WO2011083358A1

WO2011083358A1 - Device for treating an ocular pathology by applying doses of laser energy

Info

Publication number: WO2011083358A1
Application number: PCT/IB2010/000495
Authority: WO
Inventors: Fabrizio Romano; Laurent Farcy; Philippe Chapuis
Original assignee: Eye Tech Care
Priority date: 2010-01-11
Filing date: 2010-01-11
Publication date: 2011-07-14

Abstract

The present invention relates to device for treatment of an ocular pathology characterized in that it comprises: at least one eye ring (1 ) wherein the proximal end of said eye ring (1 ) is suitable to be applied onto the globe and means to deliver laser energy connected to the eye ring, wherein said means to deliver laser energy comprise a network of optical fibers for guiding the laser energy in order to treat the ocular pathology, each optical fiber comprising a working end arranged onto the eye ring according to a treatment pattern.

Description

DEVICE FOR TREATING AN OCULAR PATHOLOGY BY APPLYING DOSES OF LASER ENERGY

The present invention is generally directed to a surgical treatment for ocular pathology, and relates more particularly to a device and method for generating doses of laser energy onto at least one annular segment of the ciliary body of an eye affected by glaucoma

In the field of ophthalmologic disease, it is well known that glaucoma is a significant public health problem, between 1 to 2% of population being suffering from this pathology, because glaucoma is a major cause of blindness.

The World health organisation considers glaucoma as the third cause of blindness in the world, responsible of 15% of declared blindness occurrences, with an incidence of 2.4 millions persons per year.

The evolution of glaucoma is slow. Glaucoma is an insidious health disease because at the first stage glaucoma is asymptomatic; the patient does not feel any pain or any visual problem. When the first visual troubles appear, lesions are commonly already large and despite irreversible.

The blindness that results from glaucoma involves both central and peripheral vision and has a major impact on an individual's ability to lead an independent life.

Glaucoma is an optic neuropathy, i.e. a disorder of the optic nerve, which usually occurs in the setting of an elevated intraocular pressure. The pressure within the eye increases and this is associated with changes in the appearance and function of the optic nerve. If the pressure remains high enough for a long enough period of time, total vision loss occurs. High pressure develops in an eye because of an internal fluid imbalance.

The eye is a hollow structure that contains a clear fluid called "aqueous humor." Aqueous humor is formed in the posterior chamber of the eye by the ciliary body. The fluid, which is made at a fairly constant rate, then passes around the lens, through the pupillary opening in the iris and into the anterior chamber of the eye. Once in the anterior chamber, the fluid drains out of the eye through two different routes. In the "uveoscleral" route, the fluid percolates between muscle fibers of the ciliary body. This route accounts for approximately ten percent of the aqueous outflow in humans. The primary pathway for aqueous outflow in humans is through the "canalicular" route that involves the trabecular meshwork and Schlemm's canal.

With the increased pressure in the eye, the aqueous fluid builds up because it cannot exit fast enough. As the fluid builds up, the intraocular pressure (IOP) within the eye increases. The increased IOP compresses the axons in the optic nerve and also may compromise the vascular supply to the optic nerve. The optic nerve carries vision from the eye to the brain. Some optic nerves seem more susceptible to abnormally elevated IOP than other eyes.

The only therapeutic approach currently available in glaucoma is to reduce the intraocular pressure.

The clinical treatment of glaucoma is approached in a step-wise fashion. Medication often is the first treatment option except for congenital glaucoma wherein surgery is the primary therapy.

Administered either topically or orally, these medications work to either reduce aqueous production or they act to increase outflow. Currently available medications may have many serious side effects including: congestive heart failure, respiratory distress, hypertension, depression, renal stones, aplastic anemia, sexual dysfunction and death.

