Congenital microcoria deletion in mouse links Sox21 dysregulation to disease and suggests a role for TGFB2 in glaucoma and myopia.

Congenital microcoria (MCOR) is a rare hereditary developmental defect of the iris dilator muscle frequently associated with high axial myopia and high intraocular pressure (IOP) glaucoma. The condition is caused by submicroscopic rearrangements of chromosome 13q32.1. However, the mechanisms underlying the failure of iris development and the origin of associated features remain elusive. Here, we present a 3D architecture model of the 13q32.1 region, demonstrating that MCOR-related deletions consistently disrupt the boundary between two topologically associating domains (TADs). Deleting the critical MCOR-causing region in mice reveals ectopic Sox21 expression precisely aligning with Dct, each located in one of the two neighbor TADs. This observation is consistent with the TADs' boundary alteration and adoption of Dct regulatory elements by the Sox21 promoter. Additionally, we identify Tgfb2 as a target gene of SOX21 and show TGFΒ2 accumulation in the aqueous humor of an MCOR-affected subject. Accumulation of TGFB2 is recognized for its role in glaucoma and potential impact on axial myopia. Our results highlight the importance of SOX21-TGFB2 signaling in iris development and control of eye growth and IOP. Insights from MCOR studies may provide therapeutic avenues for this condition but also for glaucoma and high myopia conditions, affecting millions of people.

Jasmine and Iris: population-scale structural variant comparison and analysis.

The availability of long reads is revolutionizing studies of structural variants (SVs). However, because SVs vary across individuals and are discovered through imprecise read technologies and methods, they can be difficult to compare. Addressing this, we present Jasmine and Iris ( https://github.com/mkirsche/Jasmine/ ), for fast and accurate SV refinement, comparison and population analysis. Using an SV proximity graph, Jasmine outperforms six widely used comparison methods, including reducing the rate of Mendelian discordance in trio datasets by more than fivefold, and reveals a set of high-confidence de novo SVs confirmed by multiple technologies. We also present a unified callset of 122,813 SVs and 82,379 indels from 31 samples of diverse ancestry sequenced with long reads. We genotype these variants in 1,317 samples from the 1000 Genomes Project and the Genotype-Tissue Expression project with DNA and RNA-sequencing data and assess their widespread impact on gene expression, including within medically relevant genes.

Mitigation of human iris angiogenesis through uPAR/LRP-1 interaction antagonism in an organotypic ex vivo model.

Rubeosis Iridis (RI) is characterized by an increase in neovascularization and inflammation factors in the iris. During angiogenesis, the urokinase plasminogen activator (uPA) and its receptor (uPAR) play a pivotal role in extracellular matrix remodeling, where uPAR regulates endothelial cell migration and proliferation through assembly with transmembrane receptors. Here, in the context of hypoxia-induced angiogenesis, the uPA/uPAR system blockage was investigated by using UPARANT in a novel ex vivo human iris organotypic angiogenesis assay. The effects of uPA/uPAR system antagonism in the humanized model of ocular pathologic angiogenesis were analyzed by sprouting angiogenesis and protein assays (western, dot blots, and co-immunoprecipitation) and correlated to vascular endothelial growth factor (VEGF) inhibition. Phosphoprotein and co-immunoprecipitation assay illustrated an unidentified antagonism of UPARANT in the interaction of uPAR with the low-density lipoprotein receptor-related protein-1 (LRP-1), resulting in inhibition of ß-catenin-mediated angiogenesis in this model. The effects of uPA/uPAR system inhibition were focal to endothelial cells ex vivo. Comparison between human iris endothelial cells and human retinal endothelial revealed an endothelial-specific mechanism of ß-catenin-mediated angiogenesis inhibited by uPA/uPAR system blockage and not by VEGF inhibition. Collectively, these findings broaden the understanding of the effects of the uPA/uPAR system antagonism in the context of angiogenesis, revealing non-canonical ß-catenin downstream effects mediated by LRP-1/uPAR interaction.

