The Utilization of Topical Insulin for Ocular Surface Diseases: A Narrative Review.

Various etiologies, including diabetic keratopathy (DK), dry eye disease (DED), and neurotrophic keratopathy (NK), can disrupt corneal homeostasis, exacerbating corneal epithelial defects. Topical insulin has emerged as a promising therapy for promoting corneal wound healing and addressing underlying pathologies. This review systematically evaluates the efficacy of topical insulin across different corneal disorders. A literature review was conducted across the PubMed, Google Scholar, and Scopus research databases. The search resulted in a total of 19 articles, consisting of clinical trials, retrospective studies, and case reports. In DK, topical insulin accelerates corneal wound healing post-vitreoretinal surgery with lower concentrations showing higher outcomes when compared to conventional therapy, possibly due to improved epithelial stem cell migration. In comparison, the dry-eye disease results are inconclusive regarding patient-reported outcomes and corneal staining. For NK, topical insulin accelerates corneal wound healing and restores corneal nerve sensation. Other persistent epithelial defect (PED) etiologies that have been treated with topical insulin are infection, immune-mediated, mechanical and chemical trauma, and chronic ocular surface alterations. Although individual mechanisms for the benefits of topical insulin for each of these etiologies have not been studied, the literature demonstrates that topical insulin is efficacious for PEDs regardless of etiology. Future clinical trials need to be conducted to further evaluate optimal dosing, duration, and use of topical insulin for the restoration of the corneal surface.

Estimating Cognitive Workload Using Task-Related Pupillary Responses in Simulated Drilling in Cochlear Implantation.

OBJECTIVES: Training of temporal bone drilling requires more than mastering technical skills with the drill. Skills such as visual imagery, bimanual dexterity, and stress management need to be mastered along with precise knowledge of anatomy. In otorhinolaryngology, these psychomotor skills underlie performance in the drilling of the temporal bone for access to the inner ear in cochlear implant surgery. However, little is known about how psychomotor skills and workload management impact the practitioners' continuous and overall performance. METHODS: To understand how the practitioner's workload and performance unfolds over time, we examine task-evoked pupillary responses (TEPR) of 22 medical students who performed transmastoid-posterior tympanotomy (TMPT) and removal of the bony overhang of the round window niche in a 3D-printed model of the temporal bone. We investigate how students' TEPR metrics (Average Pupil Size [APS], Index of Pupil Activity [IPA], and Low/High Index of Pupillary Activity [LHIPA]) and time spent in drilling phases correspond to the performance in key drilling phases. RESULTS: All TEPR measures revealed significant differences between key drilling phases that corresponded to the anticipated workload. Enlarging the facial recess lasted significantly longer than other phases. IPA captured significant increase of workload in thinning of the posterior canal wall, while APS revealed increased workload during the drilling of the bony overhang. CONCLUSION: Our findings contribute to the contemporary competency-based medical residency programs where objective and continuous monitoring of participants' progress allows to track progress in expertise acquisition. Laryngoscope, 2024.

The intracellular domain of Sema6A is essential for development of the zebrafish retina.

Semaphorin6A (Sema6A) is a repulsive guidance molecule that plays many roles in central nervous system, heart, and bone development, as well as immune system responses and cell signaling in cancer. Loss of Sema6A or its receptor PlexinA2 in zebrafish leads to smaller eyes and improper retinal patterning. Here we investigate a potential role for the Sema6A intracellular domain in zebrafish eye development and dissect which phenotypes rely on forward signaling and which rely on reverse signaling. We performed rescue experiments on zebrafish Sema6A morphants with either full-length Sema6A (Sema6A-FL) or Sema6A lacking its intracellular domain (Sema6A-ΔC). We identified that the intracellular domain is not required for eye size and retinal patterning, however it is required for retinal integrity, the number and end feet strength of Müller glia and protecting against retinal cell death. This novel function for the intracellular domain suggests a role for Sema6A reverse signaling in zebrafish eye development.

Attentional Bias, Pupillometry, and Spontaneous Blink Rate: Eye Characteristic Assessment Within a Translatable Nicotine Cue Virtual Reality Paradigm.

