Vision Update

Cataract surgery has been performed for many years, and new developments have dramatically improved the post-op vision. The lens is a normal structure of the internal part of the eye. We are all born with clear, natural lenses whose function is to focus light onto the retina, and also absorb dangerous wavelengths of light. Over time, this clear lens will become yellow, as its chemical structure changes as a result of years of light absorption, and general oxidative stress on the body.

Early cataract surgery involved simply removing the cloudy lens from the eye. In order to see, the patient then had to wear very thick eye glasses, or a contact lens. As technology advanced, anterior chamber Intraocular lenses(IOL) were developed. These were artificial lenses that were placed in front of the iris to replace the removed lens. They worked very well, but over time the corneas were damaged in most of these patients. These anterior chamber lenses vibrated as a result of aqueous humor (fluid) flow from the back of the eye toward the front. These vibrations over time damaged the endothelial (bottom) layer of the cornea resulting in swollen corneas, and cloudy vision.

The next big change was the development of posterior chamber IOLs. These are placed behind the iris, and thus eliminated the vibrations; sparing the cornea from trauma. Over time, improvements were made to these lenses; smaller, better quality and flexible so they could be implanted with very small suture-less incisions. The basic problem with all of these implants was that unlike the natural lenses of the eye, only distance correction could be achieved. Reading glasses were necessary to see objects up close. This brings us to the next big change in the IOL implants. In an effort to meet the challenges of allowing patients to see distance and near post surgically, multi-focal implants have been developed.

The major new players in this game of multi-focal IOLs include Restore by Alcon, Rezoom by AMO, Array and Tecnis also by AMO and Crystalens by Eyeonics. They are all designed to give the patients a full range of vision from distance to near without the need for any eyeglasses. Each type achieves this goal through different modalities.

The Restore implant is manufactured with multiple small concentric rings, similar to the rings of a dart board. These concentric rings alternate between distance and near vision. Multiple images are projected onto the retina, and the brain must then decide which image it wants to see clearly. Most patients say that they see adequately in the distance, and usually test to about 20/40 vision. Near vision is a bit better in most patients. The primary complaint, aside from less then perfect distance vision is glare at night. Approximately 80% of these patients do not wear any type of glasses post surgically.

The Rezoom lens works in the same manner as the Restore, but has larger concentric rings. This improves the distance vision, but reduces the near vision. 81% of these patients are happy with their reading vision, but 29% still require reading glasses to see at near. With both the Restore and Rezoom implants, Alphagan eye drops are employed to reduce bothersome glare by reducing the pupil size.
The Tecnis IOL is not as yet available, but since it is made as an Aspheric lens and not concentric rings, there is less glare and halos and better reading in dim light. It also permits reading with a greater range. More research will bring to light the true value, and short comings of this implant.

The Crystalens is the first IOL that has an adjustable focusing ability, much like the natural lens of the eye. The implant is placed behind the iris, and has 2 flexible hinges 180 degrees apart from each other. As the ciliary muscle contracts, and relaxes it causes the implant to move forward and back changing the effective power of the lens. This mimics the natural lens’s power change with focusing. It is therefore the first and only Accommodating implant that allows for bothe near and far vision. Substantial adaptation is required, and may take weeks to even months to reach an acceptable level of vision. There is, however a decrease in contract sensitivity ,and some distortion may be induced. Reading glasses may be required for the intermediate distances, and in patients with larger pupils night time vision issues may be present.

Which implant would be best for any given patient will vary, and depend on factors such as expectations, side effects, need for bilateral surgeries (since some implants work best when each eye has one) and cost. Insurance plans do not pay for these specialty implants, and the combined costs with the doctor’s fees may be over $2000.00 per eye.

Finally, some patients have astigmatism following cataract surgery. Since the implants do not correct for this, corneal incisions can be made post surgically to reduce or eliminate that component.. When deciding to have cataract surgery it is important to see an experienced surgeon who is knowledgeable with all these new developments, and can best asses which implant would be best for which patient.