Cell atlas of the human ocular anterior segment: Tissue-specific and shared cell types.

The anterior segment of the eye consists of the cornea, iris, ciliary body, crystalline lens, and aqueous humor outflow pathways. Together, these tissues are essential for the proper functioning of the eye. Disorders of vision have been ascribed to defects in all of them; some disorders, including glaucoma and cataract, are among the most prevalent causes of blindness in the world. To characterize the cell types that compose these tissues, we generated an anterior segment cell atlas of the human eye using high-throughput single-nucleus RNA sequencing (snRNAseq). We profiled 195,248 nuclei from nondiseased anterior segment tissues of six human donors, identifying >60 cell types. Many of these cell types were discrete, whereas others, especially in the lens and cornea, formed continua corresponding to known developmental transitions that persist in adulthood. Having profiled each tissue separately, we performed an integrated analysis of the entire anterior segment, revealing that some cell types are unique to a single structure, whereas others are shared across tissues. The integrated cell atlas was then used to investigate cell type-specific expression patterns of more than 900 human ocular disease genes identified through either Mendelian inheritance patterns or genome-wide association studies.

The ocular immunological alterations in the process of high-risk corneal transplantation rejection.

PURPOSE: This study aims to reveal the immunopathogenesis of the high-risk corneal transplantation using a comparative proteomic approach. METHODS: The immunological properties of ocular tissues (including corneal grafts, aqueous humour, and iris-ciliary body) were analysed using a high-risk rabbit corneal transplantation model employing a comparative proteomic approach. RESULTS: The corneal grafts revealed a dramatic increase in the immune response both at the early (postoperative day 7) and rejection stages, along with the appearance of transplantation stress-induced cellular senescence in the early stage. The aqueous humour (AH) displayed persistent pathological alterations, indicated by the significant enrichment of complement and coagulation cascades pathway in the early stage and interleukin (IL)-17 signalling pathway in the rejection stage. More surprisingly, the pronounced elevation of immune response was also observed in the iris-ciliary body (I-CB) tissues at the early and rejection stages. The enriched immune-related pathways were associated with antigen processing and presentation, complement and coagulation cascades, and IL-17 signalling pathway. Furthermore, proteomic analysis revealed that the implantation of Cyclosporine A drug delivery system (CsA-DDS) into the anterior chamber obviously mitigated corneal transplantation rejection by inhibiting immunoreaction both in the corneal grafts and I-CB tissues. CONCLUSION: The results highlighted the involvement of intraocular immunity both in the grafts and I-CB tissues during corneal transplantation rejection, further suggesting the anterior chamber as an optimal drug-delivery site for its treatment.

Prospective analysis of anatomic features predisposing patients to intraoperative floppy iris syndrome.

PURPOSE: To aid preoperative risk assessment by identifying anatomic parameters corresponding with a higher risk of intraoperative floppy iris syndrome (IFIS) during cataract surgery. METHODS: Prospective cohort study of 55 patients with α1-adrenergic receptor antagonist (α1-ARA) treatment and 55 controls undergoing cataract surgery. Anterior segment optical coherence tomography (AS-OCT), video pupilometer, and biometry measurements were performed preoperatively and analyzed regarding anatomic parameters that corresponded with a higher rate of IFIS. Those statistically significant parameters were evaluated with logistic regression analysis and receiver operating characteristic (ROC) curve. RESULTS: Pupil diameter was significantly smaller in patients who developed IFIS compared to those who did not develop IFIS (AS-OCT 3.29 ± 0.85 vs. 3.63 ± 0.68, p = 0.03; Pupilometer 3.56 ± 0,87 vs. 3.95 ± 0.67, p = 0.02). Biometric evaluation revealed shallower anterior chambers in the IFIS group (ACD 3.12 ± 0.40 vs. 3.32 ± 0.42, p = 0.02). Cutoff values for 50% IFIS probability (p = 0.5) were PD = 3.18 mm for pupil diameter and ACD = 2.93 mm for anterior chamber depth. ROC curves of combined parameters were calculated for α1-ARA medication with pupil diameter and anterior chamber depth, which yielded an AUC of 0.75 for all IFIS grades. CONCLUSION: The combination of biometric parameters with history of α1-ARA medication can improve assessment of risk stratification for IFIS incidence during cataract surgery.

