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. 2015 Aug;99(8):1137-42.
doi: 10.1136/bjophthalmol-2014-306065. Epub 2015 Mar 31.

Defining the ideal femtosecond laser capsulotomy

Mark Packer  1 , E Valas Teuma  2 , Adrian Glasser  3 , Steven Bott  2
Affiliations

Defining the ideal femtosecond laser capsulotomy

Mark Packer et al. Br J Ophthalmol. 2015 Aug.

Abstract

Purpose: We define the ideal anterior capsulotomy through consideration of capsular histology and biomechanics. Desirable qualities include preventing posterior capsular opacification (PCO), maintaining effective lens position (ELP) and optimising capsular strength.

Methods: Laboratory study of capsular biomechanics and literature review of histology and published clinical results.

Results: Parameters of ideal capsulotomy construction include complete overlap of the intraocular lens to prevent PCO, centration on the clinical approximation of the optical axis of the lens to ensure concentricity with the capsule equator, and maximal capsular thickness at the capsulotomy edge to maintain integrity.

Conclusions: Constructing the capsulotomy centred on the clinical approximation of the optical axis of the lens with diameter 5.25 mm optimises prevention of PCO, consistency of ELP and capsular strength.

Keywords: Treatment Lasers.

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Figures

Figure 1
Figure 1
Diagram of the capsule after Fincham, 1937, scaled to an equatorial diameter of 9.8 mm with one half of the capsule divided into 200 divisions in 10 division steps. The thickest part of the capsule, in accordance with the results from Barraquer, is between divisions 40 and 50 and occurs at a diameter of approximately 5 mm or greater.
Figure 2
Figure 2
Testing apparatus.
Figure 3
Figure 3
Breakdown of the capsulotomy elongation (El): First, the stretcher pins are inserted into the capsular bag and positioned apart with a distance necessary for the pins to enter into contact with the capsular rim (bottom diagram). This position is considered as the test initial position. Then, the test starts with the moving probe elongating the edge until it ruptures. During the elongation of the capsular rim, the capsular edge changes shape, from circular (initial shape) to oblong shape (Xo) and then stretches until rupture (Xs, top image.)
Figure 4
Figure 4
Break force and maximum extension for laser capsulotomies of diameters 4.0, 5.0 and 5.5 mm. The larger diameter capsulotomies exhibit higher average break forces and maximum extensibilities. Error bars are one SD.
See this image and copyright information in PMC

References

    1. Dooley IJ, O'Brien PD. Subjective difficulty of each stage of phacoemulsification cataract surgery performed by basic surgical trainees. J Cataract Refract Surg 2006;32:604–8. 10.1016/j.jcrs.2006.01.045 - DOI - PubMed
    1. McCannel CA, Reed DC, Goldman DR. Ophthalmic surgery simulator training improves resident performance of capsulorhexis in the operating room. Ophthalmology 2013;120:2456–61. 10.1016/j.ophtha.2013.05.003 - DOI - PubMed
    1. Davidorf JM. Impact of capsulorrhexis morphology on the predictability of IOL power calculations. Paper presented at: The American Academy of Ophthalmology Annual Meeting; 11 November 2012; Chicago, IL.
    1. Friedman NJ, Palanker DV, Schuele G, et al. Femtosecond laser capsulotomy. J Cataract Refract Surg 2011;37:1189–98. 10.1016/j.jcrs.2011.04.022 - DOI - PubMed
    1. Nagy Z, Takacs A, Filkorn T, et al. Initial clinical evaluation of an intraocular femtosecond laser in cataract surgery. J Refract Surg 2009;25:1053–60. 10.3928/1081597X-20091117-04 - DOI - PubMed

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