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

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

ASCRS News: EyeWorld Journal Club 
June 2022

by Jasdeep Sabharwal, MD, PhD, and Fasika Woreta, MD

Fasika Woreta MD
Fasika Woreta, MD Residency Program Director
Wilmer Eye Institute Johns Hopkins Medicine
Baltimore, Maryland

In this large database analysis of 2.8 million patients who underwent cataract surgery, annual posterior capsular rupture (PCR) rate decreased from 1.44% in 2008 to 0.6% in 2018. The major risk factors for PCR included male sex, older age, glaucoma, diabetic retinopathy, worse initial visual acuity, and a hyperopic target. Intraoperative factors such as small pupil, white cataract, corneal opacities, and pseudoexfoliation were also associated with higher rate of capsular rupture. 

Introduction

Cataract surgery is one of the most commonly performed surgery worldwide.1 Though cataract surgery is extremely safe, understanding the rates and risk factors for the various complications is important to counsel patients and take action to prevent them.2 PCR may occur during cataract surgery and is associated with an increased risk of complications such as cystoid macular edema and retinal detachment. Risk factors for PCR in the literature include pseudoexfoliation, previous intravitreal injections, small pupils, older age, and high myopia.3 In this report, Segers et al. sought to identify risk factors by using a large, multi-national, ophthalmology specific database to study the rate and risk factors for PCR.4

Jasdeep Sabharwal, MD, PhD
Jasdeep Sabharwal, MD, PhD
Resident
Wilmer Eye Institute
Johns Hopkins Medicine
Baltimore, Maryland

Design and methods

The European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) was established in 2008. It is a volunteer database where surgeons from 22 countries report consecutive cases to provide data on cataract and refractive surgery. In this report, the data obtained from January 1, 2008, to December 31, 2018, was assessed.

Demographic information included in this database include age, sex, year of surgery, and laterality. The preoperative data included corrected distance visual acuity (CDVA, logMAR), target refraction. Comorbid ocular diseases were also noted, which included AMD, glaucoma, diabetic retinopathy, and other sight-threatening eye diseases. Intraoperative parameters included mechanical pupil dilation, use of trypan blue, corneal opacities, and other difficulties encountered during surgery. PCR in this study was identified as an intraoperative tear in the posterior capsule with or without zonular dialysis and vitreous loss. 

To assess change in PCR with time and risk factors associated with PCR the authors used logistic regression. A multivariate logistic regression was used to identify the risk factors. 

Results

There was a total of 2,853,376 cataract surgeries included in the database during the study period. The vast majority (97%) were extracapsular cataract extraction. The average age of patients was 73.9 years (+/–9.7), and 58.7% were female. PCR occurred in 31,749 cases (1.1%). Among patients with PCR the average age was 74.8 (+/–10.5), and 55.5% were female. The annual rate of PCR ranged from 0.6% to 1.65% with a decreasing trend across the study years. 

Multivariate analysis was performed using variables, which were significant in a univariate analysis using a backward stepwise method. The presence of amblyopia, AMD, and previous vitrectomy were not significantly associated with a higher risk of PCR. The multivariate analysis was carried out for a total of 1,722,022 patients, and the major risk factors and the adjusted odds ratio (OR, 95% CI) were shown. 

Patients who were male, older, or had a diagnosis of glaucoma or diabetic retinopathy had a higher association with PCR. Worse preoperative visual acuity and a target refraction that was hyperopic had a higher association with PCR. Finally, intraoperative factors that were associated with higher risk included mechanical pupil dilation, trypan usage, corneal opacity, and pseudoexfoliation.

Discussion and conclusions

Overall PCR rates decreased with time and were less than 1%, consistent with the other studies in the literature.5–7 Some explanations for this decreasing trend include improvements in phacoemulsification equipment or techniques during the study period as well as more experience among the surgeons providing data. Though each year added only minimal risk, an 80-year-old would have 20% higher odds of a PCR than a 55-year-old patient. Age as a risk factor was present in most of the other studies as well. Other ocular diseases were also associated with higher risk. Diabetes has been shown as a risk factor, and other studies have specifically shown previous intravitreal injections are associated with higher risk of PCR.6,8,9 Glaucoma was shown to be significant in previous studies, but one found that exclusion of pseudoexfoliation made the findings not significant.10,11 In this study, glaucoma and pseudoexfoliation syndrome were associated with higher risk of PCR.

