Abstract:
A removable tip for a light energy handpiece comprises a hollow conduit configured to surround a light guide in the handpiece; a support extension having a length longer than a length of the hollow conduit; and a shielding extension coupled to the support extension at an angle less than 180 degrees and located in front of the hollow conduit. The shielding extension is configured to be inserted behind an eyelid and extend to the fornix, the shielding extension comprised of a thermally insulative material.

Description:
BACKGROUND 
     Light energy sources, whether incoherent such as LEDs or Intense Pulsed Light (IPL), or coherent, such as a carbon dioxide (CO2) gas laser, Nd:YAG or Er:YAG solid state lasers, fiber or diode lasers, have been used for various applications such as surgical, dermatological and/or aesthetic treatments on areas of skin and various external and internal body organs and tissues. However, using energy sources for application to skin surface areas, particularly in the vicinity of the eye, such as the eyelids and adjacent regions of the face, also referred to as ocular and periocular/circumocular areas, may raise safety concerns. For example, heat dissipation from IPL can cause detrimental damage, either temporary or permanent, to various ocular structures, such as the cornea which is the organ responsible for approximately 70% of the human eye refraction power. 
     SUMMARY 
     In one embodiment, a removable tip for an energy light producing handpiece is provided. The removable tip comprises a hollow conduit/cavity configured to surround a light guide in the handpiece; a support extension having a length longer than a length of the hollow conduit/cavity; and a shielding extension coupled to the support extension at an angle less than 180 degrees and located distally to the hollow conduit/cavity. The shielding extension is configured to be inserted behind an eyelid and extend to the fornix, the shielding extension comprised of a thermally insulative material. 
    
    
     
       DRAWINGS 
       Understanding that the drawings depict only exemplary embodiments and are not therefore to be considered limiting in scope, the exemplary embodiments will be described with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1  is a block diagram of one embodiment of alight delivery system. 
         FIG. 2  is a block diagram of one embodiment of a handpiece and handpiece tip. 
         FIG. 3  is a block diagram of one embodiment of a removable handpiece tip. 
         FIG. 4  is a block diagram of another embodiment of a removable handpiece tip. 
         FIG. 5  is a block diagram of yet a further embodiment of a removal handpiece tip. 
         FIG. 6  is an exemplary diagram depicting one embodiment of a removable tip placed to protect ocular tissue. 
         FIG. 7  is a flow chart depicting one embodiment of a method of protecting ocular tissue. 
     
    
    
