Optimization of individualized faricimab dosing for patients with diabetic macular edema: Protocol for the SWAN open-label, single-arm clinical trial.

PURPOSE: In patients with diabetic macular edema (DME) from YOSEMITE/RHINE, dual angiopoietin-2/vascular endothelial growth factor-A (VEGF-A) inhibition with faricimab resulted in visual/anatomic improvements with extended dosing. The SWAN trial (jRCTs031230213) will assess the efficacy, durability, and safety of faricimab during the treatment maintenance phase in patients with DME using a treat-and-extend (T&E)-based regimen adapted to clinical practice and the characteristics of patients achieving extended dosing intervals. METHODS: SWAN is a 2-year, open-label, single-arm, interventional, multicenter trial enrolling adults with center-involving DME. All patients will receive three initial faricimab 6.0 mg doses every 4 weeks (Q4W). From week 12 onwards, in patients without active DME, dosing intervals will be extended in 8-week increments up to Q24W. In contrast, patients with active DME (central subfield thickness [CST] >325 µm and intraretinal fluid [IRF] or subretinal fluid [SRF] resulting in vision loss/disease aggravation) will receive a dose within a day and the dosing interval will be shortened by 4 weeks to a minimum of Q8W relative to the previous dosing interval. Recruitment commenced in August 2023 across a planned 16 sites in Japan. RESULTS: The primary endpoint is change in best-corrected visual acuity (BCVA) from baseline at 1 year (averaged over weeks 52, 56, and 60). Key secondary endpoints include: change from baseline in BCVA, CST, and National Eye Institute Visual Function Questionnaire scores over time; proportion of patients with BCVA (decimal visual acuity) ≥0.5, ≥0.7, ≥1.0, or ≤0.1; proportion of patients with absence of DME, and IRF and/or SRF over time. Safety endpoints include incidence/severity of ocular/nonocular adverse events. CONCLUSIONS: The SWAN trial is expected to provide evidence to support individualized faricimab dosing regimens, with the potential to reduce the burden of frequent treatments on patients, caregivers, and healthcare systems.

Relationship between dry eye disease and myopia: A systematic review and meta-analysis.

Background/objectives: Dry eye disease (DED) and myopia are common ocular disorders. This systematic review and meta-analysis investigated the association between DED and myopia. Methods: PubMed and EMBASE were searched for articles published between 1984 and 2022. Study quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist, and analysis was conducted using the DerSimonian-Laird random-effects model. Results: Of the 1,313 studies identified, 15 studies on DED and myopia were included. The meta-analysis revealed that the overall prevalence of subjective DED symptoms in the myopia population was 45.1 % (95 % confidence interval: 0.287-0.616). There was a significant association between DED and myopia. The myopia population had higher Ocular Surface Disease Index scores and shorter tear film breakup times than the non-myopia population. Additionally, the meta-regression analysis showed that spherical equivalent was significantly associated with the prevalence of DED symptoms in adults with myopia. Conclusion: Interventions to prevent DED are required in the myopia population. Enhancing patient awareness and self-management for DED, in addition to early screening and detection, is especially critical for younger populations who are at a higher risk of developing myopia.

The impact of COVID-19 on hay fever treatment in Japan: A retrospective cohort study based on the Japanese claims database.

