The principal objective of this application is to apply novel magnetic resonance imaging techniques to the examination of water transport by the cornea and the lens in vivo.
The specific aims are: (1) analyze corneal water transport under anaerobic stress using a T2 contrast agent H217O; and (2) image water self- diffusion, free- and bound-water interchange, and waterbulk-flow in metabolically stressed lenses. We will use rabbits as the experimental animal. The experimental models include acute galactosemic cataract and corneal oxygen deprivation. The effects on water transport of pericorneal factors such as lacrimation, limbal circulation and aqueous flow are tested by pharmaceutically altering these factors. These are simple yet effective models that can be used to develop advanced ocular MRI techniques. The proposed studies are essential to the establishment of MRI-based functional assessment of anterior segment diseases and their therapies. The results will provide useful information on (1) normal and pathological corneal interaction with water - important in the evaluation of, for example, dry eyes, wound-healing and contact lens wear; and (2) water movement in different regions of the lens during metabolic cataractogenesis - important in the further understanding of the biophysical changes during cataract formation and testing of the efficacy of anti-cataract therapy.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY007620-06A2
Application #
2161620
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1988-04-01
Project End
1997-06-30
Budget Start
1994-07-01
Budget End
1995-06-30
Support Year
6
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Massachusetts Eye and Ear Infirmary
Department
Type
DUNS #
073825945
City
Boston
State
MA
Country
United States
Zip Code
02114
Cheng, Hong-Ming (2002) Water diffusion in the rabbit lens in vivo. Dev Ophthalmol 35:169-75
Tsubota, K; Kwong, K K; Lee, T Y et al. (1999) Functional MRI of brain activation by eye blinking. Exp Eye Res 69:1-7
Cheng, H M; Singh, O S; Kwong, K K et al. (1992) Shape of the myopic eye as seen with high-resolution magnetic resonance imaging. Optom Vis Sci 69:698-701
Cheng, H M; Kuan, W P; Garrido, L et al. (1992) High-resolution MR imaging of water diffusion in the rabbit lens. Exp Eye Res 54:127-32
Yoshida, A; Kwong, K K; Chang, C et al. (1992) Magnetic resonance microscopy of rabbit eyes. Vision Res 32:37-40
Yoshida, A; Cheng, H M; Lashkari, K et al. (1992) Comparison between B-scan ultrasound and MRI in the detection of diabetic vitreous hemorrhage. Ophthalmic Surg 23:693-6
Cheng, H M; Aguayo, J B; Moore, G J et al. (1991) Analysis of diabetic cataractogenesis using chemical-shift nuclear magnetic resonance microscopy. Magn Reson Med 17:62-8
Cheng, H M (1991) Magnetic resonance imaging of the human eye in vivo. Optom Vis Sci 68:976-80
Cheng, H M (1991) Fate of water in the soft contact lens immediately after lens placement onto the cornea. Optom Vis Sci 68:414-7
Yoshida, A; Cheng, H M; Kwong, K K et al. (1991) Magnetic resonance imaging of intraocular tamponades. Ophthalmic Surg 22:287-91

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