Association of sodium-glucose cotransporter-2 inhibitors and the risk of retinal vascular occlusion: A real-world retrospective cohort study in Taiwan.

AIMS: Sodium-glucose cotransporter-2 inhibitors (SGLT2is) are proposed to alleviate the development of inflammatory eye diseases. However, the association between SGLT2i and retinal vascular occlusion remains unclear. Therefore, this study aims to explore the effects of SGLT2i on the incidence of retinal vascular occlusion. MATERIALS AND METHODS: This retrospective cohort study analysed electronic medical records data from the largest multi-institutional database in Taiwan. Individuals who initiated SGLT2is and dipeptidyl peptidase 4 inhibitors (DPP4is) between 2016 and 2019 were included in our analysis. To conduct a homogenous comparison, inverse probability of treatment weighting with propensity scoring was employed. The primary outcome was retinal vascular occlusion, and the secondary outcomes were retinal vascular occlusion-related complications (macular oedema, vitreous haemorrhage, and tractional retinal detachment) and conditions requiring vitreoretinal intervention (intravitreal injection, retinal laser therapy, and vitrectomy). RESULTS: In total, 12,074 SGLT2i users and 39,318 DPP4i users were included. The incidence rate of retinal vascular occlusion in the SGLT2i and DPP4i groups was 1.2 (95% confidence interval [CI], 0.9-1.4) and 1.6 (95% CI, 1.3-1.8) events per 1000 person-years, respectively, which yielded a subdistribution hazard ratio (SHR) of 0.74 (95% CI, 0.55-0.99). Similar risk reductions were observed in the retinal vascular occlusion-related complications (SHR, 0.76; 95% CI, 0.69-0.84) and conditions requiring vitreoretinal intervention (SHR, 0.84; 95% CI, 0.77-0.94). CONCLUSIONS: In this multi-institutional study in Taiwan, SGLT2i use was associated with a reduced risk of retinal vascular occlusion. Further prospective studies are required to ascertain this association.

A comparative study of stereopsis in term and preterm children with and without retinopathy of prematurity.

PURPOSE: To evaluate stereopsis in term-born, preterm, and preterm children with and without retinopathy of prematurity (ROP) and its treatment. METHODS: The cross-sectional study included 322 children between 3 and 11 years of age born term or preterm, with or without ROP, and with or without treatment for ROP. The ROP treatments were laser therapy, intravitreal injection (IVI) of anti-vascular endothelial growth factor, or their combination. Stereoacuity was measured using the Titmus Stereo Test, and the results among various age groups were analyzed. RESULTS: Stereopsis was found to improve with increasing age at testing (P < 0.001) across the entire study population. The term group exhibited significantly better stereoacuity than the preterm group (P < 0.001). At 3-5 years and 6-8 years, the preterm children without ROP exhibited significantly better stereoacuity than did those with ROP (P < 0.001 and P = 0.02, respectively); however, at 9-11 years, both groups exhibited similar stereoacuity (P = 0.34). The stereoacuity in the children with untreated ROP was similar to that of the children with treated ROP in all age groups (P > 0.05). No significant differences in stereopsis were identified between children with ROP treated with laser versus with IVI (P > 0.05). From multivariate analysis, younger age at testing (P = 0.001) and younger gestational age (P < 0.001) were associated with poorer stereopsis. CONCLUSIONS: Stereopsis development gradually improved with age in all groups. The children born preterm exhibited poorer stereoacuity than those born term. Children with ROP treated with laser photocoagulation versus IVI may exhibit similar levels of stereoacuity. Younger age at testing and gestational age were independent risk factors for poorer stereoacuity.

Mitochondria in Retinal Ganglion Cells: Unraveling the Metabolic Nexus and Oxidative Stress.

