Introduction: The aim of this study was to compare the occurrence of diabetic retinopathy in targ... more Introduction: The aim of this study was to compare the occurrence of diabetic retinopathy in targeted screening diabetic patients (Group I) with newly diagnosed diabetic patients in general practice (Group II). Materials and Methods: This was an observational cross-sectional study. Data were obtained from 25,313 subjects who participated in the diabetic screening camps, and 128 newly diagnosed diabetes who presented to the diabetic retinopathy screening camps in general practice in rural and urban south India. The study variables were collected from all patients who underwent eye examination from the target screening detected diabetics [(n = 173) Group I] and those newly diagnosed in general practice [(n = 128) Group II]. The variations in prevalence of diabetic retinopathy and sight-threatening diabetic retinopathy in Group I and Group II and the factors affecting it were identified. Results: The occurrence of diabetic retinopathy was 6.35% (95% CI, 2.5-9.5) in Group I and 11.71% (...
Purpose: To evaluate retinal sensitivity over hard exudates in correlation with the spectral doma... more Purpose: To evaluate retinal sensitivity over hard exudates in correlation with the spectral domain optical coherence tomography (SD-OCT) findings in eyes with diabetic retinopathy. Methods: Twelve eyes of 10 patients with hard exudates associated with diabetic retinopathy were enrolled in this study. All subjects underwent a complete ophthalmic examination including SD-OCT (Copernicus, Zawiercie, Poland) and microperimetry (MP1; Nidek Technologies, Padova, Italy). Retinal sensitivity was measured, over the areas with hard exudates and compared to corresponding locations devoid of hard exudates, using a semi-automatic program. The size of the hard exudate plaque was measured using the measurement software in the microperimeter. Retinal thickness in the area of the hard exudates and foveal thickness were measured using SD-OCT. Results: Mean retinal sensitivity over hard exudates was 4.97 ± 4.17 dB which was significantly (P = 0.0001) reduced as compared to locations devoid of hard exudates. No significant correlation (r=-0.23, P = 0.45) was found between the size of the hard exudates and retinal sensitivity. A significant negative correlation was found between retinal sensitivity and retinal thickness at the area of the hard exudates (r=-0.65, P = 0.05), and between retinal sensitivity and foveal thickness (r=-0.91, P = 0.001). Conclusion: In eyes with diabetic retinopathy, retinal sensitivity was reduced due to the presence of hard exudates in the outer retinal layers and retinal thickening but this was not correlated with the size of the hard exudates.
To estimate the prevalence of diabetic macular edema, both clinically significant macular edema (... more To estimate the prevalence of diabetic macular edema, both clinically significant macular edema (CSME) and nonclinically significant macular edema (non-CSME), and report the associations of dyslipidemia on them. Design: A population-based cross-sectional study in India. Participants: After all exclusions, 1414 subjects with diabetes underwent an examination. Methods: The CSME was defined according to the Early Treatment Diabetic Retinopathy Study (ETDRS) guidelines; stereo digital fundus pairs were studied. The dyslipidemia cases were classified according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III). Main Outcome Measures: Prevalence of CSME and non-CSME and association of serum lipids with them. Results: The prevalence was 31.76% (95% confidence interval [CI], 26.04-37.47) for overall diabetic macular edema, 25.49% (95% Ci, 20.14-30.84) for non-CSME, and 6.27% (95% Ci, 3.29-9.24) for CSME. Univariate analysis identified macroalbuminuria and microalbuminuria, poor glycemic control, high total serum cholesterol, high serum low-density lipoprotein (LDL) cholesterol, and high serum non-high-density lipoprotein (HDL) cholesterol related to non-CSME and CSME (trend chi-square test, PϽ0.05). Logistic regression analysis (after adjusting variables such as age, gender, body mass index, duration, smoking, hypertension, glycosylated hemoglobin, macroalbuminuria and microalbuminuria, and insulin use) revealed high serum LDL cholesterol (odds ratio [OR], 2.72], high serum non-HDL cholesterol (OR, 1.99), and high cholesterol ratio (OR, 3.08) related to non-CSME, and poor glycemic control (OR, 8.06), microalbuminuria (OR, 14.23), and high serum total cholesterol (OR, 9.09) related to CSME. Conclusions: One third of the subjects had diabetic macular edema, and 6% of them showed evidence of CSME necessitating laser photocoagulation.
The application of new technologies for analysis of retinal images, neural networks for automated... more The application of new technologies for analysis of retinal images, neural networks for automated retinopathy grading, and teleophthalmology have been shown to have great value in ophthalmology. India has only one ophthalmic surgeon for every 107,000 population. Given this situation, teleophthalmology can play a vital role in addressing to the eye care needs of the country. The objective of this study was to assess patient satisfaction levels and factors influencing it during teleophthalmology consultation in India. A patient satisfaction questionnaire was prepared to assess the prominent aspects of patient satisfaction, including teleophthalmology screening, confidence in the technology used to transfer the fundus images, comprehensiveness of information available to the doctor in the central hub, and graded the opinion regarding the teleophthalmology. A cross-sectional survey among patients who attended a teleophthalmology screening conducted across eight villages in rural Tamilnadu. Responses were then subjected to qualitative analysis and conclusions made. The number of respondents was 348. Of this, 56.4% were males. The mean age of was 50 ؎ 17 years. Age ranged from 2 years to 83 years. 44.4% of the respondents were satisfied with teleophthalmology screening. (95% confidence interval [CI]: 38.58%-49.42%) No association was found between age, gender, education, and occupation, respectively, with satisfaction levels. We found that patients who asked questions during the screening were 2.18 times more likely to be satisfied with teleophthalmology than those who did not (odds ratio [OR] ؍ 2.19, 95% CI 1.37-3.5). This study highlights sentiments of the rural subjects when they underwent teleophthalmology consultations. This study provides valuable insights about patient's preferences and satisfaction levels with this newer technology.
