Abstract:
A tube device for insertion into a lacrimal passage, optimized according to the structure of a lacrimal passage and capable of being operated without impairing the functional effect of a lacrimal passage endoscope. A tube device for insertion into a lacrimal passage comprises a pair of tubes to be placed in the lacrimal passage. Openings are formed at both ends of the pair of tubes. A reinforcement body is disposed and held in the vicinity of each opening at a position located at a predetermined distance from the opening.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a tube device for insertion into a lacrimal passage used for treatment of lacrimal passage obstruction. 
       BACKGROUND ART 
       [0002]    Examples of the treatment of lacrimal passage obstruction that causes epiphora include (i) probing by a lacrimal passage bougie, placement of a tube device for insertion into the lacrimal passage, (iii) dacryocystorhinostomy (DCR), (iv) lacrimal canaliculoplasty, (v) nasolacrimal duct plasty, and (vi) lacrimal caruncle moving surgery. 
         [0003]    The probing by a lacrimal passage bougie (i) opens an obstruction area by insertion of a narrow tube called a bougie into a lacrimal passage and reconstructs a flow path of tears. This treatment is performed as the first treatment because it is easy and minimally invasive. The dacryocystorhinostomy (DCR) (iii), the lacrimal canaliculoplasty (iv), the nasolacrimal duct plasty (v), and the lacrimal caruncle moving surgery (vi) are highly effective but relatively highly invasive treatments because such a treatment makes an incision in the face or makes a hole in the bone. Hence, such a treatment is performed as the last means. 
         [0004]    The tube device for insertion into the lacrimal passage (such as a lacrimal passage tube) used for the placement of a tube device for insertion into the lacrimal passage (ii) is placed in order to maintain the flow path and to reconstruct the tissue after the probing by a lacrimal passage bougie (i). The placement of a tube device for insertion into the lacrimal passage (ii) is easier and less invasive and has larger effect comparing with each treatment method of (iii) to (vi) and thus is widely performed around the world. Specifically, so-called a nunchaku-type lacrimal passage tube (for example, see  FIG. 1 ) as described in Patent Document 1 has been widely used, and in the nunchaku-type lacrimal passage tube, the center part of the tube is formed from a thin and soft tube or rod and each end is formed from a hard and thick tube. 
         [0005]    The nunchaku-type lacrimal passage tube includes a tube and a pair of bougies, and the bougie is inserted from a slit on each end of the tube. The bougie is operated to introduce the tube into the lacrimal passage for placement. As shown in  FIG. 2 , the lacrimal passage includes the lacrimal puncta ( 21 ,  22 ), the lacrimal canaliculi ( 23 ,  24 ), the lacrimal sac ( 26 ), the nasolacrimal duct ( 27 ), and the like. Into the lacrimal passage, the nunchaku-type lacrimal passage tube is inserted. 
         [0006]    However, in order to insert the nunchaku-type lacrimal passage tube, the operation is fumbled in the lacrimal passage and the bougie is operated blindly. Hence, such an operation may break the tube or may make a hole on an area other than the normal lacrimal passage (a false passage) to give poor treatment results. 
         [0007]    On this account, in recent years in order to avoid such a trouble, the operation is often carried out using a lacrimal endoscope for the observation of the lacrimal passage. 
         [0008]    However, even when the lacrimal endoscope is used for the insertion of the lacrimal passage tube, the safety is not sufficiently secured. This is because the lacrimal endoscope must be removed out from the body in order to insert the lacrimal passage tube after the observation in the lacrimal passage using the lacrimal endoscope, the operation cannot be performed while observing a correct position and the like on a monitor of the lacrimal endoscope, and, as a result, the bougie is blindly operated to give insufficient effect. 
         [0009]    Furthermore, the tube has blind ends, and hence a flow examination cannot be performed through the tube. 
       CITATION LIST 
     Patent Literature 
       [0010]    Patent Document 1: Japanese Patent No. 2539325 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0011]    In view of the above problems, an object of the present invention is to provide a tube device for insertion into a lacrimal passage that is optimized based on the structure of the lacrimal passage and to provide a tube device for insertion into a lacrimal passage that can be operated without impairing the functional effect of a lacrimal endoscope. 
       Solution to Problem 
       [0012]    The inventors have intensively studied in order to solve the problems. As a result, the inventors have found that a tube device for insertion into a lacrimal passage, the tube device having an opening at each end of an integrated tube as the component of the tube device and having a reinforcement body near the opening at a position located at a predetermined distance from the opening, can use a lacrimal endoscope in combination, can secure a visual field of the lacrimal endoscope, and can remove the lacrimal endoscope after the use and place the tube device for insertion into a lacrimal passage (such as a lacrimal passage tube) at a position where a health professional desires, and the invention has been accomplished. 