This review explored the role of mitochondria in retinal ganglion cells (RGCs), which are essential for visual processing. Mitochondrial dysfunction is a key factor in the pathogenesis of various vision-related disorders, including glaucoma, hereditary optic neuropathy, and age-related macular degeneration. This review highlighted the critical role of mitochondria in RGCs, which provide metabolic support, regulate cellular health, and respond to cellular stress while also producing reactive oxygen species (ROS) that can damage cellular components. Maintaining mitochondrial function is essential for meeting RGCs' high metabolic demands and ensuring redox homeostasis, which is crucial for their proper function and visual health. Oxidative stress, exacerbated by factors like elevated intraocular pressure and environmental factors, contributes to diseases such as glaucoma and age-related vision loss by triggering cellular damage pathways. Strategies targeting mitochondrial function or bolstering antioxidant defenses include mitochondrial-based therapies, gene therapies, and mitochondrial transplantation. These advances can offer potential strategies for addressing mitochondrial dysfunction in the retina, with implications that extend beyond ocular diseases.

LONG-TERM CLINICAL OUTCOMES AND GENOTYPE-PHENOTYPE CORRELATION IN FAMILIAL EXUDATIVE VITREORETINOPATHY IN A TERTIARY REFERRAL CENTER.

BACKGROUND/PURPOSE: To evaluate clinical outcomes and assess genotype-phenotype correlations in patients with familial exudative vitreoretinopathy (FEVR). METHODS: Clinical charts of 40 patients with FEVR were reviewed. FEVR was staged per Pendergast and Trese, and retinal dragging and folds further classified per Yaguchi et al. We performed whole-exome sequencing and compared clinical characteristics between genetic-positive and genetic-negative groups. RESULTS: The mean duration of follow-up was 5.4 years (range: 0.33, 15) for genetic-positive and 6.9 (range: 1, 20) for genetic-negative patients. The mean age at diagnosis was 5.6 years (0.25, 27) for genetic-positive and 6.0 (0, 32) for genetic-negative patients. Genetic-positive patients reported 100% full-term births and genetic-negative patients reported 45% full-term births ( P = 0.0012). There were more patients with retinal folds with all major vessels affected (Yaguchi's Group 4) in genetic-positive compared with genetic-negative patients (21.4% vs. 2.6%, P = 0.045). TSPAN12 was the most common (57.1%) genetic mutation in our population of which 50% exhibited asymmetric presentation. CONCLUSION: Patients who test positive for a typical FEVR gene mutation reported more term births and had more severe disease by Yaguchi's classification. TSPAN12 was the most common genetic mutation in our population and had highly asymmetrical disease.

Cytomegalovirus Glycoprotein B Genotype in Patients with Anterior Segment Infection.

(1) The glycoprotein B (gB) on the viral envelope, encoded by the most widely characterised polymorphic gene, gpUL55, is responsible for cytomegalovirus (CMV) entry into the host and could serve as a potential marker of pathogenicity. The aim of the present study is to investigate the distribution of the CMV gB genotype in anterior segment infection in Taiwan and its correlation with clinical manifestations and outcomes. (2) Fifty-seven patients with CMV anterior segment infection were identified according to clinical features and positivity for CMV DNA in aqueous humour samples. CMV gB genotyping was performed through polymerase chain reaction assays. Patients' medical records were retrospectively reviewed. (3) Among the 57 aqueous humour samples tested for gB, 40 (70.28%) had multiple gB genotypes, and only 17 (29.82%) had a single gB genotype. Compared with single-genotype infection, multiple-genotype infection was correlated with higher CMV loads (p < 0.001) but not correlated with outcome. A higher proportion of patients with the gB3 genotype had received filtering surgery before antiviral treatment than those without the gB3 genotype (p = 0.046). (4) Multiple-genotype infection was highly prevalent in CMV anterior segment infection in Taiwan, and gB1 and gB3 were predominant. Multiple-genotype infection was correlated with higher CMV loads but not with specific clinical manifestations or prognostic outcomes. The gB3 genotype may be correlated with poor intraocular pressure control.

Retrospective Analysis of Surgical Outcomes on Axial Length Elongation in Eyes with Posterior and Combined Persistent Fetal Vasculature.