Analysis of pupillary responses in pediatric patients with vitamin D deficiency.

PURPOSE: To evaluate the effects of vitamin D deficiency on pupillary responses in the pediatric population. METHODS: The study was conducted using data from the right eyes of 52 children with vitamin D deficiency and 52 healthy children. Measurements were taken under static and dynamic conditions with automatic pupillometry. Static measurements were performed at scotopic, mesopic, and photopic light intensities. The mean pupil dilation speed was calculated by observing the changes in pupil dilation over time according to dynamic measurements. Differences between patient and control groups were analyzed for the static and dynamic measurements and the mean pupil dilation speed. RESULTS: While the two groups were similar in terms of scotopic, mesopic, the first dynamic measurements, and the pupil dilation speed data (p > 0.05), a significant difference was found in the photopic conditions (p = 0.001). The mean pupil diameter of the patient group was 4.46 ± 0.928 mm and 3.95 ± 0.556 mm in the control group under photopic conditions. CONCLUSIONS: Pediatric patients with vitamin D deficiency have significantly larger pupil diameters in photopic conditions than healthy children. These results suggest that there is an autonomic dysfunction in vitamin D deficiency in the pediatric population, especially pointing to the parasympathetic system.

The correlation of anterior segment structures in primary congenital glaucoma by ultrasound biomicroscopy with disease severity and surgical outcomes.

PURPOSE: To evaluate the anterior segment structures using ultrasound biomicroscopy (UBM) in primary congenital glaucoma (PCG) and explore their correlation with disease severity and surgical outcomes. METHODS: Clinical information of PCG patients who underwent UBM prior to their first glaucoma surgeries from September 2014 to March 2021 were reviewed. The study included 214 UBM images of 154 PCG eyes and 60 fellow unaffected eyes. Anterior segment characteristics were analyzed. UBM parameters, including the iris thickness (IT) at variant distances from the pupil edge and iris root, anterior chamber depth (ACD), and pupil diameter (PD), were compared between two groups and their relationship with clinical factors and surgical outcomes were analyzed in PCG eyes. RESULTS: PCG eyes had unclear scleral spur, thin iris, wide anterior chamber angle, deep anterior chamber, rarefied ciliary body, elongated ciliary processes, and abnormal anterior iris insertion. ITs were thinner, ACD was deeper, and PD was larger in PCG eyes than fellow unaffected eyes (all P < 0.001). In PCG eyes, thinner ITs correlated with bilateral involvement and earlier age at presentation, and larger PD correlated with earlier age at presentation (P = 0.030) and higher intraocular pressure (P < 0.001). Thinner IT2 (P = 0.046) and larger PD (P = 0.049) were identified as risk factors for surgical failure. CONCLUSION: UBM is a powerful technique to exam anterior segment structures in PCG. The anatomical features are associated with disease severity and surgical outcomes, providing essential clinical insights.

Iris neovascularization and neurotrophic keratopathy following ultrasound cycloplasty in refractory glaucoma: case series.

BACKGROUND: Ultrasound cycloplasty is a noninvasive surgery used to reduce intraocular pressure in patients with glaucoma, with fewer severe complications. This report presents several cases of iris neovascularization and neurotrophic keratopathy following ultrasound cycloplasty. CASE PRESENTATION: Six patients diagnosed with refractory glaucoma underwent ultrasound cycloplasty at our clinic. Three cases developed iris neovascularization at postoperative day 3, week 2 and week 4 respectively, with intraocular pressure ranging from 12 to 24 mmHg. The other three cases developed neurotrophic keratopathy at postoperative week 3, week 6 and week 8 which completely healed within 60 days. CONCLUSIONS: Iris neovascularization and neurotrophic keratopathy can be triggered after ultrasound cycloplasty, which are uncommon and self-limited but potentially vision-threatening. Preoperative risk assessment and regular postoperative follow-up are recommended to manage complications effectively.