Background: Incentive salience processes are important for the development and maintenance of addiction. Eye characteristics such as gaze fixation time, pupil diameter, and spontaneous eyeblink rate (EBR) are theorized to reflect incentive salience and may serve as useful biomarkers. However, conventional cue exposure paradigms have limitations that may impede accurate assessment of these markers. Objective: This study sought to evaluate the validity of these eye-tracking metrics as indicators of incentive salience within a virtual reality (VR) environment replicating real-world situations of nicotine and tobacco product (NTP) use. Methods: NTP users from the community were recruited and grouped by NTP use patterns: nondaily (n=33) and daily (n=75) use. Participants underwent the NTP cue VR paradigm and completed measures of nicotine craving, NTP use history, and VR-related assessments. Eye-gaze fixation time (attentional bias) and pupillometry in response to NTP versus control cues and EBR during the active and neutral VR scenes were recorded and analyzed using ANOVA and analysis of covariance models. Results: Greater subjective craving, as measured by the Tobacco Craving Questionnaire-Short Form, following active versus neutral scenes was observed (F1,106=47.95; P<.001). Greater mean eye-gaze fixation time (F1,106=48.34; P<.001) and pupil diameter (F1,102=5.99; P=.02) in response to NTP versus control cues were also detected. Evidence of NTP use group effects was observed in fixation time and pupillometry analyses, as well as correlations between these metrics, NTP use history, and nicotine craving. No significant associations were observed with EBR. Conclusions: This study provides additional evidence for attentional bias, as measured via eye-gaze fixation time, and pupillometry as useful biomarkers of incentive salience, and partially supports theories suggesting that incentive salience diminishes as nicotine dependence severity increases.

The severity of dry eye symptoms and risk factors among university students in Saudi Arabia: a cross-sectional study.

Dry eye syndrome (DES) is a tear film disorder caused by increased tear evaporation or decreased production. The heavy workload on the eye and the increased usage of digital screens may decrease blink frequency, leading to an increased evaporation rate and an upsurge in the incidence and severity of DES. This study aims to assess the severity of DES symptoms and the risk factors among university students. A cross-sectional study was conducted at Umm AlQura University to evaluate the severity of DES among students and explore its potential association with digital screen use. Validated questionnaires were used to assess the severity of DES and digital screen usage. The study included 457 participants, of which 13% had symptoms suggestive of severe DES. Furthermore, multiple risk factors had a significant association with the severity of DES, including gender, use of monitor filters, monitor and room brightness, and smoking habits. DES symptoms were prevalent among university students, particularly female students. Although there was no significant association with the duration of screen usage and collage distribution. Other factors however, such as the usage of screen monitors and the brightness of both the monitor and the room, were significantly associated with the severity of DES symptoms.

Multifunctional Cerium Oxide Nanozyme for Synergistic Dry Eye Disease Therapy.

Dry eye disease (DED) is a chronic multifactorial ocular surface disease mainly caused by the instability of tear film, characterized by a series of ocular discomforts and even visual disorders. Oxidative stress has been recognized as an upstream factor in DED development. Diquafosol sodium (DQS) is an agonist of the P2Y2 receptor to restore the integrity/stability of the tear film. With the ability to alternate between Ce3+ and Ce4+, cerium oxide nanozymes could scavenge overexpressed reactive oxygen species (ROS). Hence, a DQS-loaded cerium oxide nanozyme was designed to boost the synergistic treatment of DED. Cerium oxide with branched polyethylenimine-graft-poly(ethylene glycol) as nucleating agent and dispersant was fabricated followed with DQS immobilization via a dynamic phenylborate ester bond, obtaining the DQS-loaded cerium oxide nanozyme (defined as Ce@PBD). Because of the ability to mimic the cascade processes of superoxide dismutase and catalase, Ce@PBD could scavenge excessive accumulated ROS, showing strong antioxidant and anti-inflammatory properties. Meanwhile, the P2Y2 receptors in the conjunctival cells could be stimulated by DQS in Ce@PBD, which can relieve the incompleteness and instability of the tear film. The animal experiments demonstrated that Ce@PBD significantly restored the defect of the corneal epithelium and increased the number of goblet cells, with the promotion of tear secretion, which was the best among commercial DQS ophthalmic solutions.

