Altered chromatin topologies caused by balanced chromosomal translocation lead to central iris hypoplasia.

Despite the advent of genomic sequencing, molecular diagnosis remains unsolved in approximately half of patients with Mendelian disorders, largely due to unclarified functions of noncoding regions and the difficulty in identifying complex structural variations. In this study, we map a unique form of central iris hypoplasia in a large family to 6q15-q23.3 and 18p11.31-q12.1 using a genome-wide linkage scan. Long-read sequencing reveals a balanced translocation t(6;18)(q22.31;p11.22) with intergenic breakpoints. By performing Hi-C on induced pluripotent stem cells from a patient, we identify two chromatin topologically associating domains spanning across the breakpoints. These alterations lead the ectopic chromatin interactions between APCDD1 on chromosome 18 and enhancers on chromosome 6, resulting in upregulation of APCDD1. Notably, APCDD1 is specifically localized in the iris of human eyes. Our findings demonstrate that noncoding structural variations can lead to Mendelian diseases by disrupting the 3D genome structure and resulting in altered gene expression.

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.

A method for extracting corneal reflection images from multiple eye images.

The incident light reflected from the cornea is rich in information about the human surroundings, and these reflected rays are imaged by the camera, which can be used for research on human consciousness and gaze analysis, and produce certain help in the fields of psychology, human computer interaction and disease diagnosis. However, limited by the low corneal reflection ability, when a high-definition camera captures corneal reflecting rays, a large amount of color and texture interference from the iris can seriously contaminate the corneal reflection images, resulting in low usability and ubiquity of corneal reflection images. In this paper, we propose a corneal reflection image extraction method with multiple eye images as input. We align the iris regions of multiple eye images with the help of iris localization method, and by comparing multiple iris regions, we obtain the complementary iris regions, so that the iris interference in the corneal reflection region can be stripped completely. A large number of experiments have demonstrated that our work can effectively mitigate iris interference and effectively improve the quality of corneal reflection images.

Retinitis pigmentosa with iris coloboma due to miR-204 gene variant in a Chinese family.

PURPOSE: To characterize the phenotype and genotype of a Chinese family with autosomal-dominant retinitis pigmentosa (RP) accompanied by iris coloboma. METHODS: The proband, a 34-year-old male, was examined with his family by using fundus photography, optical coherence tomography (OCT), autofluorescence, and full-field electroretinography (ffERG). Genetic analyses were conducted through whole-exome sequencing (WES) to screen for variations. RESULTS: Three members of this Chinese family were shown to be bilateral iris coloboma. The male proband and his mother exhibited typical RP feature. The proband's late grandfather had been documented manifestation of iris coloboma. The mode of inheritance was confirmed to be autosomal dominance. Through linkage analysis and WES, a heterozygous variation in the miR-204 gene (n.37C>T), a noncoding RNA gene, was identified in these three members. CONCLUSIONS: In this third independent and the first Asian family, the existence of a miR-204 variant associated with RP accompanied by iris coloboma was confirmed. Our findings reinforce the significance of miR-204 as an important factor influencing visual function in the retina. When phenotypes like RP accompanied by iris coloboma in an autosomal-dominant pattern, including in Chinese patients, miR-204 aberrations should be considered.

Anterior segment swept-source optical coherence tomography and ultrasound biomicroscopy in iris and ciliary body lesions.

OBJECTIVES: Differentiation of iris and ciliary body lesions as benign or malignant and cystic or solid is important. The aim of this study was to compare anterior segment swept-source optical coherence tomography (AS SS-OCT) and ultrasound biomicroscopy (UBM) findings in iris and ciliary body tumors. RESEARCH DESIGN AND METHODS: Forty-two eyes of 38 cases with iris and ciliary body tumors imaged with UBM and AS SS-OCT between September 2018 and September 2023 were evaluated retrospectively. RESULTS: Of 42 eyes, 14 had melanoma, 14 iris pigment epithelial (IPE) cysts, 7 nevi, 3 Lisch nodules, 2 iris stromal cysts, 1 pars plana cysts, and 1 iris mammillations. An equivalent (100%) visualization of the anterior tumor margin was obtained with both techniques. Compared to AS SS-OCT, UBM was superior for posterior margin visualization in melanocytic tumors and IPE cysts. Bland-Altman plots demonstrated good agreement between UBM and AS SS-OCT for melanocytic tumors < 2.5 mm in base diameter and < 2 mm in thickness. CONCLUSIONS: Although, UBM is the gold standard for ciliary body and iridociliary tumors. AS SS-OCT should be considered as an excellent alternative to UBM, especially in minimally elevated iris lesions.

Treat the individual and not the angle.

