Numerical and clinical analysis of an eyeball injuries under direct impact.

OBJECTIVES: The objective of this study was to develop a numerical model of the eyeball and orbit to simulate a blunt injury to the eyeball leading to its rupture, as well as to conduct a comparative analysis of the results obtained using the finite element method against the clinical material concerning patients who had suffered an eyeball rupture due to a blunt force trauma. MATERIAL AND METHODS: Using available sclera biometric and strength data, a numerical model of the eyeball, the orbital contents, and the bony walls were developed from the ground up. Then, 8 different blunt force injury scenarios were simulated. The results of numerical analyses made it possible to identify possible locations and configurations of scleral rupture. The obtained results were compared against the clinical picture of patients hospitalized at the Department of Ophtalmology, Medical University of Gdansk in 2010-2016 due to isolated blunt force trauma to the eyeball. RESULTS: It has been demonstrated that the extent of damage observed on the numerical model that indicated a possible location of eyeball rupture did not differ from the clinically observed configurations of the scleral injuries. It has been found that the direction of the impact applied determines the location of eyeball rupture. Most often the rupture occurs at the point opposite to the clock-hour/positions of the impact application. The eyeball rupture occurs in the first 7-8 ms after the contact with the striking rigid object. It has been established that the injuries most often affected the upper sectors of the eyeball. Men are definitely more likely to sustain such injuries. Eyeball ruptures lead to significant impairment of visual acuity. CONCLUSIONS: This study may contribute to a better understanding of injury mechanisms and better treatment planning. It may also contribute to the development of eyeball protection methods for employees exposed to ocular injuries. Int J Occup Med Environ Health. 2023;36(2):263-73.

Intra-operative scleral rupture during 23 gauge pars plana vitrectomy: a case report.

BACKGROUND: Use of perfluorocarbon liquid (PFCL) has been increasingly growing as an adjuvant in vitreo-retina surgeries. Some commonly encountered complications with its use include subretinal migration, formation of sticky silicone oil or retained PFCL in vitreous cavity and anterior chamber. Scleral rupture during PFCL injection has a rare occurrence. We report an unexpected event of scleral rupture during PFCL injection and discuss the management challenges faced by the surgeon. CASE PRESENTATION: A 66 year indo-aryan male was undergoing pars-plana vitrectomy (PPV) with diagnosis of subtotal rhegmatogenous retinal detachment (RD) with Proliferative Vitreo-retonipathy (PVR)-B. After near total vitrectomy PFCL was being injected and then there was sudden poor visualization of fundus with development of bullous RD and globe hypotony. The surgeon was not able to figure out the cause of hypotony and air was switched on in the infusion cannula. This further complicated the situation resulting in migration of air in the anterior chamber, posterior dislocation of intraocular lens complex, 180° inferior retinal dialysis and ballooning of the conjunctiva which gave a clue of probable scleral rupture. Conjunctival peritomy was performed superiorly and scleral defect was noted. Intraocular tissue incarceration and air leak was visible from the wound. This confirmed scleral rupture during PFCL injection. Repositioning of incarcerated retina was not possible and retinectomy was performed followed by repair of scleral rupture with lots of difficulty in a vitrectomised eye. CONCLUSION: PFCL injection, a crucial step of vitreoretina surgery, should be performed slowly with extreme caution maintaining an optimal intraocular pressure to prevent devastating complications like scleral rupture.

Patient creates filtering bleb: hypotony following traumatic rupture of an old scleral incision for intracapsular cataract surgery.

An 86-year-old woman presented with symptomatic hypotony on the left eye since a few weeks, blurry vision and a very sensitive eye. She had a history of bilateral intracapsular cataract extraction (ICCE) in 1982 and secondary intraocular lens implantation in 1988. The patient mentioned a fall on the left side of the head 6 months earlier. The diagnosis of a superior scleral fistula was made, confirmed by gonioscopy and anterior segment optical coherence tomography. Direct surgical repair of the fistula led to a favourable outcome. This case demonstrates the occurrence of symptomatic hypotony due to the traumatic creation of a scleral fistula with an inadvertent filtering bleb many years after ICCE, and the resolution of signs and symptoms after surgical repair. Conventional as well as contemporary modalities can be valuable in the assessment of such fistulae. Management depends on the clinical course and the mechanism and extent of fistulation.

