Abstract

About a third of people in the developed world will undergo cataract surgery in their lifetime. Currently, cataract surgery is a manual procedure highly dependent on the surgical skills and complicating factors. We developed and tested an image-guided laser system to improve the precision and reproducibility of cataract surgery. A long-range Optical Coherence Tomography automatically discerns the anterior and posterior surfaces of the lens and cornea, and a co-registered femtosecond laser then performs capsulotomy, lens segmentation and corneal incisions. Capsular strength following laser capsulotomy and mechanical capsulorhexis were compared on cadaveric eyes, and retinal safety was verified on rabbits. 50 patients have undergone cataract surgery using the laser system. Eyes were examined ophthalmoscopically, and extracted capsules were analyzed using histology and SEM. Capsular strength after laser capsulotomy was more than twice higher than after manual capsulorhexis: 152 mN vs. 66 mN. Average deviation from intended size in laser capsulotomy was 12 times better than with manual procedure: ±25 µm vs. ±305 µm. Roundness of laser capsulotomy improved by a factor of 5 compared to capsulorhexis: deviation of 5% vs. 23%. Histology and SEM of incised capsules showed smooth clean edges. Lens segmentation facilitates its disassembly into easily separable quadrants and nucleus fragmentation reduces the perceived hardness of the nuclear sclerotic cataract by two grades, making its emulsification much easier and faster. Multi-planar corneal incisions provide for unique self-sealing wound constructions. No retinal damage or other laser-related adverse events have been observed. This integrated system offers a previously unattainable surgical exactitude, including improved centration of IOLs and correction of residual corneal astigmatism.

© 2011 OSA

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