The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian po... more The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian population older than 40 years. Design: A population-based cross-sectional study. Participants: Five thousand nine hundred ninety-nine subjects residing in Chennai, India, were enumerated. Methods: A multistage random sampling, based on socioeconomic criteria, was followed. Identified subjects with diabetes mellitus (based on the World Health Organization criteria) underwent detailed examination at the base hospital. The fundi of all patients were photographed using 45°, 4-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on Klein's classification of the Early Treatment Diabetic Retinopathy Study scale. Main Outcome Measures: These included age-and gender-adjusted prevalence of diabetes and diabetic retinopathy, and correlation of prevalence with history-based risk factors. Results: The age-and gender-adjusted prevalence rate of diabetes in an urban Chennai population was 28.2% (95% confidence interval [CI], 27.0-29.3), and the prevalence of diabetic retinopathy in general population was 3.5% (95% CI, 3.49-3.54). The prevalence of diabetic retinopathy in the population with diabetes mellitus was 18.0% (95% CI, 16.0-20.1). History-based variables that were significantly associated with increased risk of diabetic retinopathy included gender (men at greater risk; odds ratio [OR], 1.41; 95% CI, 1.04-1.91); use of insulin (OR, 3.52; 95% CI, 2.05-6.02); longer duration of diabetes (Ͼ15 years; OR, 6.43; 95% CI, 3.18-12.90); and subjects with known diabetes mellitus (OR, 2.98; 95% CI, 1.72-5.17). Differences in the socioeconomic status did not influence the occurrence of diabetic retinopathy. Conclusions: The prevalence of diabetic retinopathy was 18% in an urban population with diabetes mellitus in India. The duration of diabetes is the strongest predictor for diabetic retinopathy.
Purpose: To report the non-participation rates in a cross-sectional study, compare participants w... more Purpose: To report the non-participation rates in a cross-sectional study, compare participants with non-participants, elucidate barriers for non-response and evaluate the influence of non-responders on the outcome measure. Methods: The Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study had 2 steps in which non- participation was possible. Step 1 was an estimation of fasting blood sugar at the participants’ homes, and step 2 a base hospital examination. The sociodemographic information was collected at the time of enumeration. The barriers against participation were noted at refusal. The data of the participants were compared with the urban Tamil Nadu population data from the 2001 census. Results: The non-participation rate was 3.6% in the field (step 1), and 13.9% at the base hospital (step 2). At step 1, older men and unemployed women had a lesser odds ratio for non-participation than younger age groups. At step 2, employment was significant for non-...
Aim: To compare the prevalence of diabetic retinopathy (DR) and risk factors in patients with a k... more Aim: To compare the prevalence of diabetic retinopathy (DR) and risk factors in patients with a known onset of diabetes before 40 years and after 40 years of age. Methods: This is a population-based study for which 1,414 diabetics were recruited. The fundi were photographed using 45-degree 4-field stereoscopic digital photography. The diagnosis of DR was based on Klein’s classification of the Early Treatment Diabetic Retinopathy Study scales. Results: The prevalence of DR was 33.3% (95% confidence interval, CI: 26.6–39.9) in known onset of diabetes (≤40 years) compared to 15.6% (95% CI: 13.6–17.6) in those with late onset (>40 years; p < 0.0001). In the group with age of known onset of diabetes ≤40 years, the risk factors, associated with any DR, were poor glycemic control (odds ratio, OR: 1.36 for every g% increase in glycosylated hemoglobin), insulin use (OR: 4.21), increasing known duration of diabetes (OR: 1.10 for increase of every year in known duration of diabetes) and ...
Background/Aims: Growth factors have been implicated in the pathogenesis of diabetic retinopathy ... more Background/Aims: Growth factors have been implicated in the pathogenesis of diabetic retinopathy (DR). IGF-1 is known to trigger a critical cascade of molecular events that initiate retinal angiogenesis. Increased vitreous IGF-1 levels have been correlated with the severity of ischemia-associated diabetic retinal neovascularization. In the present study, a cytosine-adenine (CA)n repeat in the promoter of the IGF-1 gene is studied for association with DR. Methods: A total of 127 patients with retinopathy (cases: DR+) and 81 patients without retinopathy (controls: DR–) who had type 2 diabetes were recruited for the study. Patients underwent detailed clinical examination and DR was graded based on stereoscopic digital fundus photographs. Frequencies of alleles and genotypes between the two groups were analyzed for significance using relevant statistical tests. (CA)17 and (CA)18 repeats were the more frequent alleles. Results: The frequency of the 18-repeat genotype was significantly hi...