This study aims to investigate the outcomes and risk factors associated with poor vision (vision less than counting fingers, 2.0 logMAR, Snellen vision 20/2000) in patients with posterior or combined persistent fetal vasculature (PFV), with or without surgery. We retrospectively reviewed the medical records of patients who were diagnosed with PFV from January 2008 to April 2021. We included 51 eyes of 44 patients who presented with PFV, of which 38 eyes underwent surgical correction (pars plicata/plana vitrectomy, with or without lensectomy, and intraocular lens implantation) at the median age of 6.0 months (range: 0.7 to 82.0). The mean follow-up was 68.8 months ± 38.0 months. The axial length change in the eyes undergoing surgery was significantly higher than the eyes without surgery (p = 0.025). Initial anterior chamber collapse and retinal detachment were associated with poor vision (p = 0.006 and p = 0.002, respectively). In addition, 37% of eyes with posterior or combined PFV had vision better than counting fingers. Surgery for eyes with PFV could result in better eye growth. Visual outcomes remained poor and were associated with the level of macular abnormality. Initial anterior chamber collapse and retinal detachment at presentation were the risk factors for poor visual outcomes. Vitrectomy for selected PFV eyes is valuable and associated with a better cosmetic outcome (better eye growth).

MicroRNA-152-3p and MicroRNA-196a-5p Are Downregulated When Müller Cells Are Promoted by Components of the Internal Limiting Membrane: Implications for Macular Hole Healing.

Müller cells play a critical role in the closure of macular holes, and their proliferation and migration are facilitated by the internal limiting membrane (ILM). Despite the importance of this process, the underlying molecular mechanism remains underexplored. This study investigated the effects of ILM components on the microRNA (miRNA) profile of Müller cells. Rat Müller cells (rMC-1) were cultured with a culture insert and varying concentrations of ILM component coatings, namely, collagen IV, laminin, and fibronectin, and cell migration was assessed by measuring cell-free areas in successive photographs following insert removal. MiRNAs were then extracted from these cells and analyzed. Mimics and inhibitors of miRNA candidates were transfected into Müller cells, and a cell migration assay and additional cell viability assays were performed. The results revealed that the ILM components promoted Müller cell migration (p < 0.01). Among the miRNA candidates, miR-194-3p was upregulated, whereas miR-125b-1-3p, miR-132-3p, miR-146b-5p, miR-152-3p, miR-196a-5p, miR-542-5p, miR-871-3p, miR-1839-5p, and miR-3573-3p were significantly downregulated (p < 0.05; fold change > 1.5). Moreover, miR-152-3p and miR-196a-5p reduced cell migration (p < 0.05) and proliferation (p < 0.001), and their suppressive effects were reversed by their respective inhibitors. In conclusion, miRNAs were regulated in ILM component-activated Müller cells, with miR-152-3p and miR-196a-5p regulating Müller cell migration and proliferation. These results serve as a basis for understanding the molecular healing process of macular holes and identifying potential new target genes in future research.

CLINICAL OUTCOMES OF PATIENTS WITH ENDOPHTHALMITIS AFTER DEXAMETHASONE INTRAVITREAL IMPLANT.

PURPOSE: To report a case series of endophthalmitis associated with intravitreal dexamethasone injections in a single practice and to discuss the clinical findings and visual outcomes of each case. METHODS: All endophthalmitis cases following intravitreal dexamethasone injections performed from January 1, 2014 to October 20, 2020 were identified using Wills Eye/MidAtlantic billing records. The diagnosis, clinical information, and microbiology were confirmed for each case. Data were analyzed using Excel (Microsoft Excel, Redmond, WA). RESULTS: Four cases of endophthalmitis were identified from 3,925 intravitreal dexamethasone injections in a single practice and one case was referred from an outside institution, resulting in an incidence of 0.102% (1 in 981 injections). Mean age was 82.3 years (range, 63-88 years) with a mean of 11.3 intravitreal dexamethasone injections performed (range, 2-30 injections) before endophthalmitis. Cases presented with endophthalmitis a mean (SD) of 3.6 (1.64) days after causative injection. Three cases grew gram-positive organisms. All patients responded to intravitreal antibiotics. Mean logarithm of the minimal angle of resolution visual acuity at causative injection, endophthalmitis presentation, 3 months, and last follow-up was 0.44 (20/55), 2.22 (20/3,319), 1.18 (20/303), and 1.46 (20/577), respectively. CONCLUSION: Endophthalmitis following intravitreal steroid injections may occur more frequently than other intravitreal injections. Dexamethasone-attributed endophthalmitis remains uncommon, and prompt intravitreal antibiotic treatment seems to be effective in this series.

