Cataract and laser femtosecond VICTUS™ platform
VICTUS platform: description
VICTUS platform was originally developed by the company Technolas Perfect Vision (Munich, Germany), and is currently jointly proposed for cataract surgery by the firm of Bausch & Lomb. It is one of the 4 main platforms currently proposed for the realization of the assisted cataract surgery by the femtosecond laser. It also allows the realization of corneal surgeries (covers of) LASIKintra stromal incisions: Intracor), the possibility to make the incisions of cataract surgery entry should be available soon.
Video of surgery of cataract with laser femtosecond Victus (Dr. Damien Gatinel, Rothschild Foundation):
The platform includes:
-a laser cavity, which are generated pulses them femtoseconds,
-a system that guides the laser radiation and which end is the interface with the patient's eye
-a visualization system of the anterior segment of the eye, assured by an OCT (Optical Coherence Tomography) device that allows real-time anatomical 'cuts' interesting the cornea, the lens, and the space understood between the two (anterior Chamber). These images are displayed on two monitors. These images are currently captured dynamically, allowing you to see in real time the effect of the laser impacts in the anterior segment of the eye.
-a bed intended to receive the patient and position it under the licensing system
-a "consumable" said material, which includes a suction ring and an interface for single use. This interface is curved, in order to marry the corneal curvature, and minimize the deformations of it (the presence of folds of the cornea that can induce a loss of laser impacts, and responsible for optical distortion of less precision in the representation of the anterior segment in OCT).
Characteristics of the anterior segment OCT visualization
The dimensions of the anterior segment of the eye are in a cylinder of close 12mm diameter (the diameter of the cornea), and thick variable, generally less than 8 mm (i.e. the distance between the top of the cornea and the posterior capsule of the lens). Cuts OCT diameter is 13 mm, and the depth of the cuts extension is 9 mm. The path to the location of cuts aimed at cutting the anterior capsule (capsulorhexis) as well as impacts to the fragmentation of the cristallinien kernel appear superimposed.
Example of capsulorhexis femtosecond laser:
The capsulorhexis is an important time of cataract surgery: it corresponds to the opening of the capsular bag, and cristallinien fragmenting hardware access. The precision and reproducibility of the cutting automated laser of the anterior capsule to achieve a near-perfect circularity of its edge. The diameter of the capsulorhexis can be adjusted with precision (ex: 5.3 mm). The clinical benefit expected from this "geometric" capsulotomy for stability of the implant, that is to say the holds of its axial position in the anterior segment. The studies do not demonstrate the benefit of a cutting laser towards a hand cutting, when these two cuts are conducted in a satisfactory manner.
The following video shows the realization of circular cutting laser femtosecond (capsulorhexis):
Patterns of fragmentation to the femtosecond laser
The femtosecond laser has the ability to fragment 'in situ' the lens. The spatial distribution of the laser impact is designed to split the lens into pieces (sous-fragments), realizing (route "dotted") joint impacts the way the stamp post, but in a volume, that is to say "three dimensional". The pre fragmentation allows to reduce the amount of ultrasound necessary for removal of the lens, as well as the machinations of cleavage of the lens ("cracking").
In addition to the previous video, some examples of "patterns" of fragmentation of the nucleus of the lens:
In 2015, the interest of the femtosecond laser cataract surgery is being heated debates in the community of cataract surgeons. Apart from the financial aspects (use of the laser represents a cost of several hundred euros per procedure), some aspects of this surgery are discussed.
The realization of an automated circular cutting (capsulorhexis) is a definite advantage for the beginner surgeon, but does not represent a major advantage for a seasoned surgeon.
The pre-cut (fragmentation of the lens) can certainly facilitate phacoemulsification stage and reduce the rate of ultra sounds issued to complete the extraction of the crystalline fragments. But she exposed to some local effects such as reduction of the diameter of the IRIS pupil, which can then reduce complicate the achievement of surgery.
Assistive technology for cataract surgery femtosecond laser is undergoing rapid changes, and benefits from progress related to Imaging (OCT 'live'), and progress made in the area of delivery of the laser impacts. It is likely to take more and more in the area of cataract surgery. This place is definitely more important the day the clinical benefits of the use of the laser in cataract surgery femtosecond will be proven.