         [0013]    Namely, the summary of the present invention is as below. 
         [0014]    [1] A tube device for insertion into a lacrimal passage includes an integrated tube to be placed in the lacrimal passage. The integrated tube includes two ends, each end being formed with an opening, a reinforcement body is disposed and held near the opening, and a disposed position of the reinforcement body is located at a predetermined distance from the opening. 
         [0015]    [2] The tube device for insertion into a lacrimal passage according to the item [1] further includes a lock means for disposing and holding the reinforcement body. 
         [0016]    [3] In the tube device for insertion into a lacrimal passage according to the item [1] or [2], each end of the integrated tube has an edgeless shape. 
         [0017]    [4] In the tube device for insertion into a lacrimal passage according to any one of the items [1] to [3], a constituent material of the reinforcement body is stainless steel. 
         [0018]    [5] In the tube device for insertion into a lacrimal passage according to any one of the items [1] to [4], a constituent material of the integrated tube includes a resin composition of an isobutylene block copolymer (A) and a thermoplastic polyurethane resin (B) at a weight ratio of (A)/(B)=1/99 to 99/1. 
         [0019]    [6] In the tube device for insertion into a lacrimal passage according to any one of the items [1] to [5], the opening has a diameter of 0.5 to 0.8 mm. 
         [0020]    [7] In the tube device for insertion into a lacrimal passage according to any one of the items [1] to [6], the predetermined distance is 2 mm or less. 
       Advantageous Effects of Invention 
       [0021]    The tube device for insertion into a lacrimal passage of the present invention has the openings in the tube and hence can secure the visual field of a lacrimal endoscope through the opening and can perform a flow examination. The visual field can be secured from a lacrimal endoscope. Thus, a pathway in which the tube passes can be surely identified to avoid troubles, for example, the tube makes a false passage and damages a mucosa and the like to cause bleeding. The tube can be smoothly inserted into the lacrimal passage using the force to a lacrimal endoscope. The reinforcement body works as a stopper to reduce the risk of pushing a lacrimal endoscope out from the opening. In addition, the tube device includes an integrated tube, and thus the tube can be inserted into both of the upper and lower lacrimal passages that are a specific structure to the lacrimal passage. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0022]      FIG. 1  is a schematic view showing a conventional nunchaku-type lacrimal passage tube. 
           [0023]      FIG. 2  is an explanatory view showing an anatomical structure of the lacrimal passage. 
           [0024]      FIG. 3(   a ) is a cross-sectional view showing an example of a placement part of the tube device for insertion into a lacrimal passage of the present invention. 
           [0025]      FIG. 3(   b ) is a cross-sectional view showing a leading end in the example in  FIG. 3(   a ) with a lacrimal endoscope inserted. 
           [0026]      FIG. 3(   c ) is a cross-sectional view showing another example of the leading end of the placement part of the tube device for insertion into a lacrimal passage of the present invention. 
           [0027]      FIG. 4  is a schematic view for explaining a measurement method of the push out strength of the reinforcement body and the tube in examples. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0028]    The present invention will be described in detail hereinafter. 
         [0029]    The lacrimal passage in the present invention includes, as shown in  FIG. 2 , the superior/inferior lacrimal puncta ( 21 / 22 ), the superior/inferior lacrimal canaliculi ( 23 / 24 ), the common canaliculus ( 25 ), the lacrimal sac ( 26 ), the nasolacrimal duct ( 27 ), the nasal cavity (not shown in the drawing), and Hasner&#39;s valve (not shown in the drawing), and is a duct (an accessory organ of the eye) that delivers a tear fluid produced from the lacrimal gland (not shown in the drawing) from the eye surface to the inferior nasal meatus ( 28 ).  FIG. 2  is a schematic anatomical structure of the lacrimal passage. The duct from the superior lacrimal punctum ( 21 ) through the superior lacrimal canaliculus ( 23 ) and the common canaliculus ( 25 ) to the inferior nasal meatus ( 28 ) is called the superior lacrimal passage, while the duct from the inferior lacrimal punctum ( 22 ) through the inferior lacrimal canaliculus ( 24 ) and the common canaliculus ( 25 ) to the inferior nasal meatus ( 28 ) is called the inferior lacrimal passage. 
         [0030]    The tube device for insertion into a lacrimal passage of the present invention includes an integrated tube to be placed in the lacrimal passage. 
         [0031]    The term “integrated” means that two tubes to be correspondingly inserted into the superior/inferior lacrimal passages are connected to be one tube as a whole. 
