WO2025190993A1

WO2025190993A1 - Cryogenic probe device for ophthalmic surgery

Info

Publication number: WO2025190993A1
Application number: PCT/EP2025/056714
Authority: WO
Inventors: Goran Petrovski
Original assignee: Universitetet i Oslo; Oslo Universitetssykehus hf
Current assignee: Universitetet i Oslo; Oslo Universitetssykehus hf
Priority date: 2024-03-13
Filing date: 2025-03-12
Publication date: 2025-09-18
Anticipated expiration: 2026-09-13

Abstract

A device for ophthalmic surgery is provided. The device may be a device for the treatment of retinal breaks, holes, or tears, in order to prevent formation of retinal detachment. The device includes a cryogenic probe and at least one optical element coupled to the cryogenic probe. The optical element may form part of a lighting system. The optical element transmits light from a light source to indicate a region of contact between the probe and a sclera. This may enhance visibility during surgical procedures. The device may also include the light source and power supply, and these may be provided in a handle of the device. There is also provided a lighting system comprising a housing, the optical element, a light source, a power supply, and a coupling mechanism for coupling the housing to a cryogenic probe.

Description

CRYOGENIC PROBE DEVICE FOR OPHTHALMIC SURGERY

FIELD OF THE INVENTION

The present invention relates to a device for use in ophthalmic surgery, and more specifically a device for treating retinal breaks, holes, or tears.

BACKGROUND OF THE INVENTION

Retinal detachment is the separation of the neurosensory retina from the underlying retinal pigment epithelium, which can occur due to retinal breaks, holes, or tears. For conciseness, references to retinal tears below can be considered to refer to any retinal break, hole, or tear. This is potentially a vision-threatening condition. It is preceded by visual disturbances for the subject, such as floaters, flashing lights, blurring, or shadowing in the vision, or a reduction in peripheral vision, which may worsen if left untreated, before becoming visionthreatening. Accordingly, it is desirable to address retinal tears as quickly as possible to avoid occurrence of retinal detachment and vision loss.

Various treatments may be used for retinal tears. The treatment may depend on the location and/or the severity of the issue. Laser therapy or surgery may be used, but it may not be appropriate for use where the retinal tears have formed peripherally and towards the anterior part of the eye. For retinal tears, cryogenic therapy, which may be referred to as cryopexy or cryosurgery, is preferable. During cryopexy, extreme cold is applied to the eye to necrotise the tissue where the retinal tear has occurred. This will create scar tissue that stabilises the retinal tear. Stabilising the tear may prevent retinal detachment or further tearing.

For cryopexy to be performed, the subject is moved to an operating room or theatre and is treated with a cryoprobe. The cryoprobe, which may be referred to as a cryogenic probe or more simply a probe, is cooled by applying a cold gas to a metallic surface, and this metallic surface is applied to the sclera of the patient for a short period of time. The cryoprobe is directed into contact with the sclera by an eye surgeon, who is viewing the eye through a microscope and using an external light source to illuminate the eye. The gas is released by a nurse at the direction of the eye surgeon or the surgeons themself.

Requiring an operating room for such surgery may cause delays in how quickly the treatment can be provided. For example, if such an operating room is not set up at a clinic or available at the time, a subject may not be able to be treated there. It may be that an operating room is set up but that it is being used for other procedures or needs to be booked in advance. Operating rooms may also require specialist technicians or nurses to be present. These considerations may mean that a subject cannot be treated as quickly as desired to prevent the retinal tear from worsening or to prevent detachment from occurring. A delay in treatment may result in retinal tear or retinal detachment that is harder and more costly to treat. A delay in treatment may cause worse post-surgery results, such as redetachment(s) and/or difficulties in regaining vision.

Furthermore, because the cry oprobe is being directed to a region of the eye that cannot be viewed directly by the eye surgeon, it can be difficult to correctly position the cry oprobe, both in terms of location and orientation. Improper positioning may increase the affected necrotising area by enlarging it or simply missing the retinal tear. Best results may be achieved by applying the cryoprobe precisely at the location of the retinal tear and fully onto the region with the probe at 90 degrees to the sclera. Achieving both of these requirements can be difficult using the existing techniques.

SUMMARY OF INVENTION

According to a first aspect, there is provided a device comprising: a cryogenic probe having: an elongate body; a tip at a distal end of the elongate body, the tip having a contact surface for contacting a first region of a sclera of a subject; and a cooling system for cooling the contact surface using a cryogenic fluid; and the device further comprising at least one optical element coupled to the cryogenic probe for transmitting light from a light source to indicate the first region.

Providing an optical element in addition to the cryogenic probe enables the sclera to be transilluminated during cryosurgery. This may avoid or reduce the requirement for external, separate illumination of the eye. As a result, the procedure may be performed outside of an operating room or theatre.

