Ignite Creation Date:
2024-05-05 @ 11:22 AM
Last Modification Date:
2024-10-26 @ 9:02 AM
Study NCT ID:
NCT00001613
Status:
COMPLETED
Last Update Posted:
2008-03-04
First Post:
1999-11-03
Brief Title:
Cataract Surgery to Obtain Human Lens Material for the Study of Nuclear Cataracts
Sponsor:
National Eye Institute NEI
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Use of Human Lens Material for the Study of Nuclear Cataracts
Status:
COMPLETED
Status Verified Date:
2002-05
Last Known Status:
None
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:
Cataract in which the lens of the eye is opacified is the major cause of blindness This study will examine protein material of the lens called crystallins to try to determine what causes nuclear cataracts a type of cataract that forms in the central lens nucleus
Men and women age 45 years or older with a cataract may be eligible for this study Candidates will be screened to determine what type of cataract they have and will undergo a complete eye examination including a vision test eye pressure test and examination of the lens and retina
Patients selected for study will have a complete physical and eye examination including photography of various parts of the eye and ultrasound measurements of the eye They will then have cataract surgery either with or without intraocular lens implantation and will have follow-up examinations 1 week 3 weeks 5 weeks and 8 weeks after surgery
Tissue from the lenses removed during surgery will be given to NEI scientists for research on the causes of age-related nuclear cataracts
Men and women age 45 years or older with a cataract may be eligible for this study Candidates will be screened to determine what type of cataract they have and will undergo a complete eye examination including a vision test eye pressure test and examination of the lens and retina
Patients selected for study will have a complete physical and eye examination including photography of various parts of the eye and ultrasound measurements of the eye They will then have cataract surgery either with or without intraocular lens implantation and will have follow-up examinations 1 week 3 weeks 5 weeks and 8 weeks after surgery
Tissue from the lenses removed during surgery will be given to NEI scientists for research on the causes of age-related nuclear cataracts
Detailed Description:
Progress has been made in elucidating causative factors for some cataracts but little is yet known about those factors involved in development of aging-related nuclear cataracts The predominant theory of nuclear cataractogenesis is that the lens crystallins accumulate covalent modifications which ultimately lead to increased light scattering This theory is based on several lines of evidence Crystallins the predominant components of the lens are present at very high concentration and determine the refractive properties of the lens A relationship between crystallin alterations and cataract formation comes from studies on animal cataract models where mutations in crystallin genes have been identified Numerous studies have also demonstrated that covalent modification of crystallins occurs in the human lens These modifications are reported to be developmentally related age related andor the result of toxic environmental influences Data from this lab demonstrated that the human lens crystallins undergo extensive covalent modification as part of normal lens fiber cell maturation Crystallin modifications that cause cataracts would have to be superimposed on these normally occurring modifications
We have begun a study under the protocol entitled Use of Human Lens Material for Possible Causes of Cataract to compare crystallins in nuclear cataracts with those in normal lenses The goal was to identify uniquely altered crystallins isolate the modified species and determine the covalent modifications that could possibly be involved in cataract formation Surprisingly our preliminary findings indicated that the pattern of protein spots on a 2-dimensional display of the total lens proteins soluble water insoluble and membrane in the nuclear region of nuclear cataracts is essentially the same as found in the nucleus of normal lenses Only the relative concentrations of these protein species varied The number of pure nuclear cataracts available was too few 1 to determine the relationship between nuclear cataracts and crystallin covalent modification and 2 to establish the significance of concentration differences in crystallin species between normal lenses and nuclear cataracts Therefore the purpose of this protocol is to recruit enough subjects with pure nuclear cataracts to complete this study which should provide significant insights into the mechanisms underlying nuclear cataract
We have begun a study under the protocol entitled Use of Human Lens Material for Possible Causes of Cataract to compare crystallins in nuclear cataracts with those in normal lenses The goal was to identify uniquely altered crystallins isolate the modified species and determine the covalent modifications that could possibly be involved in cataract formation Surprisingly our preliminary findings indicated that the pattern of protein spots on a 2-dimensional display of the total lens proteins soluble water insoluble and membrane in the nuclear region of nuclear cataracts is essentially the same as found in the nucleus of normal lenses Only the relative concentrations of these protein species varied The number of pure nuclear cataracts available was too few 1 to determine the relationship between nuclear cataracts and crystallin covalent modification and 2 to establish the significance of concentration differences in crystallin species between normal lenses and nuclear cataracts Therefore the purpose of this protocol is to recruit enough subjects with pure nuclear cataracts to complete this study which should provide significant insights into the mechanisms underlying nuclear cataract
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
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 97-EI-0121 | None | None | None |