         [0032]    The integrated tube means a soft tube device for insertion that is inserted for the reconstruction treatment of the lacrimal passage and that has a predetermined length. 
         [0033]    The integrated tube has both ends each formed with an opening. The tube has the openings in this manner, and thus through the opening, the visual field can be secured from a lacrimal endoscope and a flow examination can be performed. 
         [0034]    Examples of the structure of the integrated tube include a cylindrical tube having both ends formed with openings and having a hollow portion through which the openings communicate with each other. Examples of the cylindrical tube include a tube having substantially constant inner and outer diameters over the full-length and a tube including a center part having a substantially constant small diameter. 
         [0035]    Other examples of the structure of the integrated tube include a tube including a center part in a rod shape and, at each end, a cylindrical part having an end with an opening and having a hollow portion that continues to the opening. In this case, the integrated tube may have a substantially constant outer diameter over the full-length or may have a substantially constant small diameter part in the center part in a rod shape. 
         [0036]    Among the integrated tubes exemplified above, more specifically, the tube including the center part having a substantially constant small diameter part may employ the cylindrical part at each end as the part for placing from the lacrimal sac to the nasolacrimal duct and may employ the part in a rod shape for placing from the lacrimal punctum to the lacrimal canaliculus. The tube device for insertion into a lacrimal passage having such a shape and such a structure and having the center part that is softer than both side parts is referred to as a so-called nunchaku-type lacrimal passage tube as described above. 
         [0037]    The nunchaku-type lacrimal passage tube means a lacrimal passage tube that is named after a nunchaku used in martial arts in China because the shape is similar to that of the nunchaku. A preferred tube has such a soft center part as the tube becomes a reversed U-shape when the tube is held up while holding the center point in a longitudinal direction of the tube. 
         [0038]    The shape of each end of the integrated tube is not specifically limited but is preferably an edgeless shape in order to prevent damage to the lacrimal passage. Examples of the shape of each end include, but are not necessarily limited to, an obtuse outer shape such as substantially a cone shape and a pyramid shape, a chamfered edge shape, and a radius shape. 
         [0039]    In the present invention, the integrated tube may include an insert part for inserting a bougie or a lacrimal endoscope. In particular, in many cases of the so-called nunchaku-type lacrimal passage tube, commonly, a bougie or a lacrimal endoscope cannot be inserted into the center part. Hence, in order to insert a lacrimal endoscope or the like into the hollow portion of the cylindrical part that is provided on each side of the center part, an insert part is required to be provided for the continuity between the outside and the hollow portion. The insert part is preferably provided on a side wall of the cylindrical part. The structure of the insert part is not specifically limited and may be properly selected from a small hole, a slit, and the like. 
         [0040]    The constituent material (material) of the integrated tube is not specifically limited, and examples include, but are not necessarily limited to, resin compositions containing silicone, polyurethane, an isobutylene copolymer, an alloy of them, and the like. 
         [0041]    In the present invention, the alloy is not specifically limited, but when an alloy of polyurethane and an isobutylene copolymer is used, the control of the ratio of the isobutylene block copolymer (A) and the thermoplastic polyurethane resin (B) can achieve the hardness control of the tube. The thermoplastic polyurethane resin (B) having a larger ratio can increase the hardness of the tube. From the viewpoint of anti-thrombogenic properties, surface slidability, and flexibility, the isobutylene block copolymer (A) is preferably contained in an amount of 1% by weight or more (namely, the ratio (A)/(B) of the isobutylene block copolymer (A) and the thermoplastic polyurethane resin (B) is preferably 1/99 to 99/1 in a weight ratio). Specifically, from the viewpoint of abrasion resistance, the ratio (A)/(B) of the isobutylene block copolymer (A) and the thermoplastic polyurethane resin (B) is preferably 1/99 to 70/30 in a weight ratio. In particular, from the viewpoint of compressive stress, the ratio (A)/(B) of the isobutylene block copolymer (A) and the thermoplastic polyurethane resin (B) is preferably 1/99 to 50/50 in a weight ratio. The resin composition for the integrated tube used in the present invention may be composed of the isobutylene block copolymer (A) and the thermoplastic polyurethane resin (B) alone and may be mixed with other components. 