Furthermore, the arrangement of the optical element, being coupled to the cryogenic probe, enables a user of the device to manoeuvre the device to adapt the illumination, allowing for more control over which parts of the eye are illuminated. This may enable greater precision when using the probe, allowing treatment to be more controlled. This may also make the procedure using the probe faster and more effective. Providing the optical element so that it indicates the first region also provides an advantage. Cryogenic probes are typically used with separate, external light sources which illuminate the entire eye via the pupil. The user is manipulating the cryogenic probe in a space between the eye and the eye socket or orbit, making it difficult to know the orientation and/or position of the probe relative to the eye. The user has to view the probe through the pupil of the eye, making it difficult to achieve precision in the placement of the probe. By providing the optical element with the probe, greater precision may be achieved. Precision may be improved because the optical element indicates the first region, meaning that the probe can be positioned better. The optical element may enable orientation of the probe to be determined, based on how the light displays through the eye. For example, a circular shape may indicate a correct orientation while an oval/ellipsoid shape may indicate incorrect orientation, as will be explained in more detail below.

The optical element may enable proximity of the probe to the sclera to be determined based on its intensity. As a result of such improved precision, procedures may be performed more quickly, more precisely, and/or more effectively. As the user can more quickly and accurately position the probe, the probe may touch the eye fewer times, reducing the potential to cause damage to the eye.

The device may be referred to as a medical device. The cryogenic probe may be referred to as a cryoprobe or as a probe. The device may be a device for performing cryosurgery, and optionally a device for performing cryosurgery on an eye of a subject. The cryosurgery may be cryopexy. The cryosurgery may be applied to a sclera, and indirectly via the sclera, to a choroid, or retina of the subject. The cryosurgery may be used to treat a retinal break, hole, or tear.

The cryogenic probe may be any known cryogenic probe. The elongate body may have a tubular structure, such that the elongate body comprises a central lumen. The central lumen may be closed at a distal end by the tip. The cooling system may deliver cryogenic fluid into the central lumen to cool the tip. The cooling system may have a delivery conduit for delivering the cryogenic fluid. The delivery conduit may extend from a proximal end, for connection to a fluid source, to a distal end within the central lumen. The distal end of the delivery conduit may be open to deliver the cryogenic fluid into the central lumen. The cooling system may comprise a removal conduit for removing cryogenic fluid from the central lumen. The removal conduit may be connected to or positioned within the lumen. The removal conduit and delivery conduit may enable circulation of cryogenic fluid within the lumen. The tip may be formed from a metallic material. The metallic material may be a biocompatible, inert or non-reactive metallic material. The metallic material may be resistant to the low temperatures used. The metallic material may be thermally conductive. The elongate body may also be formed from the metallic material or a different metallic material having the above properties. The metallic material may be aluminium or an aluminium material. The cryogenic fluid may cool the tip to temperatures below -50°C, below -60°C, below -70°C, below -80°C, below -90°C, or below -100°C.

The elongate body may be straight and unbent. In other words, the elongate body may form a tube extending along a longitudinal axis. A distal end and proximal end of the elongate body may be aligned. Alternatively, the elongate body may include a distal portion and a proximal portion. The distal portion may be angled relative to the proximal portion. The tip may be provided on the distal portion. The distal portion may be angled relative to the proximal portion at an angle between 0° and 90°, such as 10° to 80°, 20° to 70°, or 30° to 60°. The proximal portion may have a proximal longitudinal axis and the distal portion may have a distal longitudinal axis. The distal longitudinal axis may be at an angle to the proximal longitudinal axis. The angle may be an obtuse angle. The angle may be an acute angle. Cryogenic probes having an angled distal portion may enable the tip to be positioned more easily with their contact surface to contact the sclera following the natural curvature of the eye bulb. It may be desirable to apply the contact surface to the sclera and to cool the tip when the longitudinal axis of the distal portion or of the elongate body as a whole, where the elongate body is straight, is perpendicular to the sclera. The tip may have a hemispherical, or rounded form. The tip may form a blunt end of the probe. The contact surface may comprise a portion of the tip that is perpendicular to the longitudinal axis of the portion of the elongate body to which it is connected. In other words, the contact surface may comprise a flat or substantially flat portion of the tip. During application, other portions of the tip may contact the sclera. The contact surface may have a circular profile.

By “transmitting” light, it is meant that the optical element allows the light to leave a substrate of the optical element into a different substrate, such as air, residual fluid, or the sclera. Such transmission may be referred to as transillumination, and particularly scleral transillumination when the light is transmitted into the sclera. The optical element therefore provides a boundary at which light can leave the optical element. The optical element may provide a transmission path along which the light can travel from the light source before exiting the optical element and being transmitted to indicate the first region. The optical element may therefore have a transparent or translucent body through which the light travels.

The optical element may comprise an optical fibre or a lens. The optical element may form part of the light source. For example, the light source may be a light-emitting diode (LED) and the optical element may be a lens or casing of the LED. The optical element may have a proximal end for connection to the light source and a distal end for transmitting the light.

The optical element may be arranged to illuminate or transilluminate the eye. Indicating the first region may be defined as providing illumination or transillumination of a portion of the eye that enables the first region to be identified, and particularly when the eye of the subject is viewed by a user of the device from the front side of the subject’s face. The first region may be visible when the eye is open, i.e., on a forward-facing surface of the eye, or may be on a surface that is within the eye socket or eye orbit when the eye is open.

