This study aims to provide an overview of surgically treated OGI at the RWTH Aachen University Hospital and assess the current medical care there compared to the literature.
Epidemiology
The current study identified two age peaks for men: one between 20–40 years, which is usually working age and accounts predominantly for work and spare time injuries, and a second peak between 60–80 years. Women were affected almost exclusively above the age of 60 and mostly by syncopal episodes. Toride et al. described a similar age and gender distribution for Japan, a country with a comparable demographic and economic setting to Germany [
20].
In contrast to the present results, previous papers as well as the literature from developing countries detected only a single peak for patients (10–50 years) and a higher male-to-female ratio [
8‐
10,
13,
21,
22]. For example, Kuhn et al. analyzed the United States Eye Injury database (USEIR) and discovered that 81% of all patients were male and that both genders were single-peaked (m: 20–60 years, f: 70–80 years). This might be because the USEIR includes data of military personnel, which are obviously younger in age. In an older study in Germany, Schrader also found 84% male patients (male:female = 5.9:1) and only 9% of OGI in elderly patients, which might reflect worse work safety standards 20 years ago on the one hand [
11]. On the other, demographic change has also affected the incidence of OGI in elderly patients in Germany [
23,
24]. To the best of the authors’ knowledge this is the first study to clarify that male predominance has decreased in recent decades (male:female = 1.8:1). Based on the data presented here, a shifting of the first peak towards a higher second peak for both genders can be expected. Thus, one can expect to see increasing numbers of older patients with less male predominance.
The authors’ annual incidence rate for hospitalized OGI (per 100,000/year) of 0.8 was significantly lower compared to 3.7 in the US [
25], 3.1 in Israel [
26], 6.0 in Sweden [
10] and 12.6 in Singapore [
13]. Patients’ economic status and educational level were not evaluated. Both factors might impact the low incidence rate found in the current study.
Follow-up times showed great variance as most patients were referred to the authors’ tertiary center only for surgical treatment, and data supplied by ophthalmologists were incomplete in several patients. Reasons for loss of follow-up were death, relocation or change of treating ophthalmologist.
Mechanism of injury
In the present study, penetration by metal items had the best final visual outcome (
t-test,
p < 0.000), which occurred mostly in men (87.5%). In previous studies, metal objects were the main cause of injury in 32.4–72.7% [
27,
28]. Although metal items have been identified as the causative factor for posterior OGI in young men [
16], former studies have also reported that penetrating injuries resulted in better visual results [
27]. These findings suggest that visual outcome depends on the mechanism of injury as well as the material of IOFB. One possible reason might be that metal splinters tend to be sharp and perforate the cornea or sclera with less trauma. Depending on the velocity of the IOFB, the penetration depth results in varying damage. Although size of IOFB was not assessed in this study, previous studies have shown a strong correlation to final vision [
27,
29].
Women were frequently injured after syncopal episodes, which occurred exclusively at home or during leisure time activities. An increase in domestic OGI was also noted by Schrader in 2004. Domestic injury rates were found to be as high as 71% [
22,
30].
Work-related OGI occurred in 8.8% of cases, which is lower compared to other studies (34–49%) [
8,
10]. The incidence of work-related injuries might depend on working safety standards and socioeconomic factors not evaluated here. Gender imbalance in work-related injuries was striking in the current study. The authors did not find a single female patient with a work-related injury. This imbalance was also previously found by others [
8,
20].
The main mechanism of injury resulting in enucleation was rupture (75%). This was also shown by Savar and several other authors [
11,
15,
27,
31].
Risk factors
The actual existence of risk factors for poor visual outcome in OGI patients has been questioned by Page et al. [
12]. While many have acknowledged the existence of risk factors for poor visual outcome, others have rejected this.
In their study, the authors evaluated the following risk factors: location of injury, vitreous prolapse, pseudophakia at presentation and initial BCVA including NLP patients.
They found that radial scleral injury with or without eye muscle involvement had a significant impact on final visual outcome, which is in line with the previous literature [
14,
15,
27].
Furthermore, patients with or without vitreous prolapse (25% vs 75%) did not differ in visual outcome, although the former needed more surgical procedures, including vitrectomy.
The role of pseudophakia at presentation has been discussed with contradictory results [
27,
32]. While cataract surgery has evolved in recent decades, its leading role in eye ruptures has decreased due to the small self-sealing incisions used in modern cataract surgery from 40% of all OGI in 1985 [
11] to 10% in the present study.
In line with the previous literature, the data presented here outline pseudophakia as a risk factor for poor visual outcome. However, as the percentage of pseudophakia and the number of syncopal episodes and multimorbidity increase with age, this result might be biased.
Many previous studies have shown a correlation between initial BCVA to final BCVA [
7,
14,
25,
26,
28,
33]. However, the authors found a group of interest that had visual impairment after treatment (
n = 14). In general, the impairment was statistically non-significant (
t-test,
p = 0.09). Nevertheless, they want to point out the highly individual course which may result in a worse visual outcome. Of those 14 patients, four had endophthalmitis, three had only minimal visual impairment, which may be due to error in measurement, two had phthisis and two had retinal detachment. Three patients received only primary reconstruction due to age (>88 years) and multimorbidity.
Ocular Trauma Score and no light perception
The OTS was introduced as an alternative to predict the visual outcome of OGI patients. The authors showed a significant correlation between OTS and visual outcome. However, effective prediction of the outcome remains uncertain. Kuhn et al. stated that OTS 1 has a 75% probability to have NLP as final BCVA [
6]. In the authors’ dataset, only 22% of OTS 1 had NLP as final outcome. In addition, their data showed an improvement for 69% of all NLP patients up to a BCVA of 0.73 logMAR.
Therefore, they conclude that conventional risk factors and OTS are insufficient to guide whether or not to proceed with further therapy. They propose deciding on a case-by-case basis and performing therapy if socioeconomic circumstances permit.
In line with the authors’ results, Soni et al. found that NLP is a risk factor for poor visual outcome [
34]. NLP is often associated with severe ocular tissue destruction, including the retina or optic nerve. The current patient cohort did surprisingly well with 69% improving up to CF or HM. Han et al. reported that 11.1% reached a final BCVA of light perception or better [
35].
Therapy
Fig.
4 shows that after three surgeries, patients have no further improvement and reach a plateau vision of about 2 logMAR, which equals hand motion. Gursoy et al. found that number of surgeries did not have a significant effect on final BCVA [
36]. Therefore, surgical procedures should be considered especially with regard to patient age, condition and risk of general anesthesia.
A prospective randomized study would be preferable, but might fail due to low numbers or inhomogeneous patient characteristics.