Ignite Creation Date:
2024-05-05 @ 11:51 AM
Last Modification Date:
2024-10-26 @ 9:15 AM
Study NCT ID:
NCT00155857
Status:
UNKNOWN
Last Update Posted:
2005-11-23
First Post:
2005-09-09
Brief Title:
The Genetic Study of Primary Angle-Closure Glaucoma
Sponsor:
National Taiwan University Hospital
Organization:
National Taiwan University Hospital
Study Overview
Official Title:
National Taiwan University Hospital
Status:
UNKNOWN
Status Verified Date:
2005-06
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The purpose of this study is to evaluate the possible candidate gene of Primary Angle-Closure Glaucoma
Detailed Description:
Glaucoma has long been recognised as a leading cause of blindness and that the scale of the problem will only increase with future population growth and increasing life expectancy 1
The epidemiological information available in 1993 in the World Health Organizations WHO global data bank on blindness was reviewed by Thylefors and Négrel 1 They developed a simple model estimating the number of glaucoma blind people in each World Bank region Primary open angle glaucoma POAG was judged to be responsible for three million blind primary angle closure glaucoma PACG for two million and for congenital glaucoma the figure was 200 000 giving a total of 52 million blind This represents 15 of global blindness The number of people affected by glaucoma was estimated to be about 20 million
In 1996 Quigley used 111 published reports of glaucoma prevalence to construct a statistical model of the number of people affected by glaucoma worldwide 2 Data were included only if the study design methods and reported results met certain specific criteria The countries of the world were arranged in seven groups according to similarities in ethnicity and presumed characteristics of glaucoma For each region the available age specific prevalence of OAG and ACG were applied to population projections for the year 2000 It was estimated that 668 million people were affected by OAG and ACG with nearly equal numbers of people affected by each disease Few prevalence studies described secondary glaucoma separately but an estimate of six million for secondary glaucoma was reached making a total without childhood glaucoma of around 73 million affected Of these 67 million were thought to be blind 2
There was reliable epidemiologic evidence to suggest that PACG is more common among Eskimos 3 and Chinese 4 As POAG was common in the western countries there was a large population at risk in Asia 5 PACG among Asians was more frequently chronic and has few symptoms 6 Therefore persons might not be motivated by symptoms to present to medical attention until significant visual damage has occurred in this region A population-based study of screening techniques for PACG was performed in the township of Jin Shan in rural Taiwan 7 This joint US-Taiwanese project published in 1996 identified a target population of 5441 people aged 40 years and older of whom 562 were examined A gonioscopic examination was carried out on all subjects PACG was diagnosed in people with a narrow angle and either an IOP 18 mm Hg an increase in IOP 8 mm Hg on dark prone provocation test or a previous acute episode of angle closure with an iridectomy The diagnosis did not depend on the presence of a visual field defect or structural optic neuropathy There were 17 people diagnosed as suffering PACG 30 Only 35 of cases gave a history of symptoms characteristic of acute angle closure Two of these 17 people 12 were blind in both eyes 7 As aforementioned Taiwan has a high prevalence of PACG which usually leads to blindness ultimately There are many reported studies on genes of POAG and normal-tension glaucoma from Asia including Japan 142129 China 25 and Korea 24 However studies about genetics of PACG were lacking Hence in this study we use the model of genomewide microsatellite genotyping with method of linkage disequilibrium to study the possible candidate gene of PACG Then we will further sequence the cDNA forPAX6 to find out the possible mutation in the family with well-defined pedigree
The epidemiological information available in 1993 in the World Health Organizations WHO global data bank on blindness was reviewed by Thylefors and Négrel 1 They developed a simple model estimating the number of glaucoma blind people in each World Bank region Primary open angle glaucoma POAG was judged to be responsible for three million blind primary angle closure glaucoma PACG for two million and for congenital glaucoma the figure was 200 000 giving a total of 52 million blind This represents 15 of global blindness The number of people affected by glaucoma was estimated to be about 20 million
In 1996 Quigley used 111 published reports of glaucoma prevalence to construct a statistical model of the number of people affected by glaucoma worldwide 2 Data were included only if the study design methods and reported results met certain specific criteria The countries of the world were arranged in seven groups according to similarities in ethnicity and presumed characteristics of glaucoma For each region the available age specific prevalence of OAG and ACG were applied to population projections for the year 2000 It was estimated that 668 million people were affected by OAG and ACG with nearly equal numbers of people affected by each disease Few prevalence studies described secondary glaucoma separately but an estimate of six million for secondary glaucoma was reached making a total without childhood glaucoma of around 73 million affected Of these 67 million were thought to be blind 2
There was reliable epidemiologic evidence to suggest that PACG is more common among Eskimos 3 and Chinese 4 As POAG was common in the western countries there was a large population at risk in Asia 5 PACG among Asians was more frequently chronic and has few symptoms 6 Therefore persons might not be motivated by symptoms to present to medical attention until significant visual damage has occurred in this region A population-based study of screening techniques for PACG was performed in the township of Jin Shan in rural Taiwan 7 This joint US-Taiwanese project published in 1996 identified a target population of 5441 people aged 40 years and older of whom 562 were examined A gonioscopic examination was carried out on all subjects PACG was diagnosed in people with a narrow angle and either an IOP 18 mm Hg an increase in IOP 8 mm Hg on dark prone provocation test or a previous acute episode of angle closure with an iridectomy The diagnosis did not depend on the presence of a visual field defect or structural optic neuropathy There were 17 people diagnosed as suffering PACG 30 Only 35 of cases gave a history of symptoms characteristic of acute angle closure Two of these 17 people 12 were blind in both eyes 7 As aforementioned Taiwan has a high prevalence of PACG which usually leads to blindness ultimately There are many reported studies on genes of POAG and normal-tension glaucoma from Asia including Japan 142129 China 25 and Korea 24 However studies about genetics of PACG were lacking Hence in this study we use the model of genomewide microsatellite genotyping with method of linkage disequilibrium to study the possible candidate gene of PACG Then we will further sequence the cDNA forPAX6 to find out the possible mutation in the family with well-defined pedigree
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None