The first region may be indicated in one of several ways. For example, the at least one optical element may be arranged to transmit light from the light source onto the first region. The first region may therefore be indicated because it is illuminated. In other words, the optical element may be arranged to illuminate a region of contact between the tip, at the contact surface, and the eye. Illuminating the first region may be useful to enable the retinal tear to be highlighted to the user of the device. Illuminating the first region may also be useful to enable the user of the device to know when the contact surface is in the correct position for treatment. The light source may be configured to vary the light emitted to indicate the first region. For example, the light may pulse or flash to indicate the first region.

The optical element may be arranged to illuminate the first region. This may be achieved by the optical element being provided within or being part of the contact surface. In other words, the optical element may be central within or arranged at the tip. The optical element may, for example, be an optical fibre that passes along a central lumen of the elongate body and transmits light from the tip. Alternatively, the optical element may be provided outside the elongate body and may transmit light at an angle relative to the elongate body towards the tip or a position in front of the tip. The at least one optical element may be arranged to transmit light from the light source onto a second region of the sclera. The light may be transmitted onto at least the second region, and may be transmitted onto the first region also. The second region may be a region adjacent the first region. The second region may comprise a single point adjacent the first region. The second region may have a known orientation relative to the first region, so that the first region is clearly indicated. The at least one optical element may be arranged to transmit light from the light source onto a plurality of points of the sclera. The plurality of points may be around the first region, and may indicate the first region by being distributed around the first region.

The second region may surround the first region. The second region may form a ring around the first region. Providing an optical element or optical elements arranged to form an illuminated area, i.e., the second region that surrounds a region of contact between the tip and the sclera enables the first region to be clearly identified as within the second region. Such a second region may also enable a correct orientation of the probe relative to the sclera to be determined. When the probe is at an incorrect orientation, i.e., the contact surface is angled relative to the sclera, rather than being parallel with it, the second region may be distorted. If the second region forms a ring, the ring may have an oval-shaped outline rather than circular. When the probe is at the correct orientation, and the contact surface is parallel or tangential to the sclera, the second region will be as expected and not distorted. The second region may, in this case, have a circular outline. A ring may be formed by positioning the optical element along the elongate body such that the elongate body and/or tip block at least some of the light dispersing into the first region.

In some examples, the second region may partially or fully overlap the first region. Here, the second region may still form a ring around the first region, but may also illuminate some of the first region. This may bring similar benefits as where the second region surrounds the first region while also allowing the first region to be viewed by the user of the device. The second region may partially or fully overlap the first region where the optical element(s) is arranged to transmit light from a position along the probe that is closer to the contact surface, because the light may diffuse from the optical element within the sclera or may not be blocked by the elongate body or tip. Where the second region partially or fully overlaps the first region, it may be circular. Again, when the probe is at the correct orientation, the second region may have a circular shape, whereas at an incorrect orientation, the second region may have an oval shape.

To achieve such illumination of the second region, the optical element may be arranged in a particular way relative to the cryogenic probe. The optical element may be positioned to be in contact with the sclera when the contact surface is in contact with the sclera. In other words, a distal end or an outermost surface of the optical element from which the light is transmitted may be in the same plane as the contact surface or may be arranged to be a short distance from the contact surface. Providing an optical element in this way may enable an intensity of the light to be used to determine proximity of the probe to the sclera. The optical element may be positioned so that its end or surface from which the light is transmitted begins before the tip of the cryogenic probe. The end or surface may be aligned with a distal end of the elongate body. The optical element may be provided to transmit light along a portion of the elongate body and/or along the tip. The optical element may also be provided to transmit light along a distal portion of the elongate body, which may be angled relative to a proximal portion.

The at least one optical element may be arranged to transmit light in a direction that is normal to, or perpendicular to, the contact surface. The contact surface may be perpendicular or normal to a longitudinal axis of the cryogenic probe, or of the elongate body. Accordingly, light may be transmitted by the at least one optical element in a direction that is parallel to the longitudinal axis of the cryogenic probe. The direction may be along the cryogenic probe in a direction towards the tip. Transmitting light in such a direction may further improve how the light can be used to improve orientation of the probe relative to the sclera.

The at least one optical element may comprise a first optical element arranged to transmit light in a first direction. The at least one optical element may comprise a second optical element arranged to transmit light in a second direction. The second direction may be parallel to the first direction. The second direction may be at an angle to the first direction. The first and second directions may be angled so that light travelling along the first and second directions combines at a focal point. In other words, two optical elements may be provided to yield a greater light intensity at a focal point such as the first region.

The first optical element and the second optical element may be spaced apart around a circumference of the cryogenic probe. The at least one optical element may comprise a plurality of optical elements arranged around the circumference of the cryogenic probe. The plurality of optical elements may be evenly spaced around the circumference of the cryogenic probe. The optical elements may comprise optical fibres, lenses, or a combination of optical fibres and lenses. For example, a plurality of optical fibres may be provided that extend from a light source along the elongate body within a casing or sheath, and the optical fibres may connect to a lens, diffuser or other waveguide that creates a uniform beam around the elongate body.

