Methods and Probes for Intrascleral Laser Surgery
20220175580 · 2022-06-09
Assignee
Inventors
Cpc classification
A61F9/00736
HUMAN NECESSITIES
A61F9/00781
HUMAN NECESSITIES
International classification
Abstract
Methods of treating an eye are provided that entail partially penetrating the sclera and delivering light energy from an optical fiber within the penetration to treat the a target tissue in the eye, for example, to coagulate vasculature underlying the sclera within a planned incision area. Also provided are treatment probes for treating an eye of a patient includes an elongate body that defines a handle and an advanceable penetrating member and optical fiber housed within the elongate body. The probe is configured to advance the penetrating member so as to penetrate the sclera, only partially, and advance the treatment fiber into the penetration to deliver treatment light energy to coagulate the vasculature underlying the sclera. The probe can include one or more penetrating members and corresponding optical fibers to form one or more penetrations concurrently within the planned incision area.
Claims
1. A method of treating an eye of a patient, the method probe comprising: identifying an incision area in which an incision is to be formed in a sclera of the eye; penetrating the sclera, only partially, with a penetrating member within the incision area at a first location; delivering an optic fiber into the partly penetrated sclera at the first location; delivering treatment light energy through the fiber at the first location so as to coagulate vasculature underlying the sclera within the incision.
2. The method of claim 1, wherein penetrating the sclera comprises advancing a needle or cannula into the sclera.
3. The method of claim 1, wherein the planned incision area is over the sclera adjacent the limbus.
4. The method of claim 1, wherein the light energy is within the visible light spectrum.
5. The method of claim 4, wherein the light energy is laser energy with a green or yellow light range of the visible light spectrum.
6. The method of claim 1, further comprising: positioning a probe, the probe having the penetrating member and optical fiber operably disposed within, at a desired location along the identified incision area.
7. The method of claim 6, wherein positioning the probe comprises: placing an alignment edge of a contact surface of the probe against a reference feature of the eye, wherein the reference feature is a limbus.
8. The method of claim 7, wherein the penetrating member is spaced apart from the alignment edge by 1 mm to 5 mm.
9. The method of claim 6, further comprising: advancing the penetrating member from the probe, thereby partially penetrating the sclera; and advancing the treatment fiber from the probe into the partially penetrated sclera.
10. The method of claim 9, wherein advancing the penetrating member comprises advancing the penetrating member until the penetrating member or associated support member engages a stop, the stop corresponding to a desired depth of the scleral penetration.
11. The method of claim 10, wherein the desired depth is 25% of estimated or measure scleral thickness or greater.
12. The method of claim 10, further comprising: adjusting a depth control of the probe that sets the stop to the desired depth.
13. The method of claim 10, wherein adjusting the depth control is based on an estimate or assessment of scleral thickness.
14. The method of claim 9, wherein the penetrating member comprises a cannula or needle.
15. The method of claim 14, wherein advancing the fiber comprises advancing the fiber through the cannula or needle.
16. The method of claim 6, further comprising: penetrating the sclera, only partially, with the penetrating member within the incision area at a second location within the incision area; delivering the optic fiber into the partly penetrated sclera at the second location; and delivering treatment light energy through the optical fiber at the second location so as to coagulate the vasculature underlying the sclera within the incision area.
17. The method of claim 16, further comprising: penetrating the sclera, only partially, with the penetrating member within the incision area at one or more additional locations within the incision area; delivering the optic fiber into the partly penetrated sclera at each of the one or more additional locations; and delivering treatment light energy through the optical fiber at each of the one or more additional locations so as to coagulate the vasculature underlying the sclera within the incision area, wherein the first, second and one or more additional penetrations are spaced apart such that the vasculature coagulated underlies the entire planned incision area.
18. The method of claim 17, wherein the partial penetrations at the first, the second and the one or more additional locations are formed sequentially by moving the probe between each location.
19. The method of claim 18, further comprising: placing a template on the eye to facilitate precise spacing of the probe at the first, the second and the one or more additional locations.
20. The method of claim 18, further comprising: forming the incision along the planned incision area identified for placement of the implant.
21. The method of claim 6, wherein the penetrating member comprises a first penetrating member, and the optical fiber comprises a first optical fiber, the method further comprising: penetrating the sclera, only partially, by advancing one or more additional penetrating members of the probe at one or more additional locations within the planned incision area; advancing one or more additional optic fibers into the partly penetrated sclera at the one or more additional locations; and delivering treatment light energy through the fibers at the one or more additional locations so as to coagulate the vasculature underlying the sclera within the incision area, wherein the first, second and one or more additional locations are spaced apart such that the vasculature coagulated underlies the entire planned incision area.
