Closed globe and adnexal eye injuries: Epidemiology, clinical and surgical outcomes, and an economic cost analysis

To examine the epidemiology, visual outcomes, surgical interventions, and socioeconomic costs of closed globe (CGI) and adnexal injuries.

K E Y W O R D S closed globe and adnexal injuries, epidemiology, indirect costs, non-perforating mechanical trauma, ocular trauma 1 | INTRODUCTION Ocular trauma remains a leading cause of preventable visual impairment and blindness. [1][2][3] As a subset of ocular trauma, closed globe injuries (CGI) refers to a contusion or partial thickness, nonpenetrating, wound of the globe. 4 CGI represents a prevalent cause for hospital presentations due to its association with work or sporting activities. 5,6 The blunt impact force in CGI can lead to coup and contrecoup injuries with resulting posterior segment sequelae associated with poor visual outcomes. [7][8][9][10] Adnexal and associated injuries, such as retrobulbar haemorrhage, orbital fracture, and eyelid laceration with canalicular involvement, frequently occur concomitantly with CGI and these warrant study given the potential for complications necessitating emergent or surgical management. 11 However, while open globe injuries have been more comprehensively examined in the literature, [12][13][14][15][16][17][18][19] there remains a paucity of studies investigating the epidemiology and variables predictive of visual and surgical outcomes in adult CGI. 11,[20][21][22][23][24][25] Recently, the Revised Globe and Adnexal Trauma Terminology as part of the International Globe and Adnexal Trauma Epidemiology Study (IGATES) has been published, 26,27 which updates the widely accepted Birmingham Eye Trauma Terminology (BETT). 4 To our knowledge, this revised IGATES classification system has not been studied in a cohort of CGI.
From a public health perspective, it is important to understand the current incidence of CGI in at-risk populations who may benefit from prevention programs. 3,14,28 Furthermore, evaluation of the economic burden of CGI to patients, healthcare systems and society is lacking with limited reports from the United States, 29,30 Europe, 31,32 and Australia. 33,34 The annual cost of open globe injuries in Australia was estimated to be AUD48.1-60.5 million (USD37.3-47.0 million) in 2019, 14 but there has been no similar dedicated analysis of CGI for over 25 years. 33 Updated economic analysis is vital to characterise the burden of CGI and determine the cost-effectiveness of implemented public health strategies. 32 This study aimed to fill these knowledge gaps by examining CGI at a major tertiary referral trauma centre over an 11-year period. Specifically, this report investigated the epidemiology of at-risk populations, applied the Revised Globe and Adnexal Trauma Terminology, examined visual and surgical outcomes, and provided an economic analysis that estimated the medical and societal burden of CGI.