The device may comprise a housing or casing that houses the at least one optical element. The device may comprise a sheath. The sheath may form part or all of the housing or casing. The sheath may have a tubular form. The sheath may circumferentially surround at least part of the elongate body. The sheath may house the at least one optical element. The optical element may extend along the sheath. The sheath may comprise a biocompatible polymer material or a rubber material. The sheath may be fixed to the elongate body. The sheath may be removable from the elongate body. The sheath may be separable from the elongate body, so that it may be reused with other cryogenic probes. The sheath may be configured to have a central bore or hole for receiving the elongate body. The sheath may be configured to expand to receive the elongate body, so that the sheath is retained on the elongate body by friction during use. The sheath may protect the optical element and may prevent light escaping from the optical element during transmission until the light reaches a distal end of the optical element. The sheath may protect the optical element from the extreme cold temperatures applied to the elongate body by the cryogenic gas.

The sheath may comprise the light source. For example, the sheath may include an LED. The sheath may comprise a power supply for powering the light source. The power supply may be a battery cell. Where the sheath contains the light source and the power supply, the sheath may be self-contained, and may not require additional connection to other features. The sheath may comprise a control system for activating and deactivating the light source. In other examples, the light source may be active as long as the power supply is connected to the light source.

The casing may be coupled to the cryogenic probe, and specifically to the elongate body. The casing may be coupled to the cryogenic probe by an adhesive or by friction. A fastening may be provided to couple the cryogenic probe and the casing. The casing may be flexible to conform to a shape of the cryogenic probe, and particularly to a shape of the elongate body.

The casing may maintain the optical element in a fixed orientation and position relative to the cryogenic probe. The optical element may alternatively be provided within the cryogenic probe. The optical element is fixed in relation to the cryogenic probe so that it moves with the cryogenic probe. Accordingly, the light transmitted by the optical element can also be considered to be constant relative to the cryogenic probe, i.e., it is transmitted with a fixed orientation and position relative to the cryogenic probe.

The device may comprise the light source. The light source may be provided separately from the sheath and the optical element. For example, the cryogenic probe may comprise a handle. The light source may be provided within the handle. The light source may be provided externally to the handle. In some examples, the light source may be provided within the elongate body or tip. The light source may comprise one or more LEDs. Alternatively, or additionally, the light source may comprise one or more lightbulbs or other light-emitting devices. The light source may emit visible light. The light source may emit white or coloured light. The light source may be a variable light source to allow the colour or wavelength of the light to be varied. The light source may be a cold light source. The light produced by the light source may be cold light. Cold light sources are light sources that do not produce thermal energy in the generation of light, and therefore do not generate heat in their surroundings. Cold light may be light generated by a cold light source, meaning that the cold light also does not generate heat within its surroundings. The light source may be a xenon light source or a mercury vapor light source. The light source may have a power output or rating that allows light transmitted by the optical element to be visible to a user of the device when the sclera is transilluminated.

The device may comprise a power supply. The power supply may be for powering the cooling system. The power supply may be for powering the light source. The power supply may be for powering the cooling system and the light source. The power supply may be arranged to power both the cooling system and the light source. The power supply may be connected to the light source and/or the cooling system. The power supply may comprise a battery cell or mains power. The power supply may be rechargeable. The power supply may be provided within the handle of the device or may be provided separately. A control system may be provided for operating the cooling system and/or the light source. The control system may comprise a button or other instrument or switch on the handle of the device, for operation by a user of the device. The control system may be configured to selectively operate the cooling system and/or the light source as desired. The control system may comprise a transmitter connected to the switch and a receiver connected to the cooling system and/or light source. The transmitter may transmit a signal from the switch to the receiver, which may operate the cooling system and/or light source based on the signal. Separate switches may be provided for the cooling system and the light source. Separate transmitters and receivers may also be provided for the cooling system and the light source. The transmitter and receiver may be wired or wireless. A wireless transmitter and receiver may send signals using a short-range communication protocol, such as Bluetooth® or Zigbee.

According to a further aspect, there is provided a lighting system for a cryogenic probe that includes an elongate body, a tip at a distal end of the elongate body, the tip having a contact surface for contacting a region of a sclera of a subject, and a cooling system for cooling the contact surface using a cryogenic fluid, the lighting system comprising: a housing; a light source within the housing; a power supply within the housing for powering the light source; at least one optical element within the housing, the at least one optical element being arranged to transmit light from the light source away from the housing; and a coupling mechanism for coupling the housing to the elongate body of the cryogenic probe in a first orientation in which the at least one optical element transmits light to indicate the first region.