The commonly used medications are Prostaglandin or analogs like latanoprost

(Xalatan), bimatoprost (Lumigan) and travoprost (Travatan) which increase uveoscleral outflow of aqueous humor ; Topical beta-adrenergic receptor antagonists such as timolol, levobunolol (Betagan), and betaxolol which decrease aqueous humor production by the ciliary body ; Alpha2-adrenergic agonists such as brimonidine (Alphagan) which work by a dual mechanism, decreasing aqueous production and increasing uveo-scleral outflow ; Less-selective sympathomimetics like epinephrine and dipivefrin (Propine) which increase outflow of aqueous humor through trabecular meshwork and possibly through uveoscleral outflow pathway; Miotic agents (parasympathomimetics) like pilocarpine which work by contraction of the ciliary muscle, tightening the trabecular meshwork and allowing increased outflow of the aqueous humour ; Carbonic anhydrase inhibitors like dorzolamide (Trusopt), brinzolamide (Azopt), acetazolamide (Diamox) which provide a reduction of aqueous humor production by inhibiting carbonic anhydrase in the ciliary body. The two most prescribed medications are currently topical Prostaglandin Analogs and Betablockers.

Compliance with medication is a major problem, with estimates that over half of glaucoma patients do not follow their correct dosing schedules. Fixed combinations are also prescribed extensively since they improve compliance by simplifying the medical treatment.

When medication fails to adequately reduce the pressure, often surgical treatment is performed as a next step in glaucoma treatment. Both laser and conventional surgeries are performed to treat glaucoma. Generally, these operations are a temporary solution, as there is not yet a cure which is completely satisfactory for glaucoma.

There are two different approaches to treat glaucoma: either the surgeon tries to improve aqueous humor drainage, or he tries to reduce its production.

The most practiced surgeries intended to improve the aqueous humor drainage are: canaloplasty, laser trabeculoplasty, laser peripheral iridotomy (in case of angle closure glaucoma), trabeculectomy, deep non perforating sclerectomy and glaucoma drainage implants.

The most practiced surgery intended to reduce aqueous humor production is the cyclodestruction technique. When cyclodestruction is performed with a laser, it is called cyclophotocoagulation. High Intensity focused Ultrasound can be used to obtain a cyclodestruction.

Canaloplasty is an advanced, nonpenetrating procedure designed to enhance and restore the eye's natural drainage system to provide sustained reduction of IOP. Canaloplasty utilizes breakthrough micro catheter technology in a simple and minimally invasive procedure. To perform a canaloplasty, a doctor will create a tiny incision to gain access to a canal in the eye. A micro catheter will circumnavigate the canal around the iris, enlarging the main drainage channel and its smaller collector channels through the injection of a sterile, gel-like material. The catheter is then removed and a suture is placed within the canal and tightened. By opening the canal, the pressure inside the eye will be relieved. Laser trabeculoplasty may be used to treat open angle glaucoma. A laser spot is aimed at the trabecular meshwork to stimulate opening of the mesh to allow more outflow of aqueous fluid. Usually, half of the angle is treated at a time.

There are two types of laser trabeculoplasty:

· Argon laser trabeculoplasty (ALT) uses a laser to open up the drainage angle of the eye.

• Selective laser trabeculoplasty (SLT) uses a lower-level laser to obtain the same result.

Laser peripheral iridotomy may be used in patients susceptible to or affected by angle closure glaucoma. During laser iridotomy, laser energy is used to make a small full-thickness opening in the iris. This opening equalizes the pressure between the front and back of the iris, causing the iris to move backward.

The most common conventional surgery performed for glaucoma is the trabeculectomy. Here, a partial thickness flap is made in the scleral wall of the eye, and a window opening made under the flap to remove a portion of the trabecular meshwork. The scleral flap is then sutured loosely back in place. This allows fluid to flow out of the eye through this opening, resulting in lowered intraocular pressure and the formation of a bleb or fluid bubble on the surface of the eye.

