The present invention relates generally to systems and methods for treating eye disorders, and more particularly, to systems and methods that treat extracellular matrices of the eye to address disorders, such as scleral progressive myopia.
Pathological extracellular matrices (ECM) of the eye are implicated in keratoconus (KCN) and scleral progressive myopia due to tissue structural instabilities. For example, these disorders are prevalent in 0.05% and 30% of Asian populations, respectively, while being prevalent in 0.05% and 2% of U.S./European populations, respectively. Cross-linking of corneal tissue provides treatment for KCN, but treatments of the posterior and equatorial sclera to treat scleral progressive myopia are far more invasive to implement, often requiring 360 degree peritomies and rectus muscle/Tenon's manipulation in young patients when implanting scleral buckles, for example.
Equatorial and posterior scleral (fibrillar) thinning are the initial signs of scleral progressive myopia due mainly to a loss of collagen tissue resulting from biochemical imbalances/pathologies (such as inhibition of lysyl oxidsase activity). Studies report 35% reduction in collagen type I mRNA indicating collagen production is decreased at the same time that ECM degradation increases. Similarly, glycosaminoglycans (GAGs, hence proteoglycans) have been shown to be diminished with a net negative change in the ECM, although DNA synthesis appears unaltered. Bio-mechanical thinning is accompanied by significantly increased scleral creep (>200%). Altered integrin expression, and reduced fibroblast to myofibroblast differentiation are also noted. In all, the confluence of these conditions results in scleral elongation under physiologic intraocular pressure (IOP) but with reduced collagen content (˜7%).
Aspects of the present invention provide systems and methods that improve the health of the extracellular matrices (ECM) by modulation of transforming growth factor beta (TGF-β) isoforms, which are cytokines known to be involved in cell growth inhibition, embryogenesis, differentiation, wound healing and apoptosis in part. Aspects of the present invention remodel scleral and/or corneal ECM via growth factor activation in combination with additional treatments such as cross-linking and exogenous cytokine augmented repair of ECM that are the primary determinant of follow-on high myopia and/or corneal ectasia.
According to one example embodiment, a system for conducting a corrective scleral procedure for an eye, includes at least one insert configured to be positioned at a selected area of scleral tissue (e.g., equatorial sclera, posterior sclera, etc.). The at least one insert includes at least one channel and at least one illumination guide. A cross-linking agent source is coupled to the at least one channel. An illumination source is coupled to the at least one illumination guide. The at least one insert delivers the cross-linking agent to the selected area of scleral tissue via the at least one channel. The at least one insert delivers photo-activating light from the illumination source to the selected area of scleral tissue via the at least one illumination guide after the cross-linking agent has been delivered. The photo-activating light includes one or more doses necessary for generating cross-linking activity in the scleral tissue by activating the cross-linking agent and for activating TGF-β isoforms for improving health of extracellular matrices in the selected area of scleral tissue.
According to another example embodiment, a method for a corrective scleral procedure includes positioning at least one insert at a selected area of scleral tissue. The at least one insert includes at least one channel and at least one illumination guide. A cross-linking agent source is coupled to the at least one channel. An illumination source being coupled to the at least one illumination guide. The method also includes delivering the cross-linking agent to the selected area of scleral tissue via the at least one channel. The method additionally includes delivering photo-activating light from the illumination source to the selected area of scleral tissue after the cross-linking agent has been delivered. The photo-activating light includes one or more doses necessary for generating cross-linking activity in the scleral tissue by activating the cross-linking agent and for activating TGF-β isoforms to improve health of extracellular matrices in the selected area of scleral tissue.
According to yet another example embodiment, a system for conducting a corrective procedure for an eye includes a contact lens structure, which includes at least one channel and at least one illumination fiber. The contact lens is configured for application over at least a cornea of the eye. A cross-linking agent source is coupled to the at least one channel. An illumination source is coupled to the at least one illumination fiber. The contact lens structure delivers the cross-linking agent to a selected area of the eye via the at least one channel. The contact lens structure delivers photo-activating light from the illumination source to the selected area of the eye via the illumination fiber after the cross-linking agent has been delivered. The photo-activating light including one or more doses necessary for generating cross-linking activity in the scleral tissue by activating the cross-linking agent and for activating TGF-β isoforms to improve health of extracellular matrices in the selected area of the eye.
Additional aspects of the invention will be apparent to those of ordinary skill in the art in view of the detailed description of various embodiments, which is made with reference to the drawings, a brief description of which is provided below.
While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit of the invention.