Case report: novel PCDH15 variant causes usher syndrome type 1F with congenital hearing loss and syndromic retinitis pigmentosa.

BACKGROUND: Usher syndrome (USH) is an autosomal recessive disorder primarily responsible for deaf-blindness. Patients with subtype Usher syndrome type 1 (USH1) typically experience congenital sensorineural hearing loss, abnormal vestibular function, and retinitis pigmentosa (RP). Here we present a case of Usher syndrome type 1F (USH1F) with a novel homozygous variant in the calcium-dependent cell-cell adhesion protocadherin-15 (PCDH15) gene. CASE PRESENTATION: Ophthalmic examinations were evaluated over a course of 10 years and the disease-causing variant was identified by whole exome sequencing (WES). Initial and follow-up examination of color fundus photos after 10 years revealed an increase in bone spicule pigment deposits in both eyes. A parafoveal hyper-AF ring in both eyes was shown in fundus autofluorescence (FAF) with a progressive diameter-wise constriction observed over 8 years. Outer nuclear layer (ONL) loss was observed in parafoveal and perifoveal regions of both eyes on spectral domain-optical coherence tomography (SD-OCT). Full-field electroretinography (ffERG) showed extinguished global retinal function. WES identified a novel two-base-pair deletion, c.60_61del (p.Phe21Ter), in the PCDH15 gene, confirming the diagnosis of USH1F. CONCLUSIONS: We report a novel homozygous PCDH15 pathogenic variant expected to lead to nonsense-mediated decay (NMD) of PCDH15 mRNA. The patient exhibits a loss of function with USH1F, experiencing congenital hearing loss and syndromic RP.

Staphylococcus aureus Keratitis in Taiwan: Genotyping, Antibiotic Susceptibility, and Clinical Features.

Staphylococcus aureus is an important pathogen for keratitis, a vision-threatening disease. We aimed to investigate the genotyping, antibiotic susceptibility, and clinical features of S. aureus keratitis, and to explore the possible role of Panton-Valentine leucocidin (PVL), a major virulence factor of S. aureus. We recruited 49 patients with culture-proven S. aureus keratitis between 2013 and 2017 at Chang Gung Memorial Hospital, Taiwan. PVL gene, multilocus sequence type (MLST), staphylococcal cassette chromosome mec (SCCmec), and pulsed-field gel electrophoresis (PFGE) were performed. Antibiotic susceptibility was verified using disk diffusion/E test. There were 49 patients with S. aureus keratitis; 17 (34.7%) were caused by methicillin-resistant S. aureus (MRSA) and 9 (18.4%) isolates had PVL genes. The predominant genotyping of MRSA isolates was CC59/PFGE type D/SCCmec VT/PVL (+). All methicillin-sensitive S. aureus (MSSA) and approximately 60% MRSA were susceptible to fluoroquinolones. No significant differences in clinical features, treatments, and visual outcomes were observed between MRSA/MSSA or PVL(+)/PVL(-) groups. In Taiwan, approximately one third of S. aureus keratitis was caused by MRSA, mainly community-associated MRSA. Although MRSA isolates were more resistant than MSSA, clinical characteristics were similar between two groups. Fluoroquinolones could be good empiric antibiotics for S. aureus keratitis.

Effects of TIMP-2 Polymorphisms on Retinopathy of Prematurity Risk, Severity, Recurrence, and Treatment Response.