         [0042]    The isobutylene block copolymer (A) is preferably “SIBSTAR102T” that is a styrene-isobutylene-styrene block copolymer (hereinafter, also referred to as SIBS) and is manufactured by Kaneka Corporation. Preferred examples of the thermoplastic polyurethane resin (B) (hereinafter, also referred to as TPU) include “Miractran E385PNAT” manufactured by Nippon Miractran Co, Ltd. and “Tecothane TT1074A” manufactured by Noveon that are ether aromatic ring polyurethanes, “Tecoflex EG100A” and “Tecoflex EG85A” that are manufactured by Noveon and are ether alicyclic polyurethanes, and “Carbothane PC3575A” that is manufactured by Noveon and is a polycarbonate polyurethane. 
         [0043]    In the present invention, a reinforcement body is disposed and held near the opening formed at each end of the integrated tube. The reinforcement body may be disposed near at least one of the openings formed on both ends of the integrated tube. Namely, the reinforcement body may be disposed near one opening of the integrated tube and may be disposed near the openings at both ends. For example, for the case that the tube device for insertion into a lacrimal passage is placed through one of the superior/inferior lacrimal canaliculi and for the case that the tube device for insertion into a lacrimal passage is inserted from the common canaliculus to be placed due to a scarring of the superior/inferior lacrimal canaliculi, the reinforcement body may be disposed near one of the openings formed at both ends of the integrated tube, while for the case that one tube device for insertion into a lacrimal passage is placed through both the superior/inferior lacrimal canaliculi, the reinforcement bodies may be disposed near the openings formed at both ends of the integrated tube. In the former case, the insert part for inserting an endoscope and the like may be formed so that such an apparatus is inserted from the opening without disposing the reinforcement body. 
         [0044]    For the case that the reinforcement body is disposed near the opening formed at each end of the integrated tube, in combination of, for example, a disposed position described later of the reinforcement body, the tube can be easily placed in the superior/inferior lacrimal passages using one tube device for insertion into a lacrimal passage. 
         [0045]    The shape of the reinforcement body is not specifically limited as long as the reinforcement body can be disposed near the opening of the integrated tube, can secure a visual field of the lacrimal endoscope inserted in the hollow portion of the tube, and can work as the stopper for the lacrimal endoscope. Examples of the shape may include a substantially ring shape. 
         [0046]    The disposed position of the reinforcement body is set so as to be near the opening and to have a predetermined distance from the opening (the most end position of the opening). The predetermined distance is determined from the viewpoints of the role as the stopper for a lacrimal endoscope and securement of the visual field of the lacrimal endoscope. For example, in order to secure the visual field of the lacrimal endoscope, the position of a lens at the leading end of the lacrimal endoscope is preferably 2 mm or less from the most end position of the tube opening. In order to secure a visual field range of the lacrimal endoscope of 70% or more, the position of a lens at the leading end of a lacrimal endoscope is more preferably 1.5 mm or less and even more preferably 1 mm. Therefore, from the viewpoint of the securement of the visual field of the lacrimal endoscope, the predetermined distance is preferably 2 mm or less, more preferably 1.5 mm or less, and even more preferably 1 mm or less, from the opening (the most end position of the opening). 
         [0047]    The visual field range of a lacrimal endoscope can be also affected by the diameter of the opening (especially, the diameter of the end of the opening) except for a so-called viewing angle of the lacrimal endoscope. The diameter of the opening (also referred to the opening diameter) is preferably as large as possible from the viewpoint of the securement of the visual field of the lacrimal endoscope. Meanwhile, the opening having a larger diameter reduces the wall thickness of the end part of the tube and thus the reinforcement body is difficult to be held. Hence, when the tube is inserted into the lacrimal passage using the force to a lacrimal endoscope, the reinforcement body may be pushed out from the opening. To address this, in order to hold the reinforcement body to prevent the pushing out and to secure the visual field of the lacrimal endoscope, the diameter of the opening (opening diameter) is preferably 0.5 to 0.8 mm and more preferably 0.65 to 0.75 mm. 
         [0048]    As mentioned above, the reinforcement body is disposed near the opening at the end of the tube at a position located at a predetermined distance from the opening, and hence the tube can be smoothly inserted into the lacrimal passage using the force to a lacrimal endoscope while securing the visual field of the lacrimal endoscope. The accidental risk of pushing a lacrimal endoscope out from the opening can be also reduced because the reinforcement body works as a stopper. Such an effect can be further increased by the control of the opening diameter of the opening to the above range in addition to the distance from the opening. 
