A Composite Risk Score for Capsule Complications Based on Data from the Swedish National Cataract Register: Relation to Surgery Volumes

Surgical time and efficacy of illuminated chopper-assisted cataract surgery involving miosis after femtosecond laser pretreatment

PURPOSE

To evaluate the efficacy of the illuminated chopper-assisted cataract surgery in terms of shortening the surgical time in eyes with miosis after femtosecond laser pretreatment.

METHODS

As retrospective study, three hundred thirty-six eyes of 336 consecutive patients who underwent the femtosecond laser and illuminated chopper-assisted cataract surgery were included. Cases with pupil less than 6 mm after femtosecond laser pretreatment were included in the miosis group. Pupil diameter, surgical time, and improved efficacy (100/surgical time×pupil size) were compared between eyes with and without miosis.

RESULTS

Of 336 eyes, 20 were included in the miosis group (6.0%). Pupil diameter was smaller in eyes with miosis than in those without miosis (5.23 ± 0.38 mm vs 7.35 ± 0.64 mm, p < 0.001); however, surgical time was not different (6.86 ± 0.73 min vs 6.60 ± 1.27 min, p = 0.071) between the two groups. Mechanical pupil dilations were not needed in any cases. As a result, improved efficacy was calculated to be higher in patients with miosis (2.83 vs 2.14, p < 0.001).

CONCLUSION

In terms of surgical time and improved efficacy, using the illuminated chopper simplified cataract surgery involving miosis after femtosecond laser pretreatment. The use of an illuminated chopper is expected to be a good solution for femtosecond laser-assisted cataract surgeries.

Impact of a handpiece with a built-in fluidics pressure sensor on phacoemulsification: a multicentre prospective comparative study

OBJECTIVE

We assessed whether the immediate pressure adjustments provided by a phacoemulsification handpiece with a built-in pressure sensor (Active Sentry, AS) could decrease the amount of energy delivered in the eye during cataract surgery.

METHODS AND ANALYSIS

The Study of Active Sentry in Cataract Surgery was a multicentre prospective clinical trial. The Centurion system (Alcon Labs) was used and we compared phacoemulsifications performed with the AS handpiece with procedures using a sensor placed in the phacoemulsifier (non-AS). The primary outcome measure was the cumulative dissipated energy (CDE) used during the procedures. The secondary outcome measures were the total, longitudinal and torsional ultrasound (US) times, the duration of the surgery and the amount of fluid used during the surgeries.

RESULTS

The study analysed 1432 (800 AS and 632 non-AS) procedures. The mean patient age was 72.4±10.0 years. The median CDE was respectively 6.3 (IQR 3.5-9.9) and 6.7 (IQR 4.5-11.5) with and without AS (p=0.0001). The median US time was, respectively, 48.0 s (IQR 34.0-68.0) and 55.0 s (IQR 38.0-80.0) with and without AS (p<0.0001). Torsional and longitudinal US times were reduced with AS. The median duration of the procedure was, respectively, 9.0 min (IQR 7.0-12.0) and 10.0 min (IQR 7.0-13.0) (p=0.0002) with and without AS. The median balanced salt solution volume used was 52.0 cm3 (IQR 41.0-72.0) and 57.0 cm3 (IQR 42.0-81.0) with and without AS (p=0.0018).

CONCLUSION

The phacoemulsifications performed with a pressure sensor built in the handpiece delivered less energy in the eye and were shorter.

TRIAL REGISTRATION NUMBER

NCT04732351.

Development of machine learning models to predict posterior capsule rupture based on the EUREQUO registry

PURPOSE

To evaluate the performance of different probabilistic classifiers to predict posterior capsule rupture (PCR) prior to cataract surgery.

METHODS

Three probabilistic classifiers were constructed to estimate the probability of PCR: a Bayesian network (BN), logistic regression (LR) model, and multi-layer perceptron (MLP) network. The classifiers were trained on a sample of 2 853 376 surgeries reported to the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) between 2008 and 2018. The performance of the classifiers was evaluated based on the area under the precision-recall curve (AUPRC) and compared to existing scoring models in the literature. Furthermore, direct risk factors for PCR were identified by analysing the independence structure of the BN.

RESULTS

The MLP network predicted PCR overall the best (AUPRC 13.1 ± 0.41%), followed by the BN (AUPRC 8.05 ± 0.39%) and the LR model (AUPRC 7.31 ± 0.15%). Direct risk factors for PCR include preoperative best-corrected visual acuity (BCVA), year of surgery, operation type, anaesthesia, target refraction, other ocular comorbidities, white cataract, and corneal opacities.

