Lenticular refractive surgery of presbyopia, other refractive errors, and cataract retardation

Abstract

Methods for the creation of microspheres treat the clear, intact crystalline lens of the eye with energy pulses, such as from lasers, for the purpose of correcting presbyopia, other refractive errors, and for the retardation and prevention of cataracts. Microsphere formation in non-contiguous patterns or in contiguous volumes works to change the flexure, mass, or shape of the crystalline lens in order to maintain or reestablish the focus of light passing through the ocular lens onto the macular area, and to maintain or reestablish fluid transport within the ocular lens.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The application claims benefit to and is a Continuation-in-Part of U.S. patent application Ser. No. 09 / 897,585 filed Jun. 29, 2001, now abandoned, which is a Continuation of U.S. patent application Ser. No. 09 / 312,518, filed May 14, 1999, now abandoned, which in turn is a Continuation of U.S. patent application Ser. No. 08 / 821,903, filed Mar. 21, 1997, now abandoned, which claims priority to U.S. Provisional Application No. 60 / 036,904, filed Feb. 5, 1997, and U.S. Provisional Application No. 60 / 013,791, filed Mar. 21, 1996.[0002]BACKGROUND[0003]1. Field of Invention[0004]The invention comprises the use of electromagnetic energy to make physical and biochemical alterations to the ocular lens of a mammalian eye for the correction of visual impairments, particularly presbyopia and including other ametropias such as myopia, hyperopia and regular and irregular astigmatism, and the retardation of cataract development.[0005]2. Description of Rel...

AI Technical Summary

Benefits of technology

"The invention is about treating the eye's crystalline lens to correct refractive errors and prevent cataracts. The treatment involves creating small bubbles in the lens (microspheres) using a focused laser. The microspheres can improve visual acuity, reduce the need for glasses or lens implants, and treat other ocular anomalies. The treatment is safe, can be performed as an outpatient procedure, and may even restore natural accommodation. The invention also includes a method for reducing the formation of microspheres that may cause cataracts."

Problems solved by technology

Vision impairment is an exceedingly common problem in humans.

In a vast majority of people needing vision correction the problem is associated with the crystalline lens of the eye.

Two primary problems that occur in the crystalline lens are (a) insufficient flexibility resulting in the inability to correctly focus incoming light and (b) light scattering also resulting in blurred vision.

Astigmatism is a refractive error that results in the eye's inability to focus along a first axis in a plane perpendicular to the line of sight being different from the eye's ability to focus along a second axis in the same plane perpendicular to the first axis, thus producing an image incapable of focusing at any distance.

Of the ametropias, presbyopia stands out as a significant problem because of its prevalence and because it is not corrected as successfully as are myopia and hyperopia with the current treatment methods.

Presbyopia is the focusing error caused by a loss of flexibility of the ocular lens.

Cataracts, however, can occur much earlier as a result of risk factors including disease, trauma, and family history.

However, disulfide bonds are weak chemical bonds, and are subject to modification and breakage with relatively little energy.

Bifocal contact lenses are uncommonly used because, for fitting or for technical reasons, they are optically inferior to bifocal spectacles.

All of these techniques have one or more of the following disadvantages: a) they do not have the continuous range of focusing that natural accommodation provides; b) they are external devices placed on the face or eye; or c) they cut down the amount of light that normally focuses in the eye for any one particular distance, a particular problem because middle-aged individuals actually need more light because of light loss due to the development of light scattering, as described above.

None of these treatments has been widely accepted.

Alternative treatment methods to glasses have been more successful in correcting such refractive errors as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism compared with their limited success in treating presbyopia.

These procedures are of limited utility specifically because they treat the static cornea and do not account for the dynamics of the crystalline lens, which change over time as evidenced by the occurrence of presbyopia.

Another disadvantage of the present photorefractive procedures is that they generally involve fairly invasive surgery.

Above the threshold, ultraviolet or infrared light can cause damage to the eye, including the establishment of cataracts or even tissue destruction.

The size of the initial tissue destruction using these lasers is relatively large, however.

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