Application of modified Yamane technique in intrascleral intraocular lens fixation combined with or without iris reconstruction.

AIMS: To explore the application and long-term clinical effects of modified Yamane technique in intrascleral intraocular lens (IOL) fixation combined with or without iris reconstruction. SETTINGS AND DESIGN: The data of patients receiving IOL fixation with modified Yamane technique in an ophthalmology department between December 2021 and August 2023 were analyzed retrospectively. The longest follow-up duration was > 12 months. METHODS AND MATERIAL: The trailing haptic was fixed with the needle before the leading haptic. The silicone haptic stoppers were used to stabilize the IOL when iris reconstruction was combined. Preoperative and postoperative best-corrected visual acuity (BCVA), corneal endothelial cells (CECs), postoperative intraocular pressure (IOP), surgical indications and methods, and postoperative complications were recorded. Anterior segment optical coherence tomography (OCT) was used to evaluate IOL decentration and tilt. The paired sample t-test or Wilcoxon rank sum test were used to compare the results of the same index before and after the operation. RESULTS: Twelve patients (12 eyes) were included in this cohort. There were 1 case of IOL dislocation, eight cases of lens dislocation or subluxation, and three cases of aphakia. Traumatic lens dislocation was the main cause of aphakia. Primary lens extraction was performed in previous surgeries, and all three were combined with pars plana vitrectomy (PPV). Four of 12 patients underwent IOL fixation and iris reconstruction. The mean age of participants was 63 ± 10.61 years. The mean BCVA increased from 0.89 ± 0.72 logMAR to 0.39 ± 0.56 logMAR at the last visit (p < 0.05). The postoperative relative refractive error was - 0.13 ± 0.42 D (-0.60 D to + 0.57 D). The OCT showed that the IOLs were well centered, with a mean decentration of 0.20 ± 0.13 mm and a mean tilt of 2.31°±0.93°. Ten patients did not experience any complications. CONCLUSIONS: The modified Yamane technique in IOL fixation surgery, especially combined with iris reconstruction, reduces operation difficulty, increases operational stability and safety, and improves postoperative visual acuity without serious intra- or postoperative complications. The long-term improvement effect was remarkable.

Simultaneous evaluation of iris area and subfoveal choroidal thickness in Fuchs uveitis syndrome.

BACKGROUND/AIMS: To simultaneously evaluate iris area (IA) and subfoveal choroidal thickness (SFCT) in eyes with Fuchs Uveitis Syndrome (FUS). METHODS: We prospectively recruited a case series of patients with FUS at our institution, simultaneously measuring IA with anterior segment spectral domain optical coherence tomography (SD-OCT) and SFCT with enhanced depth imaging optical coherence tomography (EDI-OCT). Iris images were analyzed by ImageJ software. We tested the differences in intereye IA and SFCT with the healthy eye (HE) using the Wilcoxon test, and clinical interpretation was controlled by intraclass correlation coefficient (ICC) between two masked specialists. RESULTS: Sixteen patients with unilateral FUS were included. Six were female, and the age range was 37 to 67 (median age 48 years, IQR 41-60). ICC of 98.9%, with a lower confidence interval of 97%. Eyes with FUS had a significant thinning of the total iris median area (p < 0.002), restricted to the temporal and nasal areas compared to the HE (p < 0.01 and < 0.001, respectively). SFCT was also significantly thinner compared to the HE (p < 0.0001). A low correlation was found between iris and choroidal thinning in FUS eyes (rs = 0.21; p = 0.4). CONCLUSIONS: This study found reduced iris area and subfoveal choroidal thickness in eyes with FUS compared to the normal fellow eye.