BACKGROUND: Glaucoma, the silent thief of sight, is one of the most common vision-threatening conditions. Even though POAG (primary open angle glaucoma) is more common, PACG (primary angle closure glaucoma) is the dreaded variant. ISGEO (International Society for Geographical and Epidemiological Ophthalmology) has classified primary angle closure as PACS (primary angle closure suspect), PAC (primary angle closure), and PACG (primary angle closure glaucoma. The inconspicuous nature of PACS makes its diagnosis and treatment very tricky. PURPOSE: To determine which cases are best suited for laser peripheral iridotomy. SYNOPSIS: Laser peripheral iridotomy is the gold standard for acute primary angle closure glaucoma treatment. But there is a lot of confusion regarding its use in PACS as a prophylactic measure. We have tried to throw light on laser peripheral iridotomy, a much debatable topic. The video focuses on various trials regarding laser peripheral iridotomy, the indications, side effects, and contraindications. We have also discussed its use as a therapeutic and prophylactic procedure. HIGHLIGHTS: The video highlights that the approach of laser peripheral iridotomy should be on a case-by-case basis. VIDEO LINK: https://youtu.be/kiEYI9ct2Oo.

Reverse pupillary block with pigment dispersion and elevated intraocular pressure following bilateral phakic intraocular lens implantation.

The authors describe a case of reverse pupillary block with pigment dispersion following sequential phakic intraocular lens (pIOL) implantation for high myopia, in a young female patient. The intraocular pressure (IOP) elevation began 3 weeks postoperatively, for which Nd-YAG laser peripheral iridotomies (PIs) were attempted elsewhere. Despite maximum medical therapy, the IOP was uncontrolled. She was referred to our institute for further management. Examination showed anteriorly displaced iris-pIOL diaphragm, iris pigment dispersion and raised IOP. The PIs were incomplete. Based on clinical evaluation and investigations, we concluded that the excess area of contact of the posterior iris over the pIOL caused a reverse pupillary block and pigment dispersion. The IOPs were controlled by repeating laser iridotomies and with medical therapy. Subsequently, the patient developed a low lens vault leading to bilateral cataract. Sequential explantation of the pIOL along with cataract extraction was performed and her vision was restored.

Comparative study of the ciliary body and iris morphology in the anterior eye chamber of five different vertebrate classes.

One crucial component of the optical system is the ciliary body (CB). This body secretes the aqueous humour, which is essential to maintain the internal eye pressure as well as the clearness of the lens and cornea. The histological study was designed to provide the morphological differences of CB and iris in the anterior eye chambers of the following vertebrate classes: fish (grass carp), amphibians (Arabian toad), reptiles (semiaquatic turtle, fan-footed gecko, ocellated skink, Egyptian spiny-tailed lizard, Arabian horned viper), birds (common pigeon, common quail, common kestrel), and mammals (BALB/c mouse, rabbit, golden hamster, desert hedgehog, lesser Egyptian jerboa, Egyptian fruit bat). The results showed distinct morphological appearances of the CB and iris in each species, ranging from fish to mammals. The present comparative study concluded that the morphological structure of the CB and iris is the adaptation of species to either their lifestyle or survival in specific habitats.

[Clinical characteristics and surgical management outcomes of glaucoma secondary to congenital ectropion uveae: a preliminary analysis of penetrating Schlemm's canaloplasty].

Objective: To investigate the clinical characteristics and treatment outcomes of glaucoma secondary to congenital ectropion uveae (CEU) using penetrating Schlemm's canaloplasty. Methods: This was a retrospective case series study. Medical records of patients diagnosed with glaucoma secondary to CEU and undergoing penetrating Schlemm's canaloplasty at the Eye Hospital of Wenzhou Medical University between August 2020 and December 2021 were collected. Clinical characteristics including the extent and location of iris ectropion, type of glaucoma, were analyzed. Follow-up visits were conducted at 1, 3, 6 months, and 1 year postoperatively. Visual acuity, intraocular pressure (IOP), anterior segment and fundus condition, filtering bleb morphology, use of IOP-lowering medications, ultrasound biomicroscopy results, and other indicators were analyzed to summarize surgical outcomes. Results: Six cases (6 eyes) of glaucoma secondary to CEU were included, all unilateral, with 3 left eyes and 3 right eyes; median age was 10.0 (5.3, 28.8) years; including 3 males and 3 females. Preoperative IOP was (31.7±10.0) mmHg (1 mmHg=0.133 kPa), and the preoperative number of IOP-lowering medications used was 2.0 (2.0, 3.2). The extent of iris ectropion in the 6 cases ranged from 270 ° to 360 °, with peripheral anterior synechiae corresponding to the location of iris ectropion, and angle closure with the degree of synechiae extending beyond Schwalbe's line. No surgical complications occurred in any of the 6 cases postoperatively. At 1 month postoperatively, the IOP was (16.4±3.2) mmHg, with a median of 0.0 (0.0, 1.5) medications used. At 3 months postoperatively, the IOP was (14.8±6.0) mmHg, with a median of 0.0 (0.0, 2.2) medications used. At 6 months postoperatively, the IOP was (18.1±6.1) mmHg, with a median of 0.0 (0.0, 0.5) medications used. Among them, 5 patients had a follow-up period of 1 year postoperatively, all achieving controlled IOP without the use of IOP-lowering medications, with an average IOP of (15.5±3.1) mmHg. No obvious filtering bleb formation was observed at the surgical site in all patients. Conclusions: Glaucoma secondary to CEU manifests primarily as closed-angle glaucoma, with a correspondence between the closure range of anterior iris adhesions in the angle and the extent of iris ectropion. Penetrating Schlemm's canaloplasty demonstrates favorable and stable efficacy for its treatment.

