Database IDs risk factors for iris damage, dropped nucleus

The European Registry for Quality Outcomes in Cataract and Refractive Surgery (EUREQUO) has amassed an enormous data that identifies risk factors for cataract surgery patients. 

This article was reviewed by Mats. H. Lundstrom, MD

The European Registry for Quality Outcomes in Cataract and Refractive Surgery (EUREQUO) is a collaboration established in 2008 between the European Union and the European Society of Cataract and Refractive Surgery. Data on both cataract and refractive surgeries can be entered through interface or manual input into the two registries contained in the EUREQUO, according to Mats H. Lundstrom, MD.

Data from almost 3 million surgeries have been entered into the database to date. The recorded data are comprehensive and reflect the entire range of the relevant information about the cataract surgeries from baseline including demographics, preoperative visual acuity, and risk factors through follow-up including the visual and refractive outcomes and any postoperative complications. 

Related: Understanding the surgical learning curve 

The surgical information reflects the type of surgery and the IOL implanted as well as any surgical complications that might have occurred, such as posterior capsular rupture, vitreous loss, dropped nucleus, iris damage, and any others.

Dr. Lundstrom, who is adjunct professor emeritus in ophthalmology, Department of Clinical Sciences, Ophthalmology, Faculty of Medicine, Lund University, Kariskrona, Sweden, focused on the complications of dropped nucleus and iris damage.

Iris damage
In the study period that ranged from Jan. 1, 2008 to Dec. 31, 2018, of the 1,715,348 reported procedures, iris damage during phacoemulsification occurred in 4,971 (0.3%) cases. Analysis of the registry data indicated that the rate of iris damage decreased from 0.41% in 2008 to 0.20% in 2018.

Logistic regression analysis of the surgical data showed that the independent variables related to iris damage were male gender, older age, small pupil, white cataract, poor preoperative visual acuity, and glaucoma (p < 0.001 for all comparisons).

Related: Light-adjustable IOL technology creates novel treatment window 

The mean postoperative logarithm of the minimum angle of resolution visual acuity in patients with iris damage was slightly worse than in patients without iris damage, i.e., 011 ± 0.22 versus 0.06 ± 0.17, a difference that reached significance (p < 0.001), Dr. Lundstrom reported.

The refractive outcome regarding the mean absolute biometric prediction error was also significantly (p < 0.001) different between patients with and without iris damage, 0.58 D versus 0.43 D, respectively. Those with iris damage also had significantly (p < 0.001) more postoperative complications compared with those who did not, 7.2% versus 2.0%.

Dropped nucleus
When considering this complication during the same time period and in the same number of recorded surgeries, a dropped nucleus occurred in 1,221 cases (0.07%). This complication also decreased over time, from 0.093% in 2008 to 0.036% in 2018, Dr. Lundstrom reported.

The independent variables that were found by logistic regression analysis to be related to a dropped nucleus included a white cataract, previous vitrectomy, poor preoperative visual acuity, small pupil, pseudoexfoliation, diabetic retinopathy, and gender.

Related: 9 best practices in refractive-cataract surgery planning 

Visual outcomes linked with dropped nucleus were worse than those associated with iris damage. The mean postoperative visual acuities in patients with a dropped nucleus compared with those without a dropped nucleus were 0.24 ± 0.32 versus 0.05 ± 0.17 (P < 0.01). The respective mean absolute biometric prediction errors were 1.02 D versus 0.43 D (P < 0.01) and the respective rates of postoperative complications were 18.1% versus 2.0% (P < 0.01). The specific postoperative complications were corneal edema, high intraocular pressure, and endophthalmitis, among others, he reported.

The importance of the EUREQUO to provide such valuable data is underscored by the ability to identify risks factors in patients undergoing cataract surgery. 

Dr. Lundstrom concluded that iris damage and dropped nucleus have decreased over a decade. Several risk factors have been identified. 

“Combinations of risk factors increase the risk,” he said. “The visual and refractive outcomes are worse compared with no complication. The poor outcomes are explained partly by the risk factors.”

Read more surgery content 

Mats H. Lundstrom, MDE: mats.lundstrom@karlskrona.mail.telia.com
Dr. Lundstrom has no financial interest in any aspect of this report.