Trabeculectomy is associated with many problems. Fibroblasts that are present in the episclera proliferate and migrate and can scar down the scleral flap. Failure from scarring may occur, particularly in children and young adults. Of eyes that have an initially successful trabeculectomy, eighty percent will fail from scarring within three to five years after surgery. To minimize fibrosis, surgeons now are applying antifibrotic agents such as mitomycin C (MMC) and 5-fluorouracil (5-FU) to the scleral flap at the time of surgery. The use of these agents has increased the success rate of trabeculectomy but also has increased the prevalence of hypotony. Hypotony is a problem that develops when aqueous flows out of the eye too fast. The eye pressure drops too low (usually less than 6.0 mmHg); the structure of the eye collapses and vision decreases. Antimetabolites directly applied on the surgical site can be used in order to improve the surgical prognosis, especially in high risk of failure (black patients, juvenile glaucoma...). Trabeculectomy creates a pathway for aqueous fluid to escape to the surface of the eye. At the same time, it creates a pathway for bacteria that normally live on the surface of the eye and eyelids to get into the eye. If this happens, an internal eye infection can occur called endophthalmitis. Endophthalmitis often leads to permanent and profound visual loss. Endophthalmitis can occur anytime after trabeculectomy. Another factor that contributes to infection is the placement of a bleb. Eyes that have trabeculectomy performed inferiorly have about five times the risk of eye infection than eyes that have a superior bleb. Therefore, initial trabeculectomy is performed superiorly under the eyelid, in either the nasal or temporal quadrant.

In addition to scarring, hypotony and infection, there are other complications of trabeculectomy. The bleb can tear and lead to profound hypotony. The bleb can be irritating and can disrupt the normal tear film, leading to blurred vision. Patients with blebs generally cannot wear contact lenses. All of the complications from trabeculectomy stem from the fact that fluid is being diverted from inside the eye to the external surface of the eye.

More recently a new surgical technique has been described, called Non- perforating deep sclerectomy ab externo. This technique allows avoiding to open the anterior chamber of the eye and consequently reduces the risk of postoperative complications. The major limitation of this technique is that it is a very difficult surgical technique and only a few surgeons are able to perform it successfully.

When trabeculectomy or sclerectomy doesn't successfully lower the eye pressure, the next surgical step often is an aqueous shunt device. There are several different glaucoma drainage implants. These include the original Molteno implant, the Baerveldt tube shunt, or the valved implants, such as the Ahmed glaucoma valve implant or the ExPress Mini Shunt and the later generation pressure ridge Molteno implants. These are indicated for glaucoma patients not responding to maximal medical therapy, with previous failed guarded filtering surgery (trabeculectomy). The flow tube is inserted into the anterior chamber of the eye and the plate is implanted underneath the conjunctiva to allow flow of aqueous fluid out of the eye into a chamber called a bleb. The prior art includes a number of such aqueous shunt devices, such as U.S. 4,936,825, U.S. 5,127,901 , U.S. 5,180,362, U.S. 5,433,701 , U.S. 4,634,418, US 4,787,885, U.S. 4,946,436, U.S. 20040015140A1 and U.S. 5,360,399.

Many complications are associated with aqueous shunt devices. A thickened wall of scar tissue that develops around the plastic plate offers some resistance to outflow and in many eyes limits the reduction in eye pressure. In some eyes, hypotony develops because the flow through the tube is not restricted. The surgery involves operating in the posterior orbit and many patients develop an eye muscle imbalance and double vision post-operatively. Moreover, because they are open to the surface of the eye, a pathway is created for bacteria to get into the eye and endophthalmitis can potentially occur.

All the strategies mentioned above are intended to improve aqueous humor drainage. Another strategy consists in destroying a significant proportion of a circular intraocular organ, placed behind the iris: the ciliary body. This organ and particularly the double layer epithelium cells are responsible for aqueous humor production. The destruction of a significant proportion of the ciliary body, technique called cyclodestruction, reduces the production of aqueous humor and consequently reduces the Intra Ocular Pressure.