Clinicopathological study of ophthalmic cutaneous and mucocutaneous non-langerhans cell histiocytic lesions.

BACKGROUND: The "C group" of the histiocytic disorders is characterized by non-Langerhans-cell histiocytic lesions in the skin, mucosal surfaces, or both, out of which Juvenile xanthogranuloma (JXG) is the most common typically affecting the skin. The eye is the most common extra-cutaneous site of JXG., we aim at providing our clinical and histopathological experience with this group of diseases including the adult-onset xanthogranuloma (AXG). METHODS: This is a retrospective cohort study of all patients with the tissue diagnosis of ocular and periocular cutaneous and mucocutaneous non-LCH disorders who presented to us over a period of 25 years (January 1993 to December 2018). RESULTS: Twenty patients were diagnosed as "Group C" disease with an age range of 2 months-60.9 years. Eleven patients were females (55%) and nine were males (45%). The involvement was mostly unilateral in 80.9%. All cases fell into the xanthogranuloma family with 11 JXG patients, 8 AXG patients of skin and ocular surface, and one patient with solitary reticulohistiocytoma (SRH). The clinical site of involvement in JXG was primarily in the eyelid in 5 patients (45%), ocular surface lesions in 2 (18%), iris in 2 (18%), choroidal and bilateral orbital lesions in 1 patient each (9%). The group of AXG, presented equally with eyelid lesions in 4/8 and ocular surface lesions in 4/8. The non-Langerhans' histiocytic infiltrate showed supportive immunohistochemical staining properties (reactive to CD68 marker and negative to S-100 and langerin markers). CONCLUSION: Among the rare histiocytic disorders, xanthogranulomatosis is the commonest and has wide clinical manifestations. Accurate diagnosis needs to be supported by typical histopathological findings. JXG was the commonest in our study with relatively older mean age at presentation and frequent eyelid rather than iris involvement. AXG is often confused with xanthelasma when involving the eyelids with corneal limbal involvement is relatively frequent.

Changes in IOL power after laser peripheral iridotomy based on multivariate analysis.

BACKGROUND: This study aimed to investigate the effect of laser peripheral iridotomy (LPI) on intraocular lens (IOL) power in patients with primary angle closure disease (PACD), and to construct mathematical models to assess changes in IOL power. METHODS: This study included 58 eyes of PACD patients. IOL Master700 was used to analyze and compare the changes of IOL power and ocular related parameters in each formula before and after LPI. The number of cases with IOL power changes greater than 0.5 diopters (D) in each group were counted and significant differences were analyzed using Fisher's exact test. Pearson's linear correlation analysis was used to ascertain the relationship between IOL power changes and ocular parameter changes to establish mathematical models. RESULTS: No significant difference was found in calculated IOL power changes before and after LPI in each group. There was significant difference in the number of cases with IOL change values greater than 0.5D between the primary angle closure glaucoma (PACG) and the other two groups for each formula. IOL power changes were mainly associated with △K and △AL. Mathematical models of IOL power changes after LPI were constructed based on linear regression analysis.(PAC group: △IOLHaigis=0.026-2.950×△AL-1.414×△K, △IOLHoffer Q=-3.578×△AL-1.412×△K, △IOLSRK/T=-3.152×△AL-1.114×△K, △IOLHolladay 1=-3.405×△AL-1.291×△K, △IOLHolladay 2=-3.467×△AL-1.483×△K, △IOLBUII=-3.185×△AL-1.301×△K; PACG group:△IOLHaigis=-1.632×△K, △IOLHoffer Q=-3.770×△AL-1.434×△K, △IOLSRK/T=-3.427×△AL-1.102×△K, △IOLHolladay 1=-3.625×△AL-1.278×△K, △IOLHolladay 2=-4.764×△AL-1.272×△K, △IOLBUII=-4.935×△AL-1.304×△K). CONCLUSIONS: LPI will cause changes in some ocular parameters in patients with PACD, with great effects on IOL power calculations was observed in patients with PACG. Mathematical models based on multivariate analysis hold promise for predicting IOL power changes subsequent to LPI.

