IRIS Registry Analysis Explores Epidemiology, Clinical Features, and Visual Outcomes after Intraocular Foreign Body Removal
Key findings
- The multicenter, retrospective cohort study analyzed epidemiologic, sociodemographic, and clinical data from the American Academy of Ophthalmology IRIS® Registry (2016–2024) to characterize presentation and outcomes of IOFB injuries in the U.S.
- A total of 4,784 eyes (4,584 patients) undergoing IOFB removal were included, representing a mean annual incidence of 2.28 (95% CI: 2.09–2.49) per 100,000 patient-years, with a small gradual decline from 2017 to 2023
- Sociodemographic factors, including male sex, race and ethnicity, and rural residence, were associated with greater risk of IOFB removal, while older age and higher income were associated with lower risk
- Visual improvements were seen at 2 months, after which there were gradual improvements that were maintained to month 18 post-IOFB removal
- Patients with endophthalmitis (3.9% of eyes) or retinal detachment (12.5% of eyes) at baseline were more likely to have poorer visual outcomes; post-IOFB visual outcomes were tightly linked with pre-IOFB visual acuity
Intraocular foreign body (IOFB) injuries are serious, vision-threatening ophthalmic emergencies. Despite their clinical relevance, previous studies of these injuries have been limited in size, leaving gaps in understanding their population-level risk factors and visual outcomes. Large real-world data can help address these gaps and inform counseling and prevention strategies.
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Ines Lains, MD, PhD, and colleagues at Mass Eye and Ear, in collaboration with Moorfields Eye Hospital in the United Kingdom, published a study in Ophthalmology Retina aiming to better understanding the contemporary presentation, management, and factors influencing visual prognosis of IOFBs in routine clinical practice.
The study found that sociodemographic characteristics, certain baseline clinical features, and vision prior to the IOFB injury were associated with both injury risk and visual outcomes.
Methods
The researchers used data from the American Academy of Ophthalmology Intelligent Research in Sight (IRIS®) Registry, a large electronic health record-based registry of over 80 million patients across the U.S. As one of the largest structured clinical databases, the IRIS Registry provides a rich dataset for performing longitudinal real-world investigations.
Between January 2016 and October 2024, 4,784 eyes (4,684 patients) had documented IOFB removal without additional confounding procedures within three days. Key sociodemographic information, baseline clinical characteristics, details on methods for removal, and visual acuity (VA) before, at, and up to 18 months after removal were analyzed.
Findings
Epidemiology and baseline characteristics
The mean annual incidence of IOFB removal for the 8-year study period was 2.28 (95% CI: 2.09–2.49) per 100,000 patient-years, which was reduced from 2.84 (95% CI: 2.61–3.10) in 2017 to 1.95 (95% CI: 1.80–2.12) in 2023.
More than half (54.5%) of eyes had vision worse than 1.00 LogMAR, or 20/200 Snellen, at baseline. Common complications at presentation were retinal detachment (12.5%), cataract (10.5%), vitreous hemorrhage (7.9%), and endophthalmitis (3.9%).
Factors associated with IOFB removal
Male sex (Odds ratio [OR], 3.44; 95% CI: 3.22—3.67), Hispanic/Latino ethnicity (OR, 1.49; 95% CI: 1.35—1.64), and residing in a rural area (OR, 1.65; 95% CI: 1.52—1.79) were independently associated with increased risk of IOFB removal.
Risk decreased for patients who were older (OR, 0.88 per decade over 65; 95% CI: 0.87—0.90) and had a median income of $75,000–$149,999 (OR, 0.80; 95% CI: 0.74—0.86), higher than the majority of patients included in the study.
Changes in VA over 18 months
The most pronounced and significant VA improvement was seen in the second month after IOFB removal (0.38 reduction in LogMAR on average, 95% CI: –0.41 to –0.34). After that, VA continued to improve gradually to 0.59 LogMAR and was maintained through month 18 (95% CI: –0.69 to –0.48).
Presence of endophthalmitis (β, 0.42; 95% CI: 0.05–0.79) or retinal detachment (β, 0.418; 95% CI: 0.17–0.67) at baseline were associated with poorer VA in follow-up visits. Those with IOFB affecting both the anterior and posterior segment (1.6% of eyes) also showed less improvement (β, 0.50; 95% CI: 0.07–0.93).
The strongest predictor of visual outcomes was VA prior to injury. Patients with pre-IOFB VA >1.0 LogMAR improved less than those with moderate and good VA.
These findings have the potential to help guide individualized decisions around treatment and follow-up care.