The most common technique currently used is the cyclophotocoagulation obtained with a laser diode (810nm). During cyclophotocoagulation surgery, the surgeons point a laser at the white part of the eye (sclera). The laser passes through the sclera to the ciliary body. The laser damages parts of the ciliary body so that it will produce less aqueous humor, which lowers eye pressure. The procedure is performed with local anaesthesia. The problem with cyclophotocoagulation is that many shots are necessary all around the eye globe, so that a sufficient part of the ciliary body is destroyed. At each point the surgeon places manually the laser applicator in contact with the sclera approximately at 2mm from the limbus and with an incidence ideally perpendicular to the surface of the eye. Then he performs a laser shot. Then he moves the applicator to the next site for a new laser shot. This manual technique is quite empiric, non reproducible, long and not easy. Moreover, the surgeon starts the laser shot without any control on the precise position and direction of the laser beam and without any feedback on the result of the shot on the ciliary body.

DE 44 30 720 describes an apparatus for diode laser cyclophotocoagulation to improve the technique and reduce the risk of empiric manipulation. As shown on figures 2a and 3 of DE 44 30 720, the apparatus comprises laser means (3, 33) for applying laser radiation for cyclophotocoagulation, an ultrasonic head (4, 40) of an ultrasonic bio microscope for monitoring said laser cyclophotocoagulation, and fixing means for holding the laser means and the ultrasonic head.

The ultrasonic head generates low intensity ultrasounds to obtain high resolution echographic images of the region to be treated.

The fixing means serves both to stabilize the patient's eye in the course of the treatment and also to keep the liquid in place on the patient's eye. The fixing means comprise two cylinders: an outer cylinder 20a, and an inner cylinder 20b. The outer cylinder is adapted to be disposed on the eye of the patient. The inner cylinder is destined to support the laser means and the ultrasonic means. The inner cylinder is adjoined to the outer cylinder and is adapted to rotate relative to the outer cylinder.

As described in DE 44 30 720, during the treatment, the laser means generate laser radiations punctually for cyclophotocoagulation of a punctual zone of the region to be treated. Then, the ultrasonic head and the laser means are displaced by rotating the inner cylinder in order to treat another punctual zone of the region of interest. These steps are repeated until all the circumference of the eye has been treated.

This method presents the inconvenient that it is necessary to repeat the operation (i.e. rotate the inner cylinder, acquire an image, verify that the apparatus is still in place, produce a laser shot) many times to treat the whole region to be treated. In other words, the operation have to be repeated many times so that the all the circumference of the eye can be treated.

Furthermore, this method may induce damages to the visual functions due to misalignment between the ultrasonic head, the laser means and the fixing means.

Moreover, considering the region which is treated (i.e. the eye) and the size of such apparatus, it is easy to imagine the difficulties of manipulating such apparatus, and in particular to rotate the inner cylinder comprising the laser means and the ultrasonic means without inducing displacements of the outer cylinder.

Finally, the need of repeating an operation many times increases the operative time and thus the error risk factor.

In the treatment of other ocular pathologies, other systems and methods have been proposed.

There is a need for an accurate, safe, effective and inexpensive method of treating an ocular pathology by applying easily and safely laser energy onto the eye to be treated and for a device thereof.

The above-mentioned need is addressed by the embodiments described herein in the following description of the invention which allows unlike other laser treatments to treat the whole circumference of the eye in only one step, without the necessity to manipulate the device during the procedure.

In one embodiment, a device for treatment of an ocular pathology is disclosed. Said device comprises at least one eye ring wherein the proximal end of said eye ring is suitable to be applied onto the globe and means to deliver laser beam fixed on the distal end of the eye ring.

More particularly, the device comprises:

- at least one eye ring wherein the proximal end of said eye ring is suitable to be applied onto the globe and

- means to deliver a laser energy, wherein said means to deliver a laser energy comprise a network of optical fibers for guiding the laser energy in order to treat the ocular pathology, each optical fiber comprising a working end arranged onto the eye ring according to a treatment pattern.