Endophthalmitis after strabismus surgery: incidence and outcome in relation to age, operated eye muscle, surgical technique, scleral perforation and immune state.

PURPOSE: Identify risk factors for endophthalmitis after strabismus surgery (EASS) and relate these to incidence and outcome. METHODS: Ophthalmologists, who had operated, diagnosed or treated EASS, completed a case record form with 71 questions in six domains: Preoperative, Surgery, Perforation, Postoperative, Outcome and Experts' opinion. To estimate the age-specific incidence per number of strabismus operations in the Netherlands during 1994-2013, the age distribution of Dutch cases was compared with the age-specific rates of strabismus surgery in the Dutch Registry of Strabismus Operations and with population data. Exploratory data analysis was performed. The immune state was evaluated in six patients. Five enucleated eyes were studied histopathologically. RESULTS: None of the 26 patients (27 eyes with EASS) were between 9 and 65 years old, except for one patient with retinal haemorrhage followed by endophthalmitis. In the Netherlands during 1994-2013, the rate of EASS was approximately one per 11 000 strabismus operations, but one per 4300 for children aged 0-3 and one per 1000 for patients 65 and older. Endophthalmitis was diagnosed on postoperative day 1-4 in children aged 0-3. In all 15 children aged 0-5, the 16 affected eyes were phthisical, eviscerated or enucleated. The involved eye muscle had been recessed in 25 of 27 cases. It was a medial rectus in 15 of 16 children aged 0-6. It was a lateral (6), inferior (2) or medial (1) rectus in elderly. Scleral perforation went unnoticed in all children (no record in three) and in two of seven elderly (no record in two). Histopathology showed transscleral scarring compatible with scleral perforation in four patients but, in a two-year-old girl who had EASS together with a transient medial rectus palsy, the sclera underneath the former suture tract was not perforated but did contain the long posterior ciliary artery. CONCLUSIONS: Endophthalmitis after strabismus surgery (EASS) affects children and elderly, with a grave outcome in young children. It occurs after recession of the medial rectus muscle in children, and it may occur without scleral perforation. Age and perforation are key determinants that interact with other factors that determine the occurrence and fulminance of EASS.

Incidence and seasonality of major ocular trauma: a nationwide population-based study.

We designed this study to identify the epidemiological characteristics and trends of various types of ocular trauma in the population of the Republic of Korea. We conducted a nationwide, population-based, cross-sectional study using the Korean National Health Insurance claims database for January 2010 to December 2018. We compiled the monthly numbers of patients diagnosed with hyphema and those who received open reduction surgery due to orbital blowout fracture (BOF), primary closure of the cornea or sclera (PCCS), or intraocular foreign body (IOFB) removal. We obtained annual and monthly incidence rates, and differences according to age, sex, yearly trends, and seasonal variations. The incidence rate (per 100,000 person-years) was high in the order of hyphema (18.43), BOF (11.58), PCCS (1.99) and IOFB removal (0.39). Male predominance was evident in all types of major ocular trauma, but the age distribution varied with the type: hyphemas were most prevalent at 10-14 years of age, BOFs at 25-29 years of age, and open globe injuries (OGIs) at age 60 and older. Although all types of trauma showed significant seasonality, hyphemas (amplitude: 174.81) and BOFs (23.17) showed higher amplitudes compared to OGIs (PCCS: 11.96; IOFB removal: 6.72). While the incidence of blunt trauma injuries, including hyphemas and orbital BOFs, decreased steadily from 2010 to 2018, that of OGIs showed no remarkable change.

Self-sealing posterior scleral perforation in airgun ocular trauma, surgical tip: a case report.