BACKGROUND: Hay fever (HF) presents with various symptoms, including allergic conjunctivitis and rhinitis, and requires cross-organ treatment. This study assessed the impact of the coronavirus disease 2019 (COVID-19) pandemic on HF treatment trends. METHODS: This retrospective cohort study utilized data from the JMDC database collected between January 2018 and May 2021. Patients with HF were identified based on the relevant International Classification of Diseases 10th Revision diagnosis codes and the prescription of HF-related medications. The treatment approaches were compared during the cedar and cypress pollen allergy season (January to May in Japan) before and during the COVID-19 pandemic (2018 and 2019, and 2020 and 2021, respectively). RESULTS: This study included 2,598,178 patients with HF. The numbers of prescribed HF-related claims in 2018, 2019, 2020, and 2021 were 3,332,854, 3,534,198, 2,774,380, and 2,786,681 times, respectively. Oral second-generation antihistamine prescriptions decreased by >10% from 2019 to 2020, with a <10% change in the subsequent year. Anti-allergic eye drop prescriptions also decreased by >10% from 2019 to 2020 but increased by >10% from 2020 to 2021. Compared with 2018, 2019, and 2020, the number of claims in the rhinitis symptoms dominant group was significantly decreased in 2021 (p < 0.001, all). In contrast, the number of claims in the eye symptoms dominant group and the rhinitis and eye symptoms dominant group increased in 2021 compared with that in 2018, 2019, and 2020 (p < 0.001, all). CONCLUSION: Changes in HF treatment and related outcomes could be attributed to lifestyle modifications resulting from the COVID-19 pandemic. Measures, such as limiting outdoor activities and adopting mask-wearing practices may have influenced HF symptoms, preventive behaviors, and the overall approach to treating HF.

Impact of the Coronavirus Disease 2019 Pandemic on Outpatient Visits for Diabetic Retinopathy in Japan: A Retrospective Cohort Study.

Purpose: Long-term ramifications of the coronavirus disease 2019 pandemic on various care-seeking characteristics of patients with diabetic retinopathy remain unclear. This study aimed to identify risk factors for dropout from regular fundus examinations (RFEs) in patients with diabetic retinopathy in Japan. Methods: We extracted demographic and health checkup data (April 2018 to March 2021) from the JMDC database. Patients with diabetes identified using diagnosis-related and medication codes were included. The dropout and continuation groups included patients who discontinued and continued to undergo RFEs during the coronavirus disease 2019 pandemic, respectively. Results: The number of RFEs was significantly lower during the mild lockdown period (April and May 2020) than during the prepandemic period. Of the 14,845 patients with diabetes, 2333 (15.7%) dropped out of RFEs during the pandemic, whereas before the pandemic, of the 11,536 patients with diabetes, 1666 (14.4%) dropped out of RFEs (P = 0.004). Factors associated with dropout in the multivariate logistic regression analysis included younger age, male sex, high triglyceride levels, high γ-glutamyl transpeptidase levels, smoking habit, alcohol consumption, weight gain of more than 10 kg since the age of 20 years, and certain stages of lifestyle improvement. Factors associated with continuation included low body mass index and high glycosylated hemoglobin levels. Conclusions: Our findings can assist in identifying patients with diabetes at risk of dropout. Translational Relevance: These results have implications for public health and identifying patients with diabetes at risk of dropout. Education and tailored monitoring regimens could be pivotal role in fostering adherence.

Macular hole retinal detachment in extensive myelinated retinal nerve fiber and high myopia with Straatsma syndrome: A case report.

Purpose: We present a case of macular hole retinal detachment (MHRD) in a patient with Straatsma syndrome, a rare condition characterized by extensive unilateral myelinated retinal nerve fibers (MRNF), high myopia, and amblyopia. This study aimed to highlight the clinical presentations, diagnostic challenges, and success of surgical interventions. Observation: A 32-year-old Asian woman with a history of high myopia and poorly corrected vision in her right eye since childhood presented with a sudden loss of vision in the right eye. Examination revealed extensive MRNF and retinal detachment with a macular hole. A standard three-port pars plana vitrectomy was performed, and tight vitreous retinal adhesions were observed. PFCL-assisted inverted internal limiting membrane (ILM) flap technique was performed. Silicone oil was used owing to its tight vitreous retinal adhesion. Postoperatively, the macular hole was closed, the retina was reattached, and partial disappearance of the MRNF was observed. Conclusion and importance: This case report describes a successful surgical intervention for MHRD associated with Straatsma syndrome. The PFCL-assisted inverted ILM flap technique is effective for managing complicated cases of MHRD. The partial disappearance of MRNF after vitrectomy suggests potential nerve fiber layer damage, possibly due to retinal detachment or the use of silicone oil. This case highlights the unique features of MHRD, a rare disease associated with Straatsma syndrome.

