Stratifying Risk factors affecting Visual Outcome in Intraocular Foreign Bodies: Study
Intraocular foreign bodies (IOFB) refer to foreign objects that penetrate the ocular globe wall and become lodged in the eye. IOFB injuries, which cause varying degrees of damage to ocular tissues, are severe and complex open-globe injuries. In industrialized nations, IOFB injuries are among the most common ophthalmological emergencies causing severe damage to the visual function of young adult men.
IOFB can cause not only mechanical damage to the eyeball but also cause endophthalmitis and visual function damage, especially IOFB-related endophthalmitis, which is often an emergency. If it is not treated in a timely and effective manner, it may lead to serious consequences and even eyeball removal; therefore, IOFB should be assessed properly.
In the present study, Liang et al performed a retrospective analysis of the clinical data of patients with IOFB injuries who underwent surgical treatment at the Ophthalmology Department of the Second Hospital of Hebei Medical University between January 1, 2008, and December 31, 2019, in order to investigate the clinical characteristics of patients with IOFBs, evaluate factors affecting visual outcome, and determine the risk factors for the development of endophthalmitis.
In total, 242 patients (242 eyes) who were hospitalized and underwent surgical treatment for IOFB were included. The demographic data, cause of injury, characteristics of IOFBs, post injury ocular manifestations, and surgical details of the subjects were collected, and the factors affecting visual outcome and endophthalmitis development were analyzed.
The most common cause of IOFBs was the propulsion of foreign bodies into the eye due to hammering (149 cases, 61.57%), followed by foreign body penetration (57 cases, 23.55%). Most of the subjects were young adult men who sustained injuries in the work environment.
Poorer visual outcomes were found in subjects with initial presenting symptoms visual acuity (PVA) < 0.1, largest IOFB diameter ≥ 3 mm, IOFBs located in the posterior segment, wound length > 5 mm, entrance wound length larger than the largest IOFB diameter, concomitant retinal detachment, concomitant vitreous hemorrhage, concomitant endophthalmitis, and concomitant proliferative vitreoretinopathy (PVR).
Factors related to the development of endophthalmitis included lens capsule rupture, time of stage 1 repair surgery ≥ 24 h after trauma, removal of IOFBs ≥ 24 h after trauma, and nonadministration of intravitreal antibiotic injection.
Factors Influencing Visual Outcome
Open-globe injury with concomitant IOFB is a complex medical condition, and visual outcomes are affected by a wide variety of factors. A retrospective analysis revealed that initial PVA< 0.1 was a risk factor for poor visual outcomes in patients with IOFBs. As initial PVA reflects the degree of damage inflicted by IOFBs on the eye to a certain extent, a poorer initial PVA indicates greater ocular damage, which leads to poorer visual outcome.
Longer wounds were also associated with a poorer final visual acuity in the subjects. This can be attributed to a greater extent of ocular involvement in longer wounds, which leads to a higher possibility of retinal involvement. In the present study, subjects with an IOFB diameter ≥ 3 mm had poorer visual outcomes than subjects with an IOFB diameter < 3 mm.
IOFB location also exerted a significant influence on visual outcome as the presence of IOFBs in the posterior segment of the eye was associated with poorer visual outcomes in subjects. Once IOFBs cause retinal damage, it is highly likely that retinal detachment will occur, with involvement of the macula usually causing irreversible vision loss.
Factors Affecting Endophthalmitis Development
With the occurrence of lens capsule rupture, the normal aqueous humor circulation is disrupted, which leads to decreased removal of harmful bacteria in the eye. The ruptured lens may also facilitate bacterial reproduction and cause the entry of bacteria into the vitreous body
A total of 88 subjects exhibited lens capsule rupture, and of these, 16 (18.18%) developed endophthalmitis. Among subjects without lens capsule rupture, 11 (7.14%) developed endophthalmitis.
Based on the environment where the injury occurred, the nature of work performed by the patient, level of cleanliness of the foreign body, and ocular manifestations of the patient during medical consultation, preventive intravitreal injections of norvancomycin 1 mg/0.1 ml and ceftazidime 1 mg/ 0.1 ml, which are routine drugs for endophthalmitis prevention, were administered to patients at high risk of developing endophthalmitis. It was evident that intravitreal antibiotic injection was a protective factor against endophthalmitis development.
Study results also indicated that the incidence of endophthalmitis was 3.33% in 120 subjects undergoing IOFB removal within 24 h of trauma, which was considerably lower than that among subjects undergoing IOFB removal > 24 h after trauma (18.85%). Initial PVA< 0.1, wound length greater than the largest IOFB diameter, concomitant endophthalmitis, and concomitant PVR were the risk factors for poor BCVA.
The development of endophthalmitis in patients with IOFBs was also affected by various factors. The logistic regression analysis showed that lens capsule rupture was a risk factor for endophthalmitis development, while preventive administration of intravitreal antibiotic injection was a protective factor against endophthalmitis development.
Based on these results, the authors recommend stage I repair surgery for wound closure in a timely manner and the administration of intravitreaantibiotic injection at the earliest possible time to prevent the development of endophthalmitis in patients with IOFBs.
Source: Yanyan Liang, Shuang Liang, Xiaoli Liu, Danyan Liu and Jialiang Duan; Hindawi Journal of Ophthalmology Volume 2021