Synthetic Iris Images: A Comparative Analysis between Cartesian and Polar Representation.

In recent years, the advancement of generative techniques, particularly generative adversarial networks (GANs), has opened new possibilities for generating synthetic biometric data from different modalities, including-among others-images of irises, fingerprints, or faces in different representations. This study presents the process of generating synthetic images of human irises, using the recent StyleGAN3 model. The novelty presented in this work consists in producing generated content in both Cartesian and polar coordinate representations, typically used in iris recognition pipelines, such as the foundational work proposed by John Daugman, but hitherto not used in generative AI experiments. The main objective of this study was to conduct a qualitative analysis of the synthetic samples and evaluate the iris texture density and suitability for meaningful feature extraction. During this study, a total of 1327 unique irises were generated, and experimental results carried out using the well-known OSIRIS open-source iris recognition software and the equivalent software, wordlcoin-openiris, newly published at the end of 2023 to prove that (1) no "identity leak" from the training set was observed, and (2) the generated irises had enough unique textural information to be successfully differentiated between both themselves and between them and real, authentic iris samples. The results of our research demonstrate the promising potential of synthetic iris data generation as a valuable tool for augmenting training datasets and improving the overall performance of iris recognition systems. By exploring the synthetic data in both Cartesian and polar representations, we aim to understand the benefits and limitations of each approach and their implications for biometric applications. The findings suggest that synthetic iris data can significantly contribute to the advancement of iris recognition technology, enhancing its accuracy and robustness in real-world scenarios by greatly augmenting the possibilities to gather large and diversified training datasets.

Limbal reconstruction in uveitic glaucoma patient with exposed Ahmed valve coincident with corneal melting and iris prolapse using multiple corneoscleral allografts.

Aim: To present a complex case of Ahmed tube exposure 6 months after the implantation associated with corneal melting and iris prolapse, and the surgical reposition that required multiple allografts and limbal reconstruction. Methods: A 60-year-old patient arrived at the emergency room with tube exposure combined with corneal melting and iris prolapse from a previously placed Ahmed valve 6 months prior. Our approach was to use one corneoscleral graft to repair the melted cornea and avoid further iris prolapse and a second scleral graft to cover the repositioned tube. Upon completion of conjunctival dissection, cleaning and deepithelization of the melted cornea and the tube by application of alcohol 100% followed. A new entry point was made for the tube and was covered using an alcohol-preserved scleral allograft and the previous entry point was repaired using a corneoscleral allograft with the corneal aspect restoring the limbus and avoiding further iris protrusion. Results: 6 months follow-up of the patient showed excellent recovery, anatomical restoration, and IOP normalization. Conclusion: Surgical repair of these cases can be very demanding, and requires surgical improvisation and prolonged surgical time. The literature remains very limited on how a surgeon should approach similar cases, which are the crucial tips, and which are the missteps that should be avoided. In this case, we used multiple scleral/corneoscleral allografts in a specific orientation and different sutures to reconstruct the damaged limbal area and restore the anatomy. Abbreviations: VA = Visual Acuity, GDD = Glaucoma Drainage Device, IOP = Intra Ocular Pressure.

In Vivo Imaging of Liver Spheroids Engrafted in the Anterior Chamber of the Mouse Eye.

Biomedical studies of the liver in mammals are hindered by the lack of methods for in vivo noninvasive longitudinal imaging at cellular resolution. Until now, optical imaging of the liver in situ is possible by intravital imaging, which offers high-resolution imaging at the cellular level but cannot be performed multiple times and, therefore, longitudinally in the same animal. Noninvasive imaging methods, such as bioluminescence, allow repeated imaging sessions on the same animal but do not achieve cell resolution. To address this methodology gap, we have developed a platform for noninvasive in vivo imaging of liver spheroids engrafted in the anterior chamber of the mouse eye. In the workflow described in this study, primary mouse liver spheroids are generated in vitro and transplanted into the anterior chamber of the eye of recipient mice, where they engraft on the iris. The cornea acts as a natural body window through which we can image the engrafted spheroids by conventional confocal microscopy. The spheroids survive for months in the eye, during which the cells can be studied in contexts of health and disease, as well as being monitored in response to different stimuli over repeated imaging sessions using appropriate fluorescent probes. In this protocol, we provide a breakdown of the necessary steps to implement this imaging system and explain how to best harness its potential.

