Patent Description:
LASIK surgery is a type of laser refractive surgery that is performed on the eye for the purpose of improving visual acuity and quality and to thereby remove the need for using external refractive accessories with the eye.

LASIK is the abbreviation of laser in situ keratomileusis and LASIK surgery is designed to correct refractive errors. LASIK surgery is commonly referred to as laser eye surgery or laser vision correction and is applied for the correction of myopia, hyperopia, and astigmatism. For most people, LASIK surgery provides a long-lasting alternative to glasses or contact lenses.

The LASIK surgery procedure involves steps of i) creating a corneal flap using a microkeratome or femtosecond laser, ii) reshaping the cornea using an excimer laser to remove tissue from the underlying stromal bed, and iii) putting the flap back in place.

As of <NUM>, roughly <NUM> million Americans have had LASIK surgery. Globally, between <NUM> and <NUM>, more than <NUM> million LASIK surgeries were performed. However, LASIK surgery seems to be a declining option in the United States, and the number of surgeries has dropped more than <NUM>%, from about <NUM> million surgeries in <NUM> to <NUM>,<NUM> in <NUM>, according to the Market Scope eye-care data source. A study in the Cornea journal determined the frequency with which LASIK was searched on Google from <NUM> to <NUM>. Within this time frame, LASIK searched declined by <NUM>% in the United States. Countries such as the UK and India also showed a decline, <NUM>% and <NUM>%, respectively. Canada, however, showed an increase in LASIK searches by <NUM>%. By <NUM> in the United States, LASIK declined by <NUM>%. This decrease in interest can be attributed to several factors such as the emergence of refractive cataract surgery, the economic recession in <NUM>, and unfavorable media coverage from the FDA's <NUM> press release on LASIK.

Before LASIK surgery, the excimer laser, suction ring, microkeratome and blade (or femtosecond laser settings) are checked by the technician and the surgeon. The surgeon also confirms that the correct treatment data are entered into the laser computer. An eyelid speculum is placed in the operative eye, which has been anesthetized with drops, and the fellow eye is covered. The cornea is marked to aid in postoperative flap alignment. A suction ring is placed on the eye to achieve fixation. The microkeratome (or femtosecond laser) is used to create a hinged corneal flap. After the flap has been created, it is reflected away from the cut surface to an opened position. Excimer laser ablation is performed, centered on the pupil or on the corneal vertex. Eye-tracker and iris registration technology are increasingly used to ensure a well-centered laser treatment. Following the excimer laser ablation, the flap is put back in place.

Complications occur in LASIK surgery as in any other surgical procedure. Serious adverse complications leading to significant permanent visual loss rarely occur. Less serious side effects such as dry eyes, night time starbursts, and/or reduced sensitivity occur relatively frequently.

The most common complication or side effect following LASIK surgery is dry eyes. Complications involving the LASIK flap include free, incomplete, or buttonholed flaps, striae/folds or slipped/displaced flaps. If the flap created during the LASIK surgery procedure is irregular, incomplete, or buttonholed, laser treatment cannot safely be performed in the same session. However, after a healing period, a secondary LASIK or PRK (photo-refractive keratomileusis) procedure may be performed in some cases. Flap-related complications are extremely rare when the flap is prepared using a femtosecond laser.

Complications that occur at the level of the interface between the flap and the stromal bed include diffuse lamellar keratitis, infection, and epithelial ingrowth. Post-LASIK ectasia may occur when the biomechanical stability of the cornea is altered. It is uncertain if there is any relationship between LASIK and an increased incidence of postoperative retinal detachment. Ischemic optic neuropathy is a rare complication that has been reported following LASIK.

