Quicker IOL Insertion Damages Corneal Wound Structure Less

According to a study conducted by the Ouchi Eye Clinic and Department of Ophthalmology, Kyoto Prefectural University of Medicine in Kyoto, Japan, slowly inserting IOLs (intraocular lenses) does more damage to the clear corneal wound structure than rapid IOL insertion.

According to the study’s author, “Vertical stretching of the cartridge may lead to extensive stress being exerted on the wound because a cataract surgical incision is usually made transversely.”

The study looked at 80 eyes that underwent phacoemulsification and then implantation of the AcrySof IQ IOL. This was done with a Monarch III screw plunger injector that was attached with a D cartridge. Half the eyes had the IOL inserted rapidly at one revolution per second, while another half underwent slow IOL insertion at one-quarter revolution per second.

Damage to the wound structure was assessed both before and after IOL insertion, as was surgically induced astigmatism, optical coherence tomograohy findings, and the need for corneal hydration used to seal the wound. The slow insertion group’s change in the wound size was “significantly greater” than that of the rapid insertion.

More eyes in the slow insertion group required the need for corneal hydration than they did in the fast insertion group. OCT images also showed more damage to the wound in the slow insertion group than were found in the quick insertion group.

The author of the study says further study should include different types of IOLs, injectors, and different incision designs.

If you would like to find out more information about IOLs, please find an experienced eye doctor in your area through eyes.com today.

Electronic IOL May Be the Future of Cataract Surgery

A computer-controlled, fully programmable intraocular lens (IOL) may soon give cataract surgery patients better vision than any time in their lives. One of the persistent problems in cataract surgery is properly calculating the strength of lens to be used for optimal results. Even experienced ophthalmologists find this to be challenging, and subtle, unknown factors can lead to uncertainty in the final results. In about 1-2% of cataract surgeries, the results are so bad that the patients seek reoperation, and most often this is to have a different lens implanted. Many other patients live with less-than-optimal vision, or have secondary refractive procedures (such as LASIK) to improve the results.

The electronic IOL, known as ELENZA, may eliminate that problem, as well as possible problems that may result from future changes in vision. The new IOL is fully programmable, so it can be adjusted not just immediately after cataract surgery, but at a later date in response to eye injury, glaucoma, or other visual changes. The lens is also self-accommodating, so it does not depend on potentially weakening cilia muscles, and it may even be able to surpass the accommodating ability of the eye’s natural lenses. Theoretically, the lens could be used to give its recipients telescopic vision and super visual clarity at all distances.

You may remember the LED contact lens that was announced last year. In talking about that concept, I discussed the possibility of IOLs that replace the natural lens with an LED-array. Essentially, that would involve replacing the transparent lens with an opaque camera-transmitter array, like having a tiny video camera on one side and a tiny TV on the other.

This new electronic lens is different–it still functions like a lens, only it uses liquid crystal as the refractive medium. The arrangement of liquid crystal can be controlled by small electromagnetic fields, which in this case is used to change the refractive index and therefore the focusing power of the lens. The concept has already been applied to prescription glasses, allowing the wearer to change the focus of the glasses, eliminating the need for bifocals.

One problem with electronic lenses is that they need a power source. In the case of ELENZA, developers project the power will be provided by a microscopic rechargeable lithium-ion battery. Although similar to the batteries used on cochlear implants, they will be even smaller. These batteries will need to be recharged every 3-4 days, though developers estimate their lifespan at 50 years. Chargers, they say, can be placed in pillows or in face masks worn while sleeping.

One advantage of the liquid crystal lenses over the LED display is what happens if your batteries fail. In the liquid crystal lens, it simply reverts to a monofocal lens that gives you good distance vision, suitable for driving a car and most other outdoor tasks. The LCD display, on the other hand, would simply go dark, leaving you blind.

It remains to be seen, though, whether these new implantable lenses could be synced with a computer to give you an implanted display.

The developers of ELENZA hope to begin in vivo studies in the near future, possibly as early as 2013, and hopefully FDA approval as early as 2018.

There are still a number of good IOL options for people seeking cataracts today. To learn more about your IOL options, please contact a local ophthalmologist for a consultation today.

Crystalens Accommodating IOL Performs Best at Far, Intermediate Distances

It appears that the Crystalens® accommodating IOL is effective at providing good vision at far and intermediate distances, and is somewhat less effective for close-up vision.