22. The method of claim 21, wherein the partial penetrations at the first location and the one or more additional locations are formed concurrently by the probe.
23. The method of claim 21, wherein the partial penetrations at the first location and the one or more additional locations comprise four total locations corresponding to an incision of between 2 and 5 mm in length.
24. The method of claim 22, further comprising: forming the incision along the planned incision area identified for placement of the implant.
25.-45. (canceled)
46. A method of treating an eye of a patient, the method probe comprising: identifying a target tissue in the eye for treatment by intrascleral energy delivery and determining a desired scleral penetration depth; penetrating the sclera, only partially, with a penetrating member within the incision area at one or more locations to the desired scleral penetration depth; delivering an optic fiber into the partly penetrated sclera at the one or more locations; and delivering treatment energy through the fiber at the one or more locations so as to treat the target tissue.
47. The method of claim 46, wherein treatment parameters and the desired scleral penetration depth are determined based on a relationship between one or more treatment parameters and a scleral thickness estimate or measurement.
48. The method of claim 46, wherein penetrating the sclera comprises advancing a needle or cannula into the sclera.
49. The method of claim 46, wherein the target tissue comprises any of: a choroid vasculature, a ciliary body, pigmented epithelium, limbus, Schlemm's canal, trabecular meshwork and lamina fusca.
50. The method of claim 46, wherein the energy comprises any of: light within the light spectrum, infrared, and near infrared.
51.-54. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present embodiments are described in conjunction with the appended figures:
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[0029] In the appended figures, similar components and/or features may have the same numerical reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components and/or features. If only the first numerical reference label is used in the specification, the description is applicable to any one of the similar components and/or features having the same first numerical reference label irrespective of the letter suffix.
DETAILED DESCRIPTION
[0030] The present invention pertains to methods of treatments of an eye and probes configured to perform such methods. In one aspect, the embodiments described herein provide methods and probes configured for prophylactically treating the eye to prevent bleeding from subsequently formed incisions, particularly incisions for drug-eluting implants for treatment of glaucoma. In another aspect, the embodiments described herein provide methods and probes configured for intrascleral delivery of treatment of any number of target tissues. The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the embodiments will provide those skilled in the art with an enabling description for implementing one or more exemplary embodiments, it being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.
[0031] In one aspect, embodiments of the present invention are directed towards methods of intrascleral deliver of light energy. In particular, the methods include delivering light laser energy through a probe, with the probe tip (i.e. emission/output portion) positioned within the sclera tissue and firing the beam through only a portion of the sclera for therapeutic treatment of structures behind the sclera. Typically, the methods target the vasculature of the choroid underlying the sclera along where an incision is made for implantation of an implant, typically a drug-eluting implant for slow release of drugs that reduce IOP for treatment of glaucoma. In some embodiments, the targeted region is the underlying vasculature within a planned incision area, which typically is about a 4 mm by 1 mm region that corresponds to a 3.5 mm incision that will be made through the sclera and choroid vasculature to allow an implant to be inserted with little to no intraoperative or post operative bleeding at the implant site. The objective of this prophylactic treatment is to stop bleeding without damaging surrounding structures. Typically, the incisions for such implants is about 4 mm posterior of the limbus.
[0032] Conventional probes that provide treatments of tissues within the eye by transmission of laser light typically transmit light across the intact sclera, which is a full transcleral approach. This is particularly challenging since the sclera has poor light transmissivity and strong scattering properties, particularly to visible light. These properties are what gives the sclera, also known as the “white of the eye,” an opaque appearance because the sclera blocks and scatters visible light. For these reasons, conventional probe devices typically use infrared wavelengths that allow for better transmission across the sclera; however, this approach can cause undesirable damage to certain tissues and is not well suited for coagulation of vasculature underlying the sclera. Another challenge is that the light energy that is well suited for coagulation of vasculature is within the visible light range, which is precisely the light energy wavelengths that do not transmit well across the sclera. In order to reach suitable coagulation energies, the power and spot size of the energy required would cause damage to surrounding tissues.