The network of optical fibers allows guiding the laser beam from the laser source to the eye.

The advantage of using a network of optical fibers is that they can be introduced in a device having an annular shape in which the optical fibers are not visible. Furthermore, the optical fibers present the advantages of:

- being flexible so that the manufacturing process of the device according to the invention is facilitated, - being shock resistant so that the reliability of the device according to the invention is improved

- allowing a good transmission of the laser energy so that the efficiency of the device according to the invention is increased.

Preferably, the working ends of the network of optical fibers are placed peripherally over the whole or a part of the eye ring. More preferably, the working ends of the network of optical fibers are placed circumferentially over the whole or a part of the eye ring.

In one embodiment, the means to generate a laser energy comprise a single laser source for generating a laser beam, each optical fiber of the network being connected to the laser source. In one variant of this embodiment, the laser beam generated by the laser source is split between the different optical fibers such that each optical fiber emits a part of the laser beam initially generated by the laser source simultaneously. In that case, the means to generate laser energy comprise an optical splitter connected between the laser source and the network of optical fibers, said optical splitter for splitting the laser beam generated by the laser source between the different optical fibers of the network. In another variant of this embodiment, the laser beam generated by the laser source is switched between the different optical fibers such that each optical fiber emits the laser beam generated by the laser source successively. In that case, the means to generate laser energy comprise an optical switcher connected between the laser source and the network of optical fibers, said optical switcher for switching the laser source from one optical fiber to another.

In another embodiment, the means to generate laser energy comprise a plurality of laser sources for generating a plurality of laser beams, each opening being connected to a respective laser source. The laser sources are connected to a control unit allowing activating the laser sources successively or simultaneously.

The means to deliver laser energy may further comprise mirrors or prisms placed onto the eye ring, each mirror being in front of a working end of a respective optical fiber.

The eye ring consists in a sawn-off cone element open at both ends wherein the small base is the proximal end and the large base is the distal end. The proximal end of the sawn-off cone element comprises an external annular flange suitable to be applied onto the eye globe.

The proximal edge of the sawn-off cone element comprises an annular groove communicating with at least one hose formed in the sawn-off cone element and connected to a suction device.

The internal diameter of the proximal end of the sawn-off cone element is sensibly equal to the sum of the corneal diameter plus a value comprised between 2 and 6 millimetres, and more preferably equal to the sum of the corneal diameter with a value of 5 millimetres.

The sawn-off cone element is in medical grade silicon or in medical grade polymer.

In one variant of the invention, the means to deliver laser energy and the eye ring can be in one block. In another variant of the invention, the means to deliver laser energy and the eye ring are separated. In this case, the means to deliver laser energy are fixed on the distal end of the eye ring, such that the working end of said means and the eye ring are motionless relative to one another.

One advantage of the device according to the present invention is that it allows treating the eye circumferentially without the need to move a laser source from one position to another after each shot for cyclophotocoagulation of a punctual zone of the region to be treated.

Indeed, unlike the methods and apparatuses described for instance in US 4,484,569 and in DE 44 30 720, the apparatus according to the invention allows treating the eye without the need to repeat an operation many times.

With regard to US 4 484 569 and DE 44 30 720, the invention allows in particular: - simplifying the operation procedure by providing a device which allows a treatment of the eye in one time; indeed, once the apparatus is placed and fixed onto the eye, the apparatus stay in position and the treatment of the whole circumference of the eye can be realized without the need for the operator to displace or maintain the apparatus, - providing a reproducible procedure; indeed unlike the apparatus of the prior art, the device of the present invention do not need to be displaced many times to treat different punctual zones of the region to be treated,

- reducing the operative time which reduces the error risk factor and thus improve the quality of the treatment,

- providing a treatment which is less dependent from the operator, because very easy to be performed, very easy to be learned with an extremely short learning curve, and relatively automatic during the treatment time.