Providing a separate lighting system that can be mounted or coupled to a cryogenic probe enables the lighting system to be reused with different cryogenic probes. Accordingly, the cryogenic probe, which may be single use, can be disposed of and the lighting system can be transferred to a different cryogenic probe. Furthermore, the lighting system may be used to retrofit existing or previously manufactured cryogenic probes that do not have lighting systems with lighting systems, thereby bringing the benefits of such a lighting system to existing cryogenic probes. The lighting system may be described as self-contained, as it includes everything required to provide illumination of a sclera. Providing a self-contained lighting system reduces the complexity of its use, enabling fast application to a cryogenic probe and allowing the cryogenic probe to be used more quickly with the lighting system. The cryogenic probe may be a known cryogenic probe as described above. The lighting system, and particularly the optical element, may have features as described above in relation to the device. The coupling mechanism may be a feature of the housing. For example, the housing may comprise a sheath, and the coupling mechanism may be a hole for receiving the elongate body therethrough, the sheath being formed of an elastic material that stretches to receive the elongate body and thereafter conforms to the shape of the elongate body and is maintained in position and coupled to the elongate body by compression of the sheath and friction. Alternatively, the coupling mechanism may be a fastener or adhesive.

According to a further aspect, there is provided a system comprising a cryogenic probe and the lighting system described above, the lighting system being coupled to the cryogenic probe. According to a further aspect, there is provided a kit of parts comprising a cryogenic probe and the lighting system described above.

According to a further aspect, there is provided a method of performing cryosurgery using the device described above. The method may comprise treating a retinal break, hole or tear using the device. The method may comprise necrotising scleral tissue to treat a retinal break, hole or tear using the device. The method may comprise providing the device described above with the cooling system being connected to a fluid source comprising cryogenic fluid and the optical element being connected to a light source. The method may comprise activating the light source. Activating the light source may cause light to be transmitted from the optical element. The method may comprise bringing the contact surface into contact with the first region of the sclera based on the light transmitted from the optical element indicating the first region. The method may comprise operating the cooling system to cool the contact surface based on the contact surface being in contact with the first region. The method may comprise repositioning the device based on the light transmitted from the optical element.

According to a further aspect, there is provided a cryogenic probe having: an elongate body; a tip at a distal end of the elongate body, the tip having a contact surface for contacting a first region of a sclera of a subject; a cooling system for cooling the contact surface using a cryogenic fluid; a handle for holding by a user of the cryogenic probe, the handle being at a proximal end of the elongate body and the cooling system being provided at least in part within the handle, and a control system for controlling operation of the cooling system, the control system comprising a switch on the handle for operation by the user of the cryogenic probe.

The control system may include a transmitter connected to the switch for transmitting a signal based on the switch being operated by the user. The control system may include a receiver for receiving the signal from the transmitter, the receiver being configured to operate the cooling system based on the signal. The transmitter and receiver may be wired or wirelessly connected. The transmitter and receiver may be configured to communicate using a short-range wireless communication protocol such as Bluetooth® or Zigbee.

Providing a switch in a handle of a cryogenic probe improves the useability of such a device. The probe can be manoeuvred and operated by the same operator, thereby reducing the number of people required for performing cryosurgery. In other devices, a pedal that is separate from the probe is pressed and released by a different user to the user manoeuvring the probe to operate the cooling system.

BRIEF DESCRIPTION OF DRAWINGS

Fig. l is a schematic diagram of a first device for use in ophthalmic surgery.

Fig. 2 is a schematic diagram of the first device in relation to an eyeball of a subject.

Figs 3 A and 3B are diagrams of an illumination of a retinal tear using the first device.

Fig. 4 is a diagram of a system including the first device.

Fig. 5 is a schematic diagram of a second device for use in ophthalmic surgery.

Fig. 6 is a schematic diagram of a third device for use in ophthalmic surgery.

Fig. 7 is a flow chart indicating a method for using any of the first device, second device, or third device.

DETAILED DESCRIPTION

Fig. 1 shows a device 100. The device 100 is a medical device that may be used for performing cryosurgery on a subject. The cryosurgery may be for treating a retinal break, hole, or tear of the subject. The device 100 comprises a cryogenic probe 110 and a lighting system 112. The cryogenic probe 110 is configured to provide extreme cold on a surface that is to come into contact with tissue of the subject in order to necrotise said tissue. The lighting system 112 is configured to provide illumination of the tissue prior to and during application of the extreme cold for the purpose of positioning and orienting the probe relative to the tissue. When the device is being used for cryosurgery, the tissue being necrotised and illuminated may be a sclera of an eyeball of the subject.

The cryogenic probe 110 has a handle 114, an elongate body 116, and a tip 118. The elongate body 116 is connected to the handle 114 at a proximal end 120 of the elongate body 116 and to the tip 118 at a distal end 122 of the elongate body 116. The tip 118 forms a terminus of the cryogenic probe 110. The tip 118 provides a contact surface 124, which is for contacting a region of a sclera of a subject which is to be treated, in order to deliver the extreme cold for necrotising the tissue. This region may be referred to as the first region. The tip 118 is formed of a thermally conductive metallic material that can be cooled to extreme cold temperatures using a cryogenic fluid. The tip 118 has a hemispherical form. The contact surface 124 is defined at its pole, and comprises a portion of the tip 118 that will come into contact with tissue of the subject when the tip 118 is applied to the tissue at a desired angle. Typically, the desired angle is perpendicular to a longitudinal axis of the elongate body 116 and top 118. The contact surface 124 may be substantially parallel to the tissue at the desired angle.