CONCLUSIONS

Our results suggest that the MLP network performs better than existing scoring models in the literature, despite a relatively low precision at high recall. Consequently, implementing the MLP network in clinical practice can potentially decrease the PCR rate.

Cataracts

94 million people are blind or visually impaired globally, and cataract is the most common cause of blindness worldwide. However, most cases of blindness are avoidable. Cataract is associated with decreased quality of life and reduced life expectancy. Most cases of cataract occur after birth and share ageing and oxidative stress as primary causes, although several non-modifiable and modifiable risk factors can accelerate cataract formation. In most patients, phacoemulsification with intraocular lens implantation is the preferred treatment and is highly cost-effective. There has been an increase in the use of comprehensive cataract surgical services, including diagnoses, treatment referrals, and rehabilitation. However, global inequity in surgical service quality is still a limitation. Implementation of preoperative risk assessment, risk reduction strategies, and new surgical technologies have made cataract surgery possible at an earlier stage of cataract severity with the expectation of good refractive outcomes. The main challenge is making the service that is currently available to some patients accessible to all by use of universal health coverage.

When should cataract surgeons seek assistance from experienced colleagues?

PURPOSE

To assess which cases should be assorted exclusively to high-volume surgeons and identify when should a cataract surgeon seek assistance from a senior colleague.

METHODS

The medical records of 2853 patients with age-related cataract were reviewed. Preoperative risk factors were documented for each case, and they were divided into surgeons who had more (> 400 surgeries/year) or less experience (< 400 surgeries/year). Ophthalmology residents were excluded from this review. The cases that involved posterior capsule rupture, dropped nucleus, zonular dehiscence and anterior capsular tear with or without vitreous loss were defined as "complicated".

RESULTS

From the 3247 cataract extraction surgeries that were reviewed, we were unable to identify any statistically significant difference in the complication rates between the two surgeon groups. In the stepwise regression analysis, both groups supported advanced age (> 85) and mature cataracts with up to fourfold odds ratios (OR). Low-volume surgeons had a fivefold OR in the presence of phacodonesis and a fourfold OR in the case of posterior polar cataract. Finally, the low- and high-volume groups had their highest complication rates in the cumulative four and five risk factors, respectively.

CONCLUSION

In the presence of advanced age, mature cataracts, phacodonesis and posterior polar cataract, the complication rates appear to be higher for the less experienced surgeons. Meticulous preoperative assessment with detailed documentation of each patient's risk factors can result in fewer complications. The medical complexity of each case can be used as indicator of whether a more experienced surgeon should perform the surgery or not.

Big data in corneal diseases and cataract: Current applications and future directions

The accelerated growth in electronic health records (EHR), Internet-of-Things, mHealth, telemedicine, and artificial intelligence (AI) in the recent years have significantly fuelled the interest and development in big data research. Big data refer to complex datasets that are characterized by the attributes of "5 Vs"-variety, volume, velocity, veracity, and value. Big data analytics research has so far benefitted many fields of medicine, including ophthalmology. The availability of these big data not only allow for comprehensive and timely examinations of the epidemiology, trends, characteristics, outcomes, and prognostic factors of many diseases, but also enable the development of highly accurate AI algorithms in diagnosing a wide range of medical diseases as well as discovering new patterns or associations of diseases that are previously unknown to clinicians and researchers. Within the field of ophthalmology, there is a rapidly expanding pool of large clinical registries, epidemiological studies, omics studies, and biobanks through which big data can be accessed. National corneal transplant registries, genome-wide association studies, national cataract databases, and large ophthalmology-related EHR-based registries (e.g., AAO IRIS Registry) are some of the key resources. In this review, we aim to provide a succinct overview of the availability and clinical applicability of big data in ophthalmology, particularly from the perspective of corneal diseases and cataract, the synergistic potential of big data, AI technologies, internet of things, mHealth, and wearable smart devices, and the potential barriers for realizing the clinical and research potential of big data in this field.

Predictors of visual acuity improvement after phacoemulsification cataract surgery

Purpose

This study aimed to assess preoperative predictors of visual outcome after phacoemulsification cataract surgery in Jordan, a Middle Eastern country.

Methods

This was a retrospective longitudinal study of adult patients who underwent phacoemulsification cataract surgery from January 2019 to July 2021. For each patient, we included only the first operated eye. We obtained pre-operative ocular history, cataract surgery complication risk based on a predesigned score, visual acuity, best correction, and best corrected visual acuity. We recorded intraoperative complications. We also obtained postoperative best corrected visual acuity and refractive error for correction after 1–3 months.

