Ocular trauma by kinetic impact projectiles during civil unrest in Chile.

BACKGROUND: The use of kinetic impact projectiles (KIPs) for crowd-control has increased worldwide. Despite having been created as non-lethal weapons, significant damage to several organs, including the eye, has been reported. In this study, we investigated cases of ocular trauma from KIPs during the civil unrest in Chile. To our knowledge, this is the largest case series recorded in international literature. METHODS: We included all patients who sought care or were referred to the Eye Trauma Unit, a national referral centre in Santiago, Chile, during the civil unrest from October 18 to November 30, 2019. We reviewed paper medical records and extracted data on suspected cause of trauma, type of trauma, visual acuity and sociodemographic data. RESULTS: We included 259 patients, out of which in 182 cases (70.5%) KIPs were the suspected cause. Cases by KIPs were predominantly male (86.6%), young (median age 26.3, interquartile range 22.0-31.4) and living in the Metropolitan Region. Eighty-nine patients (48.9%) had severe visual impairment or were blind at the first examination. The trauma was an open-globe injury in 20.3% of cases and 13 cases required evisceration of the ocular content. Compared to other causes of ocular trauma, KIPs were related to a more severe loss of visual acuity and a higher frequency of open-globe injuries. CONCLUSIONS: The use of KIPs during a period of civil unrest in Chile resulted in severe ocular trauma, visual impairment and permanent disability. KIPs should be avoided as a method of crowd-control.

Evidence of autophagic vesicles in a patient with Lisch corneal dystrophy / Evidência de vesículas autofágicas em paciente com distrofia corneana de Lisch

ABSTRACT Lisch corneal dystrophy is a rare corneal disease characterized by the distinctive feature of highly vacuolated cells. Although this feature is important, the nature of these vacuoles within corneal cells remains unknown. Here, we sought to analyze corneal cells from a patient diagnosed with Lisch dystrophy to characterize the vacuoles within these cells. Analyses using histopathology examination, confocal microscopy, and transmission electron microscopy were all consistent with previous descriptions of Lisch cells. Importantly, the vacuoles within these cells appeared to be autophagosomes and autolysosomes, and could be stained with an anti-microtubule-associated protein 1A/1B-light chain 3 (LC3) antibody. Taken together, these findings indicate that the vacuoles we observed within superficial corneal cells of a patient with Lisch corneal dystrophy constituted autophagosomes and autolysosomes; this finding has not been previously reported and suggests a need for further analyses to define the role of autophagy in this ocular disease.

RESUMO A distrofia corneana de Lisch é uma doença rara, caracterizada principalmente pela presença de células altamente vacuoladas. Embora esta característica seja importante, a natureza desses vacúolos dentro das células da córnea permanece des conhecida. Aqui, procuramos analisar as células da córnea de um paciente diagnosticado com distrofia de Lisch para caracte rizar os vacúolos dentro dessas células. Análises utilizando exame histopatológico, microscopia confocal e microscopia eletrônica de transmissão foram todas consistentes com descrições previas de células de Lisch. Importante, os vacúolos dentro dessas células pareciam ser autofagossomos e autolisossomos, e po deriam ser corados com um anticorpo proteico 1A/1B-cadeia leve 3 (LC3) da proteína anti-microtúbulo associado a microtúbulos. Em conjunto, esses achados indicam que os vacúolos observados nas células superficiais da córnea de um paciente com distrofia corneana de Lisch constituíram autofagossomos e autolisossomos. Esse achado não foi relatado anteriormente e sugere a necessidade de mais análises para definir o papel da autofagia nessa doença ocular.

Evidence of autophagic vesicles in a patient with Lisch corneal dystrophy.

Lisch corneal dystrophy is a rare corneal disease characterized by the distinctive feature of highly vacuolated cells. Although this feature is important, the nature of these vacuoles within corneal cells remains unknown. Here, we sought to analyze corneal cells from a patient diagnosed with Lisch dystrophy to characterize the vacuoles within these cells. Analyses using histopathology examination, confocal microscopy, and transmission electron microscopy were all consistent with previous descriptions of Lisch cells. Importantly, the vacuoles within these cells appeared to be autophagosomes and autolysosomes, and could be stained with an anti-microtubule-associated protein 1A/1B-light chain 3 (LC3) antibody. Taken together, these findings indicate that the vacuoles we observed within superficial corneal cells of a patient with Lisch corneal dystrophy constituted autophagosomes and autolysosomes; this finding has not been previously reported and suggests a need for further analyses to define the role of autophagy in this ocular disease.

In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy.

PURPOSE: Boston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED. METHODS: The corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range). RESULTS: Mean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485-1550) or 536 (464-650) µm and 32 (22-56) or 25 (15-34) µm, respectively. CONCLUSIONS: Corneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.

In vivo evaluation of the cornea and conjunctiva of the normal laboratory beagle using time- and Fourier-domain optical coherence tomography and ultrasound pachymetry.