BACKGROUND: Intraorbital metallic foreign bodies have varied clinical presentations. Here, we report the unusual case of intraoperative evidence of spontaneously healed posterior scleral perforation in a severe ballistic trauma without previous instrumental signs of penetrating wound and complete visual restoration after surgery. CASE PRESENTATION: The patient was hit by several lead hunting pellets in the chest, abdomen, limbs, face and orbit. Computed Tomography (CT) images revealed the presence of a pellet within the orbitary cavity, close to the optic nerve, with no signs of penetrating ocular wound. While performing vitrectomy for severe vitreous hemorrhage, a point of strong adherence between a old hemorrhage and retinal surface was identified and managed conservatively, as it was attributed to trauma related-impact area. So, lead foreign body took an unusual trajectory impacting the globe and finally lodging back in the deep orbitary cavity, in absence of significant ocular injury and with visual prognosis preservation. CONCLUSIONS: Our findings provide further information on orbital injuries from airguns, a theme of growing popularity and concern. Intraoperative recognition of hardly removable old hemorrhagic clot as self-blockage site of posterior scleral penetrating trauma, allowed for surgical stabilization and minimal solicitation of the area to avoid inadvertent perforation.

First report of traumatic scleral rupture after penetrating keratoplasty.

Globe rupture is a major postoperative complication after penetrating keratoplasty (PK). Because the corneal wound is never comparable with that of healthy corneal tissue, globe rupture following blunt trauma occurs at the corneal graft-host junction. In this study, we report a case of scleral rupture that arose from blunt trauma occurring after PK. A 60-year-old female presented with loss of vision, redness and pain in the left eye, which was the consequence of blunt trauma, was our case in this study. Slit-lamp examination revealed ecchymosis on the eyelids, diffuse subconjunctival hemorrhage and total hyphema. The donor cornea was intact. The right eye showed PK, the cornea was transparent, and the sclera was blue. A 2 mm rupture behind the limbus extending from 3 o'clock to 9 o'clock in the upper half of the sclera was observed during exploratory surgery. She did not report any coexisting medical conditions except for systemic hypertension. The differential diagnosis of the bluish discoloration of her sclera was investigated. In detailed anamnesis, the patient reported that she had been treated for severe allergic eye disease during childhood. Vernal keratoconjunctivitis complication was diagnosed. It should be kept in mind that closed scleral perforation may occur in the patient with PK and blue sclera due to blunt trauma.

Monocular elevation deficit after scleral perforation repair.

Monocular elevation deficit can result from either inferior rectus restriction, superior rectus palsy or from supranuclear causes. We report a case of monocular elevation deficit after scleral perforation repair which was managed by surgery on contra lateral eye. This improved elevation of the affected eye with no diplopia in the postoperative period.

Scleral surgical repair through the use of nanostructured fibrin/agarose-based films in rabbits.

Scleral defects can result as a consequence of trauma, infectious diseases or cancer and surgical repair with allogeneic scleral grafts can be required. However, this method has limitations and novel alternatives are needed. Here, the efficacy of acellular nanostructured fibrin-agarose hydrogel-based substitutes (NFAH) in the repair of scleral defects in rabbits was studied. For this, scleral defects of 5-mm diameter were made on 18 adult-male New Zealand rabbits and repaired with acellular NFAH, NFAH crosslinked with genipin (NFAH-GP) or glutaraldehyde (NFAH-GA), allogeneic scleral grafts as control (C-CTR) or not repaired (negative control N-CTR) (n = 3 each). Macroscopic and histological analyses were performed after 40-days. Macroscopy confirmed the repair of all defects in a comparable manner than the C-CTR. Histology showed no degradation nor integration in C-CTR while NFAH-GP and NFAH-GA biomaterials were encapsulated by connective and inflammatory tissues with partial biodegradation. The NFAH were fully biodegraded and replaced by a loose connective tissue and sclera covering the defects. This in vivo study demonstrated that the NFAH are a promising biocompatible and pro-regenerative alternative to the use of allogeneic cadaveric grafts. However, large defects and long-term studies are needed to demonstrate the potential clinical usefulness of these substitutes.

Optimal refinement of residents' surgical skills by training on induced goat's eye corneoscleral perforation.