The conclusion comes from a recent analysis that examined the results of 4,000 Crystalens® cases submitted to a database by 130 eye surgeons, according to Ocular Surgery News.

The Crystalens® is the only FDA-approved intraocular lens that moves backward and forward as your ciliary muscle responds to seeing at different distances. The ciliary muscle around your eye lens accommodates vision at various distances, allowing you to see both close-up and far away. Crystalens® IOLs are supposed to address the shortcomings of monofocal IOLs, namely that these lenses provided sharp vision only at far distances, hence patients still required glasses for reading and other close-up vision needs. Multifocal lenses are designed to let you see at various distances, but do not attempt to retain the natural function of the eye like an accommodating IOL.

Even though near vision is not perfect with Crystalens®, the accommodating IOL still provides excellent vision results for patients following cataract surgery. Out of the 4,000 cases, 87 percent of patients did not need to use eyeglasses for distance vision, while 31 percent of patients did not need glasses for reading.

To learn more about whether an accommodating IOL is right for you, please find an eye doctor in your area.

Treatment Options for Presbyopia

What is Presbyopia?

Presbyopia is the technical name for the vision impairment that comes with age. In young eyes, the lens is flexible, able to change its shape to focus light and help you see things that are both far and near. As the eye ages, however, the lens becomes stiffer, and it is unable to bend enough to focus on close objects.

If you are over 40, you have probably noticed that words on a page have become harder to read. They seem out of focus and blurry. These effects of presbyopia are simply part of the natural aging process, and while they cannot be prevented, they can be treated.

Treatment Options

Getting prescription glasses or contacts is a simple fix for presbyopia. However, if you find glasses or contacts frustrating and inconvenient, surgical treatments are also available.

Presbyopia Laser Vision Correction, also known as LASIK monovision, corrects vision so that one eye focuses on far objects and the other focuses on near objects. Though each eye focuses differently, the brain is able to coordinate the two images so you can clearly see the book on your desk and the mountains out the window beyond you.

Presbyopia lens replacement surgery is another option. In this treatment, your eye’s natural lens is replaced with an artificial one called an intraocular lens (IOL). This lens will be able to flex where your old lens could not and will correct your near vision.

Recently, doctors are experimenting with a third surgical option called presbyopic LASIK or presbyLASIK. In contrast to LASIK monovision, this treatment enables you to have binocular vision, where both eyes can focus both near and far.

Currently, presbyLASIK is not FDA approved to treat presbyopia, but it there is evidence that it could be a viable treatment option. According to one study, 81% of the 178 participants who received presbyLASIK ended up with 20/20 or better binocular vision. However, some of the patients who were in their mid to late 40s lost their near vision again in a few years as they aged. While not the current standard of care, presbyLASIK may become another successful treatment for presbyopia as technology develops and scientists gather more information.

If you suffer from presbyopia and are wondering about treatment options, please contact an experienced ophthalmologist in your area today who can answer your questions during your free consultation.

Will Synchrony Get FDA Approval This Year?

Synchrony is a new version of an accommodating IOL, an advanced intraocular lens that promises to give patients complete freedom from glasses after cataract surgery or refractive lens exchange. Accommodating IOLs differ from multifocal IOLs in that they use the eye’s natural visual system of accommodation to allow people to see at all distances, rather than a combination of optic zones or graduated visual system changes.

Accommodating IOLs are potentially better for patients because they avoid the optical artifacts such as glare and halos, that are common to multifocal IOLs. They also do not require the brain to adapt to selecting from among the variety of images presented by a multifocal IOL, avoiding the rare but serious problem that some people simply cannot adjust to multifocal IOLs.

Currently only one accommodating IOL has been approved by the FDA: Crystalens.

Synchrony differs from Crystalens because it uses a dual system of lenses to achieve accommodation. As the ciliary muscles flex, it changes the configuration of the two lenses, allowing a person to focus on objects at different distances. According to some studies, the amount of correction Synchrony gives is as much as 4 diopters, enough to give about 90% of cataract patients 20/20 or better vision and full functionality at all distances after surgery. In one study, Synchrony also showed that it was free of glare complaints that affected users of the multifocal IOL ReSTOR.

Synchrony has also been shown to give long-term visual stability. In vision tests and reading speeds, patients have been shown to retain visual acuity at one and two-years postoperative. The continued ability of the lens to accommodate has been confirmed with ultrasound biomicroscopy at six months, one year, and two years postoperative. Finally, Synchrony has had a very low rate of capsule opacity (1.9% at three years), and when it does occur, correction with Nd:YAG laser doesn’t interfere with the lens’ ability to accommodate.

