Patent Application
20200229978
Embodiments of the present invention relate to the drainage of failed glaucoma drainage devices (GDDs). Example embodiments provide techniques for managing and resolving failed GDDs in this respect and otherwise.
Approximately 15-40% of human glaucoma drainage device (GDD) implants fail to moderate an acceptable intraocular pressure (IOP) over time. For example, the GDD fails to provide sufficient drainage over an extended period of time. Currently, treatment for failed GDDs consists of either laser cyclophotocoagulation or placing a second GDD implant. Laser cyclophotocoagulation us a cyclodestructive procedure that carries the risk of long term inflammation and, if excessively done, can result in phthisis and blindness. Current therapies in cases of failed glaucoma drainage implants include (a) an additional GDD, which takes considerable time in the operating room and may not be effective in the long term, (b) a cyclodestructive procedure which may be effective but carries the risk of long term inflammation and, if excessively done, can result in phthisis and blindness, or (c) needling the bleb over the plate which is generally ineffective in the long term as the needle track generally scars closed within a few weeks.
Therefore, there is a need for improved methods of managing and resolving failed GDDs.
Example embodiments provide techniques for managing and resolving failed GDDs. In example embodiments, these techniques require only a simple office or minor-operating room procedure. In an example embodiment, a GDD has failed due to a fibrous capsule forming about the plate portion of the GDD and preventing the aqueous flowing through the tube of the GDD from the anterior chamber region from leaving the encapsulated bleb area. The failed GDD may be made to function effectively again, in an example embodiment, by placing and/or implanting a stent implant into the wall of the fibrous capsule to allow aqueous to flow through the stent into the subconjunctival space.
According to an aspect of the present invention, a method for treating a failed GDD is provided. In an example embodiment, the method comprises placing a stent implant in the wall of the capsule surrounding a posteriorly placed episcleral plate of the GDD.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The term “or” (also denoted “/”) is used herein in both the alternative and conjunctive sense, unless otherwise indicated. The terms “illustrative” and “exemplary” are used to be examples with no indication of quality level. The terms “generally” and “approximately” refer to within engineering and/or manufacturing limits, unless otherwise indicated. Like numbers refer to like elements throughout.
For example, in an example embodiment, the stent implant 10 allows aqueous which is coming up the tube 25 of the failed GDD 20 to escape a localized bleb area of the plate portion 22 and spread to the adjacent quadrant. In various embodiments, the stent implant 10 is one of a Xen45, Xen63, or ExPress implant or a similar implant. In various embodiments, the length of the stent implant 10 is in the range of 3 to 10 mm. In an example embodiment, the stent implant 10 is an approximately 6 mm long tube. For example, the stent implant 10 may be a hollow cylindrical tube with a wall that defines an external diameter and an inside diameter. In an example embodiment, the stent implant 10 has an external diameter of approximately 150 um such that the stent implant 10 may be injected using a 27-gauge needle. In various embodiments, the stent implant has an external diameter of approximately 100 to 200 um. In an example embodiment, the inside diameter of the tube of the stent implant 10 is in the range of 30 to 100 um. For example, the inside diameter of the tube of the stent implant 10 is 45 um in an example embodiment and 63 um in another example embodiment. In an example embodiment, the stent implant 10 may be made of stainless steel, silicone, Poly(methyl methacrylate) (PMMA), porcine gelatin cross-linked with glutaraldehyde, (Poly Styrene-block-IsoButylene-block-Styrene or SIBS) and/or implant appropriate material.
Sometime later (e.g., a few hours to a few days later), at block 104, the stent implant 10 is injected through the wall 35 of the capsule 30 overlying the episcleral plate (e.g., the plate portion 22) (which is usually placed in the superotemporal quadrant and is generally visible beneath the conjunctiva when the patient looks down). For example, the stent implant 10 may be injected through the wall 35 of the capsule 30 via a short subconjunctival tract from the adjacent superonasal or perhaps inferotemporal quadrant. In an example embodiment, the implant is injected using a 27-gauge dual-beveled needle. This would allow the aqueous which is coming up the tube 25 to escape the localized bleb area of the plate 22 and spread to the adjacent quadrant, at block 106.
Generally, the stent implant 10 may be implanted and/or placed as an office procedure or minor-op room under topical anesthesia (similar to current trabeculectomy bleb needling techniques) and there is no risk of hitting any other structures as the plastic of the plate 22 underlies the encapsulated bleb or fibrous capsule 30. The procedure should only take a few minutes and is expected to provide cost savings from current therapies. Thus, various embodiments provide an improved patient experience and improved treatment results.
These techniques may be used for treating failed GDDs 20 in humans and also in the Veterinary arena for dogs, for example, with failed, encapsulated GDDs 20. This occurs in an even higher percentage of cases in dogs than in humans—approaching 70-100% of cases. This technique has been used in a dog with high intraocular pressure and bleb encapsulation of a GDD 20 using mitomycin-c and a stent implant 10 of the ExPress implant type and at 16 months post-procedure the dog's intraocular pressure remains in the low normal range.
Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2018/046043 | 8/9/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62544367 | Aug 2017 | US |