International Journal of Intelligent Systems and Applications, 2015
Shuffled Frog Leap Algorithm (SFLA), a metaheuristic algorithms inspired by PSO and DE has proved... more Shuffled Frog Leap Algorithm (SFLA), a metaheuristic algorithms inspired by PSO and DE has proved its efficacy in solving discrete optimization problems. In this paper we have modified SFLA to solve constrained engineering design problems. The proposed modification integrates a simple mechanism to update the position of frog in its memeplex in order to accelerate the basic SFLA algorithm. The proposal is validated on four engineering design problems and the statistical results are compared with the state-of-art algorithms. The simulated statistical results indicate that our proposal is a promising alternative to solve these types of optimization problems in terms of convergence speed.
Background: Studies on the association of vascular endothelial growth factor (VEGF) gene-460T/C a... more Background: Studies on the association of vascular endothelial growth factor (VEGF) gene-460T/C and-2578C/A polymorphisms with diabetic retinopathy (DR) have reported conflicting results. The aim of the present study was to assess the association by using meta-analysis. Methods: A systematic search of electronic databases (PubMed, EMBASE, Elsevier Science Direct, ISI Web of Science, CBM, CNKI and VIP) was carried out until Sept 18, 2013. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to assess the strength of the association. Results: Eleven studies (-460T/C: 6 studies including 932 cases and 722 controls;-2578C/A: 6 studies including 1,071 cases and 1,137 controls) were involved in this meta-analysis.
Purpose To elucidate changes in the neurosensory retina in the macular area, using spectral domai... more Purpose To elucidate changes in the neurosensory retina in the macular area, using spectral domain OCT and correlate with functional loss on fundus-related microperimetry, in patients with diabetes and no diabetic retinopathy compared with age-matched healthy volunteers. Methods This was a prospective study enroling 39 patients in each group. All patients underwent comprehensive dilated eye examination. The foveal thickness and the photoreceptor layer thickness at the foveal centre were measured using spectral domain OCT, and the mean retinal sensitivity of central 20 degrees was measured using microperimetry. Results The mean age of the patients with diabetes was 50.92 ± 4.75 years, and of controls, 49.87±5.50 years. SD-OCT measured photoreceptor layer thickness (PLT) to be 61.62±4.48 lm in cases, and 68.79±7.84 lm in controls (Po0.0001); foveal thickness (FT) was 168.64 ± 16.46 lm in cases and 177.74 ± 14.58 lm in controls (P ¼ 0.012). The mean retinal sensitivity (MRS) of the central 20 degrees, measured on microperimetry was 15.74±3.74 db in cases and 17.70±1.5 db in controls (Po0.003). In cases compared with controls (aged under 50 years) statistically significant differences were noted in all the three outcome variables: FT, P ¼ 0.030; PLT, P ¼ 0.015; and MRS, P ¼ 0.020. The duration of diabetes influenced only the PLT (P ¼ 0.017). Statistical analysis was performed with Student's t-test and v 2 test. Conclusion Neuronal damage was observed in those eyes that did not have clinical evidence of diabetic retinopathy.
Background The Metabolic syndrome (MS) consists of central obesity, glucose intolerance, hyperins... more Background The Metabolic syndrome (MS) consists of central obesity, glucose intolerance, hyperinsulinemia, low high density lipoproteins, high triglycerides and hypertension. Different studies have observed that MS causes microvascular complications in patients with type 2 diabetes. The aim of the study was to find out the prevalence of MS in the Indian population with type 2 diabetes mellitus in relation to gender, duration of diabetes, and to evaluate the influence of MS and its individual components on microvascular complications such as diabetic retinopathy, diabetic nephropathy and diabetic neuropathy. Methods A population-based cross sectional survey was conducted with 1414 patients having type 2 diabetes mellitus. The International Diabetes Federation (IDF) criteria were used to identify the metabolic syndrome. Diabetic retinopathy was graded using the stereoscopic digital fundus photography. Neuropathy was assessed by measuring the vibration perception threshold through a se...
Aim: To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sightthreatenin... more Aim: To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sightthreatening diabetic retinopathy (STDR) in urban Chennai, Tamil Nadu, India. Methods: A total of 5999 individuals were enumerated from the Chennai metropolis. Of these, 1414 subjects with diabetes were included for data analysis in the study. STDR or non-STDR groups were classified based on the fundus photographs. HbA1c was measured (Bio-Rad DiaSTAT TM HbA1c Reagent Kit) by the liquid chromatography technique. Results: A statistically significant difference (p < 0.05) was noted in the duration of diabetes, gender, body mass index, HbA1c, micro-and macro-albuminuria between both non-STDR and STDR groups as compared to the no-diabetic retinopathy (DR) group. On multivariate analysis, HbA1c (non-STDR: odd's ratio OR = 1.23; 95% confidence interval CI = 1.15-1.32; p < 0.0001; STDR: OR = 1.31 95% CI = 1.14-1.52; p < 0.0001) was found to be significantly associated with non-STDR and STDR when compared with the no-DR group. The Receiver Operating Characteristic analysis showed that the cutoff value of 8.0 had 75.6% sensitivity and 58.2% specificity with 64.9% maximum area under the curve. Conclusion: HbA1c value >8.0% was significantly related with STDR. In a screening programme, the cutoff value of HbA1c >8.0% provided a maximum yield of STDR.