Synchrony is now approved for use in Europe, but it has not yet been approved by the FDA. Industry experts expected a decision last year, but so far there has been no decision. We don’t know whether the delay is due to regular FDA slowness or if there is some data we’re not seeing that points to a serious drawback in the system.

To learn more about the most advanced vision correction options, please contact a local ophthalmologist today.

Bausch & Lomb Releases Crystalens iPhone App

Rochester, NY – Bausch & Lomb has recently announced the release of an iPhone application called Crystalens iClear, which will provide educational materials to consumers regarding cataracts and their Crystalens intraocular lens. The iPhone app can be downloaded free of charge.

Users of the Crystalens iClear app will be able to self-evaluate their visual acuity and color vision. There is also a Crystalens iClear “picture hunt” which will provide some entertainment for users. The app also contains a “doc finder” which will help individuals suffering from cataracts find a Crystalens surgeon in their area.

Cataracts are one of the most common age-related vision issues affecting Americans today. The condition results from a clouding of your eye’s lens which prevents light from properly focusing on the retina. If left untreated, cataracts can eventually lead to blindness. Cataract surgery is required to correct the condition and prevent additional vision loss.

During cataract surgery, your ophthalmologist will remove your eye’s damaged natural lens and replace it with an artificial intraocular lens (IOL). Crystalens is an IOL manufactured by Bausch & Lomb. It is currently the only accommodating IOL which has received FDA approval.

Other IOL options are either monofocal lenses, which enable you to achieve clear vision at only one distance, or multifocal lenses, which enable you to achieve clear vision at a variety of distances, often eliminating the need for reading glasses after cataract surgery.

However, Crystalens has provided cataract surgery patients with yet another option – an accommodating IOL. These lenses enable your ciliary muscle to relax while you focus on distant objects, providing the lens with a deeper curature. When you are looking at near objects, the Crystalens lens enables your ciliary muscle to contract, making the lens flatter. This ability to expand and contract is called accommodation, and helps your lens focus light more precisely on the retina.

Night Driving Performance: Advantage ICLs over PRK

One of the more common complaints people have after refractive surgeries like LASIK and PRK is that their night vision is affected. Most importantly, night driving may be impaired by the vision effects of halos, star bursts, and other visual artifacts that occur when the pupil widens and light passes through the edge of the treatment zone or beyond. Some say that phakic IOLs, sometimes called implantable contact lenses, may be a good alternative for people concerned about these effects. The relative performance of these two treatment options were compared in a study published in the Journal of Refractive Surgery’s May 2010 issue.

In the study, 20 individuals who had Visian ICLs (Implantable Collamer Lenses) and  22 who had PRK were monitored in night driving simulators pre- and post-operatively to see if they had significant differences in their recognition and reaction time for road signs and hazards. In conditions without glare, ICL patients had significantly better improvement in recognizing road and business signs and pedestrian hazards. In conditions with glare, ICL patients had significantly better reaction times for pedestrian hazards. According to the published results, people with the ICLs had a greater than half-second reaction time improvement postoperatively.

The main question I have about the study is the decision to use PRK as a comparison, rather than LASIK.

To learn more about your vision correction options and which one is right for you, please contact a local ophthalmologist.

IOL Choice and Gender Differences

Multifocal intraocular lenses, or multifocal IOLs, are used to correct presbyopia in adults as well as cataracts. However, according to Dr. Magda Rau’s observations over 12 years of study show that there are significant gender differences in patients’ preferences and outcomes with multifocal IOLs.

Dr. Rau has found that women adjust more quickly and have fewer complaints after IOL surgery. She also found that women tend to prefer better near-vision correction, while men tend to prefer distance vision. However, Dr. Rau also says that younger women who work outside the home have shifted their preference to distance vision, while older female cataract patients with more traditional, stay-at-home gender roles stick to near vision.

While Dr. Rau speculates that these gender differences in IOL preference stem from women prioritizing reading and other near-vision activities, while men tend to desire a wide, distance view of the world. She has also noticed that women tend to hold reading materials closer than men, since women have shorter arms, on average, and tend to read with elbows bend whereas men tend to read with arms extended.

To learn more about intraocular lenses and treatment for cataracts and presbyopia in your area, please visit our directory to find a qualified ophthalmologist near you.

