The classification of stages of epiretinal membrane using convolutional neural network on optical coherence tomography image.

BACKGROUND AND OBJECTIVE: The gold standard for diagnosing epiretinal membranes is to observe the surface of the internal limiting membrane on optical coherence tomography images. The stages of the epiretinal membrane are used to decide the condition of the health of the membrane. The stages are not detected because some of them are similar. To accurately classify the stages, a deep-learning technology can be used to improve the classification accuracy. METHODS: A combinatorial fusion with multiple convolutional neural networks (CNN) algorithms are proposed to enhance the accuracy of a single image classification model. The proposed method was trained using a dataset of 1947 optical coherence tomography images diagnosed with the epiretinal membrane at the Taichung Veterans General Hospital in Taiwan. The images consisted of 4 stages; stages 1, 2, 3, and 4. RESULTS: The overall accuracy of the classification was 84%. The combination of five and six CNN models achieves the highest testing accuracy (85%) among other combinations, respectively. Any combination with a different number of CNN models outperforms any single CNN algorithm working alone. Meanwhile, the accuracy of the proposed method is better than ophthalmologists with years of clinical experience. CONCLUSIONS: We have developed an efficient epiretinal membrane classification method by using combinatorial fusion with CNN models on optical coherence tomography images. The proposed method can be used for screening purposes to facilitate ophthalmologists making the correct diagnoses in general medical practice.

Melatonin protects retinal integrity through mediated immune homeostasis in the sodium iodate-induced mouse model of age-related macular degeneration.

BACKGROUND: Age-related macular degeneration is the leading cause of visual deficiency in older adults worldwide. Melatonin (MT) can potentially reduce retinal deterioration. However, the mechanism by which MT mediates regulatory T cells (Tregs) in the retina is not yet fully understood. METHODS: The transcriptome profiles of aged or young human retinal tissues from the GEO database were analyzed for MT-related gene expression. The pathological changes in the retina in the NaIO3-induced mouse model were quantitatively determined by staining with hematoxylin and eosin. Retinal whole-mounting immunofluorescence staining was conducted to determine the expression of the Treg-specific marker FOXP3. The phenotypes of M1/M2 macrophages were representing related gene markers in the retina. The GEO database includes biopsies from patients with retinal detachment for ENPTD1, NT5E, and TET2 gene expression. A pyrosequencing assay was performed for NT5E DNA methylation on human primary Tregs, and siTET2 transfection engineering was used. RESULTS: MT synthesis-related genes in retinal tissue may be affected by age. Our study shows that MT can effectively restore NaIO3-induced retinopathy and maintain retinal structural integrity. Importantly, MT may assist the conversion of M1 to M2 macrophages to promote tissue repair, which may be caused by the increased infiltration of Tregs. Moreover, MT treatment may upregulate TET2, and further NT5E demethylation is associated with Treg recruitment in the retinal microenvironment. CONCLUSIONS: Our findings suggest that MT can effectively ameliorate retinal degeneration and regulate immune homeostasis via Tregs. Modulation of the immune response may provide a key therapeutic strategy.

Aryl hydrocarbon receptor deficiency augments dysregulated microangiogenesis and diabetic retinopathy.

Diabetic retinopathy (DR) is a pathophysiologic vasculopathic process with obscure mechanisms and limited effective therapeutic strategies. Aryl hydrocarbon receptor (AhR) is an important regulator of xenobiotic metabolism and an environmental sensor. The aim of the present study was to investigate the role of AhR in the development of DR and elucidate the molecular mechanism of its downregulation. DR was evaluated in diabetes-induced retinal injury in wild type and AhR knockout (AhR-/-) mice. Retinal expression of AhR was determined in human donor and mice eyes by immunofluorescence since AhR activity was examined in diabetes. AhR knockout (AhRKO) mice were used to induce diabetes with streptozotocin, high-fat diet, or genetic double knockout with diabetes spontaneous mutation (Leprdb) (DKO; AhR-/-×Leprdb/db) for investigating structural, functional, and metabolic abnormalities in vascular and epithelial retina. Structural molecular docking simulation was used to survey the pharmacologic AhR agonists targeting phosphorylated AhR (Tyr245). Compared to diabetic control mice, diabetic AhRKO mice had aggravated alterations in retinal vasculature that amplified hallmark features of DR like vasopermeability, vascular leakage, inflammation, blood-retinal barrier breakdown, capillary degeneration, and neovascularization. AhR agonists effectively inhibited inflammasome formation and promoted AhR activity in human retinal microvascular endothelial cells and pigment epithelial cells. AhR activity and protein expression was downregulated, resulting in a decrease in DNA promoter binding site of pigment epithelium-derived factor (PEDF) by gene regulation in transcriptional cascade. This was reversed by AhR agonists. Our study identified a novel of DR model that target the protective AhR/PEDF axis can potentially maintain retinal vascular homeostasis, providing opportunities to delay the development of DR.