Background To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiolog... more Background To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III, an ongoing epidemiological study to estimate the prevalence of Diabetes and Diabetic Retinopathy in rural population of Kanchipuram and Thiravallur districts of Tamil Nadu, India and to elucidate the clinical, anthropometric, biochemical and genetic risk factors associated with diabetic retinopathy in this rural population. Methods Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III will be a mobile van based epidemiological study; 11,760 participants aged ≥ 40 years will be recruited from the study areas. Eligible subjects will undergo blood sugar estimation to diagnose Diabetes. Oral Glucose Tolerance Test will be done to conform diabetes. All subjects with diabetes will undergo complete information of knowledge, aptitude and practice of diabetes and diabetic retinopathy, Diet questionnaire, demographic data, socioecon...
BackgroundTo report the prevalence of ear lobe crease (ELC), a sign of coronary heart disease, in... more BackgroundTo report the prevalence of ear lobe crease (ELC), a sign of coronary heart disease, in subjects (more than 40 years old) with diabetes and find its association with diabetic retinopathy.MethodsSubjects were recruited from the Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular-genetics Study (SN-DREAMS), a cross-sectional study between 2003 and 2006; the data were analyzed for the1414 eligible subjects with diabetes. All patients' fundi were photographed using 45° four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. The presence of ELC was evaluated on physical examination.ResultsThe prevalence of ELC, among the subjects with diabetes, was 59.7%. The ELC group were older, had longer duration of diabetes, had poor glycemic control and had a high socio-economic status compared to the group without ELC and the variables were statistically significant. There was no statistical dif...
The aim of the study was to report the prevalence of obesity indices in individuals with diabetes... more The aim of the study was to report the prevalence of obesity indices in individuals with diabetes and find out their association with diabetic retinopathy in the urban Indian population. Subjects (n = 1,414) were recruited from Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular Genetics Study (SN-DREAMS-I), a crosssectional study between 2003 and 2006. Anthropometric measurements were carried out, and all patients' fundi were photographed using 45°four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. Generalized obesity and abdominal obesity were defined using WHO Asia Pacific guidelines with the BMI (body mass index) cutoff as C23 kg/m 2 , WC (waist circumference) cutoffs as C90 cm in men and C80 cm in women and WHO guidelines using WHR (waist-to-hip ratio) cutoffs as C0.90 for men and C0.85 for women. Prevalence of obesity defined by BMI and WC was more in women compared to men, and that defined by WHR was more in men compared to women (P \ 0.001). The prevalence of isolated generalized obesity, isolated abdominal obesity and combined obesity were 5.4, 10.1 and 58% in men and 4.5, 10.8 and 74.4% in women, respectively. The prevalence of any diabetic retinopathy and sight-threatening diabetic retinopathy was more in the isolated abdominal obesity group (26.35 and 6.08%, respectively) than in other subgroups. On logistic regression analysis, isolated abdominal obesity (OR 2.02, 95% CI: 1.06-3.86) and increased WHR in women (OR 1.48 95% CI: 1.10-2.38) were associated with diabetic retinopathy; BMI C 23 (OR 0.66, 95% CI: 0.48-0.90) and combined obesity (OR 0.72, 95% CI: 0.53-0.99) had a protective role for any diabetic retinopathy in the overall group. In the urban south Indian population, isolated abdominal obesity and higher WHR in women were associated with diabetic retinopathy, but not with the severity of diabetic retinopathy.
dependent factors and up to some 'bulk AdS' contact terms. On the other hand the J b 0 fourpoint ... more dependent factors and up to some 'bulk AdS' contact terms. On the other hand the J b 0 fourpoint function receives an additional contribution compared to the free theory expression due to the J f 0 exchange. We find that the double discontinuity of this single trace operator J f 0 vanishes and hence it only contributes to AdS-contact term.
The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil b... more The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil borne pathogen causes severe yield loss. The molecular characterization and their interaction with its host is necessary to develop a protection strategy. 20 isolates of F. oxysporum f.sp. lycopersici (FOL) were isolated from wilt infected tomato plants across Tamil Nadu. They were subjected to cultural, morphological, molecular and virulence studies. The results revealed that all the isolates produced both micro and macro conidia with different size, number of cells. The colors of the culture and growth pattern were also varied. In addition, chlamydospores were observed terminally and intercalary. The PCR analysis with F. oxysporum species-specific primer significantly amplified an amplicon of 600 bp fragment in all the isolates. Based on the above characters and pathogenicity, isolate FOL-8 was considered as virulent and FOL-20 was considered as least virulent. Proteomics strategy was adopted to determine the virulence factors between the isolates of FOL-8 and FOL-20. The 2D analyses have showed the differential expression of 17 different proteins. Among them, three proteins were down regulated and 14 proteins were significantly up regulated in FOL-8 than FOL-20 isolate. Among the 17 proteins, 10 distinct spots were analyzed by MALDI-TOF. The functions of the analyzed proteins, suggested that they were involved in pathogenicity, symptom expression and disease development, sporulation, growth, and higher penetration rate on tomato root tissue. Overall, these experiments proves the role of proteome in pathogenicity of F. oxysporum f.sp. lycopersici in tomato and unravels the mechanism behinds the virulence of the pathogen in causing wilt disease.