| METHODS
A retrospective review of 529 CGI was conducted following exclusion of 55 records (37 concomitant open globe injuries and 18 incomplete records). This study population consisted of consecutive CGI managed at Westmead Hospital between January 2011 and December 2021, identified using the International Classification of Diseases (10th revision, Australian Modification). Westmead Hospital is a 975-bed tertiary trauma and ophthalmic referral centre in Sydney, Australia, which serves 1.1 million people. All patients were 16 years or older. Injuries may have occurred in isolation or as part of systemic trauma. Approval was obtained from the Western Sydney Local Health District Human Research Ethics Committee (Proposal 2204-04) and the tenets of the Declaration of Helsinki were adhered to.
Demographic, injury, visual, and surgical data at presentation and follow-up visits were collected and entered into a computerised database using a standardised tool based on the IGATES 27 and United States Eye Injury Registry. 35 Best-corrected visual acuity (BCVA) was recorded in Snellen format and categorised into five groups (≥6/12, 6/15-6/60, 6/120 to count fingers [CF], hand movements [HM] to light perception [LP], and no light perception [NLP]), and then converted to logarithm of the minimum angle of resolution (logMAR) for analysis. LogMAR values of 1.8, 2.3, 2.8 and 3 denoted CF, HM, LP and NLP, respectively. 36 To standardise terminology, all CGI were classified using the Revised Globe and Adnexal Trauma Terminology from the IGATES. 26,27 The zone of injury was defined by the most posterior anatomical aspect affected following the Ocular Trauma Classification Group (Zone I: external, with involvement limited to bulbar conjunctiva, sclera, or cornea. Zone II: structures in the anterior segment to the posterior lens capsule, including the pars plicata. Zone III: one or more of the remaining posterior segment structures). 37 The presence of adnexal or associated injuries was recorded.
The hospital costs were divided into direct and indirect medical costs. Direct medical costs were determined using official Australian figures for the cost per hospitalisation day, per hour of theatre operation, and per outpatient follow-up visit. 38,39 Indirect medical costs were calculated using previously published methods. 14,33 Direct societal costs were defined as lost earnings (working time), occupational absenteeism, and workers' compensation, and were calculated using the average annual full-time earnings from the Australian Bureau of Statistics, 40 Australian absenteeism data, 41 and Safe Work Australia reports. 42,43 The estimated national cost of CGI was derived using the calculated incidence rate. All costs were listed in Australian Dollars (AUD) and inflation adjusted according to the 2021/22 Consumer Price Index from the Reserve Bank of Australia. 44 The costs were then converted to United States Dollars (USD) using an exchange rate of AUD1.00 = USD0.78 to allow for comparison to a previous publication. 14 Statistical analyses were conducted using IBM SPSS Statistics for Windows version 28. Descriptive statistics were performed for all variables, and normality was determined using the Shapiro-Wilk test. The Wilcoxon signed-rank test was used to compare the median presenting and final BCVA values. Demographic, clinical, and surgical data were included in logistic regression models to examine their effects on dichotomised final visual outcome (6/60 and better vs. worse than 6/60) and number of operating theatre visits (0 vs. greater than 1). The odds ratio (OR) and 95% confidence intervals (95% CI) were estimated in these models, and a p value <0.05 was considered statistically significant. Statistically significant factors were analysed using multivariable logistic regression models. Table 1 presents the demographics, injury details, classification, and zone of injury in the CGI. The annual incidence of CGI in our population was 4.4 per 100 000 person-years. CGI affected younger and working-age individuals (median age 42 years), with a male predominance (3:1 male to female). Figure 1 illustrates the bimodal distribution observed in males and the third peak in older females.

| RESULTS
A bimodal distribution was observed in males (peaks at 21-30 and 31-40) and a third peak in females (21-30, 41-50 and 71-80). The median age was 42 (interquartile range 29-61), range 16-98. According to the Revised Globe and Adnexal Trauma Terminology, contusions were the most common (82.6%), followed by lamellar lacerations (17.0%), lens (5.5%), and severe adnexal injuries (4.7%). Foreign bodies were observed in 41 CGI (7.8%), with the most common materials being metal (58.5%) and glass (17.1%). The most prevalent location of CGI occurrence was in the home (32.5%) and affected more females (57.9% vs. 19.8%). Falls were responsible for more than half of the CGI in the home (52.3%) and predominantly affected the older population (median age, 75 years). Just over a quarter of the CGI was intentional (143 assaults and self-inflicted), and almost all sustained a concomitant adnexal or associated injury (88.1%). In the CGI due to assault, 70.6% were male and 58.5% reported substance use. Of the 42 women who suffered a CGI from assault, 24 occurred in the home, which contrasts with males (57.1% vs. 13.9%), where the most common location was a public building (43.6%). Over a fifth (21.1%) of CGI cases were work-related and almost exclusively occurred in males (89.1%). The occupations most affected were construction, metal workers, and agriculture. Eye protection was not worn in 89.1% of the 92 work-related injuries. Sports-related CGI comprised 9.6% of our cohort (92.2% males) with the most common sports being cricket (23.5%), badminton (13.7%), and soccer (11.8%). Mirroring work injuries, compliance to eye protection was extremely low, with only one (2.0%) wearing eye protection, while two wore spectacles (3.9%). Table 2 presents the affected anatomical regions and demonstrates that a high proportion of CGI (71.5%) had concurrent adnexal or associated injuries. The most common were periorbital haematoma (56.1%), eyelid laceration (20.8%, and 5.9% involving the lid margin), facial haematoma or laceration (18.5%), orbital involvement (12.5%), and facial fracture (10.2%). The orbital floor was the most frequently fractured site (12.5%), and retrobulbar haemorrhage was observed in 24 patients (4.5%). In terms of ocular involvement, anterior structures were affected in 71.1%, with conjunctival laceration in 15.7%, hyphaema in 11.3%, and lens injury in 5.5% of cases. Posterior structures were affected in 17.2% of cases, with commotio retinae in 10.6%, vitreous haemorrhage in 5.9%, and traumatic optic neuropathy in 1.7%.
The socioeconomic analysis of the CGI in our study and the predicted annual costs for Australia are presented in Table 7. The total hospital cost was AUD12.7 million (USD9.9 million), an average of AUD24 000 (USD19 000) per CGI. Direct medical costs (hospitalisation days, operating theatre visits, and outpatient followup visits) amounted to AUD4.2 million (USD3.3 million), while indirect costs (administration, health records technology, vision aids, human resources, and capital expenses) were estimated at AUD8.5 million (USD 6.6 million). Direct societal costs for the individual (lost working time, occupational absenteeism, and workers' compensation) were estimated to range from AUD8.1 to 23.3 million (USD6.3-18.2 million), an average of AUD15 000-44 000 (USD12 000-34 000) per CGI (based on a range from 2022 Safe Work Australia reports). 42,43 Therefore, hospital and direct societal costs for our study cohort equated to AUD20.8-32.1 million (USD16.2-25.0 million), an average of AUD39 000-61 000 (USD30 000-48 000) per CGI. When the calculated incidence rate is applied to the population of Australia, 45 an estimated 1131 CGI are managed in the hospital system annually in Australia. This equates to a total estimated annual cost of AUD44.5-77.0 million (USD34.7-60.1 million).

