCSC, CSC, and the relative quality gap (% difference between eCSC and CSC). Eligible studies were any version of the RAAB survey conducted since 2000 with individual participant survey data and census population data for people aged 50 years or older in the sampling area and permission from the study's principal investigator for use of data. We compared median eCSC between WHO regions and World Bank income strata and calculated the pooled risk difference and risk ratio comparing eCSC in men and women.

FINDINGS

Country eCSC estimates ranged from 3·8% (95% CI 2·1-5·5) in Guinea Bissau, 2010, to 70·3% (95% CI 65·8-74·9) in Hungary, 2015, and the relative quality gap from 10·8% (CSC: 65·7%, eCSC: 58·6%) in Argentina, 2013, to 73·4% (CSC: 14·3%, eCSC: 3·8%) in Guinea Bissau, 2010. Median eCSC was highest among high-income countries (60·5% [IQR 55·6-65·4]; n=2 surveys; 2011-15) and lowest among low-income countries (14·8%; [IQR 8·3-20·7]; n=14 surveys; 2005-21). eCSC was higher in men than women (148 studies pooled risk difference 3·2% [95% CI 2·3-4·1] and pooled risk ratio of 1·20 [95% CI 1·15-1·25]).

INTERPRETATION

eCSC varies widely between countries, increases with greater income level, and is higher in men. In pursuit of 2030 targets, many countries, particularly in lower-resource settings, should emphasise quality improvement before increasing access to surgery. Equity must be embedded in efforts to improve access to surgery, with a focus on underserved groups.

FUNDING

Indigo Trust, Peek Vision, and Wellcome Trust.

A Systematic Review of Clinical Practice Guidelines for Cataract: Evidence to Support the Development of the WHO Package of Eye Care Interventions

The World Health Organization (WHO) is developing a Package of Eye Care Interventions (PECI) to facilitate the integration of eye care into Universal Health Coverage. This paper presents the results of a systematic review of clinical practice guidelines for cataract in adults, to help inform PECI development. We searched academic and guideline databases, and websites of professional associations, for guidelines published between January 2010 and April 2020. Guidelines were excluded if there was commercial funding or unmanaged conflicts of interest. Quality appraisal was conducted using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool. We identified 3778 reports, 35 related to cataract guidelines, four of which met the inclusion criteria (United Kingdom: 2, United States: 1, Iran: 1). The recommendations across the four guidelines covered pre-operative (43%), intra-operative (37%), and post-operative interventions (20%). Most ‘strong’ recommendations were supported by good quality evidence. Differences in recommendations across guidelines may be attributable to time of publication or regional differences in surgical practice. Few guidelines met the quality criteria, and only three countries were represented. The results of this step of the PECI development process will inform subsequent phases for development of the WHO’s package of evidence-based eye care interventions for cataract.

Addressing the environmental sustainability of eye health-care delivery: a scoping review

The demand for eye care-the most common medical speciality in some countries-is increasing globally due to both demographic change and the development of eye health-care services in low-income and middle-income countries. This expansion of service provision needs to be environmentally sustainable. We conducted a scoping review to establish the nature and extent of the literature describing the environmental costs of delivering eye-care services, identify interventions to diminish the environmental impact of eye care, and identify key sustainability themes that are not yet being addressed. We identified 16 peer-reviewed articles for analysis, all published since 2009. Despite a paucity of research evidence, there is a need for the measurement of environmental impacts associated with eye care to be standardised along with the methodological tools to assess these impacts. The vastly different environmental costs of delivering clinical services with similar clinical outcomes in different regulatory settings is striking; in one example, a phacoemulsification cataract extraction in a UK hospital produced more than 20 times the greenhouse gas emission of the same procedure in an Indian hospital. The environmental costs must be systematically included when evaluating the risks and benefits of new interventions or policies aimed at promoting safety in high-income countries.

Grand Challenges in global eye health: a global prioritisation process using Delphi method

BACKGROUND

We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations.

METHODS

Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists.

FINDINGS

Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity.

INTERPRETATION

This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenges.

FUNDING

The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, The Seva Foundation, British Council for the Prevention of Blindness, and Christian Blind Mission.

TRANSLATIONS

For the French, Spanish, Chinese, Portuguese, Arabic and Persian translations of the abstract see Supplementary Materials section.