cataract surgery technology

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BY

Francis Clark, MD SENIOR SECTIONAL EDITOR

updated March 12, 2015

Source: http://www.docshop.com/education/vision/eye-diseases/cataracts/technology

Technological advancements have made it possible for patients toundergo cataract surgery in a matter of minutes, and experience life-changing improvements in vision within 24 hours.

Cataracts are a progressive clouding of the crystalline lens, which caneventually lead to blindness. Surgery is the only permanent solution.The American Society of Corrective and Refractive Surgery reports thatcataract surgery is the single most commonly performed surgery in theworld, with approximately three million surgeries taking place each year

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in the United States alone. The sophisticated tools used in moderncataract surgery make it virtually painless and incredibly effective. Infact, most patients who undergo cataract surgery today no longerrequire corrective eye wear.

By using a combination of advanced laser technology, hand-held tools,ultrasound, and custom intraocular lenses (IOLs), I have personallyhelped many patients to regain the independence and confidence thatonly clear vision can provide. Patient education is essential to thesuccess of any surgical procedure, and if you are experiencing cataractsymptoms, or if you have been diagnosed with cataracts and areconsidering surgery, it is important to understand how this technologyis used to maintain your safety and provide the best possible results.

Cataracts and the Evolution of CataractSurgeryThe crystalline lens lies behind the cornea. It helps focus light upon theretina at the back of the eye, which creates electrical impulses that arecarried to the brain and perceived as visual images. The lens isresponsible for approximately one third of the total focusing power ofthe eye. In adults, the crystalline lens is about 10 millimeters indiameter, about the same size as a pencil eraser.

The crystalline lens consists of water and protein. At any point in yourlife - usually after age 40 - the proteins can begin to clump together,causing vision to become clouded. While it is widely accepted thatexcessive ultraviolet light exposure, trauma, and other conditions canspur the development of cataracts, the precise cause of this conditionremains unknown. Having cataracts is often described as being similarto looking out of a dirty window pane. The symptoms are usuallygradual. Patients describe colors as appearing slightly faded in theearliest stages of cataracts. In later stages, vision may be limited to onlybeing able to distinguish between light and dark. In fact, the lens itselfbecomes so clouded that it appears yellowish or milky white from theoutside.

In early stages of cataracts, you can continue to see relatively clearly bymaintaining an up-to-date glasses prescription and using ample light



when reading. However, the condition can only be permanentlycorrected by surgically removing the lens and replacing it with an IOL.The modern approach to cataract surgery treats one eye at a time,usually with about a month in between surgeries.

The first documented cataractsurgery took place in the 5thCentury B.C., and it involveddislodging the lens from itsproper position, allowing it to floatfreely in the vitreous cavity of theeye. Of course, this did nothing torestore focus. It wasn't until thelate 1700s that doctors were ableto actually remove the lens. At this time, the lens had to be removed inone piece, and the incision followed half way around the circumferenceof the cornea. Because fine sutures were still many years away,patients had to be completely immobilized during recovery.

One of the most significant breakthroughs in cataract surgery occurredin 1967, when Dr. Charles Kelman used ultrasound (high-frequencysound waves) to break the lens into pieces that could be removedthrough a smaller incision. Today, the femtosecond laser is often usedto initially break the lens into quadrants. Ultrasound is still used tobreak the lens down further, and the standard device used toadminister the ultrasound doubles as a suction tool that removes thepieces.

Until the late 20th Century, there was no solution for replacing the lens,and patients had to wear especially thick glasses that afforded onlylimited vision following surgery. The first IOL, developed by Dr. HaroldRidley, gained FDA approval in 1981. Ridley treated many Royal AirForce casualties during World War II. At that time, he noticed that whenshards of acrylic plastic from exploded aircraft cockpits became lodgedin a soldier's eye, they did not trigger rejection.

