Your Comprehensive Eye Exam

Your Comprehensive Eye Exam

Being able to see clearly is important to all of us. But it is also something we have a tendency to take for granted until we notice changes in our vision. The point of the yearly comprehensive exam is to monitor your eyes before any problems arise, and address any concerns that could affect your vision later. Here is what to expect at your next comprehensive eye exam.

An eye exam involves an external examination of your eyes followed by a series of tests designed to evaluate your vision and check for eye diseases. Each test evaluates a different aspect of your vision and includes specific tests for visual acuity, pupil function, muscle function, visual fields, eye pressure and viewing the back of the eye through a dilated pupil.
cross section of eye - eye exam
External Exam
The external examination consists of inspecting the eyelids, surrounding tissues and the eyeball including the sclera (white part of the eye), iris and cornea.

Visual Acuity & Fields
Visual acuity is your eye’s ability to detect fine details and see an in-focus image at a certain distance. A Snellen chart and a phoropter are used. The standard definition of normal visual acuity is 20/20. The term 20/20 comes from even sized objects that can be seen by a “person of normal vision” atvisual acuity eye exam the specified distance. For example, if a person can see at a distance of 20 feet an object that normally can be seen at 20 feet, then they have 20/20 vision. If they can see at 20 feet what a normal person can see at 40 feet, then they have 20/40 vision. For the visual acuity test each eye is tested separately to gauge your side or peripheral vision.

Pupil Functionpupil function eye exam
An examination of the pupil begins with inspecting your pupils for equal size, regular shape, reaction to light, and direct and consensual reaction (meaning the pupil of one eye constricts when the other eye is exposed to light).

Eye Muscle Function
Eye movement is assessed two ways. First by having you move your eye quickly to a target at the far right, left, top and bottom. Then by slow tracking which uses the ‘follow my finger’ test, which tests all the muscles that move your eye.

tonometer eye examEye Pressure Measurement
Intraocular pressure, or IOP, is measured using a tonometer to determine the fluid pressure inside your eye. This test provides information regarding your potential for glaucoma.

Viewing the Back of the Eyedilated eye - eye exam
Increasing the size of your pupil with eye drops (known as dilating your eyes) allows the doctor to have a larger view of the back of your eye, including the retina, as demonstrated by this diagram. This is very important for diagnosis and tracking of macular degeneration and diabetic retinopathy.

Eye Structureslit lamp eye exam
A special, high-powered microscope, called a slit-lamp, is used to view the structures of your eye clearly and in detail, enabling early diagnosis of a variety of eye conditions such as cataracts, presbyopia and corneal injury.

Taking care of your eyes, especially as you become older, is very important. Changes in vision may be gradual, or fast, but in both cases, early diagnosis is key to successful treatment and retaining your vision. It is suggested that individuals 40 and over have a comprehensive eye exam every one to two years. Exceptions would be if you have diabetes, in which case you should see your eye doctor yearly; or there is a family history of eye diseases such as glaucoma, macular degeneration, or corneal diseases, which may require more frequent visits to your eye doctor. If you have any degree of sudden vision loss, eye pain, or significant irritation, contact your eye doctor immediately.

4/23/15

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

6 Ways Women Can Stop Vision Loss

Women account for 53% of the world’s population. However, 2/3 of the blind and visually impaired people in the world are women. While 80% of these women are in developing countries, women in developed countries like the US are still more likely to face vision loss than men.
women can stop vision loss

Why are women more prone to eye disease than men?

Women are the caregivers in families, taking care of the health of family members over themselves. In addition, with many having jobs outside the home, they don’t feel they have the time to go to the doctor until something major happens, especially related to vision.

Women live longer than men are at greater risk for age-related eye diseases such as age-related macular degeneration (AMD), diabetic retinopathy, glaucoma and cataracts.

Women are more likely to develop several autoimmune diseases that can affect their eyes including, multiple sclerosis, lupus, rheumatoid arthritis and Sj?gren’s syndrome.

75% of new breast cancer diagnosed each year is estrogen-sensitive. A common part of estrogen-sensitive breast cancer treatment includes the prescription of tamoxifen. More studies are being done, but cataracts due to tamoxifen have been identified in about 10% of the patients taking the drug.