         [0049]    During a lacrimal endoscope is used, a pathway in which the tube passes can be surely ascertained to reduce troubles, for example, the tube makes a false passage and damages a mucosa and the like to cause bleeding. 
         [0050]    The reinforcement body reinforces a vicinity of the tube end, and thus the opening processing may be performed as an after-processing. 
         [0051]    The constituent material of the reinforcement body is not specifically limited, and examples include various hard resins and metals such as stainless steel. Stainless steel is preferred in order to prevent corrosion due to the contact with a body fluid, a drug solution, and the like. 
         [0052]    In the present invention, a lock means for disposing and holding the reinforcement body may be formed. Such a lock means can hold the reinforcement body more reliably near the opening of the tube and the reinforcement body can reliably work as the stopper for a lacrimal endoscope. The lock means is preferably formed on an inner wall constituting the cylindrical hollow portion of the integrated tube. The structure of the lock means is not specifically limited as long as it can reliably hold the reinforcement body, and examples include a groove and a protrusion that are formed so as to lock the reinforcement body in the cylindrical inner wall. 
         [0053]    In order to increase insertion properties into the lacrimal passage, of the tube device for insertion into a lacrimal passage, the tube may have an outer side with a hydrophilic coating. The coating provides lubricating properties when the tube is in contact with blood and reduces the resistance when the tube is inserted. The hydrophilic coating is not specifically limited and preferably used examples include hydrophilic polymers such as poly(2-hydroxyethyl methacrylate), polyacrylamide, polyvinylpyrrolidone, and polyethylene glycol and a blend of them. 
         [0054]    Hereinafter, the tube device for insertion into a lacrimal passage of the present invention will be described based on an embodiment shown in drawings, but the present invention is not intended to be limited to the embodiment. 
         [0055]      FIG. 1  shows an example of a conventional nunchaku-type lacrimal passage tube (with bougies inserted), and  FIG. 3(   a ) is a schematic cross-sectional view of an embodiment of a tube part to be placed in the inferior nasal meatus and the like of the lacrimal passage, in the tube device for insertion into a lacrimal passage of the present invention. 
         [0056]      FIG. 3(   b ) is a schematic cross-sectional view of the end of the tube part with a lacrimal endoscope inserted in the hollow portion of the tube part in the example shown in  FIG. 3(   a ). 
         [0057]      FIG. 3(   c ) is a schematic cross-sectional view showing another example of the end of the tube part. In  FIG. 3(   c ), a lacrimal endoscope is inserted in the hollow portion of the tube part as with  FIG. 3(   b ). 
         [0058]    First, the conventional nunchaku-type lacrimal passage tube shown in  FIG. 1  will be described. 
         [0059]    The conventional nunchaku-type lacrimal passage tube  1  includes a cylinder-shaped or rod-shaped center part  4  that is disposed at an approximately center part and that is to be placed in the lacrimal punctum, the lacrimal canaliculus, the common canaliculus, and the lacrimal sac, a cylinder-shaped first cylinder part  5   a  that is formed continuously at one end of the center part  4  and that is to be placed in the lacrimal sac, the nasolacrimal duct, the Hasner&#39;s valve, and the inferior nasal meatus, and a cylinder-shaped second cylinder part  5   b  that is formed continuously at the other end of the center part  4  and that is to be placed in the lacrimal sac, the nasolacrimal duct, the Hasner&#39;s valve, and the inferior nasal meatus. The center part  4  is formed to have a smaller diameter than those of the first cylinder part  5   a  and the second cylinder part  5   b,  and hence the lacrimal passage tube has a so-called nunchaku shape. 
         [0060]    The first cylinder part  5   a  has a first end  6 , while the second cylinder part  5   b  has a second end  8 , and each end is blind and has an acute leading end. The leading end part containing the first end  6  is colored in order that an operator can easily distinguish it from the leading end part containing the second end  8 . The first cylinder part  5   a  has two marks  9   a  at positions located at predetermined distances from the first end  6 , so that an operator can visually identify an insertion depth. The second cylinder part  5   b  has marks  9   b  similarly. 
         [0061]    The first cylinder part  5   a  and the second cylinder part  5   b  have slits  7   a  and  7   b  for inserting bougies, on side walls near the center part  4 , respectively. Through the slits  7   a  and  7   b,  a first bougie  2   a  and a second bougie  2   b  are inserted into the hollow portions in the first cylinder part  5   a  and the second cylinder part  5   b,  respectively. 
         [0062]    The center part  4  has a midpoint  3  at a substantially center position of the nunchaku-type lacrimal passage tube for easily ascertaining of a insert position and a placement position. 