Alpha-adrenergic antagonists and iris dynamics: Challenges and solutions in cataract surgery.

BACKGROUND: Alpha-1 adrenergic receptor antagonists (α1-ARAs) are frequently used in treatment of Hypertension and symptomatic benign prostatic hypertrophy (BPH). Numerous studies have demonstrated the association between α1-ARAs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery. This study aims to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery. METHODS: A cross-sectional, prospective study involving 30 patients on α1-ARAs planned for cataract surgery and equal number of age and sex matched controls were subjected to evaluation of changes on iris parameters and subsequent challenges in cataract surgery. RESULTS: The study group had statistically significant lesser pupil diameter. Iris thickness at sphincter muscle region (SMR) was similar between groups (P = 0.53). Significantly lower values of iris thickness at dilator muscle region (DMR) found in treated subjects (P = < 0.001). There was statistically significant difference between DMR/SMR ratio of two groups (P < 0.001). Multiple regression analysis revealed longer duration of α1-ARAs treatment correlated with reduced DMR/SMR ratio (P = 0.001; r = 0.47). CONCLUSION: α1-ARAs have implications for pupil size regulation and surgical procedures involving the eye. Tamsulosin is more potent than alfuzosin in inducing IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Therefore, ophthalmologists, primary care physicians, urologists, and patients should be aware of the potential difficulties that these drugs pose for cataract surgery.

Outcomes of retropupillary iris claw lens implantation in patients with intraocular lens dislocation and low (less than 1000 cells/mm2) corneal endothelial cell density.

BACKGROUND: Posterior chamber intraocular lens (IOL) dislocation is a common complication of cataract surgery. Dislocated IOLs often require surgical intervention due to the potentially severe risks of leaving this condition untreated. If a patient with extremely low corneal endothelial cell density (ECD) presents with IOL dislocation, the surgeon faces a crucial dilemma of choosing the most optimal surgical treatment option. We sought to investigate the efficacy and safety of retropupillary iris claw intraocular lens (R-IOL) implantation in patients with IOL dislocation and extremely low (< 1000 cells/mm2) ECD. METHODS: We retrospectively reviewed the medical records of nine patients (all men) whose pre-operative ECD was < 1000 cells/mm2 and who underwent R-IOL implantation due to intraocular subluxation or total dislocation into the vitreous cavity between 2014 and 2020. We evaluated corneal endothelial function and visual outcomes after surgery. RESULTS: Nine patients were included in this study. The mean age at diagnosis was 64.89 ± 7.15 years (range 57-76 years), and the follow-up duration was 37.93 ± 23.72 months (range 18.07-89.07 months). No patients developed bullous keratopathy during follow-up. Compared to the initial ECD, corneal thickness (CT), coefficient variation of cell area (CV) and percentage of hexagonal cells (HEX), there was no statistically significant decrease in the ECD, CV, and HEX at last follow-up (P = 0.944, 0.778, 0.445, 0.443). There was significant improvement in the mean uncorrected distance visual acuity (UDVA) at the last follow-up (average 0.13 logMAR, 20/27 Snellen) compared to the pre-operative mean UDVA (average 1.09 logMAR, 20/250 Snellen) (P < 0.01). CONCLUSIONS: R-IOL implantation did not result in a statistically significant decline in corneal endothelial function in patients with preoperatively low ECD, and it significantly improved the mean UDVA postoperatively. R-IOL implantation appears to be a safe and effective treatment modality for intraocular lens dislocation in patients with low ECD (< 1000 cells/mm²); however, long-term follow-up studies are warranted to corroborate these findings.

Epstein-Barr virus-positive iris diffuse large B-cell lymphoma detected by metagenomic next-generation sequencing.

