Journal
EXPERIMENTAL EYE RESEARCH
Volume 72, Issue 3, Pages 199-214Publisher
ACADEMIC PRESS LTD
DOI: 10.1006/exer.2000.0937
Keywords
crystalline lens; ageing; nuclear cataracts; morphology; scanning electron microscopy
Categories
Funding
- NEI NIH HHS [EY-08148, EY-06642, EY-05722] Funding Source: Medline
Ask authors/readers for more resources
This study was conducted to quantify structural change associated with human nuclear fiber compaction as a function of ageing and nuclear cataract formation. Normal donor lenses in three age ranges. young (15-25 years), middle-aged (36-46 years) and aged (59-81 years) were compared to each other and to age-related nuclear cataracts (55-81 years) surgically removed by extracapsular extraction. Several structural modifications which occurred as a manifestation of fiber compaction were noted. In the fetal nucleus (FN). the average anterior and posterior fiber angles decreased approximately 20% with age. Additionally. there was a reduction in the thickness of both the anterior and posterior segments of fetal fibers with age. On average. the anterior-posterior (X-P) axis in the embryonic nucleus (EN) decreased 33 % with age. The average length of EN fibers decreased significantly (37 %) as a function of age. This change in EN fiber length was accomplished by effecting compaction folds along fiber length. By comparison, in nuclear cataracts the anterior and posterior angles of FN fibers were about 12 % smaller than comparably aged normal lenses. Similarly. the A-P axis and the length of EN fibers were 13 % smaller than age-matched normals. Nuclear fiber compaction in early adulthood was significant and map contribute to the lens hardening and loss of accommodative ability symptomatic of presbyopia. 3D-CAD reconstructions of fiber compaction show how the reduction in the spacing of Lateral interdigitations along fiber length causes an increase in the fiber membrane complexity along the A-P axis in relation to fiber cytoplasm as light passes through lenses. These results may explain. at least in part. how an increase in large particle scatter occurs as light is transmitted through fiber membranes. resulting in reduced lens optical quality as a function of age. By extrapolation, the significantly increased compaction of nuclear fibers in age-related nuclear cataracts may be a contributing factor for excessive scatter in nuclear opacification. (C) 2001 Academic Press.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available