It will be understood in the case of the present invention that the treatment pattern corresponds to the form defined by the regions to be treated. In the case of the treatment of the ciliary bodies, the treatment pattern may be annular or semi-annular. In other cases, the treatment pattern may be elliptical, or hexagonal or octagonal.

Embodiments of varying scope are described herein. In addition to the aspects described in this summary, further aspects will become apparent by reference to the drawings and with reference to the detailed description that follows.

- Figure 1 is a schematic perspective view of the device for treatment of an ocular pathology by applying laser energy according to the invention,

- Figure 2 is a top view of the device according to the invention,

- Figure 3 to 6 are partial views of different embodiments of the device according to the invention,

- Figure 7 is a top view of the device correctly positioned to the eye to be treated,

- Figure 8 is an elevation view of the device correctly positioned to the eye to be treated shown in figure 5.

We will disclose hereinafter a method and a device suitable for the treatment of glaucoma; nevertheless, it is obvious that the skilled person could adapt the method and the device for the treatment of any ophthalmologic pathology that necessitate surgery without departing of the scope of the invention.

Referring to figure 1 , the device according to the invention comprises an eye ring 1 wherein the proximal end of said eye ring is suitable to be applied onto the globe of the eye to be treated and (see figure 2) means 2 to deliver laser energy, said means comprising a working end being fixed on the distal end of the eye ring. Said means are connected to a control unit 3 including a burst generator and means specifying the parameters of the burst such as the power and the duration of each burst, the number of bursts to be carried out (i.e. the number of target to be treated) , etc....

Referring to figure 1 and 3, the eye ring 1 consists in a sawn-off cone element opened at both ends wherein the small base is the proximal end and the large base is the distal end.

Referring to figure 3, the proximal end of the sawn-off cone element 1 comprises an external annular flange 4 suitable to be applied onto the external surface of the eyeglobe, at approximately 2,5mm of the limbus, the limbus being the junction between the cornea and sclera of the eyeglobe. The proximal face of the annular flange 4 presents a concave profile, the radius of curvature of the concave profile being substantially equal to the radius of curvature of the eyeglobe.

Moreover, the proximal edge of the sawn-off cone element 1 comprises an annular groove 5 connected to a suction device 6 (figure 1 ) by at least one hose 7 passing through the sawn-off cone element 1 and emerging into the annular groove, said suction device 6 being advantageously controlled by the control unit 3.

It is obvious that the suction device 6 can be independent without departing from the scope of the invention.

When the sawn-off cone element 1 is applied onto the eye and the suction device

6 is operated, the depression into the annular groove 5 provide a deformation of the conjunctiva of the eye, said deformation forming an o-ring in the annular groove 5. The sawn-off cone element 1 is then closely interlinked in such a manner that said sawn-off cone element 1 will follow the micro movements of the eye during the whole treatment time taking less than 2 minutes, and maintaining the quality of the centred position of the device on the visual axis.

The sawn-off cone element 1 is advantageously obtained in medical grade silicon or in another medical grade polymer.

It is obvious that the sawn-off cone element 1 can be obtained in any suitable material for medical purposes well known by the skilled person, and which has been verified as biocompatible, such as biocompatible PVC, without departing with the scope of the invention.

Referring to figure 2 and 3, the means 2 to deliver laser energy comprise a standing crown 8 comprising a network of optical fibers 12.

In a preferred embodiment, the means 2 to generate laser energy and the eye ring are in one block.

In the case where the means 2 to deliver laser energy and the eye ring are in two blocks, the external radius of said standing crown 8 is sensibly equal to the internal diameter of the distal end of the sawn-off cone element 1.