Introduction: The aim of this study was to compare the occurrence of diabetic retinopathy in targ... more Introduction: The aim of this study was to compare the occurrence of diabetic retinopathy in targeted screening diabetic patients (Group I) with newly diagnosed diabetic patients in general practice (Group II). Materials and Methods: This was an observational cross-sectional study. Data were obtained from 25,313 subjects who participated in the diabetic screening camps, and 128 newly diagnosed diabetes who presented to the diabetic retinopathy screening camps in general practice in rural and urban south India. The study variables were collected from all patients who underwent eye examination from the target screening detected diabetics [(n = 173) Group I] and those newly diagnosed in general practice [(n = 128) Group II]. The variations in prevalence of diabetic retinopathy and sight-threatening diabetic retinopathy in Group I and Group II and the factors affecting it were identified. Results: The occurrence of diabetic retinopathy was 6.35% (95% CI, 2.5-9.5) in Group I and 11.71% (...
Purpose: To evaluate retinal sensitivity over hard exudates in correlation with the spectral doma... more Purpose: To evaluate retinal sensitivity over hard exudates in correlation with the spectral domain optical coherence tomography (SD-OCT) findings in eyes with diabetic retinopathy. Methods: Twelve eyes of 10 patients with hard exudates associated with diabetic retinopathy were enrolled in this study. All subjects underwent a complete ophthalmic examination including SD-OCT (Copernicus, Zawiercie, Poland) and microperimetry (MP1; Nidek Technologies, Padova, Italy). Retinal sensitivity was measured, over the areas with hard exudates and compared to corresponding locations devoid of hard exudates, using a semi-automatic program. The size of the hard exudate plaque was measured using the measurement software in the microperimeter. Retinal thickness in the area of the hard exudates and foveal thickness were measured using SD-OCT. Results: Mean retinal sensitivity over hard exudates was 4.97 ± 4.17 dB which was significantly (P = 0.0001) reduced as compared to locations devoid of hard exudates. No significant correlation (r=-0.23, P = 0.45) was found between the size of the hard exudates and retinal sensitivity. A significant negative correlation was found between retinal sensitivity and retinal thickness at the area of the hard exudates (r=-0.65, P = 0.05), and between retinal sensitivity and foveal thickness (r=-0.91, P = 0.001). Conclusion: In eyes with diabetic retinopathy, retinal sensitivity was reduced due to the presence of hard exudates in the outer retinal layers and retinal thickening but this was not correlated with the size of the hard exudates.
To estimate the prevalence of diabetic macular edema, both clinically significant macular edema (... more To estimate the prevalence of diabetic macular edema, both clinically significant macular edema (CSME) and nonclinically significant macular edema (non-CSME), and report the associations of dyslipidemia on them. Design: A population-based cross-sectional study in India. Participants: After all exclusions, 1414 subjects with diabetes underwent an examination. Methods: The CSME was defined according to the Early Treatment Diabetic Retinopathy Study (ETDRS) guidelines; stereo digital fundus pairs were studied. The dyslipidemia cases were classified according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III). Main Outcome Measures: Prevalence of CSME and non-CSME and association of serum lipids with them. Results: The prevalence was 31.76% (95% confidence interval [CI], 26.04-37.47) for overall diabetic macular edema, 25.49% (95% Ci, 20.14-30.84) for non-CSME, and 6.27% (95% Ci, 3.29-9.24) for CSME. Univariate analysis identified macroalbuminuria and microalbuminuria, poor glycemic control, high total serum cholesterol, high serum low-density lipoprotein (LDL) cholesterol, and high serum non-high-density lipoprotein (HDL) cholesterol related to non-CSME and CSME (trend chi-square test, PϽ0.05). Logistic regression analysis (after adjusting variables such as age, gender, body mass index, duration, smoking, hypertension, glycosylated hemoglobin, macroalbuminuria and microalbuminuria, and insulin use) revealed high serum LDL cholesterol (odds ratio [OR], 2.72], high serum non-HDL cholesterol (OR, 1.99), and high cholesterol ratio (OR, 3.08) related to non-CSME, and poor glycemic control (OR, 8.06), microalbuminuria (OR, 14.23), and high serum total cholesterol (OR, 9.09) related to CSME. Conclusions: One third of the subjects had diabetic macular edema, and 6% of them showed evidence of CSME necessitating laser photocoagulation.
The application of new technologies for analysis of retinal images, neural networks for automated... more The application of new technologies for analysis of retinal images, neural networks for automated retinopathy grading, and teleophthalmology have been shown to have great value in ophthalmology. India has only one ophthalmic surgeon for every 107,000 population. Given this situation, teleophthalmology can play a vital role in addressing to the eye care needs of the country. The objective of this study was to assess patient satisfaction levels and factors influencing it during teleophthalmology consultation in India. A patient satisfaction questionnaire was prepared to assess the prominent aspects of patient satisfaction, including teleophthalmology screening, confidence in the technology used to transfer the fundus images, comprehensiveness of information available to the doctor in the central hub, and graded the opinion regarding the teleophthalmology. A cross-sectional survey among patients who attended a teleophthalmology screening conducted across eight villages in rural Tamilnadu. Responses were then subjected to qualitative analysis and conclusions made. The number of respondents was 348. Of this, 56.4% were males. The mean age of was 50 ؎ 17 years. Age ranged from 2 years to 83 years. 44.4% of the respondents were satisfied with teleophthalmology screening. (95% confidence interval [CI]: 38.58%-49.42%) No association was found between age, gender, education, and occupation, respectively, with satisfaction levels. We found that patients who asked questions during the screening were 2.18 times more likely to be satisfied with teleophthalmology than those who did not (odds ratio [OR] ؍ 2.19, 95% CI 1.37-3.5). This study highlights sentiments of the rural subjects when they underwent teleophthalmology consultations. This study provides valuable insights about patient's preferences and satisfaction levels with this newer technology.