The elongate body 116 has a proximal portion 126 and a distal portion 128. The distal portion 128 is angled relative to the proximal portion 126, such that a central longitudinal axis PLA of the proximal portion 126 and a central longitudinal axis DLA of the distal portion 128 are oriented at an angle a relative to one another. The tip 118 is provided at the end of the distal portion 128 and has the same orientation as the distal portion 128. The distal portion 128 is angled relative to the proximal portion 126 to enable a desired angle for the tip 118 when performing surgery on portions of the eye within the eye orbit or socket.

Although not visible in Fig. 1, the cryogenic probe 110 includes a cooling system for delivering a cryogenic fluid to the tip 118 in order to cool it. Such cooling systems are known in the art. In an example, the elongate body 116 may comprise a central lumen that is closed by the tip 118 within which the cooling system circulates cryogenic fluid when operated, thereby cooling the tip 118 by thermal conduction. Operation of such cooling systems is described later in relation to Fig. 4. Although the cooling system is not visible, control apparatus for operating the cooling system is shown in Fig. 1, in the form of a switch or button 190. The switch 190 is provided on the handle 114, and is operable by a user of the device 100 to control delivery of a cryogenic fluid from a fluid source to cool the tip 118. The user may depress the switch 190 to initiate delivery of the cryogenic fluid to the tip 118 and may release the switch 190 to cease delivery of the cryogenic fluid to the tip 118.

The lighting system 112 comprises a sheath 130 that circumferentially surrounds the elongate body 116 along the proximal portion 126 and the distal portion 128 and extends to the tip 118. The lighting system 112 comprises an optical element 132 arranged to transmit light from a light source (not visible in Fig. 1) to indicate the first region on the sclera of the subject at which the contact surface 124 is in contact or will be in contact with the sclera. In this example, the optical element 132 comprises a plurality of optical fibres extending along the sheath 130. The optical fibres have a proximal terminus for connecting to the light source and a distal terminus arranged at a distal surface 134 of the sheath to transmit light along the tip 118. The optical fibres are distributed circumferentially around the sheath 130 such that light is transmitted around the whole tip 118. Accordingly, a second region of the tissue is illuminated, which comprises a ring or halo surrounding the first region.

Turning to Fig. 2, the device 100 is illustrated relative to an eye 10. The eye 10 is illustrated as having a pupil 12, an iris 14, and a sclera 16. Towards the anterior part of the eye 10, a retinal tear 18 has formed on an area on the sclera 16. The retinal tear 18 may lead to the occurrence of a retinal detachment. The retinal tear 18 is to be treated using the device 100. The device 100 is positioned close to the sclera 16 in the region of the retinal tear 18. The tip 118 is brought towards the tear 18. When in contact with the sclera 16, the contact surface 124 of the tip 118 will be in contact with a first region 20 of the sclera 16. The first region 20 encompasses the retinal tear 18 in this example. Once in contact, the cooling system can be operated by operating the switch 190 to deliver a cryogenic fluid to cool the tip 118.

To indicate the first region 20, light 22 is transmitted from the lighting system 112, and specifically the optical element 132 which transmits the light 22 from a light source (not shown). The light 22 illuminates a second region 24, comprising a ring around the first region 20. The second region 24 therefore indicates the first region 20 to a user of the device 100, viewing the retinal tear 18 through the eye 10 from the front, because it surrounds the first region 20. If the retinal tear 18 is not within the first region, and bringing the tip 118 into contact with the eye 10 will not cause the contact surface 124 to contact the sclera 16 in the right place to perform the procedure, then this will be visible to the user, and the position or orientation of the device 100 can be adjusted so that the retinal tear 18 is correctly positioned in relation to the first region 20 and second region 24.

Providing light 22 from the lighting system 112 to illuminate a second region 24 that surrounds the first region 20 enables improved orienting of the contact surface 124 relative to the sclera 16, as is illustrated in Figs. 3A and 3B.

It is desirable that the contact surface 124 is at the correct angle, in which it is substantially parallel to the tissue it is being applied to, so that the first region 20 is substantially circular. If the contact surface 124 is not at the correct angle, the first region 20 may be misshapen or distorted, and may be oval-shaped. This situation is shown in Fig. 3A. In Fig. 3A, the retinal tear is shown 18. A second region 24A is illuminated by the light 22 (not shown in Figs. 3A and 3B), and the second region 24A surrounds a first region 20A. The second region 24A indicates to a user of the device 100 (not shown in Fig. 3 A and 3B) viewing the retinal tear 18 through the eye 10 (not shown in Figs. 3 A and 3B) that the retinal tear 18 is positioned centrally within the first region 20A, meaning that the tip 118 (not shown in Figs. 3A and 3B) is positioned in the correct position for performing the procedure. However, the shape of the second region 24A is oval, as is the first region 20A, meaning that the device 100 is at an incorrect or undesirable orientation relative to the retinal tear 18.

