Methods and apparatus to identify eye coverings for vision

Abstract

Methods and apparatus can fit coverings to treat eyes. The treated eye may comprise a natural eye, for example an eye treated for refractive error with a contact lens, or an eye having an epithelial defect of the eye, such as an eye ablated with PRK refractive surgery. In many embodiments, the covering can be identified so as to provide improved flow of tear liquid under the covering. The covering can be identified based on an inner corneal curvature and an outer corneal curvature and one or more of a limbus sag height or a conjunctival sag height. The covering may form a chamber when placed on the eye to pump tear liquid under at least a portion of the covering. The covering may comprise an outer portion with rigidity to resist movement on the cornea and an inner portion to contact the cornea and provide an environment for epithelial regeneration. The covering may comprise a material having high oxygen permeability, for example silicone, with a wettable coating disposed on at least an upper surface of the coating.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. application Ser. No. 13 / 885,135, which is the national of International Application No. PCT / US2011 / 057755, filed on Oct. 25, 2011, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61 / 406,504 filed on Oct. 25, 2010, and U.S. Provisional Application No. 61 / 480,231, filed on Apr. 28, 2011, each of which is incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The present invention is generally directed to vision and treatment of the eye to provide improved vision. Although specific reference is made to coverings for vision correction such as the correction of refractive error and also to treatment of eyes having epithelial defects following photorefractive keratectomy, embodiments of the present invention may comprise extended wear contact lenses that can be used to correct vision in many ways such as with one or more of aberration correction, mult...

AI Technical Summary

Benefits of technology

The patent describes a covering used during eye surgeries that has two layers. The inner layer is made of a hydrogel material that adhesively attaches to the cornea (the clear part of the eye) and the outer layer is a skimming tacky surface that attaches to the conjunctiva (the membrane covering the eye). This helps keep the covering in place and prevents it from moving after it is placed on the cornea. Overall, the covering aims to improve the precision and accuracy of the surgery.

Problems solved by technology

Many contact lenses and therapeutic coverings can be left in the eye for less than ideal amounts of time, as the patient removing and replacing the contact lens or therapeutic covering can be somewhat cumbersome and in at least some instances patients may leave the contact lens or therapeutic covering in the eye for amounts of time that can be longer than would be ideal.

Although extended wear lenses can be left in the eye for somewhat longer amounts of time, the amount of time such lenses can be left in the eye can be less than ideal.

When the corneal epithelium heals, the layer of cells forming over the defect can be at least somewhat irregular in at least some instances, such that the vision of the patient can be less than ideal.

As the post-ablation cornea may have a complex shape, many of the prior commercially available lenses may not fit the ablated cornea as well as would be ideal, and in at least some instances fitting of lenses can be time consuming and awkward.

Rigid gas permeable (hereinafter “RGP”) lenses can be uncomfortable for the patient and difficult to fit.

Commercially available contact lenses having a rigid central portion and a soft peripheral skirt can be difficult and / or time consuming to fit to the ablated cornea and may not fit very well in at least some instances.

The ablated cornea may comprise an abrupt change in curvature near the edge of the ablation, and in at least some instances it can be difficult to fit such lenses near the edge of the ablation.

Also, at least some of the commercially available contact lenses may not be suitable for extended wear and may be removed each day, which can be somewhat awkward for a patient and can result in lack of compliance and lenses remaining in the eye longer than would be ideal in at least some instances.

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