     In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the exemplary embodiments. 
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments. However, it is to be understood that other embodiments may be utilized and that logical, mechanical, and electrical changes may be made. Furthermore, the method presented in the drawing figures and the specification is not to be construed as limiting the order in which the individual steps may be performed. The following detailed description is, therefore, not to be taken in a limiting sense. 
     The embodiments described below enable safe irradiation of regions of skin covering or surrounding the eye, using various therapeutic energy light sources, such as those mentioned above. In particular, the embodiments described below provide a shield between ocular structures to be protected and the target tissue as described below. Thus, the embodiments described below provide increased protection of sensitive ocular organs as compared to other systems which rely on external protection, such as the system described in U.S. Pat. No. 7,886,748. 
       FIG. 1  is a high-level diagram of one embodiment of a system  100  for delivering light energy to ocular and periocular areas. System  100  includes a control console  110  and a handpiece  102  coupled to the control console via an umbilical sheath  108 . The control console  110  is configured to generate energy at levels appropriate for palpebral treatments. Hence, the control console  110  includes, inter alia, power-supplies and control electronics for components of the handpiece  102 . The control electronics  112  and power supplies  114  are connected to the handpiece  102  via the umbilical sheath  108 . 
     The handpiece  102  may include a light guide or crystal  120  for directing the light energy. Handpiece  102  may include an internal light source which is controlled by the control console  110 . Internal light sources may be of different types such as LEDs, lamps, diode lasers, fiber lasers or solid state lasers, to name but a few. Multiple sources, whether from the same type or from different types, may be combined into a single handpiece. Light sources located within handpiece  102  have the advantage of using multiple simple umbilical sheaths  108  lacking optical components. In yet another configuration, external light sources may be used. External light sources may be solid state lasers, fiber lasers or gas lasers which may be located in control console  110 . In this embodiment, of external light sources, requires the use of an umbilical sheath  108 , which among other things, can deliver the light energy from control console  110  to the handpiece  102 . 
     The handpiece  102  may include a conduit/cavity  116  configured to guide the light or accommodate a light guiding element. Different types of light energy sources, such as those mentioned above, may be guided and delivered onto the target tissue in different manners. In one embodiment of the present invention, the handpiece may include a lamp which is configured to generate an intense pulsed light (IPL). In this embodiment a crystal light guide  120  is placed within the handpiece conduit/cavity  116 . The crystal light guide  120  may have different lengths and cross sectional geometry. The crystal light guide  120  may have a uniform cross section or the cross section of the light guide  120  may be tapered in order to increase the energy fluence at the spot of treatment. The light guide  120  may also have the same shape and cross section which best conforms to the target tissue area. For example, the light guide  120  may have the same shape as the entire target area so that a single pulse of light may cover the entire treatment target area. A curved crescent-like shape is one which may cover the entire lower eyelid. The light guide  120  may be permanently affixed to the handpiece or may be removably affixed to the handpiece to allow the physician to select the best light guide  120  suited for the patient and treatment area. The light guide  120  may be configured to establish a direct contact with the target tissue or the light guide  120  may treat the target tissue without direct contact. The same light guide  120  may be used in a contact mode or a non-contact mode using an affixing mechanism which supports both configurations. 
     The light guide  120  may also be configured as a hollowed conduit to deliver light energy in free space to the target tissue. In yet another configuration the light guide may comprise an optical fiber or a bundle of optical fibers. The handpiece  102  may be configured to move the optical fiber in a predetermined pattern such that the fiber will scan at least a portion of the target tissue. Or the handpiece  102  may be configured to scan a light beam through free space over a target tissue using controllable optical elements. A beam splitter may be used in order to create fractional treatment to the target tissue. 
     The handpiece also includes a removable tip  104 . In particular, in some embodiments, the tip  104  is disposable. The size and shape of the tip  104  may vary according to the size and shape of the handpiece  102  to which it is attached. For example, in some embodiments, the tip  104  is configured to be compatible with a small handpiece configured for precise digital manipulation such as the handpiece described in U.S. Pat. No. 7,886,748. However, it is to be understood that other handpiece shapes and configurations can be used in other embodiments. For example, a handpiece having a shape and configuration similar to the handpiece described and shown in U.S. Pat. No. 6,758,845 or D643530 can be used in other embodiments. 
     The tip  104  is physically equipped with a shielding extension  106  which provides protection of sensitive ocular organs. For example, the shielding extension  106  may be configured to create a mechanical separation of the target tissue (e.g. an eyelid) from adjacent posterior structures (e.g. cornea or sclera) and can be used by a medical professional to create an artificial gap or distance between the respective tissues, as described in more detail below. In addition, the shielding extension  106  is made of or coated with thermally insulative materials that prevent thermal energy from dissipating or transferring to other structures which are not the intended target tissue. Furthermore, the tip  104  is made from materials that are biocompatible with ocular tissue such as, but not limited to, collagen and polymer materials that are known to one of skill in the art. Hence, the tip  104  presents minimal to no risk of abrasive damage to the ocular tissue.  FIG. 2  is a block diagram of another embodiment of a handpiece  202 . In the embodiment of  FIG. 2 , the control electronics  212 , light source  215  and handpiece  202  are combined into a small stand-alone hand-held unit. In such a configuration, the umbilical sheath  108  shown in  FIG. 1 , may be integrated into the internal electronic circuits of the system and circuitry of the handpiece  102 . In addition, the handpiece  102  includes a heat sink  217  that is thermally coupled to the shielding extension  206  via the support extension  218 . In this way, thermal energy can be dissipated via the tip  204  to the heat sink  217 . Alternatively, the heat sink  217  can be replaced with a cooling source which is thermally coupled to the shielding extension  206  via the support extension  216 . In this embodiment, the cooling source is able to cool tissue in contact with the shielding extension  206 . 
