A recent study published in Ophthalmology evaluated the risk of postoperative complications following cataract surgery in patients with a history of anterior, posterior, or panuveitis compared to controls.
Give me some background.
Cataracts are a common complication of uveitis, resulting from chronic inflammation and corticosteroid treatment in 50-78% of patients and account for 40% of vision loss in patients with uveitis.
Preoperative planning is critical to minimize the risk of postoperative inflammation and complications such as:
- Cystoid macular edema (CME)
- Glaucoma
- Posterior capsular opacification (PCO)
Note: Despite disease quiescence, anatomical challenges in uveitic eyes, such as synechiae and poor dilation, can complicate cataract surgery.
Now, talk about the study.
In this retrospective cohort study, investigators included a 5% sample of Medicare beneficiary claims from Jan. 1, 2011 to Dec. 31, 2015—with a look-back period of at least 1 year and 6 months of postoperative follow-up.
They identified postoperative complications via Current Procedural Terminology (CPT) codes and used International Classification of Diseases, 9th Revision (ICD-9) codes to define:
- Uveitis classification (i.e., anterior, posterior, panuveitis)
- Systemic comorbidities
- Ocular complications
Complications were considered associated with the cataract surgery if they occurred within 6 months postoperatively, and subsequent ocular surgeries were included if they occurred within 1 year postoperatively.
Give me some details on the study cohorts.
The study sample included:
- Anterior uveitis: 674 patients (mean age 74.0, 37.4% male)
- Posterior uveitis: 409 patients (mean age 74.6, 38.1% male)
- Panuveitis: 276 patients (mean age 75.8, 39.5%)
- Controls with no history of uveitis: 118,429 patients (mean age 74.6, 40.1% male)
Findings?
The most common postoperative complication in all cohorts was PCO.
Compared to controls, the anterior uveitis cohort (odds ratio [OR]: 5.94) and panuveitis cohort (OR: 4.06) had higher odds of developing corneal edema.
While patients with anterior uveitis had an increased risk of CME (OR 2.13), no other posterior segment complications were observed at higher rates in the uveitis cohorts.
Tell me more about the anterior uveitis cohort.
Patients with anterior uveitis had a significantly higher risk of glaucoma compared to controls:
- Open-angle glaucoma (OR: 3.10)
- Acute angle closure glaucoma (OR: 14.74)
- Steroid-induced glaucoma (OR: 13.39)
Further: This cohort was more likely to require anterior chamber paracentesis (OR: 3.93) and laser glaucoma procedures (OR: 11.29), but had similar rates of trabeculectomy and tube shunt procedures.
Anything else?
Posterior uveitis and panuveitis were not linked to higher glaucoma risk—suggesting that disruptions in aqueous humor dynamics may contribute more to the disease pathogenesis than an increased susceptibility to optic nerve damage from posterior segment inflammation.
Expert opinion?
The study authors noted that chronic angle closure is common in uveitic eyes due to anterior and posterior synechiae.
How this connects to the study: “In the setting of cataract surgery, a shallow chamber along with a higher inflammatory burden and predilection for fibrotic changes in uveitic eyes may lead to the observed increased risk of acute angle closure,” they stated.
Limitations?
These included:
- An absence of information on eye laterality in ICD-9 codes that prevented researchers from determining whether a previous history of uveitis occurred in the same eye that underwent cataract surgery and if postoperative complications occurred in the operated eye
- Meaning: Some of the eyes in the uveitis cohort may have been unaffected fellow eyes
- To address this: The research team limited the follow-up duration to increase the likelihood that observed complications were related to the surgery
- Meaning: Some of the eyes in the uveitis cohort may have been unaffected fellow eyes
- The study period from 2011-2015 could be considered dated, though the novel associations and stratified risk profiles of uveitis patients after cataract surgery likely continued to persist and remain relevant for surgeons
- The claims data analysis did not allow for the evaluation of clinical parameters or prescription information to assess preoperative disease severity and postoperative management
Take home.
These findings suggest that the risk profile for postoperative complications following cataract surgery varies significantly depending on the subtype of uveitis.
- Of note: Anterior uveitis was associated with a significantly higher risk of postoperative glaucoma.
Timely diagnosis and intervention, including the potential need for a prolonged postoperative steroid course, may improve outcomes in these high-risk patients.