Tissue inhibitors of metalloproteinases (TIMPs) play a crucial role in endogenous angiogenesis besides the regulation of matrix metalloproteinase (MMP) activity. Associations between TIMP-2 gene polymorphisms and the risk of retinopathy of prematurity (ROP) were examined. Premature infants born between 2009 and 2018 were included. Five single-nucleotide polymorphisms (SNPs) of TIMP-2 were analyzed with real-time polymerase chain reaction (PCR). Multivariate logistic regression was applied to model associations between TIMP-2 polymorphisms and ROP susceptibility and severity. The GA+AA genotype in individuals with the TIMP-2 polymorphism of rs12600817 was associated with a higher risk of ROP (odds ratio [OR]: 1.518, 95% confidence interval [CI]: 1.028-2.242) compared with their wild-type genotypes. The AA genotype (OR: 1.962, 95% CI: 1.023-3.762) and the AA+GA genotype (OR: 1.686, 95% CI: 1.030-2.762) in individuals with the rs12600817 polymorphism had higher risks of severe, treatment-requiring ROP relative to their wild-type counterparts. In patients with treatment-requiring ROP, the AG+GG genotypes in the TIMP-2 polymorphism of rs2889529 were correlated with the treatment response (p = 0.035). The TIMP-2 polymorphism of rs12600817 help in predicting ROP risks in preterm infants, while the polymorphism of rs2889529 can serve as a genetic marker in evaluating the ROP treatment response.

Congenital Stationary Night Blindness: Clinical and Genetic Features.

Congenital stationary night blindness (CSNB) is an inherited retinal disease (IRD) that causes night blindness in childhood with heterogeneous genetic, electrophysical, and clinical characteristics. The development of sequencing technologies and gene therapy have increased the ease and urgency of diagnosing IRDs. This study describes seven Taiwanese patients from six unrelated families examined at a tertiary referral center, diagnosed with CSNB, and confirmed by genetic testing. Complete ophthalmic exams included best corrected visual acuity, retinal imaging, and an electroretinogram. The effects of identified novel variants were predicted using clinical details, protein prediction tools, and conservation scores. One patient had an autosomal dominant CSNB with a RHO variant; five patients had complete CSNB with variants in GRM6, TRPM1, and NYX; and one patient had incomplete CSNB with variants in CACNA1F. The patients had Riggs and Schubert-Bornschein types of CSNB with autosomal dominant, autosomal recessive, and X-linked inheritance patterns. This is the first report of CSNB patients in Taiwan with confirmed genetic testing, providing novel perspectives on molecular etiology and genotype-phenotype correlation of CSNB. Particularly, variants in TRPM1, NYX, and CACNA1F in our patient cohort have not previously been described, although their clinical significance needs further study. Additional study is needed for the genotype-phenotype correlation of different mutations causing CSNB. In addition to genetic etiology, the future of gene therapy for CSNB patients is reviewed and discussed.

Clinico-microbiological profile of Burkholderia cepacia keratitis: a case series.

BACKGROUND: Burkholderia cepacia, an opportunistic pathogen mainly affecting patients with cystic fibrosis or immunocompromised, has rarely been documented as a cause of corneal infection. The clinical and microbiological profiles of B. cepacia keratitis are reported herein. METHODS: We retrospectively reviewed the medical record of 17 patients with culture-proven B. cepacia keratitis, treated between 2000 and 2019 at Chang Gung Memorial Hospital, Taiwan. Our data included predisposing factors, clinical presentations, treatments, and visual outcomes of B. cepacia keratitis as well as the drug susceptibility of the causative agent. RESULTS: The most common predisposing factor for B. cepacia keratitis was preexisting ocular disease (seven, 41.2%), particularly herpetic keratitis (five). Polymicrobial infection was detected in seven (41.2%) eyes. All B. cepacia isolates were susceptible to ceftazidime. Main medical treatments included levofloxacin or ceftazidime. Surgical treatment was required in five (29.4%) patients. Only four (23.5%) patients exhibited final visual acuity better than 20/200. CONCLUSIONS: B. cepacia keratitis primarily affects patients with preexisting ocular disease, particularly herpetic keratitis, and responds well to ceftazidime or fluoroquinolones. However, the visual outcomes are generally poor.

