S. Krag et al., DIATHERMIC CAPSULOTOMY VERSUS CAPSULORHEXIS - A BIOMECHANICAL STUDY, Journal of cataract and refractive surgery, 23(1), 1997, pp. 86-90
Purpose: To compare the mechanical quality of a capsulotomy opening pe
rformed by diathermy with that made by capsulorhexis (tearing). Settin
g: Department of Ophthalmology, Vejle Hospital, Denmark. Methods: This
study included 12 pairs of human cadaver eyes and 20 pairs of pig eye
s. One in each pair was randomly selected for one capsulotomy techniqu
e. The capsulotomy edge was stretched in a materials testing machine u
ntil break; force and elongation values were continuously recorded. Re
sults: In humans, the extensibility of the diathermic capsulotomy edge
was approximately half that of the capsulorhexis edge (mean 38% +/- 4
[SD] versus 68% +/- 6), and the force required to break the edge was
reduced by a factor of five (26 +/- 8 mN versus 134 +/- 36 mN). Conclu
sion: The mechanical quality of the diathermic capsulotomy edge is sig
nificantly less than that of the capsulorhexis edge, which indicates t
hat the diathermic capsulotomy edge would withstand less surgical mani
pulation.