Exome sequencing identifies novel genes underlying primary congenital glaucoma in the National Birth Defects Prevention Study.

BACKGROUND: Primary congenital glaucoma (PCG) affects approximately 1 in 10,000 live born infants in the United States (U.S.). PCG has a autosomal recessive inheritance pattern, and variable expressivity and reduced penetrance have been reported. Likely causal variants in the most commonly mutated gene, CYP1B1, are less prevalent in the U.S., suggesting that alternative genes may contribute to the condition. This study utilized exome sequencing to investigate the genetic architecture of PCG in the U.S. and to identify novel genes and variants. METHODS: We studied 37 family trios where infants had PCG and were part of the National Birth Defects Prevention Study (births 1997-2011), a U.S. multicenter study of birth defects. Samples underwent exome sequencing and sequence reads were aligned to the human reference sample (NCBI build 37/hg19). Variant filtration was conducted under de novo and Mendelian inheritance models using GEMINI. RESULTS: Among candidate variants, CYP1B1 was most represented (five trios, 13.5%). Twelve probands (32%) had potentially pathogenic variants in other genes not previously linked to PCG but important in eye development and/or to underlie Mendelian conditions with potential phenotypic overlap (e.g., CRYBB2, RXRA, GLI2). CONCLUSION: Variation in the genes identified in this population-based study may help to further explain the genetics of PCG.

Whole-eye transplantation: Current challenges and future perspectives.

Whole-eye transplantation emerges as a frontier in ophthalmology, promising a transformative approach to irreversible blindness. Despite advancements, formidable challenges persist. Preservation of donor eye viability post-enucleation necessitates meticulous surgical techniques to optimize retinal integrity and ganglion cell survival. Overcoming the inhibitory milieu of the central nervous system for successful optic nerve regeneration remains elusive, prompting the exploration of neurotrophic support and immunomodulatory interventions. Immunological tolerance, paramount for graft acceptance, confronts the distinctive immunogenicity of ocular tissues, driving research into targeted immunosuppression strategies. Ethical and legal considerations underscore the necessity for stringent standards and ethical frameworks. Interdisciplinary collaboration and ongoing research endeavors are imperative to navigate these complexities. Biomaterials, stem cell therapies, and precision immunomodulation represent promising avenues in this pursuit. Ultimately, the aim of this review is to critically assess the current landscape of whole-eye transplantation, elucidating the challenges and advancements while delineating future directions for research and clinical practice. Through concerted efforts, whole-eye transplantation stands to revolutionize ophthalmic care, offering hope for restored vision and enhanced quality of life for those afflicted with blindness.

Efficacy of recombinant human epidermal growth factor plus sodium hyaluronate eye drops in diabetic dry eye post-cataract surgery.

BACKGROUND: Dry eye syndrome (DES) after diabetic cataract surgery can seriously affect the patient's quality of life. Therefore, effective alleviation of symptoms in patients with this disease has important clinical significance. AIM: To explore the clinical effect of recombinant human epidermal growth factor (rhEGF) plus sodium hyaluronate (SH) eye drops on DES after cataract surgery in patients with diabetes. METHODS: We retrospectively evaluated 82 patients with diabetes who experienced DES after cataract surgery at Tianjin Beichen Hospital, Affiliated Hospital of Nankai University between April 2021 and April 2023. They were classified into an observation group (42 cases, rhEGF + SH eye drops) and a control group (40 cases, SH eye drops alone), depending on the different treatment schemes. The thera-peutic efficacy, dry eye symptom score, tear film breakup time (TFBUT), basic tear secretion score [assessed using Schirmer I test (SIt)], corneal fluorescein staining (FL) score, tear inflammatory markers, adverse reactions during treatment, and treatment satisfaction were compared between the two groups. RESULTS: Therapeutic efficacy was higher in the observation group compared with the control group. Both groups showed improved TFBUT and dry eye, as well as improved SIt and FL scores after treatment, with a more pronounced improvement in the observation group. Although no marked differences in adverse reactions were observed between the two groups, treatment satisfaction was higher in the observation group. CONCLUSION: rhEGF + SH eye drops rendered clinical benefits to patients by effectively ameliorating dry eye and visual impairment with favorable efficacy, fewer adverse reactions, and high safety levels. Thus, this treatment should be promoted in clinical practice.