Aspects of the present invention provide systems and methods that improve the health of extracellular matrices (ECM) by modulation of transforming growth factor beta (TGF-β) isoforms, which are cytokines known to be involved in cell growth inhibition, embryogenesis, differentiation, wound healing and apoptosis in part. Aspects of the present invention remodel scleral and/or corneal ECM via growth factor activation in combination with additional treatments such as cross-linking and exogenous cytokine augmented repair of the ECM, which are determinants of follow-on high myopia and/or corneal ectasia.
Roles of reactive oxygen species (ROS)-mediated activation of latent TGF-β isoforms in the ECM by photo-bio-modulation (i.e., use of low irradiance of near-infrared (NIR)/visible (VIS) wavelengths at less than approximately 10 J/cm2 dosage) have been investigated for dental wound healing applications and result in improved, denser, and better organized collagen formation. Aspects of the present invention significantly enhance these methods for application to the cornea and sclera (equatorial and posterior in particular) through the choice of wavelength and dosage in addition to simultaneous spatial deposition with oxygen. The wavelength and dosage may depend on the thickness of the scleral tissue, as well as safety considerations (e.g., at a wavelength of 365 nm, the dosage may be limited to 32 J/cm2). The results of these enhanced methods disclosed herein are effective, retina-safe, and efficient for cross-linking and exogenous cytokine/growth factor (e.g., epidermal growth factor (EGF))/anti-oxidant (e.g., PRDX6)-mediated augmented repair. In one aspect, the NIR/VIS light is applied to increase activated TGF-β for collagen type I ECM deposition via low doses. In another aspect, NIR/VIS light is applied to activate eosin-mediated collagen cross-linking Cross-linking via application of Riboflavin and photoactivating ultraviolet A (UVA) light can be optionally included with this method. Although cross-linking activity may be a goal, embodiments provide treatments that not only halt the progression of scleral elongation/corneal ectasia but that also normalize the collagen ECM for long term benefits.
Correspondingly,
The quad band inserts 200 can be applied with an introducer bag or standard retinal instruments (e.g., retractor, etc.). Each quad band insert 200 may also include a visible micro-LED which can be seen from the anterior side by the surgeon to facilitate the proper positioning of the quad band insert 200. The use of a small endoscopic camera may also be employed during application of the quad band inserts 200.
Flow channels 210 are embedded in the quad band inserts 200 for receiving oxygen, photosensitizers, saline, exogenous materials, and vacuum suction, etc., from their respective sources. The elements may be uniformly delivered from the flow channels 210 via micro-fluidic mechanisms 212. For example, the quad band inserts 200 may include micro-fluidic sponges that allow the elements to be delivered through micro-perforations. (In some embodiments, the equatorial insert 100 described above may also employ micro-fluidic mechanisms.)
Like the equatorial insert 100, the quad band inserts 200 may also include light-guide(s)/introducer(s) 220 (disposed along the structure of the quad band inserts 200) to receive and deliver illumination (e.g., NIR, VIS, and/or UVA light) from an illumination source to the scleral tissue. Accordingly, in an example application, the quad band inserts 200 may provide illumination with greater than approximately 80% uniformity and at greater than approximately 50 mW/cm2 at a ROC of less than approximately 12 mm.
Aspects of the equatorial inserts 100 and the quad band inserts 200 may be formed from any combination of appropriate flexible materials, available for example from Biomedical Structures (Warwick, R.I.), Secant Medical, Inc. (Perkasie, Pa.), TissueGen, Inc. (Dallas, Tex.). In addition, the equatorial inserts 100 and the quad band inserts 200 may include single face emitting light-guides, available for example from Nanocomp Oy Ltd (Lehmo, Finland). The light-guides may be configured to limit illumination to targeted tissue/structures. In some embodiments, masks or other shielding techniques may be employed to prevent illumination from reaching other more sensitive tissue/structures.
The equatorial insert 100 and the quad band inserts 200 provide an effective system for flushing, soaking, and oxygenating the equatorial and posterior sclera according to a corrective scleral procedure, e.g., to address scleral progressive myopia. The system also provides NIR, VIS, and/or UVA light, to activate TGF-β isoforms in addition to activating cross-linking agents.
Aspects of the present invention are not limited to application to the equatorial and posterior sclera. For example,
Aspects of the present invention may employ a monitoring system that may be employed to monitor the systems and methods described herein, e.g., measure the effect of the methods. Additionally, the systems may include a controller to control aspects of the operation of the systems. The controller may be communicatively coupled to the monitoring system to process the images, data, etc., from the monitoring system and to determine any necessary response to such feedback.
While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the invention. It is also contemplated that additional embodiments according to aspects of the present invention may combine any number of features from any of the embodiments described herein.
This application claims priority to U.S. Provisional Patent Application No. 61/792,463, filed Mar. 15, 2013, the contents of which are incorporated entirely herein by reference.
Number | Date | Country | |
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61792463 | Mar 2013 | US |