[0033] These challenges can be largely overcome by inserting an optical fiber of a probe some depth into the sclera tissue, then deliver the light energy from that point through the remaining scleral tissue and to the desired target tissue (i.e. choroid vasculature). This however is no easy task as the sclera is among the most rigid and difficult to cut tissues within the human body. Therefore, to allow the optical fiber to be placed within the sclera, the methods first partially penetrate the sclera, then advance the optical fiber into the sclera. By providing controlled penetration of the sclera at a controlled depth to ensure the sclera is only partially penetrated, the present methods and probes allow for improved energy delivery through the remaining portion of the sclera, which allows for coagulation of the underlying vasculature to prevent bleeding without causing damage to surrounding tissues. This approach substantially avoids the poor light transmissivity characteristics of the sclera and further allows transmission of light energy (e.g. visible light energy) that is better absorbed by the underlying vasculature in order to effect coagulation along the planned incision area, while limiting damage to surrounding tissues and vasculature.
[0034] In one aspect, the methods entails determine the desired depth of insertion, which can be a determinative parameter, since it roughly determines the remaining thickness of sclera until the choroid is reached. This thickness dictates the amount of light that will transmit through and enlarge to the spot size at the vasculature. Therefore, the depth becomes a treatment parameter where by controlling the depth of insertion and the spot size (e.g. fiber core size) the transmission % and area of the light on the choroid vasculature can be determined. These parameters can be selected to achieve a desired coagulation zone in the choroid vasculature (e.g. 4 mm by 1 mm).
[0035] In another aspect, power and time can also be determinative factors in the resulting area being treatment. Both power and time can be determined in combination with the desired depth of the probe in the sclera, as well as an estimated or measure thickness of the sclera, in order to optimize the intrascleral treatment. Most specifically the sclera depth determines the ‘effective spot size’ on the choroid vasculature. Then based on the transmission at that depth, the power and time can be optimized to achieve the therapeutic effect (e.g. coagulation). In some embodiments, the light energy used is within the visible light range, which is better absorbed by the blood vessels of the vasculature to ensure coagulation. In some embodiments, the methods and probe utilize laser light energy within the green or yellow wavelengths, (i.e., 532 or 577 nm) for the choroid vasculature. Wavelengths across the spectrum from visible to IR can be used for a given treatment. Ideally, the chosen wavelength would be selected to interact with the target tissue as desired and to minimize interaction with the scleral tissue which it propagates through. Many of the potential targets contain blood and/or pigment which become the primary absorber. Often visible spectrum light is well absorbed in blood, especially in the green to yellow range (e.g., 500 nm-600 nm, 520 nm, 532 nm, 577 nm) and can be used to target vascular tissues. Near IR light is also reasonably well absorbed by blood and is well absorbed by melanin. For example, light in the range of 700 nm-1100 nm (e.g., 810 nm) is suitable to treat targets with melanin or reasonable blood content. It is appreciated however, that the above approach is not limited to any particular wavelength and can utilize any light energy or laser energy of any particular wavelength or range of wavelengths as suited for a particular application or treatment modality.
[0036] In another aspect, the invention pertains to a probe that includes both a penetrating member and an optical fiber, each of which is advanceable (either together or separately) distally of a distal contact surface of the probe. Advantageously, the probe includes a depth control to provide a desired depth of penetration and prevent the penetrating member from fully penetrating the sclera. As the thickness of the sclera can vary widely between patients, the depth control can be adjustable by the clinician based on the estimated or measured thickness of the sclera of a given patient. The depth control can include a stop that prevents movement of the penetrating member beyond a certain depth. The probe can also include control features to facilitate advancement and retraction of the penetrating member and the optical fiber. Typically, the depth control is set to a desired depth, the penetrating member is then advanced to partially penetrate the sclera, and then the optical fiber is advanced through the penetrating member to allow intrascleral delivery of light energy to the underlying vasculature. This process can be repeated at multiple locations to treat an entire planned incision area or targeted area. In some embodiments, the probe can include multiple penetrating members and optical fibers such that a series of penetrations can be made along the entire planned incision region concurrently so as to allow delivery of energy at each penetration to deliver light energy to coagulate the vasculature underlying the entire planned incision area or to deliver energy to treat target tissues.
[0037] Having described various embodiments generally, additional aspects and features of the invention will be more readily apparent with reference to the description of the various figures provided herein below.
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[0041] The contact surface 103 is designed to ensure that the light energy is directed substantially perpendicular to the conjunctiva/sclera at the location of the penetration. As described in greater detail herein, the contact surface 115 is designed to allow the physician to administer the prophylactic treatment with the contact surface engaged against the outer surface of the eye, while the penetrating member and fiber are disposed within the sclera.