Therapeutic Potential of Tpl2 (Tumor Progression Locus 2) Inhibition on Diabetic Vasculopathy Through the Blockage of the Inflammasome Complex.

OBJECTIVE: Diabetic retinopathy, one of retinal vasculopathy, is characterized by retinal inflammation, vascular leakage, blood-retinal barrier breakdown, and neovascularization. However, the molecular mechanisms that contribute to diabetic retinopathy progression remain unclear. Approach and Results: Tpl2 (tumor progression locus 2) is a protein kinase implicated in inflammation and pathological vascular angiogenesis. Nε-carboxymethyllysine (CML) and inflammatory cytokines levels in human sera and in several diabetic murine models were detected by ELISA, whereas liquid chromatography-tandem mass spectrometry analysis was used for whole eye tissues. The CML and p-Tpl2 expressions on the human retinal pigment epithelium (RPE) cells were determined by immunofluorescence. Intravitreal injection of pharmacological inhibitor or NA (neutralizing antibody) was used in a diabetic rat model. Retinal leukostasis, optical coherence tomography, and H&E staining were used to observe pathological features. Sera of diabetic retinopathy patients had significantly increased CML levels that positively correlated with diabetic retinopathy severity and foveal thickness. CML and p-Tpl2 expressions also significantly increased in the RPE of both T1DM and T2DM diabetes animal models. Mechanistic studies on RPE revealed that CML-induced Tpl2 activation and NADPH oxidase, and inflammasome complex activation were all effectively attenuated by Tpl2 inhibition. Tpl2 inhibition by NA also effectively reduced inflammatory/angiogenic factors, retinal leukostasis in streptozotocin-induced diabetic rats, and RPE secretion of inflammatory cytokines. The attenuated release of angiogenic factors led to inhibited vascular abnormalities in the diabetic animal model. CONCLUSIONS: The inhibition of Tpl2 can block the inflammasome signaling pathway in RPE and has potential clinical and therapeutic implications in diabetes-associated retinal microvascular dysfunction.

Epiretinal Membrane Detection at the Ophthalmologist Level using Deep Learning of Optical Coherence Tomography.

PURPOSE: Previous deep learning studies on optical coherence tomography (OCT) mainly focused on diabetic retinopathy and age-related macular degeneration. We proposed a deep learning model that can identify epiretinal membrane (ERM) in OCT with ophthalmologist-level performance. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 3,618 central fovea cross section OCT images from 1,475 eyes of 964 patients. METHODS: We retrospectively collected 7,652 OCT images from 1,197 patients. From these images, 2,171 were normal and 1,447 were ERM OCT. A total of 3,141 OCT images was used as training dataset and 477 images as testing dataset. DL algorithm was used to train the interpretation model. Diagnostic results by four board-certified non-retinal specialized ophthalmologists on the testing dataset were compared with those generated by the DL model. MAIN OUTCOME MEASURES: We calculated for the derived DL model the following characteristics: sensitivity, specificity, F1 score and area under curve (AUC) of the receiver operating characteristic (ROC) curve. These were calculated according to the gold standard results which were parallel diagnoses of the retinal specialist. Performance of the DL model was finally compared with that of non-retinal specialized ophthalmologists. RESULTS: Regarding the diagnosis of ERM in OCT images, the trained DL model had the following characteristics in performance: sensitivity: 98.7%, specificity: 98.0%, and F1 score: 0.945. The accuracy on the training dataset was 99.7% (95% CI: 99.4 - 99.9%), and for the testing dataset, diagnostic accuracy was 98.1% (95% CI: 96.5 - 99.1%). AUC of the ROC curve was 0.999. The DL model slightly outperformed the average non-retinal specialized ophthalmologists. CONCLUSIONS: An ophthalmologist-level DL model was built here to accurately identify ERM in OCT images. The performance of the model was slightly better than the average non-retinal specialized ophthalmologists. The derived model may play a role to assist clinicians to promote the efficiency and safety of healthcare in the future.

