Retinal biometrics based on Iterative Closest Point algorithm.

The pattern of blood vessels in the eye is unique to each person because it rarely changes over time. Therefore, it is well known that retinal blood vessels are useful for biometrics. This paper describes a biometrics method using the Jaccard similarity coefficient (JSC) based on blood vessel regions in retinal image pairs. The retinal image pairs were rough matched by the center of their optic discs. Moreover, the image pairs were aligned using the Iterative Closest Point algorithm based on detailed blood vessel skeletons. For registration, perspective transform was applied to the retinal images. Finally, the pairs were classified as either correct or incorrect using the JSC of the blood vessel region in the image pairs. The proposed method was applied to temporal retinal images, which were obtained in 2009 (695 images) and 2013 (87 images). The 87 images acquired in 2013 were all from persons already examined in 2009. The accuracy of the proposed method reached 100%.

Determinants and risk factors for central corneal thickness in Japanese persons: the Funagata Study.

PURPOSE: To examine the association between glucose metabolism and central corneal thickness (CCT) in Japanese adults. METHODS: A sub-sample of 322 Japanese adults participating in the Funagata Study was included in this analysis. CCT was measured using a specular microscope. Glucose metabolism was examined using 75-g oral glucose tolerance test. Mean differences in CCT (µm) and 95% confidence intervals were estimated with univariate, age-sex-adjusted and multivariate models using multiple linear regression. RESULTS: The mean (± standard deviation) age of the study sample was 63.7 ± 11.4 years and 44% were men. The mean fasting plasma glucose (FPG), 2-hour post-load plasma glucose (2hPG) and haemoglobin A1c (HbA1c) concentrations were 96.8 ± 12.6mg/dl, 123.6 ± 41.2mg/dl and 5.3 ± 0.4%, respectively. CCT was normally distributed in the study sample, and the mean CCT was 544.7 ± 34.6µm. After multivariate adjustment, characteristics associated with increased CCT were 2hPG and HbA1c concentrations, impaired glucose tolerance, diabetes, body weight or body mass index and current smoking. CONCLUSION: Impaired glucose tolerance, diabetes, obesity and current smoking are associated with increased CCT. Additional studies are required to examine whether interventions to affect these characteristics may reduce CCT.

Screening for retinal vessel caliber and its association with metabolic syndrome in Japanese adults.

BACKGROUND: Retinal microvasculature provides a direct means to assess microvascular health in vivo. We examined whether retinal vessel caliber is associated with the presence of metabolic syndrome in Japanese adults in a health screening program. METHODS: We examined 1,003 Japanese adults through the health screening program conducted at the Shinoda General Hospital. Retinal vessel caliber was measured from digital fundus images using validated, semiautomated computer-assisted software. Metabolic syndrome was defined according to the definition proposed by the Joint Interim Statement in 2009. Cross-sectional associations between retinal vascular caliber and metabolic syndrome or its individual components were determined as odds ratios (ORs) using multiple logistic regression models. RESULTS: The overall prevalence of metabolic syndrome in the study sample was 29.9%. Persons with increased waist circumference and elevated triglycerides and blood pressure had significantly narrower retinal arterial diameters. Persons with increased waist circumference also had wider retinal venular diameters. Narrower retinal arterial diameters and wider retinal venular diameters were associated with a higher prevalence of metabolic syndrome (OR per -1 standard deviation (SD) change in arteriolar caliber=2.15, 95% confidence interval (CI) 1.45-3.18; OR per +1 SD change in venular caliber=1.53, 95% CI 1.04-2.26). CONCLUSIONS: We observed cross-sectional associations between retinal vessel caliber changes and metabolic syndrome and its components. We demonstrated that retinal vessel caliber assessments are feasible in health screening programs in a timely manner. Further longitudinal studies are warranted to determine whether retinal vessel caliber measurements can be used as noninvasive assessment to evaluate vascular health related to metabolic syndrome and cardiovascular diseases in health screening program.

Is retinal vasculature change associated with risk of obesity? Longitudinal cohort study in Japanese adults: The Funagata study.