[0042] Probe 100 is specifically designed for the efficient intrascleral transmission of light energy to the targeted choroidal vasculature tissue. In some embodiments, the laser energy is provided within the visible light range, preferably green (495-570 nm) or yellow (570-590 nm). Visible light, particularly yellow and green light, is particularly useful for the prophylactic therapy described herein because this range of light energy balances the considerations of transmissibility through a partly penetrated sclera and absorption by the blood vessels in the choroid vasculature sufficiently to ensure coagulation, which can include permanent or temporary coagulation.
[0043] In some embodiments, the distal end portion 102 can be configured to facilitate placement at a certain location, for example adjacent the limbus. In such embodiments, the contact surface 103 can include a limbal placement edge 115, which may be positioned on a short side of the contact surface 103. The limbal placement edge 115 can include a contact surface contour that conforms to the limbus and is generally circularly concave with a radius of about 5.25-6.0 mm. The penetrating member 110 and fiber 120 can be positioned a distance of between 1.5-6.0 mm from the limbal placement edge 115 to facilitate the optimal positioning of the puncture and prophylactic treatment region in a desired area, such as over the eye's pars plana—pars plicata junction and/or over the eye's pars plana. In a specific embodiment, the penetrating member 110 and treatment fiber is positioned a distance of between 2.0 and 5.0 mm from the limbal placement edge 115, for example about 4.0 mm.
[0044] The treatment fiber may be coupled with a light energy or laser console (not shown) that is configured to generate the light for prophylactic treatment of the patient's eye. The console may, for example, generate a visible light laser, such as yellow or green, to effect coagulation of the blood vessels of the choroidal vasculature. The console may include one or more outlets for outputting the treatment light and may be configured to couple with the treatment fiber by receiving a proximal connection end of the treatment fiber. Once coupled to the console, the treatment fiber may deliver the treatment light from the console to a distal end of the treatment probe 100 via optical waveguides, fiber optics, light conduits, light guides, light tubes, or the like.
[0045] Probe 100 further includes one or more controls 130 to facilitate advancement and retraction of the penetrating member 110 and optical fiber within and/or to control depth of penetration. As shown in
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[0048] As shown in
[0049] As shown in
[0050] As can be seen in
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[0052] In another approach, the probe can include with a distal tip 202 configured to form multiple penetrations concurrently with multiple penetrating members 210 and allow subsequent transmission of light energy through multiple optical fibers (not shown) in order to treat the entire area of the planned incision area. This approach may be advantageous as it creates all penetrations at precisely spaced increments and streamlines the sequential process described above. Such a probe can include multiple optical fibers, one for each of the penetrating members. In some embodiments, the light can be transmitted through the fibers concurrently. In other embodiments, the light can be transmitted through one or more fibers in a sequence so as to avoid excess energy from overlapping regions between treated areas. As shown, the distal tip includes four penetrating members, which is well suited for prophylactically treating a region corresponding to an incision between 2-4 mm, typically about 3.5 mm, which is a standard incision length for a typical drug-eluting implant. It is appreciated that such a probe can include various other numbers of penetrating members, including fewer or greater than four, and that such penetrating members can be spaced at regular or irregular intervals from each other. In some embodiments, the penetrating members are positioned in a linear fashion, so as to form a linear region such as that shown in
[0053] It is appreciated that the light therapy can be deliver in any suitable manner, for example, by a pulsed or continuous wave emission mode. For example, in some embodiments, the light energy may be delivered with a 30% duty cycle having an “on” time of about 500 μs and an “off” time of about 1100 μs. In other embodiments, the light energy may be delivered with a 15% duty cycle having an “on” time of about 300 μs and an “off” time of about 1700 μs, or about a 10% duty cycle having an “on” time of about 200 μs and an “off” time of about 1800 μs. Careful selection of the laser energy pulse “on” and “off” times can avoid undesired thermal damage to a target by allowing the target to cool during the “off” time of the laser before the next pulse of energy is delivered during the “on” time. The duty cycle may be selected so that cumulative thermal buildup, caused by insufficient cooling during the “off” time may be avoided. Thus, damage may be reduced to a minimum level, but is sufficient to induce a heat sufficiently to permanently coagulate the region within the planned incision.
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[0055] The method of
[0056] The method of
[0057] The method of
[0058] The advantages of this intrascleral approaches described above can be highlighted through the following examples. It is understood that the invention is not limited to the following examples or the details and assumptions associated with each example.