In the United States, contact lens solutions must go through a rigorous approval process performed by the FDA in order to make it to the drug store shelves. This process includes multiple patient clinical tests, pharmacology evaluations, adverse reactions, and careful protocol (instructions to patients) considerations. By the time the solutions reach our medicine cabinets, they are supposed to be safe, affective and easy to use. That all sounds great, except for the one fact that can not be fully evaluated in clinical trials. How will consumers actually use the solutions? Will they do exactly as they are supposed to, or will the cut corners to save time and money?

The sad fact is that consumers are non-compliant, and do not follow the instructions as they are supposed to. This leads to eye irritations, infections, red eyes, and ulcers of the eye.

Back in the old days, patients had to first make their own saline solution by mixing distilled water with a salt tablet. Unfortunately, many individuals did not use distilled water because they had to buy it; instead used tap water filled with bacteria and impurities. This ultimately led to severe problems. Additionally, problems arose with the saline tablets, and were soon removed from the market. The second step was to use a daily cleaner every day, and then rinse the lenses off with the saline solution. Next the lenses had to soak in a disinfecting solution to kill bacteria for a minimum number of hours per day. Frequently, that step fell short, because the individual wanted to wear the lenses prior to fully disinfecting them. Thus they reinserted the contacts before they were fully cleaned. The final step in this adventure was to enzyme the contacts at least once per week to remove protein deposits. That required buying yet another product, and soaking the lenses again. The enzyme pills were quite expensive, and were often not used appropriately. Another issue was that one of the main types of enzyme tablets was made from pig pancrease, and could not be used by any one who was kosher. The bottom line was that despite having a carefully laid out protocol for use, a number of these steps were not followed due to expense, and lack of convenience.

Today’s solutions are much simpler; they are multipurpose, single step and no rub. That simply means that they clean, disinfect and enzyme all at the same time, and the lenses do not have to be rubbed in order to remove surface debris. So the question that begs to be asked is why people still have problems cleaning their contact lenses? The answer is simply that there is still a protocol for use, and consumers tend to look for short cuts. The correct use of these new solutions requires that every day the old solution be discarded, and the case be cleaned. Fresh solution must be used when the contacts are removed for cleaning. Furthermore, patients are instructed to wash their hands prior to handling the lenses. Here lie the following problems:
1) patients don’t always wash their hands. They think that sticking their fingers in their mouths is an acceptable alternative to soap and water.

2) Patients do not discard the solution daily after each use, and the reason is simple. Solution is expensive and reusing it saves money. The efficacy of the solution is dramatically reduced after each use and is contaminated each time it has a lens submerged in it.
3) The contact lens case must be cleaned after each use. When the contacts are removed, the case must be cleaned in order to eliminate the dirt, bacteria and other undesirable agents left behind after use.

The contact lens solution manufacturers go out of their way in order to make a safe, and affective way to clean contact lenses. However, it requires patients to read and follow the instructions, and above all use common sense. That is the one factor that the FDA can not guarantee.

Those of us old enough to remember watching Star Trek on TV can think back to how Dr McCoy used to treat all of his patients. He would wave an instrument over the patients affected area and cure them in seconds. At the time it was purely science fiction, but today it is reality.

A new instrument called the Femtec Laser manufactured in Heidelberg, Germany was designed to perform just such a procedure. The laser focuses on the inside part of the cornea called the Stroma, and makes refractive changes without cutting the outer layers. This avoids surgical complications often found with flaps in LASIK and surface ablation with PRK. No anesthesia is required thus avoiding an additional source of complications, and there is no risk of post surgical infections since there are no wounds to heal. The procedure is completely intrastromal (below the top layer of the cornea) avoiding any contact with the top layer of the cornea.