The association of dry eye syndrome and psychiatric disorders: a nationwide population-based cohort study.

BACKGROUND: Several previous studies reported a greater prevalence of dry eye syndrome (DES) among patients with psychiatric diseases. The aim of this study is to investigate the prevalence and risk factors of DES in patients with psychiatric disorders (PD) using nationwide population-based data in Taiwan. METHODS: This population-based cohort study retrospectively identified patients with PD from 1997 to 2011. Patients with both PD and DES served as the DES cohort, and PD patients without DES comprised the non-DES cohort. PD was defined as a diagnosis of PD (ICD-9-CM 290-319) made by psychiatrists only, with at least three consecutive outpatient visits or at least one inpatient visit. DES was defined as a diagnosis of DES (ICD-9-CM 375.15) and a prescription for an eye lubricant (anatomical therapeutic chemical code, ATC code: S01XA). The main outcome measures were the prevalence of DES in these patients and associated risk factors. RESULTS: A total of 75,650 patients with PD (3665 in the DES cohort and 71,985 in the non-DES cohort) were included in the final analysis. The majority of patients in the DES group were women (72.6%), compared the non-DES group (57.8%). The mean age of patients in the DES cohort was 62.2 ± 14.9, which was significantly older than those in the non-DES group (50.9 ± 17.5). The patients with DES had a significantly greater likelihood of having dementia, bipolar disorder, depression, and neurotic disorders. Conditional regression analyses revealed that patients with dry eye disease were more likely to have schizophrenia (OR = 1.34), bipolar disorder (OR = 1.9), depression (OR = 1.54), and neurotic disorders (OR = 1.62). In addition, patients with DES were more likely to use 1st generation anti-psychotics (OR = 1.28) and had a lower risk of using 2nd generation anti-psychotics (OR = 0.64). CONCLUSION: The study demonstrated that among PD patients, DES is highly prevalence in certain subtypes of PD, such as depression, bipolar disorder, and neurotic disorders, after adjusting for the comorbidities.

Mutation spectrum and genotype-phenotype correlation of inherited retinal dystrophy in Taiwan.

BACKGROUND: Inherited retinal dystrophy (IRD) is a group of irreversible retinal degenerative disorders with significant genotypic and phenotypic heterogeneity, which cause difficulty in making a precise clinical diagnosis. Furthermore, the mutation spectrum of IRD in Taiwan remains unknown. Therefore, our study focused on investigating the spectrum of mutations among Taiwanese families with IRD using targeted exome sequencing (TES) technology. METHODS: We recruited a total of 60 unrelated Taiwanese families with IRD; most of them were retinitis pigmentosa. We employed TES to investigate 284 candidate genes. Bioinformatics analysis, Sanger sequencing-based co-segregation testing, and computational assessment were performed to validate each mutation and its pathogenicity. The genotype-phenotype correlation was analysed in all patients with mutations defined in the guidelines provided by the American College of Medical Genetics. RESULTS: We successfully identified genetic causes in 32 families (detection rate of 53.3%). Among them, 16 had a sporadic inheritance (16/36, 44.4%); eight had an autosomal recessive inheritance (8/14, 57.1%); four had an autosomal dominant inheritance (4/5, 80%); four had an X-linked inheritance (4/5, 80%). Among 38 pathological mutations in 19 known genes, 20 mutations are reported here for the first time. Novel mutation spectrum and genotype-phenotype correlations were revealed as well. CONCLUSION: Here we achieved a detection rate of 53.3% and elucidated the mutation spectrum in Taiwanese families with IRD for the first time. The results indicated that CYP4V2 and USH2A might be the most common pathogenic genes in IRD patients in Taiwan.

Association between Metformin and a Lower Risk of Age-Related Macular Degeneration in Patients with Type 2 Diabetes.

