Cataract Surgery Los Angeles

with Intra-Ocular Lens ("IOL") Implantation

(also pertains to "Clear Lens Replacement")

by Dr. David A. Wallace, M.D.
Los Angeles Cataract Surgery Specialist

View simulating cataracts: Fuzzy, murky, and cloudy. ©2002 Robert Meyers Studio

Cataract surgery is a miracle of modern medicine that has helped many Los Angeles cataract patients regain their sight. Dr. David Wallace is a highly skilled cataract surgery specialist. In the paragraphs below he describes how a cataract affects vision and how lens implant surgery is performed.

A cataract is a clouding of the eye's natural lens, with consequent blurring and degradation of vision. Most commonly, cataracts affect the senior population, though the condition may occasionally affect much younger people, and sometimes children.

Cataracts would be leading cause of blindness in the developed world, if not treated. Until the advent of laser vision correction, cataract surgery was the most common operation performed by eye doctors.

Cataract Surgery and its refractive companion, Clear Lens Replacement, describe procedures to remove the eye's natural lens and replace it with an Intra-Ocular Lens ("IOL," or lens implant). This surgery can correct extremely wide ranges of refractive error. Modern cataract surgery alone is not able to correct astigmatism as accurately as LASIK, but can be performed in combination with LASIK or other procedures for astigmatism reduction.  The most common procedure other than laser treatment for astigmatism is called limbal relaxing incision or LRI. 

Cataract:  Yellowed, turbid, light-scattering change in crystalline lens ©2002 Robert Meyers Studio

Modern cataract surgery has become perhaps one of the safest and most predictably beneficial operations performed today. Typically, it is done on an outpatient basis under local or eye drop anesthesia. In the hands of a capable surgeon, the process should take 15 minutes or less to complete. Vision improvement can be recognized as soon as the surgery is completed, and many patients are able to see a sharp 20/20 the day after their care.

Small incision cataract surgery is done through an internally self-sealing incision about 1/8" (3 mm) wide. The lens tissue (which becomes yellowed and clouded as a consequence of cataract development; see illustration at right) is removed by breaking it into microscopic fragments with an ultrasonic instrument called a phacoemulsifier ("phaco" for short). The nuclear tissue is enveloped within a clear membrane called the lens capsule (also referred to as the "capsular bag"); modern surgery intends to preserve the delicate capsule while removing the nuclear contents within. The IOL is then implanted within the capsular bag. The lens capsule is connected to the ciliary muscle (focusing muscles of the eye) by tiny fibers called zonules, thus providing support in a fashion analogous to a hammock. 

There are now numerous popular styles of lens implant.  The model and optical power or prescription of the implant can be custom-selected for each patient based on measurements made before surgery.  With proper measurements and excellent technique in the hands of an experienced surgeon, the desired optical target can be achieved in an overwhelming majority of cases such that glasses would not be required after surgery.

After Cataract Removal & IOL Implant ©2002 Robert Meyers Studio

Until about 2003, lens implants were all single-focus or fixed-focus lenses. So, even if distance vision could be rendered optimal with such care, reading glasses would still be necessary. It is self-evident that any patient who may contemplate cataract-style surgery would want to enjoy clear distance vision, clear reading vision, and clarity everywhere in between, without need to use glasses.

Significant challenges exist in designing a lens implant that is able to adjust for close focus as well as the natural lens in a young adult. Adjustable-focus lenses offer a surgical option for treatment of presbyopia.  

In May, '03 the FDA approved a new design of implant called the CrystaLens™. This implant is able to accommodate or adjust for close focus, and thus represents a true revolution in design and performance of intraocular lenses. The CrystaLens is not a "perfect" replacement for the eye's natural lens; at best it can accommodate to a limited extent (about 1.75 diopters), slightly less than the accommodative capacity of the young adult eye (about 4.0 diopters). However, it can certainly allow improved distance, intermediate and near vision compared to previous monofocal lens designs.  Reading glasses may still be necessary for sustained reading of small print. For further information about the CrystaLens and other surgical methods of restoring reading vision, please browse the Reading Recovery section of our site.

Crystalens: Position of the implanted lens is slightly forward in the eye when viewing
a near object, and further back in the eye when viewing a distant object.
© Eyeonics, Inc.