         [0063]    In the case that the tube device for insertion into a lacrimal passage of the present invention is a nunchaku-type lacrimal passage tube, the basic structure is the same as that in  FIG. 1 . There are differences in the structures of the first cylinder part  5   a  and the second cylinder part  5   b . These differences will be described below. The tube device for insertion into a lacrimal passage of the present invention can employ other components than the differences, such as the mark  9   a  ( 9   b ) and the coloring of the end in  FIG. 1 . 
         [0064]    The nunchaku-type lacrimal passage tube that is an embodiment of the tube device for insertion into a lacrimal passage of the present invention employs a tube having a cylinder-shaped structure as shown in  FIG. 3(   a ) in place of the first cylinder part  5   a  and the second cylinder part  5   b  in the nunchaku-type lacrimal passage tube  1  shown in  FIG. 1 . Namely, the tube shown in  FIG. 3(   a ) is formed continuously to each end of the center part  4  shown in  FIG. 1  in a common procedure to make the tube device for insertion into a lacrimal passage having an integrated tube of the present invention. 
         [0065]      FIG. 3(   a ) shows a cross-sectional view of one tube having a cylinder-shaped structure of the integrated tube, but the other tube has substantially the same structure, which will not be described. 
         [0066]    As shown in  FIG. 3(   a ), in the nunchaku-type lacrimal passage tube  31  as an embodiment of the tube device for insertion into a lacrimal passage of the present invention, a cylinder part  35  has an end opening  33  at an end and disposes and holds a reinforcement body  32  near the end opening  33  at a position located at a predetermined distance L from the end opening  33 . The predetermined distance L is a distance between the end face of the reinforcement body  32  opposite to the end opening  33  and the end opening  33 . The reinforcement body  32  has a ring shape and is fit and fixed to a groove  36   a  and a protrusion  36   b  that are provided on an inner peripheral face of the inner wall of the cylinder part 35 as a lock means. The end of the cylinder part  35  has a radius part  37  to make an edgeless shape. The cylinder part  35  further has a slit  34  on a side wall at a position near the center part. Through the slit  34 , the outside communicates with a hollow portion  38 , and a bougie or a lacrimal endoscope can be inserted. 
         [0067]    As shown in  FIG. 3(   b ), a lacrimal endoscope  39  inserted into the hollow portion  38  in the cylinder part  35  through a slit (not shown in the drawing) is brought into contact with the end face of the reinforcement body  32  opposite to the end opening  33 . Thus, the protrusion of the lacrimal endoscope  39  from the end opening  33  can be prevented and, using the force loaded to the lacrimal endoscope  39 , the cylinder part  35  can be readily inserted into the lacrimal passage. A distance from the leading end face of the lacrimal endoscope  39  inserted into the hollow portion  38  to the end opening  33  is set as the predetermined distance L, and thus the visual field of the lacrimal endoscope  39  can be secured. Namely, the predetermined distance L is a distance that is required for securing the visual field of the lacrimal endoscope  39 , and it is affected by an opening diameter R of the end opening  33  except for a so-called viewing angle of the lacrimal endoscope  39 . 
         [0068]    In the present example, the end part has an inner structure where the inner diameter of the hollow portion increases toward the direction from the end opening  33  to the center part  4  (the left direction in  FIG. 3(   b )) to correspond to the inner diameter of the ring-shaped reinforcement body  32 . 
         [0069]      FIG. 3(   c ) shows another structure example of the end part of the cylinder part  35  in the nunchaku-type lacrimal passage tube  31  as an embodiment of the tube device for insertion into a lacrimal passage of the present invention. In the present example, the end part has the same constitution as that in  FIG. 3(   b ) except for the inner structure, the structure of the lock means, and the structure of the reinforcement body. In the inner structure in the end part of the present example, the hollow portion has a constant inner diameter that is the same as the opening diameter R toward the direction from the end opening  33 ′ to the center part  4  (the left direction in  FIG. 3(   c )). Thus, the ring-shaped reinforcement body  32 ′ has a smaller inner diameter than that of the reinforcement body  32  in  FIG. 3(   b ). In the device having such a structure, the cylinder body from the reinforcement body  32 ′ to the end has a larger wall thickness than that of the cylinder body from the reinforcement body  32 ′ to the central part. Hence, such a device is likely to improve the prevention effect on pushing out from the reinforcement body  32 ′ when a lacrimal endoscope is inserted for pushing, comparing to the case of the inner structure in  FIG. 3(   b ). 
