«Annual Report 2010 - 2011 Much has been done, but much remains to be done. we look to the future with renewed strength to continue the mission of ...»
Annual Report 2010 - 2011
Much has been done, but much remains to be done… we look to the
future with renewed strength to continue the mission of providing
quality eye care and hope that some of what we have learned will be
useful to other eye care workers around the world.
Aravind Medical Research Foundation is recognized as a Scientific and
Industrial Research Organization (SIRO) by the Department of Scientific
and Industrial Research (DSIR).
Annual Report 2010 - 2011
MISSION To eliminate needless blindness by providing evidence through research and evolving methods to translate existing evidence and knowledge into effective action.
No.1, Anna Nagar, Madurai – 625020, Tamil Nadu, India Ph.: 91 452 4356550; Fax: 91-452-2530984; Email: email@example.com Web: www.aravind.org
ARAVIND MEDICAL RESEARCH FOUNDATION
BOARD OF MANAGEMENTDr. P. namPerumalSamy, mS, famS Dr. G. natchiar, mS, Do er. G. SriniVaSan, b.e., mS Dr.r.Kim, Do., Dnb mr. r.D. thulaSiraj, mba Dr. S. araVinD, mS, mba Dr.n.VenKateSh Prajna Dr. S.r. KriShnaDaS, Do., Dnb Do., Dnb., frcoPhth
RESEARCH ADVISORY COMMITTEE INSTITUTIONAL REVIEW BOARD (IRB)MEMBERS Chairman Chairman Dr. P. NamPerumalsamy ms. shobhaNa ramachaNDhraN Chairman - Emeritus Managing Director Aravind Eye Care System TVS Sri Chakra Ltd.
1, Anna Nagar, Madurai – 625 020 Madurai Member-Secretary Member-Secretary Dr.Vr. muthukkaruPPaN Dr. lalitha PrajNa Director Research Chief Microbiolgist Aravind Medical Research Foundation Aravind Eye Hospital 1, Anna Nagar, Madurai - 625 020 1, Anna Nagar, Madurai - 625 020 Members MEMBERS mr. G. sriNiVasaN mr. c. sriNiVasaN Director – Finance UGC Emeritus Professor Aravind Eye Care System 1, Subhash Street, Kalvi Nagar, Theni Main Road 1, Anna Nagar, Madurai – 625 020 Nagamalai, Madurai Dr. a. GNaNam Dr. l. thayumaNaVaN Former Vice Chancellor Sr. Consultant, Gastroenterologist C-2 Chitrakudal Apartments Vadamalayan Hospital, Madurai - 625 002 10,
Fundamental research in Ophthalmology opens up possibilities to improve existing treatment options by a better understanding of the disease processes. Eye research, particularly in the Indian context, is imperative to optimize treatment modalities for better treatment outcome. The infection load and pathogen profile are different in the agrarian society of India and in addition it is well known that the immunological profile of the Indian population is different when compared to the western population, consequently large scale studies using appropriate patient groups are of paramount importance. Blind extrapolation of studies done in other populations is incompatible when applied to patient groups in India.
Examining disease processes at all levels of genomic transactions is important. Large cohort studies already provided enough evidence that genome variation at individual level are very revealing when examined at the level of transcripts and proteins. At AMRF fundamental aspects of selected diseases are being examined at the level of genome, transcriptome and proteome. The approaches are designed to further the knowledge as well as to apply the research findings in clinical practice.
Molecular genetics group has been focusing on the analysis of associative Single Nucleotide Polymorphisms (SNPs) and the primary mutations that could be responsible for the disease. They examine several inherited eye diseases such as ocular cutaneous albinism, Leber’s Hereditary Optic Neuropathy (LHON), Duane Retraction Syndrome (DRS), Leber’s Congenital Amaurosis (LCA), diabetic retinopathy etc. They discovered an interesting polymorphism in the intronic region of myocilin gene in primary open angle glaucoma. They also examine the functions of selected genes in eye diseases.
Microbiology group is actively involved in the understanding of the immune response to fungal infection.
Unlike other tissues, eye is immunologically distinct. The corneal epithelium, neutrophils, macrophages and dendritic cells are the cells that are involved in innate immune response against fungi. The main receptor that recognizes the fungal components is Dectin-1. The objective of the study is to show the events leading to the development of innate immune defense, and the subsequent adaptive response. It is increasingly evident from the work of this group that adaptive response also plays a role in antifungal defense in the infected eye. Microbiology group is also involved in the development of new diagnostic tools for early detection of causative agent for Uveitis. Infective Uveitis is due to several different ocular and systemic infections. The disease mechanism behind trematode induced Uveitis is another area of study by this group.