The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian po... more The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian population older than 40 years. Design: A population-based cross-sectional study. Participants: Five thousand nine hundred ninety-nine subjects residing in Chennai, India, were enumerated. Methods: A multistage random sampling, based on socioeconomic criteria, was followed. Identified subjects with diabetes mellitus (based on the World Health Organization criteria) underwent detailed examination at the base hospital. The fundi of all patients were photographed using 45°, 4-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on Klein's classification of the Early Treatment Diabetic Retinopathy Study scale. Main Outcome Measures: These included age-and gender-adjusted prevalence of diabetes and diabetic retinopathy, and correlation of prevalence with history-based risk factors. Results: The age-and gender-adjusted prevalence rate of diabetes in an urban Chennai population was 28.2% (95% confidence interval [CI], 27.0-29.3), and the prevalence of diabetic retinopathy in general population was 3.5% (95% CI, 3.49-3.54). The prevalence of diabetic retinopathy in the population with diabetes mellitus was 18.0% (95% CI, 16.0-20.1). History-based variables that were significantly associated with increased risk of diabetic retinopathy included gender (men at greater risk; odds ratio [OR], 1.41; 95% CI, 1.04-1.91); use of insulin (OR, 3.52; 95% CI, 2.05-6.02); longer duration of diabetes (Ͼ15 years; OR, 6.43; 95% CI, 3.18-12.90); and subjects with known diabetes mellitus (OR, 2.98; 95% CI, 1.72-5.17). Differences in the socioeconomic status did not influence the occurrence of diabetic retinopathy. Conclusions: The prevalence of diabetic retinopathy was 18% in an urban population with diabetes mellitus in India. The duration of diabetes is the strongest predictor for diabetic retinopathy.
Purpose: To report the non-participation rates in a cross-sectional study, compare participants w... more Purpose: To report the non-participation rates in a cross-sectional study, compare participants with non-participants, elucidate barriers for non-response and evaluate the influence of non-responders on the outcome measure. Methods: The Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study had 2 steps in which non- participation was possible. Step 1 was an estimation of fasting blood sugar at the participants’ homes, and step 2 a base hospital examination. The sociodemographic information was collected at the time of enumeration. The barriers against participation were noted at refusal. The data of the participants were compared with the urban Tamil Nadu population data from the 2001 census. Results: The non-participation rate was 3.6% in the field (step 1), and 13.9% at the base hospital (step 2). At step 1, older men and unemployed women had a lesser odds ratio for non-participation than younger age groups. At step 2, employment was significant for non-...
Aim: To compare the prevalence of diabetic retinopathy (DR) and risk factors in patients with a k... more Aim: To compare the prevalence of diabetic retinopathy (DR) and risk factors in patients with a known onset of diabetes before 40 years and after 40 years of age. Methods: This is a population-based study for which 1,414 diabetics were recruited. The fundi were photographed using 45-degree 4-field stereoscopic digital photography. The diagnosis of DR was based on Klein’s classification of the Early Treatment Diabetic Retinopathy Study scales. Results: The prevalence of DR was 33.3% (95% confidence interval, CI: 26.6–39.9) in known onset of diabetes (≤40 years) compared to 15.6% (95% CI: 13.6–17.6) in those with late onset (>40 years; p < 0.0001). In the group with age of known onset of diabetes ≤40 years, the risk factors, associated with any DR, were poor glycemic control (odds ratio, OR: 1.36 for every g% increase in glycosylated hemoglobin), insulin use (OR: 4.21), increasing known duration of diabetes (OR: 1.10 for increase of every year in known duration of diabetes) and ...
Background/Aims: Growth factors have been implicated in the pathogenesis of diabetic retinopathy ... more Background/Aims: Growth factors have been implicated in the pathogenesis of diabetic retinopathy (DR). IGF-1 is known to trigger a critical cascade of molecular events that initiate retinal angiogenesis. Increased vitreous IGF-1 levels have been correlated with the severity of ischemia-associated diabetic retinal neovascularization. In the present study, a cytosine-adenine (CA)n repeat in the promoter of the IGF-1 gene is studied for association with DR. Methods: A total of 127 patients with retinopathy (cases: DR+) and 81 patients without retinopathy (controls: DR–) who had type 2 diabetes were recruited for the study. Patients underwent detailed clinical examination and DR was graded based on stereoscopic digital fundus photographs. Frequencies of alleles and genotypes between the two groups were analyzed for significance using relevant statistical tests. (CA)17 and (CA)18 repeats were the more frequent alleles. Results: The frequency of the 18-repeat genotype was significantly hi...