Based on this discovery, he created his first acrylic plastic IOLprototype in 1949. This marked the beginning of an arduous fight to gainacceptance in the medical community that would last more than 30years. Ironically, the IOL is now one of the most commonly administered

The first documentedcataract surgery tookplace in the 5th CenturyB.C.



prostheses used in medicine today - it is virtually unheard of for apatient to undergo cataract surgery without having an IOL placed.

Ridley himself underwent IOL implantation in the 1990s, a time whenadvancements in IOLs were presenting exciting new possibilities thathave made significant improvements in millions of patients' quality oflife.

Monofocal and Premium IOLsIOLs look fundamentally similar to the natural crystalline lens - that is,they consist of a small clear disk. However, IOLs typically have two"arms" on opposing sides of the disk that can be contracted. Once theIOL has been placed, the arms exert outward pressure, keeping thedevice firmly in place within the eye.

The first IOLs were monofocal, correcting only distance vision.Monofocal IOLs are still considered the standard, and are covered bymost insurance plans. Most patients who receive monofocal IOLs willcontinue to use glasses for reading and other tasks requiring closefocus.

Today, there are premium multifocal IOL options that can correct near(for reading), intermediate (computer use, watching television), anddistance vision. There are also several options in accommodating IOLs,which move with the action of eye muscles to achieve focus at multipledistances. If you are a candidate for a multifocal IOL, I would personallyrecommend this lens to any cataract surgery patient wishing to improvefocus at multiple distances, as I find they provide consistently betterresults.

If you have ever had perfect or near-perfect vision without glasses, it isimportant to note that multifocal lenses will not restore that samequality of vision. Nonetheless, they come very close, and can reduce oreliminate a patient's need for glasses at all distances.

Connie now enjoys 20/20 vision, and



Connie is a 60-year-old patient of mine who is experiencing tremendousbenefits after undergoing cataract surgery involving the placement of amultifocal IOL. She had suffered with severe vision problems most ofher life.

"I haven't been able to see properly since I was 5 years old," Conniesaid. "When I was offered an option to help me see normally, I wasready to do it."

Though her vision had been a constant struggle throughout her life, thefinal straw was the development of cataracts.

"My cataracts came on very quickly," Connie said. "When I went to seeDr. Clark, he told me they had developed to a point where it was unsafeto keep driving. Next, his assistant told me about multifocal lenses, and Ithought they were kidding me. Could something like this really be true? Ihad my surgery last June, and the other eye was treated in July. Theprep time and actual procedure is nothing at all to go through. It tookabout 10 minutes in all. I went in for the post-op after my secondsurgery and he told me I could drive, all in a day's time."

Connie now enjoys 20/20 vision, and does not require correctiveeyewear to read or drive.

"I can't believe what I can see - shapes, colors - I'm in an amazingworld," she said.

Toric IOLsWhile multifocal IOLs have made incredible changes in many of mypatients' lives, I'm also a big fan and early adopter of toric IOLs, whichare designed specifically to help patients with astigmatism. Astigmatismoccurs when the cornea is oval shaped instead of spherical, resulting in

does not require corrective eyewear toread or drive



blurred vision, halos, and other aberrations at all distances. Thecorrection that toric IOLs provide is highly accurate, and is capable ofrestoring 20/20 vision for some patients. Many of my patients havebeen ecstatic over the results toric lenses provide.

The Femtosecond LaserBefore the advent of the femtosecond laser in 2001, every step incataract surgery was performed using handheld instruments. In fact,diamond blades are still safely and effectively used for certainapplications in many practices, including my own. Femtosecond (or"femto") lasers are capable of delivering one quadrillion pulses of laserlight per second. In many practices, femto lasers are replacing keratomeblades as the preferred method of creating the corneal flap in LASIK eyesurgery.

Today, the femto laser can be used in four important steps of cataractsurgery:

Corneal incisions: These small incisions placed in the cornea grantaccess to the lens capsule, and serve as the avenue of removal for theclouded crystalline lens. The incisions created using the femto laser areso precise that they require no sutures following surgery.