Immunology group is also a referral center for systemic and ocular Leptospiral Uveitis. The group’s main focus is the exploration of Leptospiral Uveitis and to understand the mechanism of development of acute cataract in Leptospiral infections. They are focusing on the autoimmune component in this infection.
Stem cell biology group has developed a new two parameter approach for the identification of stem cells among limbal epithelial cells generated in vitro. They have used this approach to identify buccal epithelial stem cells as well. They have developed a simple culture method to generate stem cell -rich epithelium for transplantation in a small group of patients. The results are very encouraging and further studies are in progress to develop xeno-free, simple and cost effective method in the GMP facility.
Ocular pharmacology group is interested in the pharmacokinetics of voriconazole used for treating fungal keratitis patients. This group is also interested in the study of disease mechanism in the case of diabetic retinopathy and Age-related macular degeneration (AMD).
Proteomics group has been added recently to AMRF. Proteomics of ophthalmic diseases is emerging fast as an area of study and there are groups examining eye diseases from different populations across the globe using proteomics. Proteomics group is examining the proteome profile of the easily accessible tissues in infections.
Tear is being chosen for examining the disease specific changes in Mycotic keratitis. It has been shown that there is significant difference in the proteome profile of male and female tears. It has also been shown that very early in fungal infection one could see differences in the proteome profile of tears. Other diseases being studied are primary open angle glaucoma and diabetic retinopathy. Aqueous humor proteome is used as target tissue to examine the proteome level alterations in these diseases. Apart from identifying early events in infection, proteomics will also allow us to examine the disease mechanism.
Molecular Genetics Laboratory at Aravind Medical Research Foundation is focusing on the genetics of various inherited eye diseases in Indian population. The overall goals of our research program are to identify the candidate genes for eye diseases and to identify the genetic variations in the known candidate genes especially for aniridia, primary open angle glaucoma, albinism, diabetic retinopathy, age related cataract, retinitis pigmentosa, keratoconus, globe anomalies, familial exudative vitreoretinopathy, blepharophimosis-ptosis-epicanthus inversus syndrome, Leber’s hereditary optic neuropathy, X-linked juvenile retinoschisis and Leber congenital amaurosis in Indian population. Phenotype-genotype correlation, understanding the gene expression in relation to pathogenesis and developing molecular diagnosis for early detection of the eye disease are also our interest.
Spectrum of candidate gene mutations associated with Indian familial oculocutaneous and ocular albinism Investigators : P. Sundaresan (Aravind Medical Research Foundation, Madurai) P. Vijayalakshmi (Aravind Eye Hospital, Madurai) Asim Kumar Sil (Vivekananda Mission Ashram Netra Niramay Niketan, West Bengal) Research scholar : Ms. K. Renugadevi Funding agency : Department of Biotechnology and Department of Science and Technology Background and aim Albinism is a very rare congenital defect and the disease refers to a group of inherited conditions of melanin biosynthesis or distribution. There is no treatment available for this hereditary disorder and its frequency across the human population was estimated to be about 1 in 20,000 in worldwide. Albinism is an autosomal recessive disorder and the phenotype ranges from a complete or partial lack of melanin in ocular and cutaneous regions due to mutations in TYR, P, MC1R, TYRP1 and MATP genes or in ocular region alone due to GPR143 gene.
In 2003, incidence of albinism in eastern part of India was observed and the research team started working on the genetics of albinism in Indian population. The aim of the study was to identify the spectrum of genetic variations in Indian population and identify the genetic markers of albinism for molecular diagnosis.
A total of 141 patients from southern and eastern parts of India was recruited. The common clinical problems in these patients include, severe photosensitivity, reduced vision, nystagmus, macular/foveal hypoplasia, misrouting of optic fibers at the chiasm, and greatly decreased visual acuity. Bi-directional DNA sequencing of these Oculocutaneous (TYR, P, TYRP1, MATP) and Ocular Albinism (GPR143) candidate genes were performed. Among these candidate genes, 17.39% of variations in TYR gene were observed from most of the affected individuals. Therefore, the results suggest that prevalence of OCA type 1 is higher than the other OCA types in Indian cohort.