Targeted development and optimization of small-molecule ice recrystallization inhibitors (IRIs) for the cryopreservation of biological systems.

Despite the routine use of cryopreservation for the storage of biological materials, its outcomes are often sub-optimal (including reduced post-thaw viability, recovery, and functionality) due to the damage caused by uncontrolled ice growth. Traditional cryoprotective agents (CPAs), including dimethyl sulfoxide (DMSO), fail to prevent damage caused by ice growth and concerns over CPA cytotoxicity have fostered an increased interest in developing improved CPAs and cryoprotection strategies. The inhibition of ice recrystallization by natural antifreeze (glyco)proteins [AF(G)Ps] to improve cryopreservation outcomes has been examined; however, the ice binding properties of these substances and their challenging large-scale production make them poor CPA candidates. Therefore, the development and deployment of biocompatible, small-molecule ice recrystallization inhibitors (IRIs) for use as CPAs is a worthwhile objective. Extensive structure-activity relationship studies on AF(G)Ps revealed that simple carbohydrate derivatives could inhibit ice recrystallization. It was later discovered that this activity could be fine-tuned by delicately balancing the molecule's hydrophobicity and hydrophilicity. Current generation small-molecule IRIs have been meticulously designed to avoid binding to the surface of ice and subsequent biological testing (for both cytotoxicity and cryopreservation efficacy) has demonstrated significant improvements to the cryopreservation outcomes of several cell types. However, an individualized cell-specific approach for the simultaneous assessment of multiple cryopreservation outcomes is necessary to realize the full potential of IRIs as CPAs. This article provides a detailed overview of the development of small-molecule carbohydrate-based IRIs and highlights the crucial cell-specific biological considerations that must be taken into account when assessing cryopreservation outcomes. https://doi.org/10.54680/fr24210110112.

Cataract surgery and artificial iris implantation in patient with oculocutaneous albinism: a case report.

We present a case report detailing the successful phacoemulsification surgery with artificial iris implantation for two individuals with oculocutaneous albinism. These women suffered from cataracts, resulting in reduced visual acuity and heightened photophobia due to iris pigmentary epithelium deficiency. The patients underwent phacoemulsification along with prosthetic artificial iris implantation into the posterior chamber. This intervention resulted in improved visual acuity, reduced photophobia and glare, and an overall enhanced quality of life. Our report highlights two cases of successful phacoemulsification and artificial iris implantation in patients with oculocutaneous albinism and cataracts, leading to improved visual acuity, reduced photophobia, and enhanced quality of life. Notably, there are no prior records in South American literature of cataract surgery combined with artificial iris implantation for oculocutaneous albinism patients up to the time of this publication.

Bilateral acute depigmentation of the iris (BADI) and bilateral acute iris transillumination (BAIT): A case series from a center in Brazil.

Bilateral acute depigmentation of the iris and bilateral acute iris transillumination (BAIT) are similar clinical entities. The former causes acute-onset depigmentation of the iris stroma without transillumination, whereas the latter causes depigmentation of the iris pigment epithelium with transillumination. The etiopathogenesis of these conditions is not yet fully understood, but the proposed causes include the use of systemic antibiotics (especially moxifloxacin) and viral triggers. We present a case series of five female patients with a mean age of 41 (32-45) years, all of whom suffered acute onset of bilateral pain and redness of the eyes after moxifloxacin use (oral or topical). It is important for ophthalmologists to be aware of the two forms of iris depigmentation since this case series suggests that SARS-CoV-2 or its empirical treatment with moxifloxacin may trigger iris depigmentation. If this is the case, clinicians will likely see increased incidences of bilateral acute depigmentation of the iris and bilateral acute iris transillumination during and after the COVID-19 pandemic.

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.

Couching of cataractous lens in microphthalmic eyes with irido-fundal coloboma: revisiting the historical technique.