[0059] In Example (1), the above described approach is utilized in a prophylactic treatment in which the targeted tissue is the choroid vasculature and the desired response is coagulation of the choroid vasculature. The assumptions and approximations for this example are: a human subject, a scleral thickness of 800 μm thick, a 600 μm incident spot diameter, 532 nm light, and fluence to be delivered to the choroid vasculature is 500 J/cm.sup.2. It is appreciated that this is merely an example and that the spot size, wavelength, fluence to be delivered, pulse duration and other typical laser parameters, tissue characteristics and therapeutic goals may be different. MonteCarlo tissue modeling is well established and can be used to approximate the required incidence fluence under the given assumptions.
[0060] For a full transscleral approach, where the probe tip is not penetrating the sclera tissue, the incident fluence required to achieve 500 J/cm.sup.2 to the choroid vasculature is approximately 2,650 J. For an intrascleral approach penetration 200 μm into the sclera, leaving 600 μm of sclera material through which the light must transmit, the incident fluence required to achieve 500 J/cm.sup.2 to the choroid vasculature is approximately 1,315 J. For an intrascleral approach penetration 400 μm into the sclera, leaving 400 μm of sclera material through which the light must transmit, the incident fluence required to achieve 500 J/cm.sup.2 at the choroid vasculature is approximately 630 J. For an intrascleral approach penetration 600 μm into the sclera, leaving 200 μm of sclera material through which the light must transmit, the incident energy required to achieve 500 J/cm.sup.2 at the choroid vasculature is approximately 270 J.
[0061] This relationship of treatment parameters versus scleral thickness can be further appreciated by referring to
[0062] In Example (2), the above described approach is utilized within a treatment in which the target tissue is the ciliary body muscle and the desired response is thermal injury to cause contraction of the tissue. The assumptions and approximations for this example are: a human subject is human, a sclera of 800 μm thickness, a 600 um incident spot diameter, 810 nm light, and 2.5 Watts at the anterior scleral surface. MonteCarlo tissue modeling is well established and can be used to approximate the required incidence fluence under the given assumptions.
[0063] For a full transscleral approach, where the probe tip is not penetrating the sclera tissue, the incident irradiance on the ciliary body is approximately 1.2 W/cm.sup.2. For an intrascleral approach penetration 200 μm into the sclera, which leaves 600 μm of sclera material through which the light must transmit, the incident irradiance on the ciliary body is approximately 2.4 W/cm.sup.2, and to match the 1.2 W/cm.sup.2 incident irradiance at the ciliary body, only about 1.25 Watts of power is required at the anterior scleral surface. For an intrascleral approach penetration 400 um into the sclera, which leaves 400 μm of sclera material through which the light must transmit, the incident irradiance on the ciliary body is approximately 4.1 W/cm.sup.2, and to match the 1.2 W/cm.sup.2 incident irradiance at the ciliary body, only about 0.73 Watts of power is required at the anterior scleral surface. For an intrascleral approach penetration 300 um into the sclera, which leaves 500 μm of sclera material through which the light must transmit, the incident irradiance on the ciliary body is approximately 6.6 W/cm.sup.2, and to match the 1.2 W/cm.sup.2 incident irradiance at the ciliary body, only about 0.45 Watts of power is required at the anterior scleral surface
[0064] This relationship of treatment parameters versus scleral penetration depth can be further appreciated by referring to
[0065] While several embodiments and arrangements of various components are described herein, it should be understood that the various components and/or combination of components described in the various embodiments may be modified, rearranged, changed, adjusted, and the like. For example, the arrangement of components in any of the described embodiments may be adjusted or rearranged and/or the various described components may be employed in any of the embodiments in which they are not currently described or employed. As such, it should be realized that the various embodiments are not limited to the specific arrangement and/or component structures described herein.
[0066] In addition, it is to be understood that any workable combination of the features and elements disclosed herein is also considered to be disclosed. Additionally, any time a feature is not discussed with regard in an embodiment in this disclosure, a person of skill in the art is hereby put on notice that some embodiments of the invention may implicitly and specifically exclude such features, thereby providing support for negative claim limitations.
[0067] Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.
[0068] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.
[0069] As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a process” includes a plurality of such processes and reference to “the device” includes reference to one or more devices and equivalents thereof known to those skilled in the art, and so forth. As used herein, the term “about” means +/−10% of the respective value.