The proximal edge of the standing crown 8 comprises holes 9 from which projects the working ends of the optical fibers 12. In particular, the working end of each optical fiber 12 projects from a respective hole 9 disposed on the profile of the standing crown. The standing crown is designated to be tuned towards the eyeglobe - more particularly towards the ciliary body as shown in figure 3 - so that the working ends of the optical fibers are put in contact with the eye to be treated.

Preferably, the working ends of the network of optical fibers are placed peripherally over the whole or a part of the eye ring. More preferably the working ends of the network of optical fibers are placed circumferentially over the whole or a part of the eye ring.

Referring to figure 2, the optical fibers extend within the standing crown 8. The standing crown 8 comprises two pairs of three optical fibers 12. The working ends of the two pairs of three optical fibers 12 define two active sectors separated by two inactive sectors 13.

It will be noted that the standing crown 8 can comprise two or more optical fibers 12 distributed among the circumference in any manner without departing with the scope of the invention.

The laser energy can be transmitted to one or more optical fibers by the control unit 3 to destroy the ciliary body over the whole or a part of its circumference, each optical fiber providing an internal injury in a shape compatible with the shape of the ciliary bodies of an arc of circle. In this embodiment, adapted to the treatment of glaucoma, the internal diameter of the proximal end of the sawn-off cone element 1 is sensibly equal to the corneal diameter plus 2 to 6 mm

The internal diameter of the proximal end of the sawn-off cone element 1 , depending on the patient corneal diameter, is comprised between 12 and 18 mm and the internal diameter of the distal end of the sawn-off cone element is comprised between 26 and 34 mm.

Moreover, the height of the sawn-off cone element 1 is comprised between 8 and 12 mm. In this manner, by positioning correctly the sawn-off cone element 1 onto the eye to be treated, as described hereinafter, the whole or a part of the ciliary body of the eye will be injured by laser energy without the need to manipulate the device during the treatment.

In the embodiments illustrated on figures 4 and 5, the means 2 to generate a laser energy comprise a single laser source 42 for generating a laser beam. Each optical fiber 12 of the network is connected to the laser source 42.

In the embodiment of figure 4, an optical splitter 43 is connected between the laser source 42 and the network of optical fibers 12. The optical splitter 43 allows splitting the laser beam generated by the laser source 42 between the different optical fibers of the network. In this embodiment, the optical fibers of the network transmit the laser energy in parallel. This allows burning the ciliary bodies in one shot.

In the embodiment illustrated on figure 5, the means 2 to generate a laser energy comprise an optical switcher 44 connected between the laser source 42 and the network of optical fibers 12. The optical switcher 44 allows switching the laser source from one optical fiber 12 to another. In this embodiment, the optical fibers of the network transmit the laser energy sequentially. This allows using a laser having a lower power for burning the ciliary bodies.

Referring to figure 6 another embodiment according to the present invention is illustrated. In this embodiment, the means to generate a laser energy further comprise mirrors 45. The mirrors 45 are designated to be placed onto the standing crown 8. In this embodiment, the working end of the optical fibers 12 does not project from the standing crown anymore. Each mirror 45 is associated with the working end of a respective optical fiber 12. More precisely, each mirror 45 is in front of a working end of a respective optical fiber 12.

To apply correctly the sawn-off cone element 1 onto the eye, referring to figure 7, the surgeon must manipulate the sawn-off cone element 1 as far as the iris ring and the periphery of the cornea are centred in the distal opening of the sawn-off cone element 1 as illustrated in figure 7. If the white ring corresponding to the visible part of the sclera trough the opening of the proximal end of the ring, has a constant thickness, the centring is correct. When the sawn-off cone element 1 is centred on the pupil, the revolution axis of said sawn-off cone element 1 and the optical axis of the eye are merging, referring to figure 8. Consequently, the planes in which extend the distal edge and the proximal edge of the sawn-off cone element 1 are perfectly parallel to the planes of the eye such as iris plane, pupil plane or plane of the ciliary body,. This allows a better positioning of the device according to the invention with regard to the lesions obtained (unlike the apparatus described in US 4 484 569 and DE 44 30 720), and improves the reproducibility of the treatment.