Risk of Laser Capsulotomy Higher in Multifocal IOL

Aurora, CO – A study found that implantation of multifocal IOLs corresponds with a higher incidence of laser capsulotomy than it does with a similar monofocal lens. According to the author of the study, laser capsulotomy occurs three times more with implantation of multifocal IOLs than it does with implantation of monofocal IOLs.

The poor vision quality occurs from an interaction between the multifocal optics and the posterior capsule opacification. It does not seem to induce more posterior capsule opacification than the monofocal IOL.

Analysis

The study compared posterior capsulotomy rates for patients that were implanted with the AcrySof SN60WF one-piece monofocal IOL, or the AcrySof ReSTOR SN60D3 or SA60D3 multifocal IOL. Both these later multifocal IOLs have been discontinued in the US and replaced with another aspheric model. The study included 142 eyes implanted with the multifocal IOL, and 275 eyes implanted with the monofocal lens.

The results showed that 22 eyes in the multifocal IOL group (15.49%) and 16 eyes (5.82%) in the monofocal group underwent capsulotomy. In each case, the capsulotomy occurred less than a year post-op.

According to the study’s author, “What we hypothesize is that multifocal IOLs already have a decrease in contrast sensitivity and you get an additive effect when you have posterior capsule opacification. So, patients are more likely to become more symptomatic with minimal opacification with a ReSTOR or a multifocal lens than they would with the same degree of opacification if it’s not a multifocal lens.”

Laser capsulotomy results in blurred reading vision and poor overall vision quality.

If you would like to learn more about this or other side effects of laser vision correction, please visit eyes.com to find an experienced eye doctor in your area.

Celebrating World Animal Month: Multifocal Visual Systems in Animal Eyes

GOLDEN, CO–Every year, October 4 is recognized as World Animal Day, a tradition begun in 1931 by a gathering of ecologists in Italy, selected because it is the feast day of St. Francis of Assisi, the patron saint of animals. World Animal Day is celebrated around the world, but a smaller number of people celebrate World Animal Month, dedicated to recognizing that humanity must change in its attitude toward animals to ensure an equitable and ongoing relationship with the animals that share our world. Here at Eyes.com we are doing our part by celebrating the incredible diversity of visual systems in the animal kingdom.

One of the remarkable characteristics of many animal eyes is that they have multifocal lenses. Multifocal lenses are not uniform in focus like the natural human lens, but is more similar to those utilized by some intraocular lenses like ReZoom and ReSTOR. Multifocal lenses focus light from different distances and of different colors on the retina. This is a very good solution for allowing animals to have superior distance, close-up, and color vision outside the limits of accommodation of the lens.

For some animals, distance vision is very important, such as ruminants adapted to living on the plains, such as antelopes. Being able to focus on distant objects allows antelopes to better spot predators approaching, and multifocal lenses improve this ability with zones dedicated to near and far vision, similar to the ReZoom. For other animals, color vision is the key advantage of multifocal lenses. The cornea and lens of our eye have a prismatic effect: they bend light of different colors at different degrees, making a different focal length for lights of different colors, so seeing a clear color image can be difficult. In a relatively large eye, like the human eye, there is enough depth of focus that the different focal lengths can be overcome and we can see clearly in color without special adaptation. But in small eyes the poorly focused light of different colors creates too much blur, preventing a clear image. Multifocal lenses overcome this problem by having zones dedicated to bending each color of light differently so that they all focus on the retina.

One problem with multifocal lenses is that under bright light conditions, the pupil contracts and may shut out some of the refractive zones. The designers of the ReZoom lens overcame this problem by having zones dedicated to near vision and distance vision in both the outer and inner portion of the lens. Most animals, however, overcome this problem with slit-type pupils. When these pupils contract, they reduce the amount of light entering the eye, but ensure that the light entering the eye still passes through all the necessary refractive zones.

Some animals, though, have multifocal optical systems with round pupils, most notably the common house mouse. The house mouse has a rare visual system controlled by a “switching” pupil that remains fully open in even bright light conditions, then contracts quickly from to being almost fully closed in a very narrow range of light conditions. This controls the specific focal zones that light passes through, preventing blur and helping the mouse have quality vision under all light conditions.

Looking at the visual systems of other animals reminds us how complicated visual systems are and all the factors that have to be balanced to ensure you have clear vision under a number of light and use conditions. When you are considering refractive surgery, cataract surgery, or other procedures that alter your visual system, your ophthalmologist should talk to you about achieving the best possible balance for your eyes and how you use them.