International Journal of Intelligent Systems and Applications, 2015
Shuffled Frog Leap Algorithm (SFLA), a metaheuristic algorithms inspired by PSO and DE has proved... more Shuffled Frog Leap Algorithm (SFLA), a metaheuristic algorithms inspired by PSO and DE has proved its efficacy in solving discrete optimization problems. In this paper we have modified SFLA to solve constrained engineering design problems. The proposed modification integrates a simple mechanism to update the position of frog in its memeplex in order to accelerate the basic SFLA algorithm. The proposal is validated on four engineering design problems and the statistical results are compared with the state-of-art algorithms. The simulated statistical results indicate that our proposal is a promising alternative to solve these types of optimization problems in terms of convergence speed.
Background: Studies on the association of vascular endothelial growth factor (VEGF) gene-460T/C a... more Background: Studies on the association of vascular endothelial growth factor (VEGF) gene-460T/C and-2578C/A polymorphisms with diabetic retinopathy (DR) have reported conflicting results. The aim of the present study was to assess the association by using meta-analysis. Methods: A systematic search of electronic databases (PubMed, EMBASE, Elsevier Science Direct, ISI Web of Science, CBM, CNKI and VIP) was carried out until Sept 18, 2013. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to assess the strength of the association. Results: Eleven studies (-460T/C: 6 studies including 932 cases and 722 controls;-2578C/A: 6 studies including 1,071 cases and 1,137 controls) were involved in this meta-analysis.
Purpose To elucidate changes in the neurosensory retina in the macular area, using spectral domai... more Purpose To elucidate changes in the neurosensory retina in the macular area, using spectral domain OCT and correlate with functional loss on fundus-related microperimetry, in patients with diabetes and no diabetic retinopathy compared with age-matched healthy volunteers. Methods This was a prospective study enroling 39 patients in each group. All patients underwent comprehensive dilated eye examination. The foveal thickness and the photoreceptor layer thickness at the foveal centre were measured using spectral domain OCT, and the mean retinal sensitivity of central 20 degrees was measured using microperimetry. Results The mean age of the patients with diabetes was 50.92 ± 4.75 years, and of controls, 49.87±5.50 years. SD-OCT measured photoreceptor layer thickness (PLT) to be 61.62±4.48 lm in cases, and 68.79±7.84 lm in controls (Po0.0001); foveal thickness (FT) was 168.64 ± 16.46 lm in cases and 177.74 ± 14.58 lm in controls (P ¼ 0.012). The mean retinal sensitivity (MRS) of the central 20 degrees, measured on microperimetry was 15.74±3.74 db in cases and 17.70±1.5 db in controls (Po0.003). In cases compared with controls (aged under 50 years) statistically significant differences were noted in all the three outcome variables: FT, P ¼ 0.030; PLT, P ¼ 0.015; and MRS, P ¼ 0.020. The duration of diabetes influenced only the PLT (P ¼ 0.017). Statistical analysis was performed with Student's t-test and v 2 test. Conclusion Neuronal damage was observed in those eyes that did not have clinical evidence of diabetic retinopathy.
Background The Metabolic syndrome (MS) consists of central obesity, glucose intolerance, hyperins... more Background The Metabolic syndrome (MS) consists of central obesity, glucose intolerance, hyperinsulinemia, low high density lipoproteins, high triglycerides and hypertension. Different studies have observed that MS causes microvascular complications in patients with type 2 diabetes. The aim of the study was to find out the prevalence of MS in the Indian population with type 2 diabetes mellitus in relation to gender, duration of diabetes, and to evaluate the influence of MS and its individual components on microvascular complications such as diabetic retinopathy, diabetic nephropathy and diabetic neuropathy. Methods A population-based cross sectional survey was conducted with 1414 patients having type 2 diabetes mellitus. The International Diabetes Federation (IDF) criteria were used to identify the metabolic syndrome. Diabetic retinopathy was graded using the stereoscopic digital fundus photography. Neuropathy was assessed by measuring the vibration perception threshold through a se...
Aim: To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sightthreatenin... more Aim: To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sightthreatening diabetic retinopathy (STDR) in urban Chennai, Tamil Nadu, India. Methods: A total of 5999 individuals were enumerated from the Chennai metropolis. Of these, 1414 subjects with diabetes were included for data analysis in the study. STDR or non-STDR groups were classified based on the fundus photographs. HbA1c was measured (Bio-Rad DiaSTAT TM HbA1c Reagent Kit) by the liquid chromatography technique. Results: A statistically significant difference (p < 0.05) was noted in the duration of diabetes, gender, body mass index, HbA1c, micro-and macro-albuminuria between both non-STDR and STDR groups as compared to the no-diabetic retinopathy (DR) group. On multivariate analysis, HbA1c (non-STDR: odd's ratio OR = 1.23; 95% confidence interval CI = 1.15-1.32; p < 0.0001; STDR: OR = 1.31 95% CI = 1.14-1.52; p < 0.0001) was found to be significantly associated with non-STDR and STDR when compared with the no-DR group. The Receiver Operating Characteristic analysis showed that the cutoff value of 8.0 had 75.6% sensitivity and 58.2% specificity with 64.9% maximum area under the curve. Conclusion: HbA1c value >8.0% was significantly related with STDR. In a screening programme, the cutoff value of HbA1c >8.0% provided a maximum yield of STDR.