For the correction of low to moderate myopia of less than -6D and low to moderate astigmatism of less than 2D, results from studies in the literature have shown that LASIK is effective and predictable in terms of obtaining very good to excellent uncorrected visual acuity, and that it is safe in terms of minimal loss of visual acuity. In a study evaluating the outcome of LASIK in high myopia, Reinstein et al showed that postoperative spherical equivalent was ±<NUM> D in <NUM>% and ±<NUM> D in <NUM>% of eyes after primary treatment. After retreatment, <NUM>% of eyes where within ±<NUM> D and <NUM>% were within ±<NUM> D.

Eyes with decentered ablations had a significantly higher magnitude of induced aberrations and lower uncorrected visual acuity than eyes with well-centered ablations. To minimize higher-order optical errors, special efforts to center the ablation zone are necessary, for example, by eye-tracking systems that consider the visual axis. Active eye tracking helps improve the visual outcome and reduces postoperative cylindrical astigmatism. With eye tracking, lasers used during LASIK surgery can compensate for eye movements during the procedure, adding an important level of assurance.

Postoperative residual or induced astigmatism may limit incorrected visual acuity (UCVA) and cause starbursts and glare. Irregular astigmatism can also cause loss of best-corrected visual acuity (BCVA), monocular diplopia, and ghosting of images. It has been suggested that even subtle irregularities in the corneal flap can reduce visual acuity postoperatively and even regular normal flaps may induce optical aberrations. Creating and handling the corneal flap are crucial steps in the LASIK surgery procedure. The hinge of the flap should be created at a slightly eccentric position by placing the suction ring at a slightly eccentric position, both in superior and nasal hinges, in order to avoid ablation of the flap during the procedure, especially in the case of a large ablation zone.

Following flap lifting and before ablation ensues, attention may be given to the "protection" of the flap during the procedure, in order to protect the flap from laser ablation. Although protecting the flap during laser ablation is an accepted practice in some clinics, not all surgeons routinely protect the flap during LASIK surgery, and this procedure has yet to be validated.

As mentioned, the purpose of flap protection is to avoid inadvertent flap ablation. Proper flap protection involves making sure that the whole inner surface of the flap that is in the opened position is shielded. Inadvertent flap ablation can cause ablation of both the stromal bed and the overlying stromal side of the flap leading to a double ablation effect. As described by Reinstein et al, this double ablation may cause over-flattening of the cornea in the hinge side and therefore cause irregular astigmatism.

It is generally known that protecting the corneal flap during myopic astigmatic LASIK may prevent double ablation and lead to better refractive outcomes. Currently, most surgeons use a sponge to shield the flap from the laser during ablation. This is associated with a better efficacy index and index of success when compared with the no-protection group. However, stabilization of movements is not obtained in this way, and protection of the flap is often incomplete and inadequate.

It is known that decentered ablations have as results various symptoms such as halos, ghost images, or night driving difficulties. Similar symptoms might also be caused by accidental flap ablation.

<CIT> discloses a multi-function surgical instrument for facilitating ophthalmic surgery of the eye by laser means. Included are a lower ring and an upper ring. The lower ring includes a central aperture to capture the limbus and aid in positioning of the eye. The upper ring is disposed above the surgical bed.

It is an objective of the invention to provide better eye centralization and stabilization by avoiding unexpected eye movement and better flap protection avoiding undesirable effects of a double ablation. In view thereof, the invention provides a device as defined in claim <NUM>, which is a device that is capable of both ensuring eye fixation and protection of the corneal flap. The device has an eye fixating portion that is based on one, two, three or four points of scleral support around the cornea, and a flap protecting portion for completely covering the corneal flap. The various aspects of the invention will be apparent from and elucidated with reference to the following detailed description of a practical embodiment of a device comprising the eye fixating portion and the flap protecting portion as mentioned.

The device <NUM> according to the invention is configured to be used in a LASIK surgery procedure and to be put in an operational position on an operative eye <NUM> after a corneal flap <NUM> has been created and has been put to an opened position. As indicated in the foregoing, the operational position of the device <NUM> on the operative eye <NUM> is illustrated in <FIG>. To this end, the cornea <NUM> and the corneal flap <NUM> of the eye <NUM> are diagrammatically depicted in <FIG>, and the eyeball <NUM> and the corneal flap <NUM> of the eye <NUM> are diagrammatically depicted in <FIG>.