Moreover, the device can comprise two aiming wires 14 extending crosswise and diametrally from the internal edge of the standing crown 8 or another centring system like a circular pad supposed to be centred on the pupil. This allows facilitating the centring of the sawn-off cone element with regard to the eye. To centre the sawn-off cone element 1 , it is necessary to centre the intersection of the aiming wires 14 with the centre of the pupil.

It will be understood that the device according to the invention can comprise other centring system known from the man skilled in the art for facilitating the centring of the sawn of cone.

When the sawn-off cone element 1 is correctly centred onto the eye, the suction device 6 is activated to interlink said sawn-off cone element 1 with the eye. The depression into the annular groove 5 provides a deformation of the conjunctiva of the eye, said deformation forming an o-ring in the annular groove 5. This insures a proper maintain in position of the device during all the treatment.

The sawn-off cone element 1 is then filled with a physiological saline degassed solution, the o-ring formed by the deformation of the conjunctiva of the eye in the annular groove ensuring the sealing. The physiological saline solution provides a cooling and hydration of the eye and the device during the generation of laser beam.

Note that the treatment according to the invention is advantageously an ambulatory treatment whose duration is about 2 minutes for the patient.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The scope of the subject matter described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1 - A device for treatment of an ocular pathology characterized in that it comprises:

- at least one eye ring (1 ) wherein the proximal end of said eye ring (1 ) is suitable to be applied onto the globe and

- means to deliver a laser energy connected to the eye ring, wherein said means to deliver a laser energy comprise a network of optical fibers for guiding the laser energy in order to treat the ocular pathology, each optical fiber comprising a working end arranged onto the eye ring according to a treatment pattern.

2 - A device according to claim 1 , characterized in that the working ends of the network of optical fibers are placed peripherally over the whole or a part of the eye ring.

3 - A device according to claim 2, characterized in that the working ends of the network of optical fibers are placed circumferentially over the whole or a part of the eye ring. 4 - A device according to anyone of claims 1 to 3, characterized in that the means to generate a laser energy comprise a single laser source for generating a laser beam, each optical fiber of the network being connected to the laser source.

5 - A device according to claim 4, characterized in that the means to generate a laser energy further comprise an optical splitter connected between the laser source and the network of optical fibers, said optical splitter for splitting the laser beam generated by the laser source between the different optical fibers of the network.

6 - A device according to claim 4 characterized in that the means to generate a laser energy further comprise an optical switcher connected between the laser source and the network of optical fibers, said optical switcher for switching the laser source from one optical fiber to another.

7 - A device according to any claim 1 to 6, characterized in that the means to generate a laser energy further comprise mirrors or prisms placed onto the eye ring, each mirror being in front of a working end of a respective optical fiber.

8 - A device according to any claim 1 to 7 characterized in that the eye ring consists in a sawn-off cone element open at both ends wherein the small base is the proximal end and the large base is the distal end.

9 - A device according to claim 8 characterized in that the proximal end of the sawn-off cone element (1 ) comprises an external annular flange (4) suitable to be applied onto the eye globe.

10 - A device according to any claim 8 or 9 characterized in that the proximal edge of the sawn-off cone element (1 ) comprises an annular groove (5) communicating with at least one hose (7) formed in the sawn-off cone element (1 ) and connected to a suction device (6).

1 1 - A device according to any claim 1 to 10 characterized in that the internal diameter of the proximal end of the sawn-off cone element (1 ) is sensibly equal to the sum of the corneal diameter with a value comprised between 2 and 6 millimetres, and more preferably equal to the sum of the corneal diameter with a value of 5 millimetres.

12 - A device according to any claim 1 to 1 1 characterized in that the sawn-off cone element (1 ) is in medical grade silicon or in medical grade polymer.