UNLABELLED: Aims/Introduction: To examine the association between baseline retinal vessel caliber change and prevalence, and 5-year incidence of obesity in the adult Japanese population of the Funagata study. MATERIALS AND METHODS: Of 900 individuals (age ≥ 35 years) who underwent systemic and retinal examinations in the Funagata study during 2000-2002, 584 (64.8%) were not obese as defined by body mass index (BMI) ≥ 25 kg/m(2), and considered at risk of incident obesity. In 2005-2007, 454 patients returned for 5-year follow-up examination (52.9%). Incidence of overweight was defined as subjects who were not overweight at baseline examination (BMI < 23 kg/m(2)), but overweight (BMI ≥ 23 to <25 kg/m(2)) at follow up, and that of obesity as subjects who were not obese at baseline examination (BMI < 25 kg/m(2)), but obese (BMI ≥ 25 kg/m(2)) at follow up. RESULTS: The prevalence of obesity at baseline was 35.1% (316/900); there was a cross-sectional association between wider retinal venular diameters and obesity (adjusted odds ratio [OR] per +1 standard deviation (SD) change: 1.18; 95% confidence interval [CI]: 1.02-1.35) after adjusting for age and sex. Cumulative incidence of obesity between baseline and 5-year follow up was 10.6% (32/303). Although the risk of incident overweight or obesity was higher in persons with wider retinal venular caliber, there were no statistically significant associations between baseline venular caliber and 5-year incidence of obesity. CONCLUSIONS: Although we found significant cross-sectional associations of retinal venodilation with the prevalence of overweight, we could not confirm that retinal venodilation preceded the development of obesity in this population. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00086.x, 2011).

Effect of combined treatment with sub-Tenon injection of triamcinolone acetonide and photodynamic therapy in Japanese patients with age-related macular degeneration.

PURPOSE: To evaluate the benefit of the combination of a single sub-Tenon injection of triamcinolone acetonide (STTA) with photodynamic therapy (PDT) for the treatment of age-related macular degeneration (AMD) in Japanese patients. METHODS: The medical records of 111 eyes of 111 patients were reviewed retrospectively. Forty-five eyes underwent combined treatment with STTA and PDT, and 66 eyes underwent PDT alone. Time to vision loss, defined as a change of 0.3 or more logarithm of minimum angle of resolution (logMAR) units, and time to retreatment were evaluated using the Kaplan-Meier survival analyses. Cox regression models were used to estimate the hazard ratios for those end points to investigate clinical risk characteristics. RESULTS: Patients who underwent combined STTA with PDT had a significantly lower risk of retreatment than did those who underwent PDT alone (hazard ratio, 0.59; 95% confidence interval, 0.36-0.99). This beneficial association was found only in patients without polypoidal choroidal vasculopathy (PCV) lesions. However, combined treatment with STTA and PDT had no beneficial effect in reducing visual loss when compared with treatment with PDT alone. CONCLUSION: Combined treatment with STTA and PDT had a beneficial effect in reducing retreatment of AMD in Japanese patients. Those who had PCV lesions did not benefit from this additional treatment.

Immunohistochemical diagnosis of a rare case of epithelioid malignant peripheral nerve sheath tumor with multiple metastases.

BACKGROUND: The epithelioid variant of malignant peripheral nerve sheath tumor (MPNST) is a rare tumor with poor prognosis that sometimes involves the head and neck. The diagnosis is based principally on the histological examination, and it is generally very difficult to reach the correct diagnosis. CASE: An 84-year-old Japanese woman presented with a tumor mass of 2 week's duration in the right medial canthal region. OBSERVATIONS: Although the tumor was excised surgically, metastases occurred three times on her face and head, and the patient died of distant systemic multiple metastases. In the histopathological analysis, the tumor showed a composite pattern comprising spindle or polygonal cells arranged in irregular bands, and a population of larger epithelioid cells in solid sheets and nests. In the immunohistochemical analysis, the tumor cells were positive for S-100 protein, vimentin, and nerve growth factor receptor (NGFR), and negative for cytokeratin and HMB 45 (melanoma-associated antigen). These findings confirmed the diagnosis of MPNST. CONCLUSIONS: Epithelioid MPNST has complex histopathological findings and histopathological features similar to other epithelioid tumors, especially malignant melanoma. Immunohistochemical examination using NGFR and HMB-45 is important in the differential diagnosis.