Although in the examples shown in Figs. 1 to 3B, the light 22 is described as forming a ring around the first region 20, in other examples the lighting system 112 may be arranged so that the light 22 is transmitted onto the second region 24 and part or all of the first region 20. How much of the first region 20 is illuminated may be dependent on a proximity of the optical element 132 to the contact surface 124. Bringing the optical element 132 closer to the contact surface 124 may enable greater illumination of the first region 20. Having the optical element 132 further from the contact surface 124 may allow the tip 118 to block the light 22 from illuminating some of the first region 20. How much of the first region 20 is desired to be illuminated may be dependent on the application.

The user of the device 100 may therefore adjust an orientation of the device 100 until a correct orientation is viewed relative to the retinal tear 18. A correct orientation is shown in Fig. 3B, in which the second region 24B, and therefore the first region 20B that it indicates and surrounds, are fully circular. A circular first region 20B and second region 24B indicates that the contact surface 124 is substantially parallel with the surface of the sclera 16 in the first region 20B, and that a longitudinal axis DLA of the distal portion 128 is perpendicular to the surface of the sclera 16 in the first region 20B.

Turning now to Fig. 4, a system 400 is shown. The system 400 includes the device 100. In the system 400, the cooling system 150 is depicted, which includes a fluid source 152 for supplying cryogenic fluid to the tip 118 via one or more conduits 154 that extend into a central lumen of the elongate body 116. The cooling system 150 may include a power supply (not shown in Fig. 4).

The lighting system 112 in Fig. 4 includes, in addition to the sheath 130 and optical element 132, a light source 140 connected to the optical element 132, and a power supply 142 for powering the light source 140. Although depicted as being outside of the device 100 in this example, at least part or all of the light source and power supply may be provided within the handle 114 of the device 100 or within the elongate body 116. Similarly, part of the cooling system 150 may be provided within the handle 114 or within the elongate body 116.

A control system 170 is also provided as part of the system 400. The control system 170 has a first controller 172 for the lighting system 112 and a second controller 174 for the cooling system 150. The first controller 172 may send a first signal 176 to the lighting system 112 to activate or deactivate the light source 140. The second controller 174 may send a second signal 178 to the cooling system 150 to initiate or cease delivery of cryogenic fluid from the fluid source 152 into the device 100. The first and second controllers 172, 174 may communicate with their respective systems by a wired or wireless connection. The lighting system 112 and cooling system 150 may include receivers to receive the signals 176, 178.

A third controller 180 may be provided that is connected to the switch 190 on the handle 114 of the device 100. The third controller 180 may send a signal 182 to the cooling system 150 and/or a signal 184 to the lighting system 112 to selectively operate those systems based on the switch 190 being operated by a user of the device 100. In some examples, only one or two of the first controller 172, second controller 174, or third controller 176 may be provided. For example, the first controller 172 may be omitted and the lighting system 112 may be active at all times. In some examples, the power supply 142 may be a shared power supply for the lighting system 112 and the cooling system 150.

Fig. 5 shows a second device 500. The second device 500 comprises a cryogenic probe 510 and a lighting system 512. The cryogenic probe 510 includes a handle 114, elongate body 116, and tip 118 as in the device 100, which will be referred to as the first device 100 for clarity. The handle 114 of the probe 510 includes the switch 190.

The lighting system 512 of the second device 500 differs from the lighting system 112 of the first device 100 because rather than having a sheath that surrounds the elongate body 116, the lighting system 512 instead has a casing or housing 530 that houses an optical element 532. The housing 530 is fastened or coupled to the elongate body 116 using a coupling 534. The optical element 532 comprises an optical fibre that extends along the housing 530 and connects to a light source at a proximal end (not shown) and is arranged to transmit light 538 from its distal end 536.

Accordingly, a single point of light is created by the optical element 532. The single point of light is formed at a second region 540 that is adjacent to the first region 20 that the contact surface 124 will be in contact with. The second region 540 in this example is therefore a point rather than a ring of light, and indicates the first region 20 by its proximity to the first region 20. In examples, the optical element 532 may be oriented relative to the elongate body 116 or positioned relative to the cryogenic probe 510 more generally such that the first region 20 is illuminated by the optical element 532.

Fig. 6 shows a third device 600. The third device 600 comprises a cryogenic probe 610 and a lighting system 612. The cryogenic probe 610 includes a handle 114, elongate body 116, and tip 118 as in the first device 100. The handle 114 of the probe 610 includes the switch 190.