PURPOSE: Cataract surgery in microphthalmic eyes is challenging due to anatomical restraints, hard bulky nucleus. This series aims to evaluate the safety and efficacy of couching of intraocular lens in irido-fundal coloboma with microphthalmos. SETTING: Tertiary care centre in South India. DESIGN: Retrospective non-comparative study in eyes with irido-fundal coloboma, corneal diameter < 7 mm and brown cataract. Visual acuity less than 6/60 in other eye. METHODS: Anterior chamber entry made, zonules broken and lens dislocated into the vitreous cavity in a controlled manner. Baseline Clinico-demographic details, corrected distance visual acuity (CDVA), Intra-ocular pressure (IOP), corneal diameter, axial length, lens status and post-surgery CDVA, IOP and complications recorded and followed up for atleast 6 months. RESULTS: Fifteen eyes of 15 subjects were evaluated with a mean age 49.4 ± 10.9 years. At baseline, mean IOP 14.5 ± 3.8 mmHg, mean axial length 19.3 ± 0.5 mm, mean corneal diameter was 6.5 ± 0.34 mm and CDVA 2 logMAR which improved to 1.5 logMAR at 3 months (p value 0.002). Transient spike in IOP in 33.3% subjects was medically managed with no significant difference in IOP (p > 0.05) at baseline (14.5 ± 3.8 mmHg), 3 months post-surgery (16 ± 2.8 mmHg) and 6 months post-surgery (14.9 ± 2.5 mmHg). One patient underwent re-couching. No other major complications were noted. CONCLUSION: Couching of cataractous lens is an effective and safe method in microphthalmic eyes with irido-fundal coloboma as last resort procedure, where no other surgical procedure may work. It provides an ambulatory gain of visual acuity in previously non-ambulatory subjects. Corneal measurements help in determining the subset of patients where couching offers viable option.

Retropupillary Iris-fixated versus Sutured Scleral-fixated Intraocular Lenses.

Aim: To compare the anatomical and functional results and patient satisfaction following retropupillary implantation of Artisan Aphakia iris-fixated intraocular lens (rAAIF) and sutured scleral fixated intraocular lens (SFIOL). Subjects and methods: We presented a prospective double-arm non-blinded study. Forty-one eyes with acquired aphakia, no age-related macular degeneration, no previous keratoplasty, no combined procedures, no AC reaction (cells, fibrin), normal intraocular pressure, no history of endothelial corneal dystrophy in relatives or fellow eye were included. Indications, complications, corrected distance visual acuity (CDVA), endothelial cell density (ECD), and patient satisfaction score were assessed. Results: Retropupillary AAIF was implanted in 21 (51.22%) eyes and SFIOL in 20 (48.78%) eyes. The most common indication was complicated cataract surgery in 18 cases (43.90%), followed by trauma in 16 (39.02%), and spontaneous dislocation in 7 (17.07%). No difference between rAAIF and SFIOL in terms of sex, laterality (χ=0.13, p=0.72), indications (χ=0.78, p=0.68), previous ocular history, and comorbidities was observed. The complications and the visual outcomes at 6 months postoperatively were similar between the two groups (p=0.95 and p=0.321, respectively). The ECD loss in the two groups was also similar (p=0.89). The patient satisfaction score was 58.67±8.80 in the rAAIF and 56.69±11.50 in the SFIOL group, which was statistically similar (p=0.764). Conclusion: Retropupillary AAIF and SFIOL showed similar results concerning visual acuity, endothelial cell loss, and patient satisfaction. Careful preoperative individual assessment is required to have optimal results with either technique. Abbreviations: AAIF = Artisan Aphakia iris-fixated intraocular lens, rAAIF = retropupillary Artisan Aphakia iris-fixated intraocular lens, CDVA = corrected distance visual acuity, ECD = endothelial cell density, IOL = intraocular lens, SD = standard deviation, SFIOL = scleral fixated intraocular lens.

Alkali injury-induced pathological lymphangiogenesis in the iris facilitates the infiltration of T cells and ocular inflammation.

Inflammatory lymphangiogenesis is intimately linked to immune regulation and tissue homeostasis. However, current evidence has suggested that classic lymphatic vessels are physiologically absent in intraocular structures. Here, we show that neolymphatic vessels were induced in the iris after corneal alkali injury (CAI) in a VEGFR3-dependent manner. Cre-loxP-based lineage tracing revealed that these lymphatic endothelial cells (LECs) originate from existing Prox1+ lymphatic vessels. Notably, the ablation of iridial lymphangiogenesis via conditional deletion of VEGFR3 alleviated the ocular inflammatory response and pathological T cell infiltration. Our findings demonstrate that iridial neolymphatics actively participate in pathological immune responses following injury and suggest intraocular lymphangiogenesis as a valuable therapeutic target for the treatment of ocular inflammation.