Surgery for Esotropia in a Case of Nanophthalmos.

Nanophthalmos, characterized by an abnormally small ocular globe, presents significant challenges in the management of strabismus due to its unique anatomical constraints. This detailed case report highlights the intricacies and outcomes of strabismus surgery in a patient with nanophthalmos, providing valuable insights into the surgical considerations and adaptations required for this rare condition. The subject of this case, a young girl diagnosed with esotropia and high hyperopia, underwent unilateral medial rectus muscle recession in an attempt to correct her esotropia. Despite the careful surgical approach and postoperative management, a two-year follow-up revealed a limited response to the intervention, with improvements in visual acuity but continued presence of esotropia and lack of stereopsis development. This case sheds light on several key considerations in the surgical treatment of strabismus in nanophthalmos patients, including the potential for reduced surgical effectiveness due to the small globe size, the importance of accurate preoperative assessment, and the challenges in predicting surgical outcomes. Additionally, it discusses the implications of these findings for future surgical planning, the potential need for revision surgeries, and the broader research context, emphasizing the necessity for a deeper understanding of the biomechanical and anatomical particularities of nanophthalmos in the context of strabismus surgery. The report concludes with recommendations for improving surgical strategies and patient outcomes, advocating for more comprehensive studies and a tailored approach to treating strabismus in individuals with nanophthalmos.

Safety and efficacy of ripasudil eye drops in preterm infants with retinopathy of prematurity: phase 1/2, open label, single-arm trial.

PURPOSE: To assess the safety and efficacy of ripasudil for retinopathy of prematurity (ROP). STUDY DESIGN: Phase 1/2, multicenter, open-label, single-arm, 12-week clinical trial. METHODS: Infants born with gestational age (GA) of ≤ 32 weeks or weight of ≤ 1500 g with zone I or II, ≥ stage 1, ROP in both eyes were enrolled. Ripasudil eye drops were administered to patients in both eyes. Phase 1 was a dose-escalation study (once daily for 1 week, then twice daily for 2 weeks); an additional dosing up to 9 weeks was allowed if no safety issues occurred. In phase 2, ripasudil was administered twice daily for up to 12 weeks. Adverse events were assessed. The proportion of patients with type 1 ROP progression, number of days for type 1 ROP progression, and progression to the most advanced ROP stage were estimated. RESULTS: Twenty-four infants were enrolled (phase 1, n = 3; phase 2, n = 21). Nineteen and four patients experienced systemic and ocular adverse events, respectively. Efficacy endpoints were not different between the ripasudil and historical control groups. However, in the GA ≤ 27 weeks subgroup, fewer patients progressed to type 1 ROP in the ripasudil than in the historical control group (P = 0.09). In the GA ≤ 27 weeks subgroups, the 25th percentile for the number of days for type 1 ROP progression was 22 days in the historical control group and 44 days in the ripasudil group. CONCLUSION: Ripasudil was safe and inhibited/delayed type 1 ROP progression, especially in infants with short GA.

Intraocular kinetics of pathological ATP after photoreceptor damage in rhegmatogenous retinal detachment.