| DISCUSSION
This study provides a comprehensive examination of the epidemiology, visual outcomes, surgical interventions, and socioeconomic burden of 529 consecutive CGI over an 11-year period. Young and working-age males were disproportionately affected by CGI sustained during work, sports, or assault. The age distribution of injuries was consistent with patterns in open globe injuries in Australia. 14 Cricket, badminton, and soccer were the most common ocular sport injuries in our cohort, in contrast to previous studies that have shown Australian rules football, rugby, and horseback riding to be frequent. 3,5 Critically, eye protection was not worn in almost all work-and sport-related injuries (10.9% and 2%, respectively). This is an extremely concerning finding and is consistent with global studies that call for strengthening of guidelines and public policy to reduce preventable blindness. 28,46,47 Barriers to eye protection include availability, cost, lack of safety regulations, or devices of inappropriate design or use for the task. 48  variable, less strictly mandated, and demonstrated lower compliance rates. 47,49,50 Importantly, regular spectacles and even, over-the counter, protective glasses may offer inadequate levels of resistance and lens thickness, and may introduce a secondary hazard if they shatter upon impact. 47,49 Therefore, education to highlight the potential for injury and recognition of risks for sport participants and organisers, improving social acceptance, and mandating the use of appropriate eye protection are essential, and will likely further reduce the frequency and severity of CGI. 22,49 In the United States, monetary penalties for employers for negligence or occupational violations have successfully reduced the incidence of ocular injury in the United States. 51 In 1995, an Australian study demonstrated that cost savings of AUD59.0 million (AUD108.0 million 2021/2022 CPI, USD84.2 million) would be achieved annually by correct eye protection use in occupational and sporting activities. 6 Therefore, the pursuit of harm minimisation via eye protection is not only cost effective but socially important, particularly given that up to 90% are preventable and the consequences T A B L E 2 Affected ocular and adnexal anatomy, and associated injuries in closed-globe injuries (n = 529).