Presurgical measurements include Keratometry(curves of the cornea), refraction(prescription) and corneal thickness. Then a customized photodisruption pattern is designed for that patient. The laser must use an interface surface to help conduct the laser, and employs a sterile contact lens.

To date the procedure has only been used to correct presbyopia (the over forty years old reading issue) not near or farsighted patients. The results have been fairly good improving patient’s reading ability from about 20/70 (J8) at near to 20/25 (J3-J2). The surgery does not affect the distance vision. The only patient complaint has been haloes and glare which appears to resolve in approximately 1-2 months.

While this new surgical laser is still in the infancy of development, it opens the door to a whole new level of medical treatment.

PRK, is a refractive procedure that reduces, or eliminates the need for eye glasses. It involves removing the Epithelium, or outer layer of the cornea by applying alcohol to the treatment area which weakens the cell’s attachments to each other. This is followed by brushing aside these dead cells exposing the inner layers of the corneal tissue. The most important zone is the stromal layer. Next, an Excimer laser is employed to ablate or vaporize a specific amount of stromal tissue, reshaping the corneal in such a way as to change the refractive power of the eye.

If an eye is nearsighted, then the cornea will be made flatter. If it is farsighted, then the cornea will become steeper. Finally, if there is astigmatism the reshaping will be according to the axis or orientation of that power.

Following the surgery, a bandage contact lens is applied in order to facilitate the regrowth of the epithial tissue. The lens acts to aid the regeneration of cells, and keeps the patient more comfortable during this healing process. The contact must be removed after approximately 3-5 days, but may be left in longer if more healing time is required. Antibiotic eye drops are used to prevent infection, and topical steroids are also used to aid the healing, reduce inflammation and prevent scarring of the cornea. The steroids will be used for at least 4-6 weeks, but may be continued if needed.

One complication that often arises is hazing of the cornea. This may be precipitated by UV light, or a natural process as a byproduct of the increased rate of metabolism. When seen in the healing patient we usually increase the dosage of topical steroids, and closely follow the patient and their intraocular pressure. Most often, this treatment will reduce or eliminate the haze, and the patient’s vision will be fine. If not, frequently the individual will complain of blurry vision, doubling or shadows in their line of sight, and glare or hazy vision.

In cases where the steroids do not effectively eliminate the corneal haze, additional surgery is required. In those cases the laser is re-employed to brush away the outer hazy layers in the hope that when the cornea heals it will be clear. Steroids are used during this second healing period. These treatment modalities most often get the results we want, and the patient has clear corneas. In extreme cases, even the second laser therapy does not eliminate the corneal haze. In those cases if bad enough, a corneal graft may be required. Fortunately, that is extremely rare.

A final note; if an individual experiences corneal or visual haze following PRK, they should immediately return to their surgeon for follows up care. The sooner it is treated the better the results will be with the least amount of discomfort will be experienced.

As another summer season approaches, the issue of sunglasses once again resurfaces. Eye care specialists are frequently asked questions whether sunglasses are necessary, and is there really a difference between the cheap ones and the expensive types? The short answer is YES to both questions.

Light, in general and, sunlight in particular is comprised of many units called wavelengths. Each wavelength has a different level of energy ranging from low energy at the red end of the spectrum, to high energy at the blue end. The ubiquitous UV light we hear so much about is situated next to the blue light, and has the highest and most dangerous amount of energy. It is this wavelength of light that we are most concerned with in regard to damage to the eyes.

When this high energy light enters the eye, it is absorbed into the ocular tissues. This energy then acts as a catalyst for an increase in tissue metabolism, and that is when the trouble begins. Individuals with a genetic predisposition toward Macular Degeneration can expect a dramatic increase in the severity of the condition, and a substantially earlier onset of the disease. Systemic disorders such as Diabetes will also put an individual at risk for this disorder. The natural lens in the eye is comprised of Alpha proteins; which are clear. When exposed to UV light, they undergo a chemical change that transforms them into Beta proteins which are yellow. This process is called cataractogenesis and results in cataract formation.