PURPOSE: Extracellular Adenosine triphosphate (ATP) released by dying cells may cause a secondary cell death in neighboring cells in retinal degeneration. We investigated intraocular ATP kinetics to gain mechanical insights into the pathology in rhegmatogenous retinal detachment (RRD). STUDY DESIGN: Retrospective clinical study. METHODS: Vitreous or subretinal fluids (SRF) were obtained from patients with RRD (n=75), macular hole (MH; n=20), and epiretinal membrane (ERM; n=35) during vitrectomy. ATP levels in those samples were measured by luciferase assay. RESULTS: Mean ATP levels in the vitreous from RRD patients were significantly higher compared to those from MH and ERM patients (2.3 and 0.3 nM, respectively. P<0.01). Mean ATP levels in the SRF from RRD (11.7 nM) were higher than those in the vitreous from RRD (P<0.01). Mean ATP levels in the vitreous with short durations (1-8 days) of RRD were higher compared to those with long durations (>8 days) (3.2 and 1.4 nM, respectively. P<0.05). Similarly, ATP in SRF with short durations were higher than those with long durations (23.8 and 3.6 nM, respectively. P<0.05). Furthermore, the concentrations of ectonucleoside triphosphate diphosphohydrolase-1 (ENTPD1), a major ATP degradative enzyme, in the vitreous from RRD were higher than those from MH/ERM (1.2 and 0.2 ng/ml, respectively. P<0.01). ENTPD1 expression was localized in the cytoplasm of CD11b-positive infiltrating cells in the vitreous and retinal cells. CONCLUSION: ATP increased in the vitreous and SRF in RRD and decreased over time with an upregulation of ENTPD1. The kinetics indicate the pathological mechanism of the excessive extracellular ATP after RRD.

Heterotypic macrophages/microglia differentially contribute to retinal ischaemia and neovascularisation.

AIMS/HYPOTHESIS: Diabetic retinopathy is characterised by neuroinflammation that drives neuronal and vascular degenerative pathology, which in many individuals can lead to retinal ischaemia and neovascularisation. Infiltrating macrophages and activated retina-resident microglia have been implicated in the progression of diabetic retinopathy, although the distinct roles of these immune cells remain ill-defined. Our aim was to clarify the distinct roles of macrophages/microglia in the pathogenesis of proliferative ischaemic retinopathies. METHODS: Murine oxygen-induced retinopathy is commonly used as a model of ischaemia-induced proliferative diabetic retinopathy (PDR). We evaluated the phenotype macrophages/microglia by immunostaining, quantitative real-time RT-PCR (qRT-PCR), flow cytometry and scRNA-seq analysis. In clinical imaging studies of diabetic retinopathy, we used optical coherence tomography (OCT) and OCT angiography. RESULTS: Immunostaining, qRT-PCR and flow cytometry showed expression levels of M1-like macrophages/microglia markers (CD80, CD68 and nitric oxide synthase 2) and M2-like macrophages/microglia markers (CD206, CD163 and macrophage scavenger receptor 1) were upregulated in areas of retinal ischaemia and around neo-vessels, respectively. scRNA-seq analysis of the ischaemic retina revealed distinct ischaemia-related clusters of macrophages/microglia that express M1 markers as well as C-C chemokine receptor 2. Inhibition of Rho-kinase (ROCK) suppressed CCL2 expression and reduced CCR2-positive M1-like macrophages/microglia in areas of ischaemia. Furthermore, the area of retinal ischaemia was reduced by suppressing blood macrophage infiltration not only by ROCK inhibitor and monocyte chemoattractant protein-1 antibody but also by GdCl3. Clinical imaging studies of diabetic retinopathy using OCT indicated potential involvement of macrophages/microglia represented by hyperreflective foci in areas of reduced perfusion. CONCLUSIONS/INTERPRETATION: These results collectively indicated that heterotypic macrophages/microglia differentially contribute to retinal ischaemia and neovascularisation in retinal vascular diseases including diabetic retinopathy. This adds important new information that could provide a basis for a more targeted, cell-specific therapeutic approach to prevent progression to sight-threatening PDR.

Anti-VEGF therapy for the long-term management of diabetic macular edema: a treat-to-target strategy based on macular morphology.

