Femtosecond Laser–Assisted Cataract Surgery with Integrated Optical Coherence Tomography

Abstract

About one-third of people in the developed world will undergo cataract surgery in their lifetime. Although marked improvements in surgical technique have occurred since the development of the current approach to lens replacement in the late 1960s and early 1970s, some critical steps of the procedure can still only be executed with limited precision. Current practice requires manual formation of an opening in the anterior lens capsule, fragmentation and evacuation of the lens tissue with an ultrasound probe, and implantation of a plastic intraocular lens into the remaining capsular bag. The size, shape, and position of the anterior capsular opening (one of the most critical steps in the procedure) are controlled by freehand pulling and tearing of the capsular tissue. Here, we report a technique that improves the precision and reproducibility of cataract surgery by performing anterior capsulotomy, lens segmentation, and corneal incisions with a femtosecond laser. The placement of the cuts was determined by imaging the anterior segment of the eye with integrated optical coherence tomography. Femtosecond laser produced continuous anterior capsular incisions, which were twice as strong and more than five times as precise in size and shape than manual capsulorhexis. Lens segmentation and softening simplified its emulsification and removal, decreasing the perceived cataract hardness by two grades. Three-dimensional cutting of the cornea guided by diagnostic imaging creates multiplanar self-sealing incisions and allows exact placement of the limbal relaxing incisions, potentially increasing the safety and performance of cataract surgery.

The journey to femtosecond laser-assisted cataract surgery: new beginnings or a false dawn?

“…Each laser incision is constructed in the posteroanterior plane, a principle that elegantly employs the posterior microcavitation bubbles to scatter the laser beam and reduce the amount of energy reaching the Laser-assisted cataract surgery S Trikha et al retina. 14 By keeping the bubbles posterior to the laser target, the focus of the laser beam is maintained and this avoids scatter before the target tissue. 14 The sequence of incision creation varies between the available FLACS platforms and although theoretical differences exist, there is currently insufficient evidence to suggest which order has superiority.…”

“…To a certain extent, it can also transmit through optically denser media such as oedematous or mildly opacified cornea. 13,14 This permits precise focusing of a 3 mm spot, accurate to within 5 mm inside the anterior chamber. 12 Second, although argon, excimer, and Nd:YAG lasers involve nanosecond (10 À 9 s) pulses, the Nd:glass FSL employs an ultrafast pulse time of 10 À 15 s. This allows far smaller amounts of energy to be used while maintaining similar power output.…”

Optical coherence tomography for precision brain imaging, neurosurgical guidance and minimally invasive theranostics

“…OCT-guided laser surgery has been developed for use in ophthalmic surgery (97,98). Boppart et al reported that it is a new approach, where the integration of real-time highresolution OCT and laser ablation can realize the treatment of brain tumors in vivo and in situ; the system could image the dynamic changes before, during, and after intraoperative laser ablation scenarios (30).…”

Femtosecond Laser-assisted Cataract Surgery

“…2,11,12,19 The unpredictable diameter observed in manual capsulorhexis may lead to an irregularly shaped capsulotomy and influence the position of the implanted IOL, which may cause a decrease in visual quality. 20 Capsulotomies created during FLACS were more regularly shaped than those in manual capsulorhexes, with better centration, and better IOL/capsule overlap compared with manual capsulorhexes.…”

“…9 The capsular openings created in FLACS have increased strength and rupture force compared with those in manual capsulorhexis in cadaveric eyes. 2,[10][11][12] This may reduce the incidence of intraoperative tears to the capsular bag, a source of complications in cataract surgery. Initial data on FLACS suggest an incidence of anterior tears of 0.2 %.…”