Results

A total of 1,370 patients were included in this study, with a mean age of 66.39 (± 9.48). 48.4% of patients achieved visual acuity ≥ 0.8, and 72.7% achieved visual acuity ≥ 0.5. The mean visual acuity improvement after phacoemulsification cataract surgery was 0.33 (95% CI 0.31–0.35). In the regression model, significant predictors that affected visual acuity improvement included the presence of diabetic retinopathy, glaucoma, and complication risk factors (i.e., high-risk surgery).

Conclusion

Predictors of visual acuity improvement vary between studies. This study was conducted in a developing country; we defined predictors of visual acuity improvement. We also provided a new preoperative phacoemulsification cataract surgery complication risk score.

Prior pars plana vitrectomy and its association with adverse intraoperative events during cataract surgery

PURPOSE

To evaluate the risk of intraoperative complications during cataract surgery in eyes with a prior vitrectomy.

METHODS

A retrospective review of data from our cataract surgery registry of all patients undergoing cataract surgery between 2014 and 2018 at the University of Colorado Hospital. Univariate and multivariate analyses were conducted, accounting for intra-patient correlation in subjects who underwent two cataract surgeries. The three main outcomes of interest, zonulopathy, posterior capsule (PC) tears and dropped lens fragments, were analysed for their association with prior pars plana vitrectomy (PPV) and clinical characteristics of patients such as history of prior intravitreal injection and surgeon level of experience.

RESULTS

10 540 eyes of 6447 patients were included in the analysis. 371 (3.5%) eyes had a prior PPV. Eyes with a prior PPV experienced more zonulopathy during cataract surgery (adjusted OR 2.2, 95% confidence interval: 1.3-3.7, p = 0.002). Combined phacoemulsification/PPV were significantly more likely to experience all 3 complications, and this effect was even greater for eyes with a prior PPV.

CONCLUSIONS

All complications were rare; however, there was a significant association with prior PPV and intraoperative zonulopathy. Cataract surgeons must be aware of a patient's prior vitrectomy and plan accordingly for the increased risk of intraoperative complications.

Risk factors for posterior capsule rupture in cataract surgery as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery

PURPOSE

To analyze the incidence and risk factors for posterior capsule rupture (PCR) in cataract surgery.

SETTING

European clinics affiliated with the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO).

DESIGN

Retrospective cross-sectional register-based study.

METHODS

Data were obtained from the EUREQUO. The database contains data on demographics, comorbidities, and intraoperative complications, including PCR for the study period from January 1, 2008, to December 31, 2018. Univariate and multivariate logistic regression analyses were performed to estimate the (adjusted) odds ratio (OR) and 95% confidence intervals (CIs).

RESULTS

We analyzed EUREQUO registry data of 2,853,376 patients, and 31,749 (1.1%) cataract surgeries were complicated by a PCR. Data were available of 2 853 376 patients, and 31 749 (1.1%) cataract surgeries were complicated by a PCR. The PCR rate ranged from 0.60% to 1.65% throughout the years, with a decreasing trend (P < .001). The mean age of the PCR cohort was 74.8 ± 10.5 years, and 17 29 (55.5%) patients were female. Risk factors most significantly associated with PCR were corneal opacities (OR 3.21, 95% CI, 3.02-3.41, P < .001), diabetic retinopathy (OR 2.74, 95% CI, 2.59-2.90, P < .001), poor preoperative visual acuity (OR 1.98, 95% CI, 1.88-2.07, P < .001), and white cataract (OR 1.87, 95% CI, 1.72-2.03, P < .001).

CONCLUSIONS

Risk factors for PCR were identified based on the EUREQUO, and the incidence of this complication is decreasing over time.

Intravitreal injection is associated with increased posterior capsule rupture risk during cataract surgery: A meta-analysis

BACKGROUND

Although observational studies have suggested that prior intravitreal therapy may predict posterior capsule rupture (PCR) during cataract surgery, this finding is still controversial.

OBJECTIVE

To summarize current evidence on the association between prior intravitreal injection (IVI) and PCR during cataract surgery.

METHODS

A systematic literature search was performed up to October 27th, 2021. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models. The potential association between IVI and PCR in future cataract surgeries was assessed using the following two models: "pooling the odds ratios of PCR in eyes with and without previous IVI(s)" and "pooling the odds ratios for PCR relative to each increase in the number of prior injections." The quality of included studies was appraised using the Newcastle-Ottawa Scale.

