Surgery – Devices transferring fluids from within one area of body to...
Reexamination Certificate
1999-02-24
2001-05-29
Weiss, John G. (Department: 3761)
Surgery
Devices transferring fluids from within one area of body to...
C604S294000, C606S107000, C606S198000
Reexamination Certificate
active
06238363
ABSTRACT:
TECHNICAL BACKGROUND
This invention relates to an apparatus for intubation of the lacrimal duct (lacrimal drainage pathway) for treatments of lacrimal duct obstruction and dry eye.
As shown in
FIG. 1
, the lacrimal gland
14
secrete tears which drain into the inferior nasal meatus
18
via the lacrimal duct after moistening the ocular surface
17
having the cornea
15
and conjunctiva
16
. The lacrimal duct consists of the upper punctum
1
, lower punctum
2
, vertical portion of the upper punctum
3
, vertical portion of the lower punctum
4
, boundary portion between the upper vertical and horizontal portions
5
, boundary portion between the lower vertical and horizontal portions
6
, upper horizontal portion
7
, lower horizontal portion
8
, common canaliculus
9
, internal common punctum
10
, lacrimal sac
11
, nasolacrimal duct
12
. The lower end
13
of the nasolacrimal duct
12
opens into the inferior nasal meatus
18
.
In patients with dry eye having hypofunction of the lacrimal gland and deficiency of tears, tears which are very important for the eye immediately drain away via the lacrimal duct.
To suppress the tear drainage, occlusion of the upper punctum
1
and/or lower punctum
2
using electric cautery is performed. Occlusion using a punctal plug (mentioned later) inserted into the upper punctum
1
and lower punctum
2
is also performed.
By blocking the upper punctum
1
and lower punctum
2
like this, tears are accumulated in the conjunctival sac and dry eye symptoms disappear in many cases.
Dry eye symptoms include asthenopia, waking irritation, grittiness, foreign body sensation, scratchiness, soreness, difficulty to open the eyes in an air conditioned room, injection, burning and so on.
Recently, aggravation of dry eye symptoms by spending time in front of a monitor has become a problem. This is due to the fact that evaporation of tears is accelerated in individuals with tear deficiency by decreased frequency of blinking which is induced by looking at a monitor.
Artificial tears are added as eyedrops in another treatment of dry eye. But the ingredients of artificial tears are far from those of natural tears. It is best for eye to be wet with natural tears. Therefore, the treatment of punctal occlusion is superior.
Unlike artificial tears, tears contain lysozyme, lactoferrin, immunoglobulin, and so on which protect eye from bacteria and viruses. And some artificial tears contain a preservative which is harmful to the eye.
The roles of tears include an optical role wherein tears make smooth the microscopically irregular surface of the cornea
15
to improve eyesight, a role of lubricant wherein tears act as lubricant and the movements of eyelids become smooth, and other roles. Artificial tears can not be expected to play these various roles.
Therefore, occlusion of the upper punctum punctum
1
and/or lower punctum
2
to wet the eye with natural tears is superior. But punctal occlusion by argon laser may induce epiphora postoperatively. In such a case, punctal and canalicular surgery are needed to reconstruct canaliculi and puncta.
The use of a punctal plug is superior because a punctal plug can be removed easily in such cases.
In 1975 Freeman reported a punctal plug as shown in
FIG. 2
for the treatment of dry eye. For example, see Freeman, J M: The punctum plug: evaluation of a new treatment for the dry eye. Trans Am Acad Ophthalmol Otolaryngol 79: op 874-879, 1975.
The punctal plug shown in
FIG. 2
consists of the tip
21
, shaft
22
, brim
23
and there is a hole
24
in the center of brim
23
. The hole
24
is continuous with a tubular lumen
25
of shaft
22
and the lumen
26
with a closed end
27
of the tip
21
. The punctal plug shown in
FIG. 2
measures 2.8 mm in total length, 1.5~2.0 mm in diameter of brim, 0.7 mm in height of brim, 1.5 mm in length of shaft and 0.7 mm in diameter of shaft.
The punctal plug in
FIG. 2
is used as shown in FIG.