In an aging population, the prevalence and burden of diabetes mellitus, diabetic retinopathy, and vision-threatening diabetic macular edema (DME) are only expected to rise around the world. Similarly to other complications of diabetes mellitus, DME requires long-term management. This article aims to review the current challenges associated with the long-term management of DME, opportunities to improve outcomes for patients, and to develop a treat-to-target strategy based on macular morphology. At present, intravitreal anti-vascular endothelial growth factor (VEGF) therapy is the standard of care for the management of DME; however, best-achievable vision outcomes with treatment are reliant on frequent injections and close monitoring, which are difficult to maintain in current clinical practice because of the burden this imposes on patients. Achieving and maintaining good vision with treatment are the most important factors for patients with DME. Landmark trials have shown that vision gains with anti-VEGF therapy are typically accompanied by anatomical improvements (e.g., reductions in retinal thickness); therefore, multimodal imaging measures of macular morphology are often used in patients with DME to guide real-world treatment decisions. We would like to propose a hypothetical treat-to-target algorithm to guide physicians on treatment strategies for the long-term management of DME. Alternative measures of retinal fluid (e.g., persistence, stability, location) may be stronger predictors of visual acuity in DME, although further research is required to confirm whether alternate quantifiable biomarkers such as subretinal fluid and intraretinal fluid volumes can be used as a biomarker of clinical improvement. Identifying novel biomarkers and treatments that target neuroinflammation and neurodegeneration, improving patient-physician communication around treatment adherence, and using treat-to-target measures may help to ensure that the long-term benefits of treatment are realized.

Effect of antihistamine-releasing contact lenses on ocular symptoms and treatment behavior in patients with seasonal allergic conjunctivitis: A retrospective study.

Purpose: This study aimed to compare subjective allergic conjunctivitis symptoms and anti-allergic eye drop use patterns between antihistamine-releasing contact lens users and daily disposable soft contact lens users during Japan's hay fever season. Methods: This web-based retrospective cohort study included daily disposable soft contact lens or antihistamine-releasing contact lens users with a history of seasonal allergic conjunctivitis who regularly used daily disposable soft contact lenses since the previous year. The total ocular symptom score (range 0-20) based on 5-item questionnaire scores and time from the start of the hay fever season to the initiation of anti-allergic eye drop treatment were compared between antihistamine-releasing contact lens users and daily disposable soft contact lens users. Results: The study included 24 participants: 17 using daily disposable soft contact lenses and 7 using antihistamine-releasing contact lenses. Antihistamine-releasing contact lens users experienced a greater reduction in total ocular symptom score from 2021 to 2022 compared with daily disposable soft contact lens users (mean total ocular symptom score [standard deviation]: daily disposable soft contact lens: -0.65 [1.4], antihistamine-releasing contact lens: -4.7 [3.6]; n = 24; Mann-Whitney U test, P = 0.010). Fourteen daily disposable soft contact lens users and five antihistamine-releasing contact lens users eventually required anti-allergic eye drops. Kaplan-Meier analysis revealed a significant delay in the initiation of anti-allergic eye drop treatment among those using antihistamine-releasing contact lenses compared with those using daily disposable soft contact lenses (median days, daily disposable soft contact lenses: 19 days, antihistamine-releasing contact lens: 57 days; n = 24; log-rank test, P = 0.045). Conclusions: Antihistamine-releasing contact lenses can potentially mitigate worsening ocular allergic responses during the hay fever season when used appropriately as a preventive measure.

A Case of Congenital Idiopathic Enlargement of Extraocular Muscles.

The purpose of this case report is to report a case of congenital idiopathic enlargement of extraocular muscles. A four-month-old girl showed limitation of adduction and supraduction in the right eye. A computerized axial tomography (CAT) scan revealed hypertrophy of the lateral rectus muscle and inferior rectus muscle of the right eye. Thyroid hormone and antibody levels were normal. No inflammatory findings on magnetic resonance imaging (MRI). A traction test under general anesthesia revealed a strong limitation of supraduction and a mild limitation of adduction. Therefore, the inferior rectus muscle was recessed 4.5 mm at the age of six months. A partial biopsy of the inferior rectus showed no inflammatory cell infiltration. After the first surgery, the patient's limitation of supraduction improved, but the limitation of adduction persisted. So, a 5 mm recession of the right lateral rectus muscle was added at one year and one month. However, the hypertropia of the sound eye became stronger after treatment of amblyopia. Because of the strong limitation of supraduction, tenotomy of the inferior rectus was performed at the age of six years. Postoperatively, no impairment of infraduction occurred, and the limitation of supraduction was mildly improved. Since the findings on MRI were not changed through our observation period, we concluded that the patient had idiopathic external ophthalmoplegia.