         [0070]    The reinforcement body  32 ′ is fit and fixed to a groove  36   c  (lock means) provided on an inner wall of the cylinder part  35 ′. The tube has no protrusion  36   b  as shown in  FIG. 3(   b).    
         [0071]    As with in  FIG. 3(   b ), a distance from the leading end face of a lacrimal endoscope  39  inserted into the hollow portion  38  to the end opening  33 ′ is set as a predetermined distance L. 
       EXAMPLES 
     Production Examples 1 to 10 
       [0072]    Predetermined amounts of a styrene-isobutylene block copolymer (hereinafter referred to as SIBS) and polyurethane (Tecoflex EG85A; manufactured by Noveon) were prepared at a weight ratio of 10:90, and the whole was kneaded with a twin screw extruder (φ 4.0, L/D=40, a rotation speed of 500 rpm). The obtained SIBS/polyurethane kneaded product having a Shore hardness of 72A was extrusion-molded to produce a tube a (an inner diameter of 0.90 mm and an outer diameter of 1.3 mm) and a tube b (an inner diameter of 0.90 mm and an outer diameter of 1.4 mm). 
         [0073]    Each of the produced tubes a and b was cut to have a predetermined length, and, using an SUS core material having an obtuse leading end, an SUS ring (an inner diameter of 0.8 mm, an outer diameter of 1.0 mm, a width and height of 0.5 mm, SUS304) as the reinforcement body was inserted into each hollow portion of the tubes a and b to be disposed at a position located at 1 to 1.5 mm from the end of each tube. 
         [0074]    Through each hollow portion of the tubes a and b disposing the SUS ring, an SUS core material (for tube holding) having an outer diameter of 0.49 mm was inserted. Next, a vicinity of the area where the SUS ring was disposed in each of the tubes a and b was inserted through a shrink tube (manufactured by Raychem, RNF-100-3/64), and using a hot air adhesion apparatus set at 200° C., the shrink tube part was locally heated to melt each of the tubes a and b and to fix the SUS ring. Consequently, the SUS ring was fixed on the inner wall in each of the tubes a and b while maintaining the inner diameter of the end part of each of the tubes a and b to be about 0.9 mm. 
         [0075]    Next, from each end of the tubes a and b that disposed and held the SUS ring as above, an SUS core material having a predetermined outer diameter was inserted so that the end opening would have a desired inner diameter R (0.5/0.6/0.7/0.75/0.8 mm) 
         [0076]    Next, in a local heater (manufactured by Nippon Avionics Co., Ltd., TCW-215), an edge part at each end part of the tubes a and b through which a desired SUS core material was inserted was set in a mold having a radius shape. The end part was heated at 100° C. for 50 seconds and then at 95° C. for 5 seconds to process the leading end into the radius shape. As a result, tubes that had tube inner and outer diameters and end part sizes (predetermined distance L and opening diameter R of the end opening) shown in Table 1 and that constituted the tube device for insertion into a lacrimal passage of the present invention were produced. The cross sectional structure of the end part was substantially the structure as shown in  FIG. 3(   c ) and had the predetermined distance L, the opening diameter R, the groove as the lock means, the radius-shaped end, and the like. 
       Evaluation 
       [0077]    Using each tube of Production Examples 1 to 10 constituting the tube device for insertion into a lacrimal passage of the present invention, a lacrimal endoscope was insert into the hollow portion in the tube to evaluate the pushing out strength from the tube opening, of the SUS ring as the reinforcement body when the tube device for insertion into a lacrimal passage of the present invention was inserted into the lacrimal passage. The evaluation method is as follows. 
         [0078]    As shown in  FIG. 4 , on a horizontal table  40 , a cylinder-shaped push-out jig  41  equipped with coaxial hollow portions ( 42 ,  43 ) having larger and smaller inner diameters was placed, and the end part of each tube of Production Examples 1 to 10 was fit into the hollow portion  42  having a larger inner diameter so that the end of each tube pointed downward in  FIG. 4 . The hollow portion  42  has such an inner diameter as the tube  45  can slide on the basis of the outer diameter of the tube  45 , while the smaller hollow portion  43  has an inner diameter that is substantially the same as the opening diameter R of the end opening  46 . A transitional part from the hollow portion  42  to the hollow portion  43  includes a face parallel to a horizontal surface of the horizontal table  40 . 
         [0079]    Next, into the hollow portion  48  of the tube  45 , a pusher  44  (a model member for a lacrimal endoscope) having an outer diameter of 0.9 mm was inserted, and using a compression tester (manufactured by Shimadzu Corporation, EZ-TEST), the maximum resistance load was determined when the pusher  44  was moved downward (toward the arrow direction) in  FIG. 4 . The measurement was carried out at a movement speed of the pusher  44  of 20 mm/min, an environmental temperature of 23° C., and an environment humidity of 50% RH. The measurement results are shown in Table 1. For the criteria, a tube having a maximum resistance load of 1.0 N or more was regarded as good. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Tube outer 
                   
