Cutting Edge of Ophthalmic Surgery by Ulrich Spandau & Gabor Scharioth

Author:Ulrich Spandau & Gabor Scharioth
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

Clinical Results

Capsulotomy Studies

During the first study the accuracy of the diameter of the anterior capsulotomies have been evaluated and compared to standard manual capsulotomies targeting also the same diameter of 5 mm and found that using the manual technique the diameter was 5.88 (±0.73) but it was 5.02 (±0.04) mm using the Alcon LenSx femtosecond laser. During the surgery of human crystalline lenses, the Alcon LenSx FSL was able to perform all capsulotomies within ±0.25 mm accuracy, whereas with the manual technique it was only achieved in 10 % of the eyes [15].

The in-the bag position with an 0.25–0.5 mm coverage of the posterior chamber lens by the anterior capsule, so the effective lens position (ELPo) is a very important parameter in predictability of postoperative achieved refraction against the planned one. Therefore exact IOL calculation especially with multifocal IOLs [10, 21] and the accuracy of the size and position of rhexis is very important regarding ELPo [14, 15] A recent study by Packer et al. reported that planning and achieving the capsulotomy centred on the optical axis of the lens with a diameter of 5.25 mm optimizes the consistency of final ELPo-s [20].

The size and central location of capsulorhexis is one of the most important factors to achieve the targeted accurate final post-operative refraction (Figs 7.3 and 7.4). In the literature there not too much about the accuracy of the standard manual technique because for more than two decades it has been the only method available, little attention has been paid to the effect of capsulotomy diameter and localization on the refractive outcome. A larger or smaller than intended rhexis may cause anterior or posterior shift of the IOL, respectively or IOL tilt [15–17]. In that cases myopic or hyperopic shift or increase in the higher order aberrations and possibly in the final ocular astigmatism may be the consequences. Irregular capsulotomies cannot provide enough defence against remaining epithelial cells so the incidence of posterior capsular opacification also may increase.

Fig. 7.4Femto-capsulotomy after removal of the crystalline lens and before implantation of the posterior chamber lens

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