Recently, five generations of two different families (Fig-1 A and B) phenotypically confirmed as Oculocutaneous Albinism type II (OCA-II) were recruited. Based on the sequencing analysis of P gene, one novel missense mutation c.1453GA (G485R) was observed in these two probands. In one of the family (Fig-1 B) the proband’s parents, maternal grandmother and first younger sister were carriers for G485R mutation. The finding sheds new light on the P gene mutation and highlights the importance of analyzing this P gene along with TYR gene in Indian patients.
Pedigree (A,B) and chromatogram of two albinism families harboring novel mutation Gly485Arg (C-F) Implication of the project The spectrum of genetic variations in the candidate genes of albinism in Indian population has been identified and molecular diagnosis for albinism is being peformed.
1. Kathirvel Renugadevi, Asim Kumar Sil, Vijayalakshmi Perumalsamy, Periasamy Sundaresan. “Spectrum of candidate gene mutations associated with Indian familial oculocutaneous and ocular albinism”.
Molecular Vision 2010; 16:1514-1524.
1. P. Sundaresan, K. Renugadevi, A.K. Sil, P. Vijayalakshmi. “Spectrum of candidate genes mutation associated with Indian familial oculocutaneous albinism patients” US-ARVO-2010 Annual meeting, Fort Lauderdale, Florida, USA (2605/A394)
2 | AMRF Annual Report - 2010-2011 Background and aim Leber’s Hereditary Optic Neuropathy (LHON) is characterized by bilateral acute or sub acute, painless, loss of central vision typically presenting between 26 and 45 years old. LHON is caused by mutations in mitochondrial DNA (mtDNA) that are passed down to 100% of offspring through maternal lineages, but has incomplete penetrance and is more common in males. Recent estimates of the prevalence of LHON in various populations have ranged from 1/30,000 to 1/53,000. The mutations G11778A, T14484C, and G3460A contribute to 95% of LHON in populations. The prevalence of LHON and the relative frequency of LHON mutations in India are unknown. Here the frequencies of the three most common known LHON mutations in a population of well-characterized south Indian patients have been assessed.
Screening of LHON primary mutations In order to determine these three LHON mutations, a total of 90 unrelated individuals with LHON;
20 family members and 50 normal controls were recruited for the study at the Aravind Eye Hospital, Madurai, Tamilnadu. Peripheral blood (5ml) was collected and total genomic and mitochondrial DNA was extracted by salt precipitation. ARMS (Amplification–Refractory Mutation System) PCR assays were used to screen DNA samples from the 90 LHON probands, 20 family members and 50 control subjects for G3460A, G11778A and T14484C. For each sample and amplimer, PCR reactions were made with one common primer and with one allele-specific primer (either specific for normal or mutant DNA sequence).
Internal control primers were included in each reaction. PCR products were analyzed using 2% agarose gel electrophoresis and confirmation of mutations by direct sequence analysis.
In this study, a total of 11 of 90 (12%) of the LHON probands had positive test results for these common mutations. Eight of 91 (8.9%) had a G11778A mutation, three of 90 (3.3%) had a T14484C mutation, and none had a G3460A mutation. No mutations were detected in 79 (88%) of 90 probands. Eight probands in our study had a positive screening test for the G11778A mutation using the ARMS PCR assay. We reported an unexpected low frequency of known mitochondrial mutations in a cohort of LHON patients from south India.
Implication of the project These results suggest that a unique set of mutations may be responsible for LHON in this patient population.
Future mutation detection studies of our cohort of LHON patients from south India may help to identify such novel disease causing mutations.
1. Sundaresan P, Kumar SM, Thompson S, Fingert JH. “Reduced frequency of known mutations in a cohort of LHON patients from India” Ophthalmic Genetics 2010; 31 (4) 196-199.
Background and aim Diabetic Retinopathy (DR) is classically defined as a microvasculopathy that primarily affects the small blood vessels of the inner retina as a complication of Diabetes Mellitus (DM).It is a complex disease with a strong genetic component. Several genes are involved in the pathogenesis of DR. The main aim of this AMRF Annual Report - 2010-2011 | 3 study was to investigate the association of a set of nine candidate genes with the development of diabetic retinopathy in south Indian population with type 2 diabetes mellitus (T2DM).