Endophthalmitis is a rare but visually devastating complication that may occur during routine cataract surgery. Acute-onset postoperative endophthalmitis is a major concern for physicians and patients given the potential impact on patient quality of life, burden of additional visits/surgical procedures (e.g., vitrectomy), and associated healthcare costs.
Endophthalmitis is often challenging to study due to its rarity. The literature indicates the incidence of endophthalmitis following cataract surgery ranges from ~0.5 to 3 cases per 1,000 procedures. Thus, the feasibility and costs associated with a large-scale prospective study are often prohibitive given the need to enroll several thousand cataract procedures to detect a safety signal.
The American Academy of Ophthalmology Intelligent Research in Sight (IRIS)® Registry is a clinical registry with aggregated real-world data from over 61 million patients in the United States. It is uniquely suited to study rare events such as endophthalmitis, given its size, coverage of ophthalmology providers, and longitudinal data.
Two recent studies that examined several factors related to endophthalmitis following cataract surgery were presented at the American Society of Cataract and Refractive Surgery (ASCRS) 2021 Annual Meeting. Studies were designed by Ocular Therapeutix with analysis performed by Verana Health. The research highlights the value of large electronic health record (EHR) derived registries in generating insights on rare events.
IRIS registry delivers insight into endophthalmitis following cataract surgery
The first retrospective study analyzed real-world data from nearly 7 million eyes in the IRIS Registry database, making it one of the largest recent reviews of acute postoperative endophthalmitis following cataract surgery. Overall, the incidence of post-cataract surgery endophthalmitis between 2016 to 2019 was 0.633 per 1,000 surgeries, which is consistent with the rates seen prior studies.
For routine cataract procedures, the incidence rate was 0.592 per 1,000 surgeries. For complex procedures, the incidence rate was 1.148 per 1,000 surgeries.
The study also revealed risk factors that are associated with statistically significant higher rates of endophthalmitis, such as undergoing concurrent vitreous procedures and a history of proliferative diabetic retinopathy, diabetic macular edema, or complex cataract surgeries.
“Incidence of Endophthalmitis Following Cataract Surgery and Risk Factors: Retrospective Study Using the IRIS Registry” was presented by Michael H. Goldstein, MD, MBA, on July 25.
Evaluating ReSure’s impact on endophthalmitis
In the second study, Ocular Therapeutix and Verana Health researchers analyzed the IRIS Registry to evaluate the difference in the incidence of endophthalmitis within 30 days of cataract surgery between practices with and without access to ReSure® Sealant. ReSure® Sealant is a hydrogel sealant used after cataract surgeries to create an in situ temporary, soft surface barrier to prevent wound leakage from clear corneal incisions.
Sites with access to ReSure had an incidence rate of 0.609 per 1,000 surgeries and sites without access to ReSure had an incidence rate of 0.660 per 1,000 surgeries (P=0.01).
Researchers concluded that there was no clinically meaningful or statistically significant difference in incidence rate of endophthalmitis between eyes treated at practices with and without access to ReSure Sealant. Similarly, no clinically meaningful or statistically significant difference in the incidence of endophthalmitis was detected among routine and complex cataract procedures among practices with and without access to ReSure.
“Retrospective Study Comparing the Incidence of Endophthalmitis Following Cataract Surgery in Practices with Access to Hydrogel Sealant” was presented by Leon W. Herndon, MD, on July 25.
New public health insights through real-world data
These two presentations demonstrate the promise of the IRIS Registry in studying rare events that may be challenging to assess in prospective trials. As the end-to-end data curation and analytics provider, Verana Health is excited to continue leveraging real-world data to support evidence-based analysis of the ophthalmology treatment landscape and provide novel insights to improve public health.
Sonya Li is Senior Manager of Life Science Partnerships at Verana Health; Matthew Cheung is Manager, Medical Affairs publications at Ocular Therapeutix; Srilatha Vantipalli is Director, Medical and Scientific Communications at Ocular Therapeutix