| 摘要 |
An ophthalmic sizing device comprises a sizing tube (15a; b) or set of such sizing tubes (15a, 15b) for use in determining a correct size of a bypass tube (10) required in lacrimal surgery, each sizing tube having a flanged end (21; 22) at one end of a longitudinal length of tubing, the remaining end of the tubing distal to the flanged end having a series of ruled markings (23) longitudinally along and towards the flange end (21; 22). When used, a set of sizing tubes includes tubes having at least two relatively different (i) absolute longitudinal lengths (18a, 18a + 18b) of tubing; and/or (ii) diameter flanges. The device can alternatively can be in the form of a dilator (27) having a sizing section. The use of such sizing devices allows the length of an ophthalmic bypass tube (10) to be determined that leaves the tip (14a) of the bypass tube (10), when in situ, to protrude an optimally desired distance beyond the outer (lateral) nasal wall and into the nasal cavity (7) of each particular patient, whilst remaining clear of the midline septum (9). Such a proud projection of bypass tubing (10) helps prevent the bypass tube (10) from being blocked after its permanent insertion. |