In terms of refraction, hyperopic targets had higher risk while myopic targets had a decreased risk. Some previous studies looking at axial length did show higher PCR with shorter axial lengths, but results with myopic were more conflicting.10–12 The narrower working space would be one explanation for this association. Intraoperative difficulties were associated with higher risk. 

Some limitations of this study include inability to assess features not included in the database (e.g., previous intravitreal injection, use of medications that could cause floppy iris syndrome). The data reported here is voluntary and reported by clinics, creating the potential for underreporting. Finally, there was a significant loss of data of about 1.1 million patients, although there were no significant differences in the demographics between these groups.

Overall, the data show that PCR is becoming a rarer complication, but there are preoperative and intraoperative factors that can help identify patients at greatest risk of PCR. Identifying these factors will not only help counsel patients appropriately but also help determine which patients are not appropriate for junior trainees. 

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

Segers MHM, et al. J Cataract Refract Surg. 2022;48(1):51–55.

  • Purpose: To analyze the incidence and risk factors of 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 was 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. Univariable and multivariable logistic regression analyses were performed to estimate the (adjusted) odds ratio (OR) and 95% confidence intervals (CI).
  • Results: Data was available for 2,853,376 patients, and 31,749 (1.1%) cataract surgeries were complicated by a PCR. The PCR rate ranged from 0.60–1.65% throughout the years, with a decreasing trend (p<0.001). The mean age of the PCR cohort was 74.8±10.5 years, and 17,629 (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<0.001), diabetic retinopathy (OR 2.74, 95% CI 2.59–2.90, p<0.001), poor preoperative visual acuity (OR 1.98, 95% CI 1.88–2.07, p<0.001), and white cataract (OR 1.87, 95% CI 1.72–2.03, p<0.001). 
  • Conclusion: Risk factors for PCR were identified based on the EUREQUO, and the incidence of this complication is decreasing over time.

References

  1. Taylor HR. Cataract: how much surgery do we have to do? Br J Ophthalmol. 2000;84:1–2. 
  2. Jaycock P, et al. The Cataract National Dataset electronic multi-centre audit of 55,567 operations: updating benchmark standards of care in the United Kingdom and internationally. Eye (Lond). 2009;23:38–49. 
  3. Chan E, et al. Complications of cataract surgery. Clin Exp Optom. 2010;93:379–389. 
  4. Segers MHM, et al. Risk factors for posterior capsule rupture in cataract surgery as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery. J Cataract Refract Surg. 2022;48:51–55. 
  5. Zetterberg M, et al. Cataract surgery volumes and complications per surgeon and clinical unit: data from the Swedish National Cataract Register 2007 to 2016. Ophthalmology. 2020;127:305–314. 
  6. Shalchi Z, et al. Risk of posterior capsule rupture during cataract surgery in eyes with previous intravitreal injections. Am J Ophthalmol. 2017;177:77–80. 
  7. Day AC, et al. The Royal College of Ophthalmologists’ National Ophthalmology Database study of cataract surgery: report 1, visual outcomes and complications. Eye (Lond). 2015;29:552–560. 
  8. Lee AY, et al. Previous intravitreal therapy is associated with increased risk of posterior capsule rupture during cataract surgery. Ophthalmology. 2016;123:1252–1256. 
  9. Chancellor J, et al. Intraoperative complications and visual outcomes of cataract surgery in diabetes mellitus: a multicenter database study. Am J Ophthalmol. 2021;225:47–56. 
  10. Zetterberg M, et al. A composite risk score for capsule complications based on data from the Swedish National Cataract Register: relation to surgery volumes. Ophthalmology. 2021;128:364–371. 
  11. Narendran N, et al. The Cataract National Dataset electronic multicentre audit of 55,567 operations: risk stratification for posterior capsule rupture and vitreous loss. Eye (Lond). 2009;23:31–37. 
  12. Zare M, et al. Risk factors for posterior capsule rupture and vitreous loss during phacoemulsification. J Ophthalmic Vis Res. 2009;4:208–12. 

Contact 

Sabharwal: jsab@jhmi.edu
Woreta: fworeta1@jhmi.edu

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