Human ocular thelaziasis with genetic analysis in Niigata Prefecture, Japan: A case report on an emerging zoonosis.

Purpose: We report the clinical findings and molecular identification of ocular Thelazia callipaeda from Niigata Prefecture in the Hokuriku area of Japan during winter. Observations: A 77-year-old male visited an ophthalmology clinic in Niigata Prefecture in January 2022 after a 2-week-duration of a conjunctival injection in the left eye and foreign body sensation. Slit-lamp microscopy revealed 11 active nematodes in the left conjunctival sac. Morphological characteristics included longer female body length than male, buccal cavity lacking teeth and lips, and serrated striations along the body surface. The specimens were determined to be T. callipaeda. Genetic analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene revealed an h9 haplotype. Conclusions and Importance: T. callipaeda infection, especially the h9 haplotype, commonly occurs in western Japan owing to its higher incidence in warmer climates, suggesting the origin of the case. Here, we report a human case of Thelaziasis diagnosed in a cold region of Japan (the Hokuriku area) during winter. This human case of T. callipaeda infection from a cold, previously unassociated region, raises concerns about the potential geographical widening of its distribution, and further investigation may be warranted to prevent its spread.

Optimal cutoff value of the dry eye-related quality-of-life score for diagnosing dry eye disease.

This retrospective study aimed to determine the optimal cutoff values of the Dry Eye-Related Quality-of-Life Score (DEQS) questionnaire for diagnosing dry eye disease (DED) and classifying DED severities. Participants completed the DEQS questionnaire, the Japanese version of the Ocular Surface Disease Index (J-OSDI) questionnaire, and DED examinations. DED was diagnosed according to the 2016 Asia Dry Eye Society diagnostic criteria based on DED symptoms (J-OSDI ≥ 13 points) and tear film breakup time ≤ 5 s. Receiver operating characteristic (ROC) analysis was used to calculate the optimal cutoff values of the DEQS summary score for detecting DED and grading its severity. Among 427 patients, 296 (69.3%) and 131 (30.7%) were diagnosed with DED and non-DED, respectively. ROC analysis determined an optimal cutoff value of 15.0 points for DED diagnosis, with 83.5% sensitivity, 87.0% specificity, and an area under the curve of 0.915. The positive and negative predictive values for DEQS ≥ 15.0 points were 93.6% and 69.9%, respectively. DEQS cutoff values of 15.0, 20.0, and 26.8 points could be accepted for severity classification of DED subjective symptoms in clinical use and represent mild, moderate, and severe DED, respectively. Conclusively, the optimal cutoff values of DEQS enable DED detection and subjective symptom severity classification.

Retinal neurovascular alteration in type 2 diabetes with renal impairment in association with systemic arterial stiffness.