OBJECTIVE: To obtain normative data for the canine cornea and conjunctiva using high-resolution time- and Fourier-domain optical coherence tomography (TD-OCT and FD-OCT) and ultrasound pachymetry (USP). ANIMALS: One hundred sixty-eight eyes of 133 healthy young intact laboratory beagles. PROCEDURES: The cornea and conjunctiva of 16 eyes of 8 healthy young intact female beagles were imaged using FD-OCT. Corneal thickness was measured with FD-OCT and USP, while corneal epithelial thickness and conjunctival epithelial thickness were measured with FD-OCT. The central corneal thickness (CCT) was determined in 152 eyes of 125 healthy young adult intact female (35) and male (90) beagles using TD-OCT. Mixed effects linear regression was used for statistical analysis. RESULTS: The CCT was (mean ± standard deviation) 497.54 ± 29.76, 555.49 ± 17.19, and 594.81 ± 33.02 µm as measured by FD-OCT, USP, and TD-OCT, respectively. The central, superior paraxial, superior perilimbal corneal epithelial thickness and superior bulbar conjunctival epithelial thickness were 52.38 ± 7.27, 56.96 ± 6.47, 69.06 ± 8.84 and 42.98 ± 6.17 µm, respectively. When comparing techniques used for measuring CCT (USP vs. FD-OCT and FD-OCT vs. TD-OCT), USP and TD-OCT generated significantly greater values in comparison with FD-OCT (both P < 0.001). For all dogs, CCT increased with increasing age and body weight (both P < 0.001) and was higher in intact males vs. females using TD-OCT (P = 0.034). CONCLUSION: High-resolution FD-OCT and TD-OCT provide detailed noninvasive evaluation of in vivo canine anterior segment structures. Normative values of the canine cornea and conjunctiva are reported.

In vivo ocular imaging of the cornea of the normal female laboratory beagle using confocal microscopy.

OBJECTIVE: To obtain normative data for the normal laboratory beagle cornea using high-resolution in vivo confocal microscopy (IVCM). ANIMALS STUDIED: Sixteen eyes of eight healthy young female intact beagles. PROCEDURES: The central cornea was imaged using IVCM. Mixed effects linear regression was used for statistical analysis. RESULTS: in vivo confocal microscopy allowed detailed visualization and quantification of epithelial cells (superficial epithelial cell diameter: 43.25 ± 6.64 µm, basal cell diameter: 4.43 ± 0.67 µm), and nerve fibers (subepithelial nerve fiber diameter: 2.38 ± 0.69 µm, anterior stromal nerve fiber diameter: 16.93 ± 4.55 µm). Keratocyte density (anterior stroma 993.38 ± 134.24 cells/mm(2) , posterior stroma 789.38 ± 87.13 cells/mm(2) ) and endothelial cell density (2815.18 ± 212.59 cells/mm(2) ) were also measured. CONCLUSION: High-resolution IVCM provides detailed noninvasive evaluation of the cornea in the normal laboratory beagle.

In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1µm swept source phase-variance optical coherence angiography.

We present nnnnnin vivo volumetric depth-resolved vasculature images of the anterior segment of the human eye acquired with phase-variance based motion contrast using a high-speed (100 kHz, 105 A-scans/s) swept source optical coherence tomography system (SSOCT). High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. The human corneo-scleral junction and sclera were imaged with swept source phase-variance optical coherence angiography and compared with slit lamp images from the same eyes of normal subjects. Different features of the rich vascular system in the conjunctiva and episclera were visualized and described. This system can be used as a potential tool for ophthalmological research to determine changes in the outflow system, which may be helpful for identification of abnormalities that lead to glaucoma.

Epithelial downgrowth after penetrating keratoplasty: imaging by high-resolution optical coherence tomography and in vivo confocal microscopy.

PURPOSE: To report the clinical utility of high-resolution anterior segment optical coherence tomography (AS-OCT) combined with in vivo confocal microscopy (IVCM) to diagnose and follow the effectiveness of treatment of 2 cases of epithelial downgrowth after penetrating keratoplasty. METHODS: A retrospective case review was performed on 2 eyes of 2 patients with a history of multiple penetrating keratoplasties that developed epithelial downgrowth 4 and 6 months after the most recent penetrating graft. At various time points, high-resolution AS-OCT images were obtained using the Spectralis (Heidelberg Engineering GmbH), and IVCM images were obtained using the Heidelberg Retina Tomograph III Rostock Cornea Module (Heidelberg Engineering GmbH). In 1 case, the diagnosis was confirmed by histopathologic evaluation. RESULTS: Two patients developed epithelial downgrowth after penetrating keratoplasty. In case 1, a 48-year-old man with a history of Acanthamoeba keratitis developed epithelial downgrowth after undergoing 2 therapeutic grafts over a 1-year period. In case 2, a 40-year-old man with a history of a corneal laceration complicated by fungal keratitis was diagnosed with epithelial downgrowth after undergoing 3 penetrating grafts, the placement of a glaucoma drainage device, and a pars plana vitrectomy over a 3-year period. In both cases, at the level of the endothelium, AS-OCT identified a highly reflective layer and IVCM revealed round hyperreflective nuclei consistent with epithelium. CONCLUSIONS: Epithelial downgrowth is an uncommon complication after penetrating keratoplasty. High-resolution AS-OCT and IVCM are noninvasive imaging modalities that may potentially be more sensitive in identifying and monitoring epithelial downgrowth than routine light biomicroscopy and may obviate the need for invasive diagnostic measures.