UV light is also absorbed into the outer layers of the eye, and will result in Pinguecula and Pterygiua. These are the yellowish bumps that form near the cornea, on the white part of the eye and the whitish growth on the cornea, respectively. Both are caused by UV exposure. These anomalies are more often found in individuals living close to the equator who are exposed to much higher amounts of UV light then northerners.

Last, but certainly not least is skin cancer. The tissue around the eyes is very thin and highly vascularized (many blood vessels) making it a perfect location for cancer. Both Basal Cell Carcinoma, and Squamous Cell Carcinoma are the result of overexposure to high amounts of UV light.

The best protection for UV light is GOOD quality sunglasses. Good being defined as one that absorbs all the harmful rays of the sun, and covers both the eyes and surrounding areas. While many cheap sunglasses claim to absorb 100% of UV light, the fact is that these do not give the maximum amount of protection that is possible. They do absorb some, but not enough of what will ultimately damage our eyes. Sunglasses bought on the street for $10 will do nothing except increase exposure to UV light. By that I mean; the tint in the lens will dilate the pupil letting in more of the damaging UV light .

The least expensive of the good quality sunglasses are the Ray Bans. They will afford maximum, efficacious protection. At the other end of the cost spectrum is Maui Jim. There are 7 layers of laminates which filter all bad light out, and give perfectly clear vision. All other sunglasses have fewer layers of laminates, but still will give good quality. Other good brands include but are not limited to Oakley, Revo, Vuarnet, Corning, Serengetti, and too many more to list. All prescription sunglasses should include an ophthalmic quality lens and UV coatings. This will make them good sunglasses as well.

When it comes to sunglasses you do get what you pay for. Years of UV light exposure will cause permanent damage to the eyes, and surrounding tissues. It would be most prudent to put aside economics, in favor of competent protection. In the long run, protection is a wise investment.

Aging is a fact of life and all the trips to the gym, nutritionist, and Dermatologist for Botox, will not prevent your eyes from needing reading glasses when you approach the ripe age of 40. While multifocal eye glass lenses have been around for many years, recent developments in contact lenses now permit comfortable, clear vision in the distance and at near.

In years past, bifocal contact lenses fell short in their goal of clear distance and near vision because of limitations in the technology. Common complaints included poor distance or near vision, glare, fluctuating vision and discomfort. Most people had to sacrifice some visual acuity and comfort in order to avoid reading glasses with the contact lenses. Some eye doctors even fit patients with Monovision, which is the wearing of one distance and one near contact lens. While in concept it seemed acceptable, in clinical practice it most often resulted in visual discomfort in the distance, near or both. In addition, monovision results in the elimination of binocular vision and thus depth perception. In my practice, only approximately 20% of these patients were happy with their vision.

Fortunately, today there are better alternatives. The ability to combine spherical and aspheric curves results in a gradual change in power from the distance to near and a more natural visual experience. In addition, the biggest development in this arena is the ability to correct astigmatism as well as near and farsightedness along with the near prescription. While there are several lenses available, I have found the Ultravue 2000T progressive soft contact lens the be the best. The edge design and availability of parameters makes it great for most patients. Once the eye doctor becomes familiar with the subtleties of the lens, fitting is straight forward and the results are spectacular. There are several Gas Permeable lenses also available and have wonderful results as well. My favorite is the Aspheric Progressive Multifocal from ICL. Fitting is more difficult, but for the right candidate, the results are outstanding.

In short, if you wear contact lenses and are having trouble reading with them in, ask your eye doctor for the new multifocal contact lenses. They will turn back the clock and make contact lens wear great again. We fit well over 95% of our patients over 40 with one of these lenses. We can’t keep your eyes young, but we can keep them seeing well.

Selling water to someone who is thirsty or a coat to a person who is cold is easy. The need is there and the results are immediately positive. There are rarely if ever any negative issues resulting from these obvious situations.