The device <NUM> comprises an eye fixating portion <NUM> configured to engage on the sclera <NUM> around the cornea <NUM> and to thereby perform a fixating action on the eye <NUM> while enabling free access to the cornea <NUM> when the device <NUM> is in the operational position on the eye <NUM>, and also comprises a generally plate-like flap protecting portion <NUM> configured to completely cover the corneal flap <NUM> in the opened position thereof when the device <NUM> is in the operational position on the eye <NUM>. Further, the device <NUM> comprises a handle portion <NUM>. In this respect, it is noted that only a part of the handle portion <NUM> is shown in the figures. In the shown example, the handle portion <NUM> is connected to the flap protecting portion <NUM> and has a curved appearance at the position of connection to the flap protecting portion <NUM>.

The eye fixating portion <NUM> comprises at least two ridge-like support elements <NUM> having a contact surface <NUM> through which the eye fixating portion <NUM> is to contact the sclera <NUM> when the device <NUM> is in the operational position on the eye <NUM>. In the framework of the invention, the number of support elements <NUM> may be chosen freely, wherein two, three or four are practical examples. In the shown embodiment of the device <NUM> according to the invention, the eye fixating portion <NUM> comprises two curved support elements <NUM> configured to contact the sclera <NUM> at opposite sides of the cornea <NUM>.

In <FIG>, it can be seen that a space <NUM> between the two support elements <NUM> along the flap protecting portion <NUM> is configured to accommodate a hinge portion 11a of the corneal flap <NUM>. In <FIG> and <FIG>, it can be seen that at a side of the device <NUM> that is configured to face the eye <NUM>, the contact surface <NUM> of the respective support elements <NUM> is at a protruding level relative to the flap protecting portion <NUM>.

In the embodiment of the device <NUM> according to the invention shown in the figures, the flap protecting portion <NUM> is generally shaped as a minor segment of a circle. As can be seen in <FIG> and <FIG>, the two support elements <NUM> extend from opposite corner areas <NUM> of the flap protecting portion <NUM> in this embodiment.

Advantageously, the eye fixating portion <NUM> and the flap protecting portion <NUM> are made as a single integral entirety. It is also possible that the eye fixating portion <NUM>, the flap protecting portion <NUM> and the handle portion <NUM> are made as a single integral entirety, which implies that the device <NUM> may be provided as a single integral entirety. On the other hand, an option such as the handle portion <NUM> being releasably coupled to the flap protecting portion <NUM> is also feasible in the framework of the invention.

It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims.

Claim 1:
Device (<NUM>) configured to be used in a LASIK surgery procedure and to be put in an operational position on an operative eye (<NUM>) after a corneal flap (<NUM>) has been created and has been put to an opened position, comprising:
- an eye fixating portion (<NUM>) configured to engage on the sclera (<NUM>) around the cornea (<NUM>) and to thereby perform a fixating action on the eye (<NUM>) while enabling free access to the cornea (<NUM>) when the device (<NUM>) is in the operational position on the eye (<NUM>), and
- a flap protecting portion (<NUM>) configured to completely cover the corneal flap (<NUM>) in the opened position thereof when the device (<NUM>) is in the operational position on the eye (<NUM>),
wherein the eye fixating portion (<NUM>) comprises at least two support elements (<NUM>) having a contact surface (<NUM>) through which the eye fixating portion (<NUM>) is to contact the sclera (<NUM>) when the device (<NUM>) is in the operational position on the eye (<NUM>),
characterized in that a space (<NUM>) between two support elements (<NUM>) along the flap protecting portion (<NUM>) is configured to accommodate a hinge portion (11a) of the corneal flap (<NUM>).