PURPOSE: This population-based, retrospective cohort study was to investigate whether metformin is associated with a lower risk of subsequent age-related macular degeneration (AMD) in patients with type 2 diabetes. METHODS: Using the Taiwan National Health Insurance Research Database from 2001 to 2013, 68205 subjects with type 2 diabetes were enrolled in the study cohort. Among them, 45524 were metformin users and 22681 were nonusers. The metformin and nonmetformin groups were followed until the end of 2013. Cox regression analyses were used to estimate hazard ratios (HRs) for AMD development associated with metformin use. Confounders included for adjustment were age, sex, and comorbidities (hypertension, hyperlipidemia, coronary artery disease, obesity, diabetic retinopathy, chronic kidney disease, and insulin treatment). Furthermore, propensity score (PS) matching method was used to choose the matched sample, and PS-adjusted Cox regression was performed. Finally, how HRs changed according to metformin treatment duration and dose was also evaluated in the metformin group. RESULTS: After adjusting for confounders, the metformin group had a significantly lower risk of AMD (adjusted HR = 0.54; 95% confidence interval [CI], 0.50-0.58). In the PS-matched sample, the significance remained (adjusted HR = 0.57; 95% CI, 0.52-0.63). In the metformin group, the adjusted HRs for the second (1.5-4 years) and third (≥4 years) tertiles of metformin treatment duration were 0.52 and 0.14, respectively, compared with the first tertile (<1.5 years). We also found significant trends of lower HRs (all p-value for trend <0.05) with increasing total and average doses. CONCLUSIONS: Among patients with type 2 diabetes, those who use metformin are at a significantly lower risk of developing AMD relative to individuals who do not use metformin. Also, the trend of a significantly lower AMD risk was found with a higher dose of metformin.

Association between normal tension glaucoma and the risk of Alzheimer's disease: a nationwide population-based cohort study in Taiwan.

OBJECTIVES: To investigate a possible association between normal tension glaucoma (NTG) and an increased risk of developing Alzheimer's disease (AD). DESIGN: Retrospective cohort study. SETTING: NTG group and the comparison group were retrieved from the whole population of the Taiwan National Health Insurance Research Database from 1 January 2001 to 31 December 2013. PARTICIPANTS: A total of 15 317 subjects with NTG were enrolled in the NTG group, and 61 268 age-matched and gender-matched subjects without glaucoma were enrolled in the comparison group. PRIMARY AND SECONDARY OUTCOME MEASURES: Kaplan-Meier curves were generated to compare the cumulative hazard of AD between the two groups. A multivariable Cox regression analysis was used to estimate the adjusted hazard ratios (HRs) of AD, adjusted for diabetes, hypertension, hyperlipidaemia, coronary artery disease and stroke. Furthermore, risk factors for developing AD among the NTG group were investigated. RESULTS: The mean age of the cohort was 62.1±12.5 years. Patients with NTG had significantly higher proportions of diabetes, hypertension, hyperlipidaemia, coronary artery disease and stroke than the comparisons. Patients with NTG had a significantly higher cumulative hazard for AD than the comparisons (p<0.0001). In the multivariable Cox regression after adjustment for confounders, the NTG group had a significantly higher risk of AD (adjusted HR 1.52; 95% CI 1.41 to 1.63). Moreover, in the NTG group, when we compared the effects of different types of glaucoma eye drops, none of the eye drops used were significant risk factors or protective factors for AD. CONCLUSIONS: People with NTG are at a significantly greater risk of developing AD compared with individuals without glaucoma. Among patients with NTG, none of the glaucoma eye drops used significantly changed the risk of subsequent AD.

Genotype-Phenotype Association Study Reveals CFI-Rs13104777 to be a Protective Genetic Marker Against Acute Anterior Uveitis.

PURPOSE: To investigate the roles of CFI, genotype-phenotype associations were identified in AAU. METHODS: A case-control study was conducted in a total of 575 subjects consisting of 279 AAU patients and 296 healthy controls. Genotypic analyses were performed using Sequenom MassARRAY technology. Analyses were stratified to a series of clinical ophthalmic confounding factors. RESULTS: A lower frequency of the CFI-rs13104777 C allele was found in the AAU cohort compared with the controls, and, thus, was significantly associated with AAU pathogenesis (p = 0.041, OR = 0.712, 95% CI: 0.513-0.987). Stratified analysis also demonstrated the associations may differ depending on the HLA-B27 status and laterality status. CONCLUSIONS: This study has revealed a significant genetic role for CFI-rs13104777 in AAU. This influence may be dependent on human leukocyte antigen (HLA)-B27 and disease laterality. Overall, the results provide evidence for a pathogenic role for CFI in AAU and expand our knowledge on the genetic basis of AAU.