On the other hand, elective cosmetic surgery takes on a whole other set of rules and expectations. The need is NOT there and the expectations may be unrealistic. I have found in my 24 years of practice, that patients do not always listen to everything that I say and often hear only what they want to hear. This can be frustrating since I always go to great lengths to fully explain all the positive and negative aspects of what I am suggesting for treatment.

While we as doctors must always do our best to inform our patients about their treatment options, there still lies a great responsibility with the patients to first listen to us and second to understand themselves realistically. Patients must realize that they can say anything they want, but will have to live with there answers if they are not truthful.

This concept is especially important when dealing with refractive surgery. The potential complications are always explained prior to surgery by all responsible surgeons, but only the patient really knows themself and can answer if they can or want to live with possible side affects.

A case history of this exact point can best explain my point. A 34 year old male came to our office wanting to get rid of his glasses. He told us that he had worn contact lenses, but never liked them and was tired of his eye glasses. A very comprehensive case history was performed and he stated that while his eyes were occasionally dry they never caused any problem for him. Presurgical testing was normal and he underwent PRK. His post operative visits were normal as he saw approximately 20/20 in each eye and his corneas fully healed. Unfortunately, he started coming in 2-3 times per week after the first month stating that he was in excruciating pain and could not live his life this way. He claimed to be putting artificial tears in his eyes every ten minutes, could not work because of the pain, and could barely see the numbers on his blackberry so he was forced to use only land lines to make calls. Please keep in mind that he was always 20/20 with clear corneas upon all his follow ups.

We treated him with steroid eye drops, lubricating gel, bandage contact lenses, wet cell eye glasses, punctal plugs and nothing cured his ” excruciating” pain. He usually told a few jokes to the front office staff on his way in and out and most often smiled despite the ” obvious” pain he was in. Approximately 4 months following his surgery with no remediation of his ” pain” he told us that ever since he was a child the smell of recent grass cuttings by the gardener made him faint. He also disliked shaving because the fumes from the shaving cream made his eye tear and frequently fainted from the pain. In college, the gravy from the mashed potatoes made his eyes turn red and riding in taxi cabs made his vision blurry. Must I go on!!!

We were finally about to lessen the pain by prescribing a “special”‘ eye drop
that was formulated for people that have excruciating pain following PRK. After using it for 3 weeks, he finally admitted it made his eye only about 30-40% better. We expect to see this patient for some time to come to “manage” his pain.

Prior to any procedure it is imperative that we all look honestly at ourselves and ask if we will be better off with that treatment. We must be willing to accept the good with the bad and know that if we have “issues” that injecting something new and different into our lives may make us a little nuttier then we already are. I for one sit at home writing these articles since I know that I do not like change and know that if I complained to my partner in the office about silliness he would close the door on me. I only wish all people were able to be honest with themselves.

The many benefits of LASIK are obvious, vision without glasses, however several side affects must always be considered prior to surgery. One of the most significant, and bothersome is Dry Eyes. Most individuals that undergo the procedure will experience at least some dryness, yet others will be greatly affected.

There has been a great deal of research, and clinical trials performed in an effort to determine the exact cause of the post operative dry eye, but the specific etiology has yet to be determined. One such theory is the Neural Feedback Loop Theory. This theory suggests that the disruption in the corneal nerve fibers; as a result of the flap creation and stoma layer ablation decreases corneal sensitivity. Consequently there is a decreased blink rate leading to an increase in tear film evaporation; thus the eyes become dryer. Clinical trials have shown that this anomaly corrects itself in most, but not all individuals.

The second theory is Goblet Cell Damage. Goblet cells manufacture the mucin layer in tears preventing tear film evaporation. Microkeratome pressure on the cornea during flap creation can damage conjunctiva Goblet cells resulting in an unstable tear mucin layer. An unstable tear mucin layer will cause the tears to evaporate quick and leave the exposed cornea dry.

