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E Valas Teuma, Gary P Gray; Tensile Strength of IntelliAxis-L: a Novel Femtosecond Laser Capsulotomy with Guiding Marks for Toric IOL Alignment. Invest. Ophthalmol. Vis. Sci. 2018;59(9):2227.
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© ARVO (1962-2015); The Authors (2016-present)
To present a novel approach for femtosecond laser capsulotomy creation that includes embedded capsular marks (IntelliAxis-L) developed to assist cataract surgeons to accurately align a Toric IOL to the axis of astigmatism; then analyze the biomechanical strength of the capsulotomy with capsular marks and compare it with the biomechanical strength of standard femtosecond laser capsulotomy.
Parameters for the IntelliAxis-L were input manually by the operator, bypassing the option for the laser system to automatically compute the required alignment from the patient’s pre-operative biometry. For assessing the tensile strength of the capsulotomy, this non-clinical study, included 36 porcine eyes. The eyes were randomly assigned to 3 cohorts (12 eyes each): the capsulotomy with capsular marks was tested in the following configurations: (1) in-line or (2) transverse to the stretching vector and compared to (3) standard capsulotomy (Control). Capsular mark parameters were optimized. Critical parameters included; sweep angle, tightness and depth. Tensile strength was tested by inserting two stretcher pins into the capsular bag. The distance between the pins was gradually increased until the capsular edge was compromised and rupturing occurred. The outcome parameters were force-displacement patterns, maximum break force and maximum extensibility at breaking force.
Force displacement patterns of the capsular rims with the capsular marks were similar to those of standard capsulotomy. Mean±SD break forces for standard, transverse load and in-line load groups were 180.57±22 mN, 178.04±20 mN and 181.05±15 mN, respectively. Mean±SD maximum extensibility for standard, transverse load and in-line load groups were 6.47±0.33 mm, 6.49±0.45 mm and 6.3±0.47 mm, respectively. These values were found to be statistically comparable for all groups (p>0.05).
Advanced technology devices such as the femtosecond laser for cataract surgery and surgical management of astigmatism can be effective ways to help meet the refractive outcome expectation at the time of cataract surgery or natural lens exchange. The capsular rim for capsulotomy with capsular marks (IntelliAxis-L) was found to be equivalent in elongation and tensile strength (ability to elongate and resistance to tearing under a radial force) to the standard capsulotomy with no capsular marks.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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