TPL2 (Therapeutic Targeting Tumor Progression Locus-2)/ATF4 (Activating Transcription Factor-4)/SDF1α (Chemokine Stromal Cell-Derived Factor-α) Axis Suppresses Diabetic Retinopathy.

RATIONALE: Diabetic retinopathy is characterized by vasopermeability, vascular leakage, inflammation, blood-retinal barrier breakdown, capillary degeneration, and neovascularization. However, the mechanisms underlying the association between diabetes mellitus and progression retinopathy remain unclear. OBJECTIVE: TPL2 (tumor progression locus 2), a serine-threonine protein kinase, exerts a pathological effect on vascular angiogenesis. This study investigated the role of Nε-(carboxymethyl)lysine, a major advanced glycation end products, and the involved TPL2-related molecular signals in diabetic retinopathy using models of in vitro and in vivo and human samples. METHODS AND RESULTS: Serum Nε-(carboxymethyl)lysine levels and TPL2 kinase activity were significantly increased in clinical patients and experimental animals with diabetic retinopathy. Intravitreal administration of pharmacological blocker or neutralizing antibody inhibited TPL2 and effectively suppressed the pathological characteristics of retinopathy in streptozotocin-induced diabetic animal models. Intravitreal VEGF (vascular endothelial growth factor) neutralization also suppressed the diabetic retinopathy in diabetic animal models. Mechanistic studies in primary human umbilical vein endothelial cells and primary retinal microvascular endothelial cells from streptozotocin-diabetic rats, db/db mice, and samples from patients with diabetic retinopathy revealed a positive parallel correlation between Nε-(carboxymethyl)lysine and the TPL2/chemokine SDF1α (stromal cell-derived factor-α) axis that is dependent on endoplasmic reticulum stress-related molecules, especially ATF4 (activating transcription factor-4). CONCLUSIONS: This study demonstrates that inhibiting the Nε-(carboxymethyl)lysine-induced TPL2/ATF4/SDF1α axis can effectively prevent diabetes mellitus-mediated retinal microvascular dysfunction. This signaling axis may include the therapeutic potential for other diseases involving pathological neovascularization or macular edema.

Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels.

Large-scale meta-analyses of genome-wide association studies (GWAS) have identified >175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 × 10-8) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 × 10-9), NCOA2 (P = 1.6 × 10-8), and NID2-PTGDR (P = 4.2 × 10-8), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 × 10-10). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log10Bayes Factor ≥6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 × 10-5) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets.

Analysis of the Interleukin-6 (-174) Locus Polymorphism and Serum IL-6 Levels with the Severity of Normal Tension Glaucoma.

PURPOSE: In normal tension glaucoma (NTG), factors other than elevated intraocular pressure are likely to have a role in the pathogenesis of optic neuropathy. Recent studies of glaucoma or retinal ganglion cells (RGCs) reveal that the cytokine interleukin-6 (IL-6) is linked to the pathogenesis of glaucoma and may regulate RGC survival or death. The IL-6 (-174) G allele has also been shown to increase the IL-6 protein. We hypothesized that the IL-6 (-174) polymorphism may be a predisposing genetic factor affecting the severity of glaucoma. The aim of the present study was to evaluate the IL-6 polymorphism and serum IL-6 levels as a potential risk factor related to the severity of NTG. METHODS: A total of 256 subjects with NTG in the Chinese population were enrolled. The patients were genotyped for the IL-6 (-174) C/G polymorphism. Genomic DNA was amplified by a polymerase chain reaction, followed by the enzymatic restriction fragment length polymorphism technique. Serum IL-6 levels were measured by ELISA. Patient age at diagnosis, cup/disc (C/D) ratio, rim area (RA), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) were analyzed. The associations between genotypes of IL-6 (-174) C/G and the clinical parameters were calculated using a logistic regression. RESULTS: The IL-6 (-174) GC genotype in NTG patients was significantly associated with a smaller C/D ratio (p = 0.04), larger RA (p = 0.04), and thicker RNFL (p = 0.05) compared with IL-6 (-174) GG patients. The allele frequency of IL-6 (-174) C was significantly higher in the NTG patients at an early-moderate stage than at an advanced stage according to the C/D ratio (OR 0.55; 95% CI 0.31-0.99). Pattern standard deviation of VF was borderline lower in IL-6 (-174) GC patients (p = 0.06), and serum IL-6 levels were borderline higher in advanced stages than in early-moderate stages (7.66 ± 3.22 vs. 4.46 ± 3.83 pg/mL; p = 0.06). CONCLUSION: The IL-6 (-174) GC genotype is associated with a smaller C/D ratio, larger RA, and thicker RNFL compared with IL-6 (-174) GG in NTG patients. We found that the IL-6 (-174) G/C polymorphism and serum IL-6 levels may be associated with the severity of NTG.

Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA.

Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies.

Pharmacokinetics and safety of intravitreal caspofungin.

Caspofungin exhibits potent antifungal activities against Candida and Aspergillus species. The elimination rate and retinal toxicity of caspofungin were determined in this study to assess its pharmacokinetics and safety in the treatment of fungal endophthalmitis. Intravitreal injections of 50 µg/0.1 ml of caspofungin were administered to rabbits. Levels of caspofungin in the vitreous and aqueous humors were determined using high-performance liquid chromatography (HPLC) at selected time intervals (10 min and 1, 2, 4, 8, 16, 24, and 48 h), and the half-lives were calculated. Eyes were intravitreally injected with caspofungin to obtain concentrations of 10 µg/ml, 50 µg/ml, 100 µg/ml, and 200 µg/ml. Electroretinograms were recorded 4 weeks after injections, and the injected eyes were examined histologically. The concentrations of intravitreal caspofungin at various time points exhibited an exponential decay with a half-life of 6.28 h. The mean vitreous concentration was 6.06 ± 1.76 µg/ml 1 h after intravitreal injection, and this declined to 0.47 ± 0.15 µg/ml at 24 h. The mean aqueous concentration showed undetectable levels at all time points. There were no statistical differences in scotopic a-wave and b-wave responses between control eyes and caspofungin-injected eyes. No focal necrosis or other abnormality in retinal histology was observed. Intravitreal caspofungin injection may be considered to be an alternative treatment for fungal endophthalmitis based on its antifungal activity, lower retinal toxicity, and lower elimination rate in the vitreous. More clinical data are needed to determine its potential role as primary therapy for fungal endophthalmitis.

Aniseikonia following pneumatic retinopexy for rhegmatogenous retinal detachment.

PURPOSE: To evaluate the characteristics of aniseikonia in patients with rhegmatogenous retinal detachment (RD) after pneumatic retinopexy. DESIGN: Prospective, interventional case series study. METHODS: Thirty patients who had undergone pneumatic retinopexy as the initial procedure for rhegmatogenous retinal detachment were selected for this study. The principal outcomes included visual acuity, postoperative aniseikonia measured by the New Aniseikonia Test, anatomical success, and measurement of central retinal thickness using optical coherence topography (OCT). These outcomes were measured postoperatively at 3, 6, and 12 months. RESULTS: The median patient age was 37 years (range, 13-57 years), with 17 cases of macula-off RD and 13 cases of macula-on RD. All of these patients achieved anatomical success, proven by OCT after surgical repair. Three months after pneumatic retinopexy, 18 patients (60.0%) developed micropsic aniseikonia and aniseikonia was diagnosed in 15 patients (88.2%) in the macula-off RD group, leaving 2 patients (11.8%) unaffected. In the macula-on RD group, 3 patients (23.1%) were found to have aniseikonia, while 10 patients (76.9%) were unaffected. The presence of aniseikonia was strongly linked to the difference in central retinal thickness, between the operated eye and the fellow eye, measured at 12 months postoperatively. CONCLUSION: Aniseikonia after pneumatic retinopexy for rhegmatogenous RD may be related to the preoperative macular status. Macula-off RD patients had a higher incidence of aniseikonia, compared to macula-on RD patients, following retina reattachment. There was a moderate to high correlation between the grading of aniseikonia and the difference in central retinal thickness.

Pterygium is related to a decrease in corneal endothelial cell density.