RESULTS

6 cohort studies were included in this meta-analysis, with a total of 1,051,097 eyes that underwent cataract surgery. Of these, 7,034 eyes were associated with previous IVI. The pooled odds of PCR in eyes with prior IVI was 2.01 (95% CI: 1.35-3.00) times higher than that of eyes without an IVI history. An increase in the number of previous IVI conferred increased odds of PCR of 1.03 (95% CI: 1.01-1.06). After excluding studies that failed to account for confounders, the significantly increased risk was not altered, and the significant heterogeneity was minimized in both models.

CONCLUSION

This meta-analysis provides evidence that previous IVI significantly increases the risk of PCR during future cataract surgery. The risk of PCR should be discussed preoperatively with patients. Further studies are required to validate our findings and explore the underlying mechanisms.

Postoperative Endophthalmitis in Immediate Sequential Bilateral Cataract Surgery: A Nationwide Registry Study

PURPOSE

To report the incidence of postoperative endophthalmitis (PE) after immediate sequential bilateral cataract surgery (ISBCS) in Sweden.

DESIGN

Retrospective cohort registry study.

PARTICIPANTS

Patient data from 1 457 172 cataract extractions, including 1 364 934 unilateral surgeries and 92 238 ISBCSs.

METHODS

Endophthalmitis cases reported to the Swedish National Cataract Register (NCR) during a 16-year period (2002-2017) were analyzed in comparison to all control cases with regard to patient characteristics, surgical technique, and capsule complication.

MAIN OUTCOME MEASURE

Incidence and determinants for PE in ISBCS compared with unilateral surgeries.

RESULTS

A total of 422 cases of PE were identified in 1 457 172 cataract extractions, yielding an overall incidence of 0.029% (95% confidence interval [CI], 0.0262-0.0317). For unilateral procedures, the rate was 0.0299% (95% CI, 0.0270-0.0328) or 408 cases in 1 364 934 operations, whereas that for ISBCS was 0.0152% (95% CI, 0.0072-0.0231) or 14 incidents in 92 238 operations (P = 0.01). In a logistic regression model including all cataract procedures, nonuse of intracameral (IC) antibiotics (ABs), capsule complication, age 85 years or more, male gender, and ocular comorbidity were found to be independent risk factors for PE. All these parameters were less frequent in ISBCS. Notwithstanding, in the same multivariate analysis, ISBCS in itself was associated with a significantly lower risk for PE. At follow-up, 5 of the 14 PE cases in the ISBCS cohort had a visual acuity (VA) of 20/200 or worse. Of these, one 93-year-old ISBCS patient developed bilateral infection.

CONCLUSIONS

After ISBCS in Sweden, PE occurred once in 6600 surgeries. The risk of sustaining a final VA of 20/200 or less was 1 incident in 18 000 operated eyes. When counseling potential ISBCS patients about the risk of PE, it seems reasonable to state that the reported risk in the literature is lower than that with unilateral surgery but not negligible. Precautions remain necessary.

Risk model for intraoperative complication during cataract surgery based on data from 900 000 eyes: previous intravitreal injection is a risk factor

BACKGROUND/AIMS

The aim of this study was to develop a risk model for intraoperative complication (IC) during cataract surgery, defined as posterior capsule rupture and/or zonular dehiscence, and to include previous intravitreal therapy (pIVT) in the model.

METHODS

This retrospective register-based study covered patients reported to the Swedish National Cataract Register (SNCR) between 1 January 2010 and 30 June 2018. Odds ratios (ORs) were used to quantify association strength of each variable with IC. Data from the SNCR were cross referenced with the Swedish Macula Register to include data on pIVT. Variables statistically significant in the univariate analyses (p<0.05) were included in a multivariate logistic regression model.

RESULTS

The inclusion criteria were met by 907 499 eyes. The overall rate of IC was 0.86%. Variables significantly associated with IC were best corrected visual acuity ≥1.0 LogMAR (OR (adjusted): 1.75, p<0.001), age ≥90 years (OR: 1.25, p<0.001), male sex (OR: 1.09, p<0.01), pseudoexfoliation (OR: 1.33, p<0.001), glaucoma (OR: 1.11, p<0.05), diabetic retinopathy (OR: 1.35, p<0.001), pIVT (OR: 1.45, p<0.05), surgeon's experience <600 surgeries (OR: 2.77, p<0.001), use of rhexis hooks (OR: 6.14, p<0.001), blue staining (OR: 1.87, p<0.001) and mechanical pupil dilation (OR: 1.52, p<0.001).

CONCLUSION

The risk model can be used in the preoperative setting to predict the probability of IC, to facilitate planning of surgery and improving patient communication. Patients who have undergone intravitreal therapy prior to cataract surgery have an increased risk of IC during cataract surgery.