                 Opening 
                   
               
               
                   
                 diameter/ 
                   
                 diameter 
                 Maximum 
               
               
                   
                 tube inner 
                   
                 R of end 
                 resistance 
               
               
                   
                 diameter 
                 Distance L 
                 opening 
                 load 
               
               
                   
                 [mm/mm] 
                 [mm] 
                 [mm] 
                 [N] 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Production Example 1 
                 1.4/0.9 
                 1.5 
                 0.50 
                 6.6 
               
               
                 Production Example 2 
                 1.4/0.9 
                 1.5 
                 0.60 
                 5.0 
               
               
                 Production Example 3 
                 1.4/0.9 
                 1.5 
                 0.70 
                 5.9 
               
               
                 Production Example 4 
                 1.4/0.9 
                 1.5 
                 0.75 
                 4.8 
               
               
                 Production Example 5 
                 1.4/0.9 
                 1.5 
                 0.80 
                 5.0 
               
               
                 Production Example 6 
                 1.3/0.9 
                 1.5 
                 0.50 
                 4.9 
               
               
                 Production Example 7 
                 1.3/0.9 
                 1.5 
                 0.60 
                 4.6 
               
               
                 Production Example 8 
                 1.3/0.9 
                 1.5 
                 0.70 
                 4.7 
               
               
                 Production Example 9 
                 1.3/0.9 
                 1.5 
                 0.75 
                 3.0 
               
               
                 Production Example 10 
                 1.3/0.9 
                 1.0 
                 0.70 
                 4.8 
               
               
                   
               
             
          
         
       
     
         [0080]      1  Tube device for insertion into a lacrimal passage (nunchaku-type lacrimal passage tube) 
         [0081]      2   a  First bougie 
         [0082]      2   b  Second bougie 
         [0083]      3  Midpoint 
         [0084]      4  Center part 
         [0085]      5   a  First cylinder part 
         [0086]      5   b  Second cylinder part 
         [0087]      6  First end 
         [0088]      7  Slit for insertion of a bougie 
         [0089]      8  Second end 
         [0090]      21  Sperior lacrimal punctum 
         [0091]      22  Inferior lacrimal punctum 
         [0092]      23  Superior lacrimal canaliculus 
         [0093]      24  Inferior lacrimal canaliculus 
         [0094]      25  Common canaliculus 
         [0095]      26  Lacrimal sac 
         [0096]      27  Nasolacrimal duct 
         [0097]      28  Inferior nasal meatus 
         [0098]      31  Tube device for insertion into a lacrimal passage (nunchaku-type lacrimal passage tube) 
         [0099]      32  Reinforcement body 
         [0100]      33  End opening 
         [0101]      34  Slit 
         [0102]      40  Table 
         [0103]      41  Push-out jig 
         [0104]      42  Hollow portion having a larger inner diameter 
         [0105]      43  Hollow portion having a smaller inner diameter 
         [0106]    L Predetermined distance 
         [0107]    R Opening diameter