Bilateral total iris atrophy, corneal decompensation and glaucoma following bilateral cosmetic artificial iris implantation: A case report of severe sequela and successful management.

PURPOSE: Cosmetic iris implants have a record of high ocular complications and are no longer in use. These complications include glaucoma, corneal decompensation, iris atrophy, uveitis, cataract and retinal detachment. CASE PRESENTATION: We report a case of a 44-year-old lady presented with bilateral total iris atrophy, glaucoma and corneal decompensation after cosmetic artificial iris implantation. The patient underwent bilateral artificial iris removal, glaucoma drainage device for the right eye, and micropulse laser for the left eye. In addition, she underwent phacoemulsification with iris-diaphragm intraocular lens implant for the right. The cornea of the right eye ended up with successful Boston keratoprosthesis after rejection of previous 2 grafts. CONCLUSIONS: To the best of our knowledge, we describe the first report of bilateral total iris atrophy following a cosmetic iris implant accompanied by bilateral glaucoma and corneal decompensation.

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.

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.

[Structural and functional features of the eye in Marfan syndrome. Report 2. Changes in the anatomical complex of the lens]. / Strukturno-funktsional'nye osobennosti glaza pri sindrome Marfana. Soobshchenie 2. Izmeneniya anatomicheskogo kompleksa khrustalika.

Analysis of lens changes in Marfan syndrome (MS), in addition to assessing the position of the lens itself, should include the possibility of examining its supporting and accommodative components (ciliary zonule and ciliary body), or what can be called the entire anatomical complex of the lens. Optical methods of studying the structures of the anterior segment of the eye, due to iris opacity, allow only to analyze the state of the lens within the natural or medically enlarged pupil width. Visualization of the structures located behind the iris is possible with the use of radiation diagnostic methods, in particular ultrasound biomicroscopy (UBM). PURPOSE: This study assesses the state of the anatomical complex of the lens in MS using UBM. MATERIAL AND METHODS: The study was carried out on clinical material previously used by us to analyze changes in the fibrous membrane of the eye in MS. At the first stage, the main (19 patients with MS, 38 eyes) and the control (24 patients with myopia, 48 eyes) groups were formed for comparative evaluation. The formed groups were standardized according to the age of the patients and the axial length of the eye. At the second stage, patients with MS were divided into subgroups depending on the absence or presence of biomicroscopic signs of ectopia lentis (22 and 16 eyes, respectively). For UBM, an ultrasound linear sensor with a scanning frequency of 50 MHz was used (Aviso device, Quantel Medical, France). Various biometric UBM indicators were determined: lens thickness, diameter of the lens, lens-axial length factor, iris-lens angle, iris-lens contact distance, posterior chamber depth, length of the fibers of ciliary zonule, thickness of the ciliary body, sclera-ciliary process angle. RESULTS: There are changes in the anatomical complex of the lens as a whole in MS (in the lens itself, the ciliary zonule, and the ciliary body), which are characterized by an increase in lens thickness and a decrease in the diameter of the lens, an increase in the length of the fibers of the ciliary zonule and a decrease in the thickness of the ciliary body. At the same time, the displacement of the lens detected by optical biomicroscopy (ectopia lentis) can be considered as an advanced stage of changes in the anatomical complex of the lens. CONCLUSION: UBM provides the possibility of full-fledged visualization of all components of the anatomical complex of the lens in terms of both diagnostics, and monitoring of changes in MS. The question of the advisability of including this method in the algorithm for diagnosing ocular manifestations in order to verify the MS remains open. Possible obstacles may be, on the one hand, related to the need for special and expensive equipment, and on the other hand, the absence of a generally accepted «normal¼ values of UBM indicators of the anatomical complex of the lens.

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.

Lensectomy as treatment for refractory or progressive retinopathy of prematurity narrow-angle glaucoma.

We present the case of a patient with a history of laser-treated retinopathy of prematurity (ROP) who developed narrow angles and intermittent angle closure. Despite laser peripheral iridotomy/iridoplasty, 1 year later, the patient had recurrent narrowing that resolved following clear lens extraction with intraocular lens placement. This case highlights the importance of continued monitoring for narrow angles in patients with ROP history.

Long-Term Efficacy of Selective Laser Trabeculoplasty in Primary Angle-Closure Disease After Laser Peripheral Iridotomy.