Surgical skill enhancement for the residents under training can be performed through various efforts. Here in this report, the authors describe a technique of corneoscleral perforation repair on goat's eye, as the tissue resemblance and the reality of experience while performing crucial steps are similar to human eyes. Beginning from tissue handling, optimal suture placement was taught with an intention to impart quality techniques of traumatic globe injury repair. Therefore, rather than training on expensive artificial eye model, training budding surgeons on goat's eye gives much more realistic tissue handling experiences in the presence of constant challenges almost similar to human eyes.

Pathomechanism of traumatic indirect choroidal rupture.

The probable chain of events responsible for choroidal rupture is as follows. During high-speed orbital injuries, the protective ocular reflexes position the eye in an elevated, and abducted position. At this point in time, the anteroposterior compressive forces on to the globe create an eccentrically positioned circle of damaging currents along the posterior ocular coats against a relatively static optic nerve. Because of this eccentricity, a longer radius of curvature is expected to lie along the temporal half of the globe leading to an elastic recoil of the retinal and scleral layers and a fracture along the RPE-Bruch's-Choriocapillaris complex manifesting clinically as choroidal rupture.

Partial Scleral Rupture Presenting 4 Years After Laser in Situ Keratomileusis.

PURPOSE: To report a case of partial scleral rupture after laser in situ keratomileusis (LASIK) surgery. METHODS: This is a retrospective case report describing a late complication of LASIK surgery. RESULTS: A 32-year-old white woman with a history of LASIK surgery performed with a mechanical microkeratome 4 years previously presented for evaluation of partial bilateral scleral ruptures. An arcuate filtering bleb along the contour of the cornea was found on the right eye with associated hypotony and corneal astigmatism. There were no signs or symptoms of prior inflammation, and rheumatologic workup was negative. Imaging revealed scleral microbreaks in the absence of adjacent thinning. CONCLUSIONS: The pattern and location of thinning without findings consistent with inflammatory disease suggest that the partial bilateral scleral rupture was because of mechanical damage at the time of LASIK, possibly compounded by the hormonal changes of pregnancy.

Investigation of scleral thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration using pig eyes.

PURPOSE: The purpose of this study was to investigate the thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration (PPPEA) using pig eyes. METHOD: Using a 20-gauge (G) vitrectomy system (Accurus®, Fragmatome; Alcon Laboratories) in both the 'open-tip' and 'closed-tip' techniques, PPPEA was performed in pig eyes and the subsequent thermal injuries generated around the scleral wound were measured by infrared thermal imaging (thermography). Post surgery, the state of the scleral wound was observed under a microscope, and a tissue slice containing the scleral wound was then prepared and observed under an optical microscope. RESULTS: Thermography measurements revealed a slight temperature rise around the scleral wound in the open-tip case, yet a marked temperature rise in the closed-tip case. The scleral wound incision produced by the open tip was linear, while that produced by the closed tip was expanded. Histological examination revealed mild degeneration of the sclera around the wound in the open-tip case, yet marked tissue degeneration by thermal injuries in the closed-tip case. CONCLUSION: Our findings showed that in PPPEA, the temperature of the tip of a 20G vitrectomy system rapidly increases due to the closed-tip technique, thus producing obvious thermal damage to the scleral wound. In order to prevent thermal injuries to the scleral wound during PPPEA, it is important to shorten the time of ultrasonic oscillation during surgery as much as possible while the tip is occluded with nuclear fragments.

Incomplete scleral penetration of dexamethasone (Ozurdex) intravitreal implant.

Ozurdex (Allergan, Irvine, California, USA) is a biodegradable sustained release intravitreal implant containing 0.7 mg dexamethasone in a solid polymer drug delivery system. In the UK, it is approved for use in patients with macular oedema secondary to retinal vein occlusion, diabetic maculopathy and non-infectious uveitis. Although the implant is meant to be injected into the vitreous cavity, it can be inadvertently injected into the crystalline lens. This can also migrate into the anterior chamber, under altered anatomical conditions of the anterior segment. We report a case of incompletely penetrated dexamethasone implant, in a patient undergoing treatment for macular oedema secondary to retinal vein occlusion. The partially penetrated implant was managed conservatively with a good outcome.