Next theory is the Change in Corneal Curvature. Changing the corneal curvature is required to alter one’s prescription, but also affects how the tear film overlays the cornea. This change causes an iron stained epithelium, resulting in a very dry eye.

In all cases, osmolarity changes because of the decreased blink rate results in damage to the cornea called Keratopathy. These are the most widely accepted theories on why eyes become dry following LASIK. It should be noted that dryness rates are much lower for PRK because there is no flap creation and many of these factors do not exist with that procedure.

Extensive dry eye testing should be performed prior to LASIK to determine if there is an underlying dry eye condition. Some routine tests that must be done are Tear film evaluation, Schirmer test, Lissamine green staining, tear meniscus height measurement, Phenol red thread testing and Fluorescein staining. While all of these need not be done, some must be performed because the surgeon must know not only if there is a dry eye condition, but how bad it is.

In cases where there is an existing dry eye, preoperative treatment can be done. The use of artificial tears, and in more serious cases, Cyclosporin commonly known as Restasis can be prescribed prior to surgery. In addition, topical steroids can also be employed to help re-mediate the condition.

During the procedure the surgeon can also lessen the dry eye affect by creating the flap with a nasal hinge instead of a superior one. This appears to cause less dryness since only one side of the nerve is severed, while with the superior hinge both sides are cut; this affects corneal sensitivity. Some studies have not supported this theory while others do. The method of flap creation is a much greater factor. The microkeratome definitely creates more damage to the corneal nerves and thus dryer eyes. The better alternative is flap creation with the femtosecond laser commonly called Intralase. Corneal tissue disruption is much less and corneal sensation returns much faster.

Post operative dryness can be dealt with most commonly with artificial tears. The best of which is Celluvisc. Restasis is also often employed, but must be used for at least 3-6 months to be affective. Inserting a collagen plug in the area of the lid where tears drain is also used in extreme cases to retain tear volume in the eyes.

In summation, extreme dry eye patients should carefully consider, and discuss with their surgeon whether LASIK is appropriate, and all refractive surgery patients must be prepared to suffer from dry eyes post operatively for at least several months and perhaps even longer.

An injury to the outer layer of the cornea, the Epithelium, usually heals with in a few days, and results in no long term damage. However, if the Epithelium does not fully reattach to the underlying layer, Bowman’s Layer, then that focal point may be a source of future problems. This is called a Recurrent Corneal Erosion, RCE.

An individual wakes up in the morning in severe pain upon opening their eyes. The affected eye is red and extremely light sensitive. It improves as the day progresses, but takes several days to fully remediate. This event re-occurs every few weeks, or months each time being worse then the time before. Lasting longer, hurting more, and not fully remediating. This is a typical course of action for RCE. Since the Epithelium did not fully re-attach to the Bowman’s layer after the injury, it gets pulled off at the point of injury. During sleep, it gets stuck to the inner layer of the eye lid and tears as a result of REM sleep. These events can be mild or extremely painful resulting in decreased vision, and constant foreign body feelings in the eyes.

Treatment varies substantially from using lubricating ointment at bedtime to keep the cornea from getting stuck to the eye lids during sleep; to Anterior Stromal Puncture. This involves sticking a needle into the cornea at the affected site in the hope of forcing the epithelium to re-heal, thereby attaching to Bowman’s membrane. It has proven to be moderately successful. The newest treatment has come about as a result of refractive surgery.

Photo therapeutic Refractive Keratotomy (PRK) has been used to fully treat this condition. The corneal area is first bathed in alcohol to delaminate the epithelium, or remove the top layer. Then PRK is performed to treat the damaged area. Upon healing, the epithelium is now fully re-attached to Bowman’s membrane.

While there have not been a significant number of these cases as of yet, this treatment has shown dramatic results. Ultimately PRK may prove to be the treatment of choice in severe cases of RCE.