BACKGROUND: Diabetic retinopathy (DR) patients should be alert for subclinical macroangiopathy. We aimed to investigate the association between retinal neurovascular alteration and systemic arterial stiffness in type 2 diabetes mellitus (type 2 DM) patients with varying degrees of renal impairment. METHODS: The study included 170 patients with confirmed diagnosis of type 2 DM aged ≥18 years old. Renal function was assessed by estimated glomerular filtration rate (eGFR). Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV) and ankle brachial index (ABI). Retinal neurovascular parameters were derived from Optical Coherence Tomography (OCT)/OCT-Angiography, represented by vessel density (VD Central, Inner, Outer, Full), foveal avascular zone (FAZ area and FAZ perimeter) of the superficial capillary plexus, the average of macular ganglion cell-inner plexiform layer thickness (ave mGC-IPLt) and the average of retinal nerve fiber layer thickness (aveRNFLt). The association between variables among the groups (according to renal function, diabetic retinopathy (DR) severity, and arterial stiffness categories) were analyzed by regression analysis with multiple hypothesis testing commands. RESULTS: Out of the 265 eyes, the mean DM duration and HbA1c were 6.21 ± 6.37 years and 8.44 ± 2.06% respectively. While the mean of eGFR, baPWV and ABI were 66.78 ± 32.80 ml/min/1.73m2, 15.49 ± 3.07 m/s, and 1.05 ± 0.12, respectively. Patients with more severe renal impairment demonstrated longer DM duration (p < 0.001), higher baPWV (p < 0.0001), and retinal vascular alteration. Proliverative DR group showed the lowest eGFR (p < 0.0001), highest baPWV (p < 0.0001), and retinal neurovascular changes. Significantly lower eGFR and retinal vascular alteration were found in the baPWV > 14 group. Some neurovascular parameters were significantly negatively correlated with baPWV; moreover, retinal neurovascular changes were also noted in the abnormal ABI group. CONCLUSIONS: The strong association between changes in the retinal neurovascular system, DR severity, renal impairment, and arterial stiffness in type 2 DM was confirmed. Patients with more severe renal impairment had higher levels of arterial stiffness, more severe DR and retinal neurovascular alteration. Retinal neurovascular changes seen in OCT/OCTA might mimic renal microvascular alteration and systemic arterial stiffness. Therefore, assessment of baPWV and OCT/OCTA should be integrated in DR screening to enhance cardiovascular risk stratification and prognosis as well as to provide clinically useful early identification of subclinical micro- and macrovascular alterations.

A nerve-goblet cell association promotes allergic conjunctivitis through rapid antigen passage.

The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although pollinosis patients manifest symptoms within minutes after pollen exposure, the mechanisms of the rapid transport of the allergens remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by stromal cells, including macrophages and CD11b+ dendritic cells, correlated with surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible, rapid GAP formation and antigen acquisition were suppressed by topical lidocaine or trigeminal nerve ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a therapeutic target for allergic conjunctivitis.

Integrating human iPSC-derived macrophage progenitors into retinal organoids to generate a mature retinal microglial niche.

In the retina, microglia are resident immune cells that are essential for development and function. Retinal microglia play a central role in mediating pathological degeneration in diseases such as glaucoma, retinitis pigmentosa, age-related neurodegeneration, ischemic retinopathy, and diabetic retinopathy. Current models of mature human retinal organoids (ROs) derived from iPS cell (hiPSC) do not contain resident microglia integrated into retinal layers. Increasing cellular diversity in ROs by including resident microglia would more accurately represent the native retina and better model diseases in which microglia play a key role. In this study, we develop a new 3D in vitro tissue model of microglia-containing retinal organoids by co-culturing ROs and hiPSC-derived macrophage precursor cells (MPCs). We optimized the parameters for successful integration of MPCs into retinal organoids. We show that while in the ROs, MPCs migrate to the equivalent of the outer plexiform layer where retinal microglia cells reside in healthy retinal tissue. While there, they develop a mature morphology characterized by small cell bodies and long branching processes which is only observed in vivo. During this maturation process these MPCs cycle through an activated phase followed by a stable mature microglial phase as seen by the down regulation of pro-inflammatory cytokines and upregulation of anti-inflammatory cytokines. Finally, we characterized mature ROs with integrated MPCs using RNAseq showing an enrichment of cell-type specific microglia markers. We propose that this co-culture system may be useful for understanding the pathogenesis of retinal diseases involving retinal microglia and for drug discovery directly in human tissue.