Predicting visual acuity in Bietti crystalline dystrophy: evaluation of image parameters.

BACKGROUND: To analyze multiple imaging modalities in patients with Bietti crystalline dystrophy (BCD) and to investigate which factors from these modalities are associated with best corrected visual acuity (BCVA). METHODS: In this retrospective study, 40 eyes from 22 patients with BCD were included and were separated into group 1 (BCVA ≤20/200) and group 2 (BCVA > 20/200). Data including BCVA and characteristic findings from near-infrared reflectance (NIR) imaging, fundus autofluorescence (FAF), and spectral domain-optic coherence tomography (SD-OCT) were analyzed and compared. The outcome measures of multimodal imaging were evaluated for correlation with BCVA. RESULTS: NIR is a good diagnostic tool for detecting either crystalline or sclerotic vessels in BCD. Patients in group 1 tended to have a thinner choroid (P = 0.047) with ellipsoid zone (EZ) disruption (P = 0.011). Calculation of the area under the curve indicated that EZ disruption detected on SD-OCT could be a good predictor of legal blindness in BCD. CONCLUSION: For the diagnosis of BCD, NIR could be a good diagnostic tool. Of the studied imaging modalities, we found that EZ disruption at the fovea were strongly associated with legal blindness, which could be easily assessed by SD-OCT.

Association of ocular diseases with schizophrenia, bipolar disorder, and major depressive disorder: a retrospective case-control, population-based study.

BACKGROUND: Psychiatric disorders and ocular neurovascular diseases may share a similar pathophysiological route of vascular structures or neurological changes. The aim of this study is to investigate the association between ocular neurovascular diseases and the risk of major psychiatric disorders. METHODS: This was a retrospective case-control, population-based study including patients aged ≥20 and were diagnosed between 1997 and 2013. Ocular neurovascular diseases diagnosed between 1997 and 2006 and newly diagnosed psychiatric disorders including bipolar disorder (BD), major depressive disorder (MDD), and schizophrenia between 2007 and 2013 were registered. Patients were propensity-score matched with control groups without psychiatric disorders in each cohort based on selected covariates. RESULTS: A total of one million sampled patients in the database were categorized based on their diagnoses; 2243 (37.4% men) were categorized into the BD group, 10,110 (35.2% men) into the MDD group, and 1623 (43.1% men) into the schizophrenia group. In the BD group, all glaucoma (OR 1.49, [1.18-1.89]), open-angle glaucoma (OR 2.08, [1.34-3.24]), and closed-angle glaucoma (OR 2.12, [1.36-3.33]) showed statistical significance of risk. In the MDD group, age-related macular degeneration (OR 1.33, [1.13-1.57]), all glaucoma (OR 1.24, [1.11-1.37]), open-angle glaucoma (OR 1.47, [1.21-1.80]), and dry eye syndrome (OR 1.22, [1.13-1.31]) were associated with a significantly higher risk. In the schizophrenia group, only all glaucoma (OR 1.47, [1.02-2.11]), glaucoma suspect (OR 1.88, [1.01-3.49]), and open-angle glaucoma (OR 2.19, [1.13-4.26]) showed statistical significance. CONCLUSIONS: In this population-based study, ocular neurovascular diseases, especially glaucoma, were associated with increased risks of BD, MDD, and schizophrenia.

TEN-YEAR EPIDEMIOLOGY OF RETINOPATHY OF PREMATURITY TREATMENT IN TAIWAN.