Capuslotomy: The crystalline lens is contained by a transparentmembrane that completely surrounds the lens. During the capsulotomy,the femto laser is used to remove the front half of the capsule, whileleaving the back half intact, where the IOL is placed.

Breaking down the Clouded Lens: Following the capsulotomy, the femtolaser is used to soften the clouded lens. This prepares the lens forphacoemulsification, the process of breaking the lens into fourquadrants using an ultrasound needle. The same device willsubsequently vacuum the pieces from within the eye through thecorneal incisions.

Limbal Relaxation Incisions (LRI): This optional step is used to correctastigmatism as part of cataract surgery. LRIs can refine the shape of



the astigmatic patient's cornea by "relaxing" the oval-like curvature toachieve a more round shape. While certainly effective in some cases, Ihave personally found that the results of LRIs are not as predictable asthose that toric lenses can provide, and I usually recommend thatpatients consider a premium IOL instead.

After using the femto laser inmore than 200 procedures, I findthat it provides the very bestadvantages when used toperform the capsulotomy and thebreaking down of the lens. Everyophthalmologist has his or herown approach, and I actuallyprefer to use a handheld tool tocreate the corneal incisions. Thefemto laser does not give me theaccuracy that I expect during thiscrucial step, though othersurgeons may feel that theyperform better with a femto laser.

Though cataract surgery is the most common surgical procedureperformed in the world today, it is important to understand that thereare several different approaches, and it always pays to be verydiscriminating when selecting surgeon. Advanced technology canundoubtedly increase your chances of undergoing a successfulprocedure with long-term benefits, but it is equally important to choosea surgeon who has a reputation for delivering excellent results.Technology, after all, is only as effective as the surgeon using it.

Cataract DiagnosisWhile the IOL and the femtosecond laser helped make invaluable stridesin the safety and effectiveness of cataract surgery, other importanttechnology used in this process has remained relatively simple,especially in the diagnostic stage. For instance, if your vision suddenlychanges - a common symptom of cataracts - your optometrist orophthalmologist will probably begin by administering a standard eye test

After using the femto laserin more than 200procedures, I find that itprovides the very bestadvantages when used toperform the capsulotomyand the breaking down ofthe lens



involving an eye chart and a refractor. These tests will measure aperson's visual acuity and give your doctor the precise measurementsneeded to aid in choosing an IOL specifically for you.

The tried-and-true tool for diagnosing cataracts and many otherconditions is the slit lamp, a device that was conceptualized in 1911, andhas continued to evolve over the years to become more accurate. Thebasic concept is that the slit lamp shines a very thin sheet (or "slit") oflight into the eye, illuminating both the posterior and anterior segmentsof the eye. A biomicroscope is then used to magnify this view, allowingyour ophthalmologist to fully analyze the cornea, crystalline lens, iris,conjunctiva, and sclera. This can require the use of special eye drops todilate the pupils in order to maximize visibility.

When viewed using a biomicroscope and slit lamp, a lens affected bycataracts will clearly show clouding. This one-of-a-kind view allowsyour doctor to identify which stage your cataracts have reached, anddetermine an appropriate course of action.

Ensuring the Highest Levels of Safety andthe Best Possible OutcomesIt is estimated that by age 80, most patients develop cataracts.Fortunately, we are living in an era when the onset of cataracts meansanything but an end to your vision. While cataract surgery patients ofthe past were fortunate to be able to achieve marginal vision followingsurgery, today's patients have options that make it possible to achieve20/20 vision.

While no one looks forward to needing cataract surgery, technology hastransformed the experience into something that is virtually painless,takes mere minutes to complete, and can provide incredible benefits forthe rest of our lives. If you have been diagnosed with cataracts, use thisinformation to ask your surgeon plenty of informed questions about thetechnology they use during surgery, and how these innovations areused to ensure the best possible outcomes.

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Source: http://www.docshop.com/education/vision/eye-diseases/cataracts/technology

Author: Francis Clark, MD

Publisher: DocShop

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cataract surgery technology

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