Percutaneous triamcinolone injection for upper eyelid retraction in thyroid eye disease.

Purpose: To evaluate percutaneous triamcinolone (TA) injection efficacy in treating upper eyelid retraction (UER) for Australian thyroid eye disease (TED) patients. Methods: We conducted a retrospective analysis across 8 years and multiple diverse Australian centres identified UER patients who received TA injections. A single operator administered 40mg/1ml TA through upper eyelid skin. Assessments at 4-6 weeks and subsequent eyelid measurements gauged treatment response and complications. Results: 24 patients and 25 eyelids were included in the study. 91.6% were female, mean age 40.8 ± 10.3 years with mean follow-up of 17.5 months (± 18.5). Pre-treatment MRD1 was 6.2mm ± 1.4, and we observed a mean improvement of 2.2mm from pre-treatment to post-treatment (p<0.001). The mean UER measurement before treatment (defined as MRD1 - 4.0mm) was 3.0mm ± 1.3 (range, 0-6mm). After treatment, the mean UER measurement was -0.1mm. Quality of life (QOL) assessment improved significantly, from pre-treatment score of 4.13 ± 2.4 to post-treatment 8.0 ±1.7 (p<0.001). Conclusions: Percutaneous injection of TA is an effective and safe treatment option for UER in patients with TED. This technique can be performed without upper eyelid eversion, which makes it more tolerable for patients and less complex for the operator compared to the transconjunctival injection approach. Our results show a significant improvement in MRD1 and UER, as well as patient QOL. Moreover, we found a low rate of complications (4.2% induced ptosis) and no cases of raised intraocular pressure. Percutaneous TA injection can greatly reduce the need for eyelid lowering surgery in this patient population.

[Graves' orbitopathy as the cause of diplopia in old age-Differences between young and old]. / Endokrine Orbitopathie als Ursache einer Diplopie im Senium ­ Unterschiede zwischen Jung und Alt.

BACKGROUND: Endocrine orbitopathy (EO) is an autoimmune disease mostly associated with a disease of the thyroid gland, which leads to inflammation, adipogenesis and fibrosis. The severity of EO can vary greatly between individuals, which makes it difficult to exactly predict the natural course of the disease; however, this is important to be able to individually adapt the treatment. The aim of this study was to compare the clinical features, course, treatment and prognosis for patients with EO under 50 years old with older patients. The results of the study with a focus on motility are presented in this special issue. PATIENTS AND METHODS: The hospital records of a randomly selected sample of 1000 patients from the EO databank in Essen (GODE), which includes 4260 patients, were analyzed. The patients were divided into two groups: group 1 ≤50 years and group 2 >50 years. Only patients with complete data sets were included in the statistical analyses. RESULTS: Younger patients (n = 484) presented significantly more frequently with milder EO (53% vs. 33%, p < 0.0001), whereas older patients (n = 448) more frequently suffered from moderate or severe forms (44% vs. 64%, p < 0.0001). Older patients showed more severe strabismus, motility and clinical activity scores (5.9 vs. 2.3 prism diopters, PD/310° vs. 330°, both p < 0.0001, CAS 2.1 vs. 1.7, p = 0.001). Proptosis and the occurrence of optic nerve compression showed no significant differences between the groups (3% each). Multiple logistic regression showed that the necessity for a second eye muscle surgery was most strongly associated with a previous decompression (OR = 0.12, 95 % CI 0.1-0.2, p < 0.0001), followed by orbital irradiation and age. CONCLUSION: In summary, younger patients with EO presented with milder clinical features, such as a lower rate of restrictive motility disorders and weaker expression of signs of inflammation. Therefore, older patients needed steroids, irradiation, eyelid and eye muscle surgery more frequently; however, the risk of dysthyroid optic neuropathy and the necessity of a second eye surgery were not or only slightly associated with age.