3
. The punctal plug is inserted into puncta
1
,
2
and vertical portion of canaliculus
3
,
4
, and the total length of the puncta
1
,
2
and vertical portions of canaliculus
3
,
4
is 2.5 mm on the average. Therefore, the total length 2.8 mm of the punctal plug is too long. Consequently, the brim
23
touches the cornea
28
and not infrequently induces a foreign body sensation.
FIG. 4
shows a punctal plug of the FCI company. This is also used for the treatment of dry eye in Japan. For example see, Junzo Hirano & Miki Hirano: Experience of the treatment for a case with Stevens-Johnson syndrome with severe keratoconus, Japanese Review of Clinical Ophthalmology 91:41-44, 1997.
The punctal plug in
FIG. 4
is a miniaturized one. This punctal plug measures 1.7 mm in total length, 1.5 mm in diameter of brim
23
, and is miniaturized as a whole. It measures 0.1 mm in thickness of brim
23
which inclines 20° against the shaft
22
.
The Punctal plug in
FIG. 4
also consists of tip
21
, shaft
22
and brim
23
, and as in the punctal plug as shown in
FIG. 2
, hole
24
is continuous with the lumen
25
with closed end
27
of shaft
25
.
In use, the tip
29
of the punctal plug is pushed into the lacrimal duct to or near the boundary portion
5
,
6
between the vertical portion
3
,
4
and horizontal portion
7
,
8
of canaliculus, by a metal probe which is inserted through the hole
24
to the closed end
27
.
FIG. 5
shows a punctal plug with a tapered shaft form. This plug is also miniaturized and consists of the tip
21
, shaft
22
and brim
23
. As in the punctal plug shown in
FIG. 2
, the hole
24
is continuous with lumen
25
with a closed end
27
of the shaft
22
. The shaft
22
becomes gradually smaller as it tapers toward the brim
23
.
Although corneal disorder is hardly induced by such a miniature punctal plug, the miniature punctal plug can migrate into the horizontal portion of canaliculus
7
,
8
as shown in
FIG. 6
, and as shown in
FIG. 7
into the lacrimal sac
11
and nasolacrimal duct
12
, resulting in canaliculitis and dacryocystitis which sometimes need surgical intervention (For example, see Rumelt S et al: silicone punctal plug migration resulting in dacryocystitis and canaliculitis. Cornea 16: 377-399, 1997.).
Let us do a little more explanation in this respect. For dry eye, punctal plugs are inserted into puncta and left in place as shown in FIG.
3
. But the punctal plug is apt to move because of the shallow insertion.
And as shown in
FIG. 6
,
7
, the punctal plug can migrate into the lacrimal duct.
Furthermore, as shown in
FIG. 2
, FIG.
4
and
FIG. 5
, the edges of the tip
29
of either punctal plug are angular and sometimes stimulate canaliculus, resulting in the growth of pyogenic granuloma (For example, see Rapoza P A & Ruddat M S: Pyogenic granuloma as a complication of silicone punctal plug. Am J Ophthalmol 113: 454-455, 1992).
Stimulation by the tip
29
of punctal plug sometimes induces canalicular obstruction between the vertical portion
3
,
4
and horizontal portion of canaliculus (For example, see Fayet B et al: Stenoses canaliculaires compliquant la pose de bouchouns lacrimaux. Incidence et mecanismus, J Fr Ophthalmol 15: 25-33, 1992.)
Granuloma sometimes pushes the punctal plug out of the puncta.
On the other hand, FIGS.
8
~
10
show various nunchaku style silicone tubings which are invented by this inventor. For example, see U.S. Pat. No. 2,539,325.
The apparatus for intubation of the lacrimal duct shown in FIGS.
8
~
10
consists of smaller soft tube
40
,
41
and larger tube
42
,
43
of a certain length, and the ends
47
,
48
of the larger tube are closed.
Smaller tube
40
,
41
extends between two larger tubes
42
,
43
, and the middle point
44
of the smaller tube
40
,
41
is marked.
The smaller soft tube
40
,
41
is connected with the larger tubes
42
,
43
. Two millimeter end lengths of the smaller tube
40
,
41
are inserted into the larger tubes
42
,
43
for connection. Therefore, the jointed portions
45
,
46
are 2 mm in length. The tips
47
,
48
of the larger tubes are sharp pointed and closed.
Cho David J.
Lorusso & Loud
MLC Limited Company
Weiss John G.
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