Three-dimensional anterior segment imaging in patients with type 1 Boston Keratoprosthesis with switchable full depth range swept source optical coherence tomography.

A high-speed (100 kHz A-scans/s) complex conjugate resolved 1 µm swept source optical coherence tomography (SS-OCT) system using coherence revival of the light source is suitable for dense three-dimensional (3-D) imaging of the anterior segment. The short acquisition time helps to minimize the influence of motion artifacts. The extended depth range of the SS-OCT system allows topographic analysis of clinically relevant images of the entire depth of the anterior segment of the eye. Patients with the type 1 Boston Keratoprosthesis (KPro) require evaluation of the full anterior segment depth. Current commercially available OCT systems are not suitable for this application due to limited acquisition speed, resolution, and axial imaging range. Moreover, most commonly used research grade and some clinical OCT systems implement a commercially available SS (Axsun) that offers only 3.7 mm imaging range (in air) in its standard configuration. We describe implementation of a common swept laser with built-in k-clock to allow phase stable imaging in both low range and high range, 3.7 and 11.5 mm in air, respectively, without the need to build an external MZI k-clock. As a result, 3-D morphology of the KPro position with respect to the surrounding tissue could be investigated in vivo both at high resolution and with large depth range to achieve noninvasive and precise evaluation of success of the surgical procedure.

High-resolution spectral domain anterior segment optical coherence tomography in type 1 Boston keratoprosthesis.

PURPOSE: To report the results of imaging using high-resolution, Fourier domain anterior segment optical coherence tomography (AS-OCT) to evaluate patients with a type 1 Boston Keratoprosthesis (KPro). METHODS: We performed a retrospective comparative study of patients in whom we implanted the Boston KPro. A total of 26 eyes of 23 patients from the Cornea Service at the University of California Davis Eye Center were included. Subjects were evaluated with the Spectralis AS-OCT (Heidelberg Engineering GmbH). RESULTS: Preoperative diagnoses for KPro surgery included failed corneal transplant (69%), chemical burn (23%), and aniridia (8%). The average age of patients was 63.2 years (range, 17-88 years). Fifty-four percent of the patients were female. The mean duration between the KPro surgery and the acquisition of high-resolution AS-OCT imaging was 35.8 months (range, 2-90 months). The most commonly observed finding was retroprosthetic membrane formation, which we found in 77% of KPro eyes. In 65% of KPro eyes, we identified epithelium behind the front plate, and in 54%, we identified an epithelial lip over the anterior surface of the KPro front plate. In 31% of KPro eyes, we identified periprosthetic cysts, gaps or spaces, and thinning in the corneal carrier graft. CONCLUSIONS: Fourier domain AS-OCT is a useful noninvasive imaging technique in patients with a KPro and provides the ability to identify changes that are sometimes difficult to appreciate by clinical evaluation. The higher resolution Fourier domain systems may aid in the clinical diagnosis and management of pathology that might not be imaged with instruments of lower resolution. AS-OCT has the potential for monitoring the anatomic stability of an implanted KPro and may also help to monitor for complications. Moreover, high-resolution imaging may enhance our understanding of periprosthetic anatomy.

Anterior segment OCT and confocal microscopy findings in atypical corneal intraepithelial neoplasia.

PURPOSE: To report a case of biopsy-proven corneal intraepithelial neoplasia (CIN) diagnosed and followed clinically using high-resolution anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM). METHODS: Observational case report. RESULTS: A 57-year-old man presented with decreased vision in the right eye for 2 months before presentation. His best-corrected visual acuity was 20/70 in the affected eye, and the slit-lamp examination revealed superficial opacification of the anterior cornea originating from the temporal limbus with a "leopard-spot" pattern more centrally. The lesion was excised at his 2-month follow-up, and the histological examination revealed squamous dysplasia consistent with CIN. Visual acuity improved, and the slit-lamp examination revealed barely visible residual disease at the temporal limbus. However, AS-OCT showed a thicker and highly reflective epithelial layer near the temporal limbus, similar to initial presentation, highlighting this residual disease. IVCM demonstrated dysplastic cells consistent with residual disease. Therefore, we treated the patient with topical interferon alpha-2b (1 million IU/mL) 4 times daily in the affected eye. At 3-month follow-up, the patient's best-corrected visual acuity was 20/20 in the affected eye with persistent but improved residual disease adjacent to the temporal limbus. In the mid-periphery of the inferonasal cornea, focal areas of iatrogenic linear scarring were confirmed to be limited to the anterior stroma by AS-OCT and IVCM at 6-month follow-up. CONCLUSIONS: AS-OCT and IVCM are noninvasive techniques that can be used to diagnose and aid in the management of CIN, which may present as subclinical disease through slit-lamp biomicroscopy alone.