Related Experiment Videos
[Scanning electron microscopy studies of human lenses]
H J Hettlich1, el-Hifnawi el-S
1Klinik für Augenheilkunde, Medizinische Universität.
Background:
In order to better understand the mechanism of tearing of the human lens capsule during circular capsulorhexis, scanning electron microscopic (SEM) examinations were made particularly of the rhexis edge.
Materials And Methods:
Anterior segments from cornea donor eyes, as well as capsular pieces extracted during cataract surgery, were studied after fixation in glutaraldehyde, critical point drying, and sputtering with gold.
Results:
The edges of the capsulorhexis were found to be very regular even in the area of zonular attachment. Neither the surface of the lens capsule nor the edge of the rhexis itself indicated any morphological influence on the direction of tearing.
Conclusion:
From the results we conclude that the rhexis of the lens capsule is only directed by the forces applied and not by particular morphological structures. To avoid radial tears, a deep anterior chamber, resulting in a relief of the anterior zonular portion seems most important. This minimizes radial forces on the anterior lens capsule, which provides the best condition for a safe rhexis.