Patients undergoing cataract surgery who have had previous intravitreal injections are at increased risk for intraoperative complications, according to findings published in the British Journal of Ophthalmology.

Data for this study were sourced from the Swedish National Cataract Register and were cross referenced with the Swedish Macula Register. Patients (N=572,536) who underwent cataract surgery between 2010 and 2018 were assessed for outcomes. Demographic and clinical characteristics were used to construct an intraoperative complication risk model.

Patients had a mean age of74.4 (range, 20-109) years, 58.9% were men, and a total of 907,499 cataract operations were performed.


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Of these patients, 3168 underwent intravitreal therapy in 3451 eyes prior to cataract surgery.

Risk for intraoperative complications associated in a univariate analysis with 4 demographic characteristics, 4 indications for surgery, 6 ocular comorbidities, 4 intraoperative difficulties, and surgeon experience. These factors were tested in a multivariate analysis.

The demographic features which remained significant included best corrected visual acuity (logMAR) ≥1.0 (adjusted odds ratio [aOR], 1.75; 95% CI, 1.64-1.87; P <.001), age ≥90 years (aOR, 1.25; 95% CI, 1.02-1.41; P <.001), and male sex (aOR, 1.09; 95% CI, 1.03-1.15; P <.01).

No indication for surgery remained significant in the fully adjusted model.

Ocular comorbidities which associated with complications included previous intravitreal therapy (aOR, 1.45; 95% CI, 1.09-1.93; P <.05), diabetic retinopathy (aOR, 1.35; 95% CI, 1.21-1.51; P <.001), pseudoexfoliation (aOR, 1.33; 95% CI, 1.24-1.43; P <.001), and glaucoma (aOR, 1.11; 95% CI, 1.02-1.20; P <.05).

The intraoperative difficulties of Rhexis hooks (aOR, 6.14; 95% CI, 5.48-6.87; P <.001), blue staining (aOR, 1.87; 95% CI, 1.70-2.06; P <.001), and mechanical pupil dilation (aOR, 1.52; 95% CI, 1.37-1.68; P <.001) increased risk for procedural complications.

Procedures with surgeons who had performed fewer than 600 operations were associated with increased risk for complications (aOR, 2.77; 95% CI, 2.59-2.96; P <.001).

“Even though outside the scope of this study, the main reason for the increased risk of [intraoperative complications] in eyes with [previous intravitreal therapy] is most likely iatrogenic damage to the lens or zonulae, following poor injection technique, which should be explored in future studies,” the investigators report.

With these associated characteristics, the investigator created a model to quantify intraoperative complication risk for each eye. For example, a man older than89 years who has glaucoma, pseudoexfoliation, and a small pupil size, likely requiring mechanical pupil dilation, has an OR for complications of 3.06 or 1.7%. If the operating surgeon was relatively inexperienced, the risk increased to 8.47 or 4.5%.

With this model, the median risk for complications among the dataset was 0.56%.

This study was limited by the predictors which were available for inclusion in the model.

These data indicated that intravitreal therapy prior to cataract surgery increased risk for intraoperative complications. Additional high-risk predictors included Rhexis hooks and surgeon inexperience.

Reference

af Segerstad PH. Risk model for intraoperative complication during cataract surgery based on data from 900,000 eyes: previous intravitreal injection is a risk factor. Br J Ophthalmol. Published online April 22, 2021. doi:10.1136/bjophthalmol-2020-318645