PURPOSE: To understand the epidemiology of retinopathy of prematurity (ROP) requiring treatment in Taiwan from 2002 to 2011. METHODS: This retrospective cross-sectional study enrolled 11,180 premature patients with a length of stay >28 days who survived during hospitalization. The incidence of the first ROP treatment was analyzed. RESULTS: Among ROP patients (n = 4,096), 6.5% (n = 265) received treatment. The most frequently performed treatment was laser administration (n = 199), followed by intravitreal anti-vascular endothelial growth factor (VEGF) injection (n = 38), scleral buckle or pars plana vitrectomy (n = 14), and cryotherapy (n = 14). The incidence of ROP requiring treatment increased during the study period, as did the use of intravitreal anti-VEGF injection. Shifts in the treatment modality from cryotherapy and scleral buckle/pars plana vitrectomy to laser treatment after 2003 and from laser treatment to intravitreal anti-VEGF injection after 2010 were observed. CONCLUSION: In Taiwan, the incidence of the use of intravitreal anti-VEGF injection for treating ROP increased between 2002 and 2011. Laser treatment was less frequently used than intravitreal anti-VEGF injection in 2011.

Enterobacteria and host resistance to infection.

Enterobacteriaceae are a large family of Gram-negative, non-spore-forming bacteria. Although many species exist as part of the natural flora of animals including humans, some members are associated with both intestinal and extraintestinal diseases. In this review, we focus on members of this family that have important roles in human disease: Salmonella, Escherichia, Shigella, and Yersinia, providing a brief overview of the disease caused by these bacteria, highlighting the contribution of animal models to our understanding of their pathogenesis and of host genetic determinants involved in susceptibility or resistance to infection.

Benzyl Alcohol-Treated CH3NH3PbBr3 Nanocrystals Exhibiting High Luminescence, Stability, and Ultralow Amplified Spontaneous Emission Thresholds.

We report the high yield synthesis of about 11 nm sized CH3NH3PbBr3 nanocrystals with near-unity photoluminescence quantum yield. The nanocrystals are formed in the presence of surface-binding ligands through their direct precipitation in a benzyl alcohol/toluene phase. The benzyl alcohol plays a pivotal role in steering the surface ligands binding motifs on the NC surface, resulting in enhanced surface-trap passivation and near-unity PLQY values. We further demonstrate that thin films from purified CH3NH3PbBr3 nanocrystals are stable >4 months in air, exhibit high optical gain (about 520 cm-1), and display stable, ultralow amplified spontaneous emission thresholds of 13.9 ± 1.3 and 569.7 ± 6 µJ cm-2 at one-photon (400 nm) and two-photon (800 nm) absorption, respectively. To the best of our knowledge, the latter signifies a 5-fold reduction of the lowest reported threshold value for halide perovskite nanocrystals to date, which makes them ideal candidates for light-emitting and low-threshold lasing applications.

Computer-aided detection of retinopathy of prematurity severity assessment via vessel tortuosity measurement in preterm infants' fundus images.

OBJECTIVE: To develop a computer-aided diagnostic system for retinopathy of prematurity (ROP) disease using retinal vessel morphological features. METHODS: A total of 200 fundus images from 136 preterm infants with stage 1 to 3 ROP were analysed. Two methods were developed to measure vessel tortuosity: the peak-and-valley method and the polynomial curve fitting method. Correlations between temporal artery tortuosity (TAT) and temporal vein tortuosity (TVT) with ROP severity were investigated, and vessel tortuosity relationships with vessel angles (TAA and TVA) and vessel widths (TAW and TVW). A separate dataset from Japan containing 126 images from 97 preterm patients was used for verification. RESULTS: Both methods identified similar tortuosity in images without ROP and mild ROP cases. However, the polynomial curve fit method demonstrated enhanced tortuosity detection in stages 2 and 3 ROP compared to the peak and valley method. A strong positive correlation was revealed between ROP severity and increased arterial and venous tortuosity (P < 0.0001). A significant negative correlation between TAA and TAT (r = -0.485, P < 0.0001) and TVA and TVT (r = -0.281, P < 0.0001), and a significant positive correlation between TAW and TAT (r = 0.204, P value = 0.0040) were identified. Similar results were found in the test dataset from Japan. CONCLUSIONS: ROP severity was associated with increased retinal tortuosity and retinal vessel width while displaying a decrease in retinal vascular angle. This quantitative analysis of retinal vessels provides crucial insights for advancing ROP diagnosis and understanding its progression.