     An exemplary tip is described in more detail with respect to  FIG. 3 . In the example of  FIG. 3 , the tip  304  comprises the shielding extension  306 , a support extension  318 , and a hollow conduit/cavity  316 . The conduit/cavity  316  prevents accidental contact with a laser guide or crystal in the handpiece used for directing the light energy. In addition, in some embodiments, the length  303  of the conduit/cavity  316  is configured as a distance guide to aid in maintaining a predetermined distance between the surface tissue to be treated and a given crystal in the handpiece. For example, the desired distance between the tissue to be treated and the crystal in the handpiece is dependent on the treatment to be applied and/or on the characteristics of the crystal selected. The length  303  of tip  304 , therefore, is manufactured, in some embodiments, to vary from one tip to another tip. Thus, for a given treatment and/or crystal, a tip  304  is selected which has a length  303  that corresponds to the desired distance between the surface tissue and the crystal for the given treatment and/or crystal. In another embodiment of the present invention, a laser light is delivered by handpiece  102  to target tissue via free space and through a conduit in the handpiece and conduit  316  of the tip  304 . In this configuration the internal surfaces of the handpiece conduit and the tip conduit  316  are configured to internally reflect the passing light and to minimize energy loss. 
     In some embodiments in which the length  303  varies from one to tip to another, the length  301  between the shielding extension  306  and the tube  316  is fixed for each tip. For example, the length  301  can be based on the average thickness of an upper or lower adult eyelid. In other embodiments, the length  303  is fixed from one tip to another and the length  301  varies to correspond with desired distances between the surface tissue and the conduit  316 . 
     The shielding extension  306  is configured to be inserted between the ocular conjunctiva and the palpebral conjunctiva and to extend to the fornix. Hence, the length  305  of the shielding extension  306  is based on an average depth of an adult fornix in some embodiments. In other embodiments, the length  305  of the shielding extension can vary from one tip to another such that a medical professional can select a shielding extension having a length appropriate for a given patient. Since the shielding extension extends to the fornix, the shielding extension  306  is also referred to herein as a fornix shield. 
     In addition to the thermal properties discussed above, the shielding extension  306  is configured to be sufficiently flexible that it can be deformed to define irregular surfaces when inserted. For example, it can deform to the contours of the ocular tissue of a given patient. Thus, the shielding extension  306  is able to prevent energy not absorbed by the target area from reaching tissue behind the target area. In addition, although the angle  307  between the shielding extension  306  and the support extension  318  is depicted as a right angle in  FIG. 3 , it is to be understood that angle  307  is not limited to a right angle. For example, the angle  307  can change when tip  304  is used due to the deformation of shielding extension  306 . In addition, as shown in  FIG. 4 , the angle  407  formed between the shielding extension  406  and the support extension  418  can be configured with an angle other than 90°. 
     In some embodiments, the shielding extension  506  may also be constructed from at least two layers, as shown in  FIG. 5 . Each layer  522 - 1  and  522 - 2  has different characteristics. In one embodiment of the present invention, the first layer  522 - 1  is a proximal layer to the handpiece and the second layer  522 - 2  is a distal layer of the shielding extension  506 . The distal layer  522 - 2  is configured to be in direct contact with posterior organs to be protected such as cornea or scleara. The proximal layer  522 - 1  is configured to be in contact with the eyelid. In one embodiment of the present invention, the distal layer  522 - 1  may have high thermal insulative properties while the proximal layer  522 - 2  may have high thermal conductivity properties and a low thermal capacity. In this configuration, the proximal layer  522 - 2  may be used to dissipate thermal energy passed through the eyelid and reach the shielding extension  506 . For example, the thermal energy can be dissipated via the shielding extension  506  and support extension  518  to a heat sink reservoir located in the handpiece to which it is thermally coupled. In yet another embodiment, the handpiece  102  may include a cooling source thermally coupled to the proximal layer  522 - 1  of the shielding extension  506 , in order to cool the target tissue. In this embodiment, the distal thermally insulative layer  522 - 2  isolates and protect posterior organs from cooling energy. 
       FIG. 6  depicts an exemplary tip  604  in operation to protect ocular tissue. As shown in  FIG. 6 , the shielding extension  606  is inserted behind the lower eyelid between the conjunctiva lining the lower eyelid (the palpebral conjunctiva) and the conjunctiva lining the sclera (the ocular conjunctiva). The shielding extension  606  is being inserted toward the fornix. Hence, the shielding extension  606  is able to protect the sclera and the cornea from energy not absorbed by the target tissue in the lower eyelid. In addition, the shielding extension  606  is sufficiently rigid that it can be used to apply a slight force that separates the lower eyelid from the sclera and cornea. Hence, a physical gap is created between the lower eyelid and the sclera/cornea. This physical gap acts as a thermal insulation barrier that provides additional protection from thermal energy. Notably, although the shielding extension  606  is inserted behind the lower eyelid in this example, it is to be understood that the shielding extension  606  can also be inserted behind the upper eyelid. 
       FIG. 7  is a flow chart depicting one embodiment of a method  700  of protecting ocular tissue. Method  700  is implemented using a handpiece having a tip with a shielding extension such as tip  304  described above. At block  702 , a removable tip having a shielding extension is attached to a handpiece. At block  704 , the distal end of the tip is inserted to the posterior side of an eyelid (e.g. the lower eyelid), in the area between the conjunctiva-covered sclera and the conjunctiva-covered inferior eyelid, until it reaches the fornix, as described above. At block  706 , a force is optionally exerted on the tip to pull the palpebral area anteriorly, thereby creating a physical separation of the eyelid from the anterior surface of the eye globe. At block  708 , external eye shielding, such as eye shielding described in U.S. Pat. No. 7,886,748, is optionally applied over the non-treated areas of the skin in the ocular and/or periocular areas to provide a second layer of protection. 
     At block  710 , the handpiece delivers light to the ocular and/or periocular treatment areas, such as on an external surface of the eyelid. The handpiece is configured to generate the heat needed for a given treatment. For example, the light can be used to treat a variety of ophthalmic and/or dermatological conditions, such as but not limited to, meibomian gland dysfunction (e.g. dry eye), wrinkles, and lesions in the skin. The light applied by the handpiece is determined based on the condition to be treated. For example, the heat generated to treat meibomian gland dysfunction is generated at a level sufficient to stimulate the meibomian gland and/or decrease palpebral telangiectasia. Thus, the level of heat for treating meibomian gland dysfunction is not necessarily the same as the level to remove wrinkles In either case, the shielding extension provides thermal protection to the ocular tissue behind the target treatment tissue. In addition, the physical separation created by force exerted on the tip adds another level of protection to the ocular tissue. Thus, the embodiments of the tip described herein provide increased protection of ocular tissue. Furthermore, the tips provide a hygienic solution for protecting the sensitive ocular tissue due to the single-use disposable characteristic of the tip in some embodiments. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.