Corneal Denervation for Treatment of Ocular Pain

Abstract

Methods and apparatus for the treatment of the eye to reduce pain can treat at least an outer region of the tissue so as to denervate nerves extending into the inner region and reduce the pain. For example, the cornea of the eye may comprise an inner region having an epithelial defect, and an outer portion of the cornea can be treated to reduce pain of the epithelial defect. The outer portion of the cornea can be treated to denervate nerves extending from the outer portion to the inner portion. The outer portion can be treated in many ways to denervate the nerve, for example with one or more of heat, cold or a denervating noxious substance such as capsaicin. The denervation of the nerve can be reversible, such that corneal innervation can return following treatment.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]The present application claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 61 / 279,612 filed Oct. 23, 2009; the full disclosure of which is incorporated herein by reference in its entirety.STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0002]NOT APPLICABLEBACKGROUND OF THE INVENTION[0003]People like to see. The eye comprises several tissues that allow a person to see, and these tissues include the cornea, the lens and the retina. The cornea and lens focus light rays on to the retina so as to form an image on the retina. The cornea comprises an outer tissue of the eye that is coupled to air with a tear film, such that a majority of the focusing power of the eye is achieved based on the shape of the cornea. The retina comprises photoreceptors that generate neural signals in response to the light image formed on the retina, and these neural signals are processed and transmi...

AI Technical Summary

Benefits of technology

[0009]Embodiments of the present invention provide systems, methods and apparatus for the treatment of the eye to reduce pain. The pain may originate from an inner region of a tissue such as the cornea, and the treatment can be applied to an outer region of the tissue to denervate nerves extending into the inner region so as to reduce the pain. For example, the cornea of the eye may comprise an inner region having an epithelial defect, for example a central region of the cornea having the epithelial defect. An outer portion of the cornea can be treated so as to reduce pain of the epithelial defect, for example with treatment of an outer region of the cornea peripheral to the central region comprising the defect. The outer portion of the cornea can be treated to denervate nerves extending from the outer portion to the inner portion, and the denervation of the cornea can inhibit pain for a plurality of days such that epithelial healing is substantial and not inhibited. For example, pain can be inhibited for a plurality of days when the epithelium regenerates over a debridement, such that the regeneration of the epithelium over the debridement is substantially uninhibited. The debridement may comprise a debridement of a PRK and regeneration of the epithelium may occur over the PRK ablation without substantial inhibition when the cornea is denervated for a plurality of days. The outer portion can be treated in many ways to denervate the nerve, for example with one or more of heat, cold or a denervating substance such as capsaicin. The outer portion can be treated with a tissue treatment profile, so as to allow the use of an increased amount of treatment to achieve the desired denervation with decreased side effects. The denervation of the nerve can be reversible, such that corneal innervation can return following treatment. For example, the neurons of the nerves may be stunned or desensitized to inhibit pain, or axons of the neurons of the nerves can be cleaved to inhibit pain such that the neurons can regenerate along the nerve sheathes into the inner portion. The outer portion may extend around a perimeter of the inner portion, for example so as to enclose the inner portion with the outer portion, and the outer portion may comprise many shapes such as annular shape, an oval shape or a disc.

Problems solved by technology

However, this innervation of the cornea, may result in substantial pain following surgery in at least some instances.

Many surgeries and therapies of the eye are directed to the treatment of the cornea, and in at least some instances significant pain can occur.

Unfortunately, many of the corneal surgeries result in pain in at least some instances.

However, in at least some instances LASIK can result in complications related to the cutting of the LASIK flap and the LASIK ablation of the exposed stromal bed that extends deeper into the cornea than PRK and LASEK ablations.

Although LASIK can result in complications in at least some instances, many patients prefer the risks of LASIK to the pain of PRK.

For example, although the use of anesthetics such as lidocaine and proparacaine have been proposed, use of these anesthetics in amounts that significantly reduce pain may delay reepithelialization, such that the safely prescribed dosage does not sufficiently reduce pain in at least some instances.

Even with the use of safe amounts of analgesics with PRK and LASEK, patients can still report undesirable pain in at least some instances.

Although the systemic use of opioids such as morphine can reduce pain, the patient may be subjected to side effects of the systemic opioid medication.

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