PURPOSE: The aim of this study was to investigate the relationship between pterygium and a decrease in the corneal endothelial cell density (ECD) in patients with unilateral primary pterygium. METHODS: In this retrospective cross-sectional study, 90 consecutive patients with unilateral primary pterygium were enrolled from January 2010 to June 2012. Corneal ECD was measured in both eyes, and the fellow eyes were considered as controls. The relationship between the percentage of pterygium to cornea and a decrease in the ECD was analyzed. An increase in astigmatism in eyes with pterygium was evaluated for association with decreased ECD using the Pearson correlation test. RESULTS: The percentage of pterygium to cornea ranged from 3.5% to 65.2%, with a median of 12.35%. The difference in the corneal ECD between eyes with pterygium and control eyes ranged from +9.6% to -37.7%, with a median of -9.75%. The results of the Pearson correlation statistical test showed a strong logarithmic correlation between a decrease in the corneal ECD and the percentage of pterygium to cornea (R = 0.688, P < 0.001). An increase in astigmatism was correlated with a decrease in the ECD in eyes with pterygium. CONCLUSIONS: Pterygium is related to a decrease in corneal ECD. Surgical intervention should be considered in patients with extensive pterygium involvement in the cornea or a significant increase in astigmatism.

Monitoring the VEGF level in aqueous humor of patients with ophthalmologically relevant diseases via ultrahigh sensitive paper-based ELISA.

The vascular endothelial growth factor (VEGF) level in aqueous humor has been used as an indicator to monitor specific diseases in the retinal ischemic condition. For clinical diagnosis, only about 200 µL of aqueous humor can be collected from the anterior chamber before the threat of anterior chamber collapse. It is necessary to develop an inexpensive diagnostic approach with the characteristics of highly sensitive, short operation duration, and requires small clinical sample quantities. To achieve the main objective of this study, we first prepared bevacizumab to be conjugated with HRP. We then deposited 2 µL aqueous humor from patients with different diseases onto each test zone of paper-based 96-well plates. After the colorimetric results were performed via ELISA protocol, the output signals were recorded using a commercial desktop scanner for analysis. In this study, only 2 µL from the aqueous humor of each patient was required for paper-based ELISA. The mean aqueous VEGF level was 14.4 pg/mL from thirteen patients (N = 13) with senile cataract as the control. However, the mean aqueous VEGF level from other patients with proliferative diabetic retinopathy (N = 14), age-related macular degeneration (N = 17), and retinal vein occlusion (N = 10) showed VEGF increases to 740.1 pg/mL, 383 pg/mL, and 219.4 pg/mL, respectively.

Polymorphism in the TNF-α(-863) locus associated with reduced risk of primary open angle glaucoma.

PURPOSE: Tumor necrosis factor-α (TNF-α), an important proinflammatory cytokine, exerts a variety of physiologic and pathogenic effects that lead to tissue destruction. Recent laboratory evidence indicates that TNF-α have either protective or adverse effects on primary open angle glaucoma (POAG). Inheritance of the TNF-α (-863) C allele has been associated with an elevated risk of Alzheimer disease. The neuronal injuries associated with Alzheimer disease have several similarities with the optic nerve changes often seen with POAG. In this study we investigated the possible association between the TNF-α (-863) polymorphism and the development of POAG. METHODS: A total of 234 patients with POAG were recruited and compared with 230 healthy controls in a Chinese population. Sequence-specific primers with 3' end mismatches were used to identify the presence of specific allelic variants by polymerase chain reaction (PCR) amplification. Patients and controls were genotyped for the A/C polymorphism at position -863 of the TNF-α gene promoter region. RESULTS: The frequency of the TNF-α (-863)A allele (22% versus 30%, respectively; p=0.007) and the carriers of the TNF-α (-863)A allele (37% versus 48%; p=0.017, OR 0.63, 95% CI 0.44-0.92) were lower in POAG patients compared with those in controls. There is a reduced risk of POAG associated with homozygosity for the TNF-α (-863)A allele (AA genotype) compared with that in the control population (AA genotype; 7% versus 11%, respectively, p=0.037; OR 0.5, 95% CI 0.26-0.98). CONCLUSIONS: The TNF-α (-863)A allele polymorphism may be a protective factor in the development of POAG.