Intraocular foreign bodies (IOFB) are one of the most common open-globe injuries (16% to 41% of all cases) that cause severe damage to ocular tissues leading to impaired visual function, most frequently among young adult men. IOFB-related endophthalmitis, if not properly treated as an emergency, could result in consequences as detrimental as eyeball removal. This retrospective study examined the visual outcomes of IOFB patients to determine which factors affect visual outcome and endophthalmitis development. The results show that although several factors contribute to poorer visual outcome, preventative injections and immediate treatment both play major roles in reducing risk of infection.
Researchers reviewed data of 242 patients (230 male) with IOFB injuries who underwent surgical treatment and completed follow-ups for three to 15 months. Most of the patients’ injuries occurred in a work environment in the absence of protective glasses, and hammering alone was responsible for more than half (61.6%). Of the 27 patients with endophthalmitis, 17 were culture-positive and infected by Gram-positive germs.
Out of the 88 subjects who exhibited lens capsule rupture, 18.2% developed endophthalmitis, while 7.1% of those without lens capsule rupture developed it. A ruptured lens is more susceptible to bacterial infection, so this may be a risk factor for endophthalmitis in some IOFB patients. Another risk factor could be receiving treatment more than 24 hours after trauma; incidence of endophthalmitis was much lower for those who underwent treatment within this timeframe (3.3% vs. 18.9%).
Only 126 patients received preventive intraoperative intravitreal antibiotic injections, while 101 did not. Researchers found that the number of patients who developed endophthalmitis after initial treatment were one 0.8% in the injection group and 10.9% in the noninjection group, meaning IOFB patients who receive the preventative injections may be at a lower risk of developing endophthalmitis.
Risk factors shown for poor visual outcomes were an initial presenting visual acuity of <0.1 and longer wounds, particularly over 5mm. The location of the IOFB in the eye also affected the visual outcome; patients with IOFBs in the posterior segment of the eye faced higher risk of poor visual outcomes. Additional risk factors included a wound length greater than the largest IOFB diameter, concomitant retinal detachment, concomitant vitreous hemorrhage, concomitant endophthalmitis and concomitant proliferative vitreoretinopathy.
As for endophthalmitis development, lens capsule rupture, nonadministration of intravitreal injection of antibiotics and repair surgery or time of IOFB removal more than 24 hours after trauma were all associated with a higher risk. “Based on these results, we recommend stage I repair surgery for wound closure in a timely manner and the administration of intravitreal antibiotic injection at the earliest possible time to prevent the development of endophthalmitis in patients with IOFBs,” the authors of the study concluded.
Liang Y, Liang S, Liu X, et al. Intraocular foreign bodies: clinical characteristics and factors affecting visual outcome. Journ of Ophthal. June 19, 2021. Epub ahead of print.