PURPOSE: Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) is a relatively rare subtype of DLBCL. Herein, we report a case of a patient with EBV-positive iris DLBCL after undergoing penetrating keratoplasty and discuss its possible pathogenesis. METHODS: A 72-year-old male patient presented to our hospital with progressive blurring of vision in the left eye for the past 4 months. Small white nodular lesions were observed on the iris and retinal surface of the left eye, with a white cloud-like opacity in the vitreous cavity. RESULTS: The patient was eventually diagnosed with EBV-positive iris DLBCL after undergoing pathological and metagenomic tests. After injecting methotrexate in the left vitreous cavity and administering systemic and local antiviral treatments, the ocular lesions disappeared. CONCLUSION: EBV infection, drug immunosuppression, and aging-related immune deterioration may play significant roles in the pathogenesis of EBV-positive iris DLBCL. SYNOPSIS: Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) is a new subtype of DLBCL, which rarely occurs. Herein, we report a case of a patient with EBV-positive iris DLBCL after undergoing penetrating keratoplasty and discuss its possible pathogenesis.

Study on the correlation between iris blood flow, iris thickness and pupil diameter in the resting state and after pharmacological mydriasis in patients with diabetes mellitus.

BACKGROUND: To investigate whether iris blood flow and iris thickness at the iris smooth muscle region affect the pupil diameter at rest and after drug-induced mydriasis in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). METHODS: T1DM patients and healthy children were recruited from the SCADE cohort. T2DM patients and healthy adults were recruited from patients undergoing cataract surgery at Shanghai General Hospital. Iris vessel density, pupil diameter (PD) and iris thickness were measured in both the resting and drug-induced mydriasis states. Iris vessel density was measured by optical coherence tomography angiography (OCTA), PD was measured by a pupilometer, and iris thickness at the iris smooth muscle regions were measured using anterior segment optical coherence tomography (AS-OCT). RESULTS: The study included 34 pediatric T1DM patients and 50 adult T2DM patients, both groups without diabetic retinopathy, and age-sex-matched healthy controls. At baseline, T1DM children and healthy children showed no differences in iris blood flow, iris thickness, or PD. However, the adult T2DM group exhibited higher vessel density at the pupil margin, thinner iris thickness at the iris dilator region, and smaller PD compared to healthy adults, with these differences being statistically significant (P < 0.05). After pupil dilation, there were no changes in iris blood flow and PD in the T1DM group compared to healthy children, whereas the T2DM group showed a significantly smaller PD compared to healthy adults. Multivariate regression analysis revealed that in the T2DM group, glycated hemoglobin was an independent factor of PD after dilation (ß=-0.490, p = 0.031), with no such factors identified in the T1DM group. CONCLUSION: The insufficiently dilated pupil diameter after drug-induced mydriasis is correlated to the level of glycated hemoglobin among T2DM patients. TRIAL REGISTRATION: The registration number on the clinical trial website was NCT03631108.

A case of iridoschisis with partial lens dislocation in both eyes.

BACKGROUND: Iridoschisis is a rare condition that primarily affects individuals aged 60-70 years. The predominant characteristics of iridoschisis involve the tissue splitting and separation of the iris stromal layers, often resulting in two distinct layers and the presence of floating fibers in the anterior chamber. This article reports the case of a 48-year-old male with iridoschisis with partial lens dislocation in both eyes. CASE PRESENTATION: Trauma is the leading factor in the development of iridoschisis. However, there is no documented case of ocular trauma in the patient's medical history. Visible white atrophic fibers were observed bilaterally in the anterior iris stroma of both eyes of the individual, accompanied by a small quantity of iris tissue within the anterior chamber. In this instance, the magnitude of the iridoschisis corresponded with the degree of lens dislocation. We were apprised that the patient had regularly used a cervical massager for a prolonged period of time, positioning it upon the ocular region. Frequent stimulation of both eyes with excessive force resulted in the development of iridoschisis and the partial dislocation of the lens.During the initial surgical procedure, phacoemulsification (Phaco) was carried out on the left eye without the placement of an intraocular lens (IOL). Following a two-month interval, we proceeded with the IOL suspension. Subsequently, the right eye underwent Phaco, accompanied by the implantation of an IOL. After closely monitoring the patient's progress for two months, it was evident that their vision had significantly improved, substantiating the success of the surgical interventions. CONCLUSIONS: This finding posits that the recurrent friction applied to both eyes may induce iridoschisis and various ocular complications. In the event of ocular intricacies manifesting, expeditious medical intervention becomes imperative.