Background To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiolog... more Background To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III, an ongoing epidemiological study to estimate the prevalence of Diabetes and Diabetic Retinopathy in rural population of Kanchipuram and Thiravallur districts of Tamil Nadu, India and to elucidate the clinical, anthropometric, biochemical and genetic risk factors associated with diabetic retinopathy in this rural population. Methods Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III will be a mobile van based epidemiological study; 11,760 participants aged ≥ 40 years will be recruited from the study areas. Eligible subjects will undergo blood sugar estimation to diagnose Diabetes. Oral Glucose Tolerance Test will be done to conform diabetes. All subjects with diabetes will undergo complete information of knowledge, aptitude and practice of diabetes and diabetic retinopathy, Diet questionnaire, demographic data, socioecon...
BackgroundTo report the prevalence of ear lobe crease (ELC), a sign of coronary heart disease, in... more BackgroundTo report the prevalence of ear lobe crease (ELC), a sign of coronary heart disease, in subjects (more than 40 years old) with diabetes and find its association with diabetic retinopathy.MethodsSubjects were recruited from the Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular-genetics Study (SN-DREAMS), a cross-sectional study between 2003 and 2006; the data were analyzed for the1414 eligible subjects with diabetes. All patients' fundi were photographed using 45° four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. The presence of ELC was evaluated on physical examination.ResultsThe prevalence of ELC, among the subjects with diabetes, was 59.7%. The ELC group were older, had longer duration of diabetes, had poor glycemic control and had a high socio-economic status compared to the group without ELC and the variables were statistically significant. There was no statistical dif...
The aim of the study was to report the prevalence of obesity indices in individuals with diabetes... more The aim of the study was to report the prevalence of obesity indices in individuals with diabetes and find out their association with diabetic retinopathy in the urban Indian population. Subjects (n = 1,414) were recruited from Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular Genetics Study (SN-DREAMS-I), a crosssectional study between 2003 and 2006. Anthropometric measurements were carried out, and all patients' fundi were photographed using 45°four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. Generalized obesity and abdominal obesity were defined using WHO Asia Pacific guidelines with the BMI (body mass index) cutoff as C23 kg/m 2 , WC (waist circumference) cutoffs as C90 cm in men and C80 cm in women and WHO guidelines using WHR (waist-to-hip ratio) cutoffs as C0.90 for men and C0.85 for women. Prevalence of obesity defined by BMI and WC was more in women compared to men, and that defined by WHR was more in men compared to women (P \ 0.001). The prevalence of isolated generalized obesity, isolated abdominal obesity and combined obesity were 5.4, 10.1 and 58% in men and 4.5, 10.8 and 74.4% in women, respectively. The prevalence of any diabetic retinopathy and sight-threatening diabetic retinopathy was more in the isolated abdominal obesity group (26.35 and 6.08%, respectively) than in other subgroups. On logistic regression analysis, isolated abdominal obesity (OR 2.02, 95% CI: 1.06-3.86) and increased WHR in women (OR 1.48 95% CI: 1.10-2.38) were associated with diabetic retinopathy; BMI C 23 (OR 0.66, 95% CI: 0.48-0.90) and combined obesity (OR 0.72, 95% CI: 0.53-0.99) had a protective role for any diabetic retinopathy in the overall group. In the urban south Indian population, isolated abdominal obesity and higher WHR in women were associated with diabetic retinopathy, but not with the severity of diabetic retinopathy.
dependent factors and up to some 'bulk AdS' contact terms. On the other hand the J b 0 fourpoint ... more dependent factors and up to some 'bulk AdS' contact terms. On the other hand the J b 0 fourpoint function receives an additional contribution compared to the free theory expression due to the J f 0 exchange. We find that the double discontinuity of this single trace operator J f 0 vanishes and hence it only contributes to AdS-contact term.
The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil b... more The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil borne pathogen causes severe yield loss. The molecular characterization and their interaction with its host is necessary to develop a protection strategy. 20 isolates of F. oxysporum f.sp. lycopersici (FOL) were isolated from wilt infected tomato plants across Tamil Nadu. They were subjected to cultural, morphological, molecular and virulence studies. The results revealed that all the isolates produced both micro and macro conidia with different size, number of cells. The colors of the culture and growth pattern were also varied. In addition, chlamydospores were observed terminally and intercalary. The PCR analysis with F. oxysporum species-specific primer significantly amplified an amplicon of 600 bp fragment in all the isolates. Based on the above characters and pathogenicity, isolate FOL-8 was considered as virulent and FOL-20 was considered as least virulent. Proteomics strategy was adopted to determine the virulence factors between the isolates of FOL-8 and FOL-20. The 2D analyses have showed the differential expression of 17 different proteins. Among them, three proteins were down regulated and 14 proteins were significantly up regulated in FOL-8 than FOL-20 isolate. Among the 17 proteins, 10 distinct spots were analyzed by MALDI-TOF. The functions of the analyzed proteins, suggested that they were involved in pathogenicity, symptom expression and disease development, sporulation, growth, and higher penetration rate on tomato root tissue. Overall, these experiments proves the role of proteome in pathogenicity of F. oxysporum f.sp. lycopersici in tomato and unravels the mechanism behinds the virulence of the pathogen in causing wilt disease.
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Papers by Tarun Sharma