Category Value
Ocular a , n (%) of long-term visual impairment or blindness in a young working-age population is significant. 28,32 One of the main barriers in the research of eye injuries is the clinical heterogeneity and feasibility of a prospective clinical trial. 46 In this context, clinical registries have an important role to document the real-world outcomes in such a mixed cohort of patients. 27 Beyond documenting clinical outcomes and trends in injury patterns, it would enable identification of organisations or occupations with a higher frequency of injury where further attention may be directed to enhance training, regulation or penalties. 32 This study also revealed a surprising proportion of CGI that did not have adequate documentation of key clinical examination findings (such as BCVA, pupils, RAPD and IOP) on presentation. Several factors in a trauma setting like the clinical urgency, fear of exacerbating an injury, time constraints, multiple competing tasks, familiarity with the examination, or availability of equipment may have posed barriers to complete documentation. 5,6 Furthermore, relatively minor cases may have been managed without formal ophthalmic review, while severe adnexal or systemic injuries generally required admission under the plastics, maxillofacial or trauma surgical teams. This is a pertinent finding as a high frequency of adnexal and associated injuries were observed (71.5%), and the literature has reported that up T A B L E 3 Best-corrected visual acuity of patients with closedglobe injuries at presentation and final follow-up (n = 395).

Best-corrected visual acuity
Presentation, n (%) Final, n (%) to 16% of patients with systemic trauma and 55% with facial fractures had ocular or orbital involvement, 11 with facial fractures increasing the risk of concomitant ocular injury by almost seven times. 52 Interestingly, eye injuries are more likely to occur in mild or moderate orbital trauma, 10 which commonly occurs as a result of assault or sport. 3 Therefore, this study highlights the need for ongoing education of clinical staff on these vital components of a comprehensive ophthalmological examination to ensure that ocular injuries are not overlooked. Furthermore, it highlights the role of a structured clinical tool such as the one found in the IGATES registry, which can assist in providing streamlined guidance to ensure these components are completed and adequately documented in stressful clinical situations. 13,27,53 Few studies have thoroughly analysed the economic costs of CGI. A 1-year study from 2002 to 2003 in Croatia of 3755 non-hospitalised cases reported a total cost of EUR210 872 (USD226 054). 32 In a 2011-2012 study of 1151 patients in Southern Finland reported a cost of EUR5.6 million (USD6.0 million) per 1 million people, though Finland's healthcare costs are recognised to be lower than other developed countries. 31 In a 6-month US study in 1985, which excluded orbital and facial fractures, an annual direct and indirect cost of USD5.0 million was reported. The present study calculated a total cost of AUD20.8-32.1 (USD16.2-25 million) for 529 hospitalised and non-hospitalised closed globe and adnexal injuries over 11 years and estimated an annual cost of AUD44.5-77 million (USD 34.7-60.1 million) in Australia. This included AUD8.1-23.3 million (USD6.3-18.2 million) of direct societal costs to account for lost productivity, occupational absenteeism, and worker's compensation. In addition, eye injuries may cause significant psychological impacts, with a previous study reporting that 45% of patients were diagnosed with either post-traumatic stress disorder, generalised anxiety disorder, or major depression using standardised mental health questionnaires. 54 When combined with a published study by the authors using a similar methodology that estimated the cost of open globe injuries to be AUD48.1-60.5 million, 14   larger with 185 500 more jobs created in the absence of work-related injuries and illnesses. 42 This highlights that the prevention of eye and adnexal injuries should be a priority area for healthcare professionals, their organisations, and governments to not only benefit the patient, but also society and the economy. This study has several limitations. The number of CGI identified in this study is likely an underestimation, as certain cases may not have presented to a tertiary centre but rather to primary care, private ophthalmology, optometry, or not sought professional healthcare. In addition, hospital databases are more likely to capture CGI that occur concomitantly with systemic and adnexal injuries, but these may also prolong the admission duration beyond what would be required for an isolated ocular injury. Finally, although we have utilised robust and official Australian economic data to calculate the hospital and direct societal costs, it is a conservative estimate of the true cost of CGI, given the difficulties in accurately estimating many societal costs. This includes long-term psychological impacts, presenteeism, early retirement or the need to change careers, welfare expenses, and the training of new staff. 14,22,42 In summary, CGI represents a prevalent preventable cause of eye injuries that impose a significant burden on patients, the workforce, and the economy. Therefore, it is imperative for vision health professionals to advocate and work collaboratively with organisational bodies and T A B L E 7 Socioeconomic cost analysis of closed globe injuries: Hospital (direct and indirect medical) and direct societal costs.