Effect of orbital decompression surgery on the choroidal profile in patients with thyroid eye disease.

This study aimed to investigate the effect of orbital wall decompression surgery and reduction of proptosis on the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in patients with thyroid eye disease (TED). Fifty-one eyes from 38 patients with controlled TED and proptosis were enrolled in this study. The majority of the patients (50.9%) had a clinical activity score (CAS) of zero, and none had a CAS greater than 2. The patients underwent a complete baseline ophthalmologic examination, and their choroidal profile alterations were monitored using enhanced depth imaging optical coherence tomography (EDI-OCT) before and during the three months after surgery. Changes in SFCT, luminance area (LA), total choroidal area (TCA), and the choroidal vascularity index (CVI) were measured as the ratio of LA to TCA in EDI-OCT images. The participants had an average age of 46.47 years, and 22 were female (57.9%). The SFCT of the patients exhibited a significant reduction over the follow-up period, decreasing from 388 ± 103 to 355 ± 95 µm in the first month (p < 0.001) and further decreasing to 342 ± 109 µm by the third month compared to baseline (p < 0.001). The CVI exhibited a drop from 0.685 ± 0.037 at baseline to 0.682 ± 0.035 and 0.675 ± 0.030 at 1 and 3 months post-surgery, respectively. However, these changes were not statistically significant, indicating comparable decreases in both LA and TCA. There was a significant correlation between improved proptosis and reduction in SFCT (p < 0.001) but not with CVI (p = 0.171). In conclusion, during the three months of follow-up following orbital wall decompression, CVI did not change, while SFCT reduced significantly. Additionally, SFCT was significantly correlated with proptosis reduction, whereas CVI was not.

Right eye metastasis of small­cell lung carcinoma: A case report.

The incidence of eye metastasis from primary malignant tumors is low. Predominantly, these primary malignant tumors consist of breast and lung carcinoma. Ocular metastatic carcinoma is often clinically overlooked. In clinical practice, it is rare for small-cell lung carcinoma (SCLC) to metastasize to the right eye. Early detection and treatment via the monitoring of clinical symptoms and auxiliary examinations of the eye are of great significance in preserving the patient's vision and improving their quality of life. Such treatments include radiotherapy or enucleation of the eyeball. A 54-year-old male patient with SCLC experienced a decline in vision and blurred vision during his systemic treatment using combined enverolumab and etoposide and cisplatin. Upon examination, including fundus photography, ocular B-scan and magnetic resonance imaging, a right eye metastasis was suspected. Within a short period of time, the patient experienced significant pain and blindness in the right eye, which required surgical removal of the right eyeball. Postoperative pathology confirmed metastasis. After six cycles of treatment, the primary lesion in the lung reduced in size. By reporting this case of SCLC metastasis to the right eye, we aim to provide a reference for the clinical diagnosis and treatment of ocular metastatic carcinoma.

Peripheral Cellular Immune Responses Induced by Subretinal Adeno-Associated Virus Gene Transfer Can Be Restrained by the Subretinal-Associated Immune Inhibition Mechanism.

After more than two decades of basic research and preclinical studies, adeno-associated virus (AAV)-mediated gene transfer has been tested successfully in clinical trials to treat inherited retinal diseases. Despite the eye's immune-privileged status, some patients display inflammatory events requiring the use of corticoids as an adjunct treatment which led us to question the immune consequences of a subretinal AAV administration. We first characterized anti-transgene immune responses induced in the periphery by injecting increasing doses of AAV8 encoding reporter proteins fused with the HY male antigen into the subretinal space of female C57BL/6 and rd10 mice. Transgene expression was monitored over time with bioluminescence imaging, and T cell immune responses in the spleen were analyzed by IFNγ ELISpot and cytokine multiplex assays. Our data show that AAV8 injections cause pro-inflammatory T cell immune response against the transgene product correlated with the transgene expression level at 2.109 vg and above. In addition, co-injection of immunodominant peptides from the transgene product, along with AAV8, modulates the immune response at all AAV doses tested. Taken together, our data suggest that injection of AAV8 in the subretinal space induces pro-inflammatory peripheral T cell responses to the transgene product that can be modulated by the subretinal-associated immune inhibition mechanism.