In Fig. 6, the lighting system 612 of the third device 600 is shown separately from the cryogenic probe 610. The lighting system 612 in Fig. 6 is separable from the cryogenic probe 610. It comprises a housing in the form of a sheath 614 having a central lumen or bore 618 for receiving the tip 118 and elongate body 116 therethrough. The sheath 614 is formed of an elastic material that allows it to expand around the elongate body 116 and tip 118 for receiving them and for holding the sheath 614 on the elongate body 116 when mounted thereon. In other examples, a separate coupling may be provided for coupling the sheath 614 to the elongate body 116. The sheath 614 includes an optical element 616 for transmitting light from its distal end 620. The sheath 614 contains the rest of the lighting system 612, including a light source 622 and power supply 624, represented schematically in Fig. 6. The power supply 624 provides power to the light source 622, and the light source 622 is connected to the optical element 616 to transmit light through the optical element 616 to the sclera of the subject. The separable nature of the lighting system 612 allows its reuse with different probes or retrofitting existing probes with the lighting system 612.

In each of the devices 100, 500, 600 described above, the optical element may be positioned to be in contact with the tissue to be illuminated when the tip of the cry oprobe is also in contact with said tissue or the optical element may be positioned to be a predetermined distance from the tissue. The positioning of the optical element relative to the tip may therefore be varied depending on which is desirable. In examples, the optical element may be in substantially the same plane as the contact surface, or may be within a few millimetres of the contact surface along a longitudinal axis of the probe.

Fig. 7 illustrates a method 700 for using any of the devices 100, 500, 600 described herein. The method 700 may be described as a method for performing cryosurgery using the device, or a method for treating retinal breaks, holes or tears using the device. The method 700 may comprise a step 701 of providing the device 100, 500, 600. At a next step 702, the light source may be activated to provide illumination from the optical element. The device may be manoeuvred at step 703 to be in contact with the sclera. At step 704, the method 700 may comprise adjusting the positioning of the device based on illumination from the light source. The device may be positioned to be in contact with the sclera where a retinal break, hole, or tear has occurred. The method may comprise, at step 705, adjusting an orientation of the device based on illumination from the light source. Once a desired position and orientation of the device has been achieved based on the light source and the retinal break, hole, or tear, at step 706, the method may comprise activating a cooling system to cool a tip of the device to apply an extreme cold temperature to the sclera. Once the extreme cold has been applied, the device may be applied repeatedly until desired result is achieved, then removed and disposed of. The above procedure may be performed after a local anaesthetic has been applied to the eye. Although each of the examples in Figs. 1 to 6 include a lighting system, in other aspects a lighting system may be omitted from the device. In such devices, the cryogenic probe may retain the switch for use in controlling the cooling system by a user of the device. Such a switch may transmit a signal to the cooling device via a short-range wireless communication protocol to enable a single user to provide treatment.

Generally, the techniques described herein provide improved devices, systems, and methods for cryogenic ophthalmic procedures. In the description of examples, reference is made to the accompanying drawings that form a part hereof, which show by way of illustration specific examples of the claimed subject matter. It is to be understood that other examples can be used and that changes or alterations, such as structural changes, can be made. Such examples, changes or alterations are not necessarily departures from the scope with respect to the intended claimed subject matter. While the steps of methods described herein may be presented in a certain order, in some cases the ordering may be changed.

Claims

1. A device comprising: a cryogenic probe having: an elongate body; a tip at a distal end of the elongate body, the tip having a contact surface for contacting a first region of a sclera of a subject; and a cooling system for cooling the contact surface using a cryogenic fluid; and at least one optical element coupled to the cryogenic probe for transmitting light from a light source to indicate the first region.

2. The device of claim 1, wherein the at least one optical element is arranged to transmit light from the light source onto the first region.

3. The device of claim 1 or claim 2, wherein the at least one optical element is arranged to transmit light from the light source onto a second region of the sclera that surrounds the first region.

4. The device of any preceding claim, wherein the at least one optical element is arranged to transmit light in a direction that is perpendicular to the contact surface.

5. The device of any preceding claim, wherein the at least one optical element comprises a first optical element arranged to transmit light in a first direction and a second optical element arranged to transmit light in a second direction that is parallel to the first direction, the first optical element and the second optical element being spaced apart around a circumference of the cryogenic probe.

6. The device of any preceding claim, comprising a sheath that circumferentially surrounds at least part of the elongate body and that houses the at least one optical element.

7. The device of claim 6, wherein the sheath comprises the light source and a power supply for powering the light source.

8. The device of any of claims 1 to 6, comprising the light source and wherein the cryogenic probe comprises a handle, the light source being provided within the handle.

9. The device of any preceding claim, comprising a power supply for powering the cooling system and the light source.

10. A lighting system for a cryogenic probe that includes an elongate body, a tip at a distal end of the elongate body, the tip having a contact surface for contacting a region of a sclera of a subject, and a cooling system for cooling the contact surface using a cryogenic fluid, the lighting system comprising: a housing; a light source within the housing; a power supply within the housing for powering the light source; at least one optical element within the housing, the at least one optical element being arranged to transmit light from the light source away from the housing; and a coupling mechanism for coupling the housing to the elongate body of the cryogenic probe in a first orientation in which the at least one optical element transmits light to indicate the first region.