Intraocular Pressure While Using Gonioscopy, SLT, and Laser Iridotomy Lenses: An Ex Vivo Study.

Purpose: The purpose of this study was to measure intraocular pressure (IOP) elevation while applying standard gonioscopy, selective laser trabeculoplasty (SLT), and laser iridotomy procedural lenses. Methods: Twelve cadaver eyes were mounted to a custom apparatus and cannulated with a pressure transducer which measured IOP. The apparatus was mounted to a load cell which measured the force on the eye. Six ophthalmologists performed simulated gonioscopy (Sussman 4 mirror lens), SLT (Latina lens), and laser iridotomy (Abraham lens) while a computer recorded IOP (mm Hg) and force (grams). The main outcome measures were IOP and force applied to the eye globe during ophthalmic diagnostics and procedures. Results: The average IOP's during gonioscopy, SLT, and laser iridotomy were 43.2 ± 16.9 mm Hg, 39.8 ± 9.9 mm Hg, and 42.7 ± 12.6 mm Hg, respectively. The mean force on the eye for the Sussman, Latina, and Abraham lens was 40.3 ± 26.4 grams, 66.7 ± 29.8 grams, and 65.5 ± 35.9 grams, respectively. The average force applied to the eye by the Sussman lens was significantly lower than both the Latina lens (P = 0.0008) and the Abraham lens (P = 0.001). During gonioscopy indentation, IOP elevated on average to 80.5 ± 22.6 mm Hg. During simulated laser iridotomy tamponade, IOP elevated on average to 82.3 ± 27.2 mm Hg. Conclusions: In cadaver eyes, the use of standard ophthalmic procedural lenses elevated IOP by approximately 20 mm Hg above baseline.

Macular corneal dystrophy with iridofundal coloboma in the same patient: a unique combination.

A young a presented with painless, progressive diminution of vision in both eyes (BE). Slit lamp examination revealed the presence of a single central corneal opacity in the right eye and multiple corneal opacities of varying sizes in the left eye (LE), limited to the anterior-mid corneal stroma. Microcornea with reduced central corneal thickness and complete inferonasal iris coloboma along with inferior fundal coloboma, sparing both the disc and macula, were noted in BE. A diagnosis of BE macular corneal dystrophy (MCD) and iridofundal coloboma (IFC) was made. The patient underwent LE sutureless anterior lamellar therapeutic keratoplasty. On histopathological examination, the excised corneal tissue revealed stromal lamellar disarray with positive colloidal iron staining, strongly suggestive of MCD. Whole-exome sequencing revealed the presence of a likely pathogenic carbohydrate sulfotransferase 6 (CHST6) mutation, confirming the diagnosis of MCD. This concurrent presence of IFC with a corneal stromal dystrophy is previously unreported in the literature, to the best of our knowledge.

Long-term results of anterior chamber iris claw intraocular lens implantation in children with ectopia lentis in Marfan syndrome.

PURPOSE: To report the long-term clinical and endothelial cell count (ECC) results of lensectomy with primary anterior chamber iris claw lens implantation in the eyes of patients ≤18-year-old with ectopia lentis due to Marfan syndrome. METHODS: The medical records of Marfan patients operated on at a single institution from September 2007 to August 2020, with minimum follow-up of 2 years, were reviewed retrospectively. The following data were analyzed: sex, age at surgery, indication for surgery, the position of the lens in relation to the undilated and dilated pupil, corneal endothelial cell counts (ECC), peri- and postoperative complications, pre- and postoperative best-corrected visual acuity. RESULTS: A total of forty-two eyes of 23 patients (12 girls and 11 boys) were included. At least two or more postoperative ECCs were collected from 33 eyes (17 patients). Median age at IOL implantation was 6.1 years (range, 1.8-18). Median overall follow-up time was 6.2 years (range, 2-13.5). Median ECC follow-up time was 6.2 years (range, 2-10). Mean best-corrected visual acuity was 0.71 ± 0.38 logMAR before surgery and 0.02 ± 0.25 logMAR at final follow-up. The mean annual ECC decline was 0.71% ± 2.24. Total cell loss from first to last postoperative measurement was 150 cells ± 394 cells/mm2 (4.81%). Pre- and first postoperative data were available for 17 eyes of 10 patients, with a mean cell loss before and directly after surgery of 269 ± 268 cells (7.94%). Surgery related complications were iris bombé due to blockage of peripheral iridectomy in 3 eyes and claw dislocation due to direct impact trauma in 3 eyes. CONCLUSIONS: In our large, pediatric study cohort, anterior chamber iris claw IOL implantation resulted in an excellent visual outcome and normal endothelial cell loss compared with normative data. Safety measures are recommended to avoid traumatic dislocation of IOLs.

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.

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.

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.

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.

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.

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.

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.