Risk factors affecting the utilization of eye care services evaluated by the CDC's behavior risk factor surveillance system from 2018 to 2021.

When thinking about major health concerns in the U.S. and around the world, eye care ranks lower compared to cardiovascular disease, cancer, and diabetes. However, people do not think about the direct connection between diabetes and eye health. Untreated diabetes can lead to visual impairments such as blindness or difficulty seeing. Studies have found that eye health associated with nutrition, occupational exposure, diabetes, high blood pressure, and heart disease are some of the known risk factors. This study aimed to identify the potential risk factors that are associated with visual impairment (VI). The data used for this analysis were obtained from the Centers for Disease Control and Prevention (CDC) - Behavioral Risk Factor Surveillance System (BRFSS) from 2018 to 2021. We found important characteristics, such as the U.S. region, general health perception, employment status, income status, age, and health insurance source, that are associated with VI. Our study confirmed that the common demographical factors including age, race/ethnicity, the U.S. region, and gender are associated with VI. The study also highlights associations with additional risk factors such as health insurance source, general health perceptions, employment status, and income status. Using this information, we can reach out to communities with large numbers of individuals experiencing vision challenges and help educate them on prevention and treatment protocols, thereby effectively addressing VI and blindness challenges within our communities, neighborhoods, and finally, the broader society.

Post-refractive Surgery Dry Eye: A Systematic Review Exploring Pathophysiology, Risk Factors, and Novel Management Strategies.

Dry eye disease frequently manifests following corneal refractive procedures, significantly impacting patients' quality of life. This review systematically synthesizes current evidence on the pathophysiological mechanisms, risk factors, and therapeutic interventions for post-refractive surgery dry eye. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of literature published until August 2023 was conducted, focusing on post-refractive surgery dry eye. Eighteen relevant studies were identified through screening and eligibility assessment. A qualitative synthesis of outcomes was performed using narrative and thematic analysis methods. Surgically induced neurotrophic deficiency, stemming from nerve transection, triggers a cascade of events including apoptosis, inflammation, and lacrimal dysfunction, ultimately leading to tear film instability. Risk factors such as female gender, thyroid eye disease, meibomian gland dysfunction, higher ablation depths, and the use of LASIK over surface ablation exacerbate the condition. While conventional treatments like artificial tears provide temporary relief, emerging interventions such as nerve growth factors, matrix metalloproteinase inhibitors, serum eye drops, and specialized contact lenses show promise in promoting nerve regeneration and epithelial healing. Strategies such as customized ablation profiles, smaller optical zones, and nerve-sparing techniques like small incision lenticule extraction demonstrate potential advantages. A multifaceted therapeutic approach targeting neuroprotection, anti-inflammatory mechanisms, and tear film stabilization is imperative for effectively managing post-refractive surgery dry eye. Future research should focus on evaluating prognostic biomarkers, exploring precision medicine approaches, and investigating neuroprotective adjuvants to further enhance treatment outcomes.

Sicca syndrome/Sjögren's disease associated with cancer immunotherapy: a narrative review on clinical presentation, biomarkers, and management.