PURPOSE: To evaluate the long-term efficacy of selective laser trabeculoplasty (SLT) in eyes with primary angle-closure (PAC) and primary angle-closure glaucoma (PACG) following a laser peripheral iridotomy (LPI). METHOD: In this prospective cross-sectional study, 45 eyes of 34 patients with PAC/PACG diagnosis, uncontrolled intraocular pressure (IOP), and visible pigmented trabecular-meshwork (TM) at least 180° on gonioscopy following a LPI were recruited. Following a detailed baseline ophthalmic evaluation, all eligible eyes underwent SLT, and the patients were examined on day1, at 1 week, 1-, 3-, and 6-months, and 1-, 2-, 3-, 4-, and 5-year subsequently. The main outcomes measured were IOP, number of IOP-lowering agents, and complications. RESULTS: The mean age of the cohort was 57.80 ± 6.44 years, the male-female ratio was 8:26, and 17 eyes were PACG, and 28 were PAC. The baseline IOP was 23.81 ± 1.78 mm Hg, and was significantly declined at all follow-ups (p < .0001). The cumulative probability of overall success was 91% and 84% at 2-, and 5-year, respectively. At 5-year SLT provided drug-freedom in 80% of PAC and 23% of PACG eyes. Six eyes had IOP spike at 1-week and two patients underwent repeat SLT after 1-year. No other complications, such as pain/discomfort, inflammation, an increase in peripheral anterior synechiae and cystoid-macular-edema, were noted. CONCLUSIONS: SLT appears a safe and cost-effective procedure in PAC/mild- moderate PACG eyes with uncontrolled IOP after laser iridotomy. The long-term effectiveness of SLT as adjuvant treatment was good, but need large sized randomized studies for more validation.

Phenotypic Features Determining Visual Acuity in Albinism and the Role of Amblyogenic Factors.

Albinism is a spectrum disorder causing foveal hypoplasia, nystagmus, and hypopigmentation of the iris and fundus along with other visual deficits, which can all impact vision. Albinism is also associated with amblyogenic factors which could affect monocular visual acuity. The foveal appearance in albinism can range from mild foveal hypoplasia to that which is indistinguishable from the peripheral retina. The appearance can be quickly and easily graded using the Leicester Grading System in the clinic. However, interquartile ranges of 0.3 logMAR for the grades associated with albinism limit the accuracy of the grading system in predicting vision. Here, we discuss the potential role of nystagmus presenting evidence that it may not be a major source of variability in the prediction of visual acuity. We also show that interocular differences in visual acuity are low in albinism despite high levels of amblyogenic factors indicating that active suppression of vision in one eye in albinism is uncommon.

Direct observation and measurement of circumlental space and its relation to anterior chamber angle characteristics in iridotomized phakic eyes with primary angle closure disease.

Primary angle closure disease (PACD) is a major cause of blindness worldwide. It has a high prevalence in East Asia, especially in China, which leads to a higher incidence of blindness than open-angle glaucoma. The aim of this study was to directly observe the circumlental space (CLS) in laser peripheral iridotomized eyes with PACD and to determine whether this structure plays a role in the pathogenesis of PACD. Fifty eyes of 50 patients with PACD, who had received laser peripheral iridotomy performed with neodymium:yttrium-aluminum-garnet were recruited from glaucoma clinics from March 2021 to May 2022, including 17 primary angle closure suspect (PACS), 16 primary angle closure (PAC) and 17 primary angle closure glaucoma (PACG). They were classified into two groups based on whether the ciliary process and the crystalline lens equator were in contact using slit-lamp photograph: the attached group and the unattached group. The demographic, clinical characteristics and anterior segment parameters measured from ultrasound biomicroscopy were compared between the attached group and the unattached group. Thirty-three eyes were assigned to the attached group and 17 eyes belonged to the unattached group. In the unattached group, the mean CLS was 0.10 ± 0.07 mm. No significant differences were identified between the different diagnosis groups in age, sex, best-corrected visual acuity, intraocular pressure, white-to-white, axial length, central corneal thickness, anterior chamber depth, flat keratometry, steep keratometry or iridotomy diameter (p > 0.05). The unattached group had shorter trabecular-ciliary process distance (p = 0.021) and larger ciliary process area (p = 0.001) compared with the attached group. Small CLS and its potential effect (partial ciliary block) might be considered as one of the mechanisms of PACD.