An analysis of iris pattern as a risk factor for skin cancer development in immunosuppressed renal transplant recipients.

INTRODUCTION: Renal transplant recipients are at increased risk of keratinocyte skin cancers with a tendency to have multiple, aggressive and difficult to treat tumours. The eye and the skin share the same embryological ectoderm. Iris pattern has recently been reported as a predictive risk factor for skin cancer in non-immunosuppressed Southern European (Grigore et al., J Eur Acad Dermatol Venereol, 2018, 1662) and Irish populations (Ridge et al., J Eur Acad Dermatol Venereol, 2022, e542). AIMS: To analyse if an individual's iris pattern is an independent risk factor for the development of keratinocyte skin cancers in renal transplant recipients. METHODS: Iris patterns of 110 renal transplant recipients were evaluated using the Simionescu visual three-step technique (iris periphery, colarette and iris freckling [Simionescu et al., Ann Res Rev Biol, 2014, 2525]). Established risk factors for skin cancer in transplant patients were recorded as confounding factors. RESULTS: Observational cross-sectional study including 110 renal transplant population. Thirty-one participants had skin cancer. In the skin cancer group, iris periphery was blue/grey in 74.3% (p = 0.053, OR 2.5), the colarette was light brown in 57.1% (p < 0.0043) and iris freckles were present in 55%(p = 0.044). Dark brown and blue colarettes were observed in controls. Binary Logistic Regression analysis showed light brown colarette is a significant independent risk factor for skin cancer (OR 4.54, p < 0.02, CI 1.56-10.57). CONCLUSION: Within this renal transplant population a blue iris periphery, light brown colarette and presence of freckling confers an independent risk for keratinocyte skin cancer. Iris pattern is a useful tool for identification of transplant patients at risk of keratinocyte skin cancer and an easy-to-use technique for risk evaluation in this cohort. This is the first study looking at iris pattern and keratinocyte skin cancer risk in renal transplant population.

The genetics and evolution of eye color in domestic pigeons (Columba livia).

The eye color of birds, generally referring to the color of the iris, results from both pigmentation and structural coloration. Avian iris colors exhibit striking interspecific and intraspecific variations that correspond to unique evolutionary and ecological histories. Here, we identified the genetic basis of pearl (white) iris color in domestic pigeons (Columba livia) to explore the largely unknown genetic mechanism underlying the evolution of avian iris coloration. Using a genome-wide association study (GWAS) approach in 92 pigeons, we mapped the pearl iris trait to a 9 kb region containing the facilitative glucose transporter gene SLC2A11B. A nonsense mutation (W49X) leading to a premature stop codon in SLC2A11B was identified as the causal variant. Transcriptome analysis suggested that SLC2A11B loss of function may downregulate the xanthophore-differentiation gene CSF1R and the key pteridine biosynthesis gene GCH1, thus resulting in the pearl iris phenotype. Coalescence and phylogenetic analyses indicated that the mutation originated approximately 5,400 years ago, coinciding with the onset of pigeon domestication, while positive selection was likely associated with artificial breeding. Within Aves, potentially impaired SLC2A11B was found in six species from six distinct lineages, four of which associated with their signature brown or blue eyes and lack of pteridine. Analysis of vertebrate SLC2A11B orthologs revealed relaxed selection in the avian clade, consistent with the scenario that during and after avian divergence from the reptilian ancestor, the SLC2A11B-involved development of dermal chromatophores likely degenerated in the presence of feather coverage. Our findings provide new insight into the mechanism of avian iris color variations and the evolution of pigmentation in vertebrates.