INTRODUCTION: Almost one-quarter of immune checkpoint inhibitor (ICI) recipients experience sicca syndrome, while Sjögren's disease (SjD) is estimated at 0.3-2.5%, possibly underreported. AREAS COVERED: This narrative review (Medline/Embase until January/31/2024) addresses the pathophysiology, incidence, demographic/clinical features, biomarkers, labial salivary gland biopsy (LSGB), fulfillment of the idiopathic SjD (iSjD) classificatory criteria, differential diagnosis, and management of sicca syndrome/SjD associated with ICIs. EXPERT OPINION: SjD associated with ICIs is underdiagnosed, since studies that performed the mandatory SjD investigation identified that 40-60% of patients with sicca syndrome associated with ICIs meet the iSjD classificatory criteria. LSGB played a fundamental role in recognizing these cases, as most of them had negative anti-Ro/SS-A antibody. Despite the finding of focal lymphocytic sialoadenitis in LSGB samples mimicking iSjD, immunohistochemical analysis provided novel evidence of a distinct pattern for sicca syndrome/SjD associated with ICIs compared to iSjD. The former has scarcity of B lymphocytes, which are a hallmark of iSjD. Additionally, patients with sicca syndrome/SjD associated with ICIs have demographical/clinical/serological and treatment response dissimilarities compared to iSjD. Dryness symptoms are more acute in the former than in iSjD, with predominance of xerostomia over xerophthalmia, and partial/complete response to glucocorticoids. Dryness symptoms in ICI-treated patients warrant prompt SjD investigation.

Robot-assisted system for non-invasive wide-range flexible eye positioning and tracking in particle radiotherapy.

Particle (proton, carbon ion, or others) radiotherapy for ocular tumors is highly dependent on precise dose distribution, and any misalignment can result in severe complications. The proposed eye positioning and tracking system (EPTS) was designed to non-invasively position eyeballs and is reproducible enough to ensure accurate dose distribution by guiding gaze direction and tracking eye motion. Eye positioning was performed by guiding the gaze direction with separately controlled light sources. Eye tracking was performed by a robotic arm with cameras and a mirror. The cameras attached to its end received images through mirror reflection. To maintain a light weight, certain materials, such as carbon fiber, were utilized where possible. The robotic arm was controlled by a robot operating system. The robotic arm, turntables, and light source were actively and remotely controlled in real time. The videos captured by the cameras could be annotated, saved, and loaded into software. The available range of gaze guidance is 360° (azimuth). Weighing a total of 18.55 kg, the EPTS could be installed or uninstalled in 10 s. The structure, motion, and electromagnetic compatibility were verified via experiments. The EPTS shows some potential due to its non-invasive wide-range flexible eye positioning and tracking, light weight, non-collision with other equipment, and compatibility with CT imaging and dose delivery. The EPTS can also be remotely controlled in real time and offers sufficient reproducibility. This system is expected to have a positive impact on ocular particle radiotherapy.

Microbiological screening of corneas stored in organ culture medium at Lions Eye Bank of Western Australia from 2011 to 2022.

PURPOSE: The purpose of this study was to analyse the contamination rate of corneal samples stored in OCM at Lions Eye Bank of Western Australia over a 12-year period. METHODS: All OCM samples used to preserve corneas from 2011 to 2022 (inclusive) underwent microbiological testing. Samples were collected into aerobic and anaerobic culture bottles on day 3-5 of corneal preservation and 24 h after transfer to thinning medium. Samples were tested for 7 days using the BACTEC FX system. Corneas remained in quarantine until clearance was obtained. RESULTS: From 2011 to 2022, 3009 corneas were retrieved and 2756 corneas were stored in OCM. Thirty one (1.1%) positive samples were reported, with 20 growths of bacterial origin and 11 fungal. Microbial contamination was mostly identified on day 1 of culture (77.5%). Donors of contaminated samples had a mean age of 55 years, with 17 male and 14 female donors. The highest incidence of contamination came from donors whose cause of death was cancer. Death to enucleation times of contaminated samples ranged from 3.5 to 25.5 h (mean = 13.5 ± 7.3) and death to preservation time ranged from 4.1 to 27.5 h (mean = 14.8 ± 7.2). These did not significantly differ from the average time from death to enucleation (mean = 13.9 ± 3) and death to preservation (mean = 16.3 ± 4.2) of non-contaminated samples. CONCLUSION: Microbiological screening of corneas stored in OCM at LEBWA showed a very low rate of positive cultures with no predictive donor characteristics.