What can women do to lessen their chances for eye disease?

Know your family history as genetics play and important role in your eye health, so know what eye diseases run in your family. Let your eye doctor know so he can look for early warning signs that can help prevent of lessen the conditions in you.

Get routine comprehensive, dilated eye exams starting at the age of 40, to create a baseline for your doctor to work from. After that you can go every 2-4 years until the age of 60. At 60+ have a compressive, dilated exam every two years if you are symptom-free and low risk.

Eat healthy and exercise. It is important to maintain a healthy weight to reduce the risk of some eye diseases. Eating fresh fruits and vegetables is also important as they can contain carotenoids an some antioxidants that appear to help with vision retention. It should also be noted that in many studies, supplements did not show the same beneficial effects as whole foods.

Stop smoking! You not only increase your risk for cancer and heart disease, but smoking is the only thing besides advancing age that has been proven to be directly related to AMD.

Avoid ultraviolet light by wearing sunglasses (with wide-brimmed hats) and indoor glasses with UV protection. While everyone knows the sun is a source of UV light, so are electronic screens such as your TV, computer, tablet or smartphone. Prescription glasses and readers can have a clear UV coating put on them that will not distort your color vision. If you don’t need vision correction, there is eyewear with no correction that is coated to protect your eyes to avoid dry eye and retinal damage.

Use cosmetics and contacts safely. Always wash your hands first. Throw away old makeup and lens solutions. Do not share cosmetics or apply while driving. Make sure to clean your lenses thoroughly before putting them in your eyes.

Because women are relied upon to take care of the family, vision loss that can impact that responsibility can be devastating to the entire family. And later in life, when they may have outlived a spouse, the isolation and depression can destroy their quality of life as they try to cope on their own.

Reach out to women you know and remind them to take an active part in their own healthcare. Especially with regards to their vision, when women are at a higher risk of vision loss than men.

4/7/15


Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Medical Research Funding Needs Individual Donors

The Need for Medical Research Funding

About 1.75 million U.S. residents currently have advanced age-related macular degeneration with associated vision loss, with that number expected to grow to almost 3 million by the year 2020.

About 8.4 million individuals worldwide are blind from primary open-angle glaucoma, with that number expected to grow to almost 11 million by the year 2020.

About 22 million Americans have cataracts affecting their vision, with that number expected to grow to more than 30 million by the year 2020.

The economic impact of this increase of people with vision loss will be tremendous.  But right now scientist are working on ways to treat and eventually cure many eye diseases.  The only problem is the funding necessary to support this sight-saving research. Here is a look at the decline of medical research funding in the US and what you can do to help.
medical research funding

3/17/15


 

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Selecting Your Best Vision Correction Options

Today technology has evolved to a point where patients either with normal refractive errors such as nearsightedness, farsightedness, astigmatism and presbyopia or those with ocular diseases that require specialized vision correction options such as those with keratoconus all have spectacular alternatives to maximize their visual performance. With the multitude of choices available, how does an individual make the decision which to take advantage of? Well let’s begin by saying that the input from your eye care professional is critically important. You need to be properly educated not only about the various options that are applicable to your individual situation but about the advantages and disadvantages of these options.eye glass fitting vision correction options

Normal Refractive Error Options

Let’s begin by discussing vision correction options available to those with normal refractive errors. Basically stated, these individuals have the ability to utilize spectacles, contact lenses or if they are appropriate candidates, consider the refractive surgical alternatives.

Glasses
Today spectacle lens technology has evolved to the point where exceptional vision quality can be achieved with lens designs that allow for the selection of almost any frame size or shape. Thin lens technologies have enabled those with high prescription powers to not only see amazingly well, but to wear glasses that remain quite thin and attractive even with some of the most extreme prescription powers. Your eye care professional can discuss the various lens material options that best work for your situation. New high index materials are not only thin but are very light weight. A concern for some however can be the significantly higher costs associated with these lens materials. For those who need multifocals, new digital and free form progressive addition lenses (PALs) have dramatically increased the success rates associated with adaptation to PALs.

Contact Lenses
Contact lens alternatives for those with normal refractive errors have also dramatically developed technologically over the past years. Today virtually every patient with normal refractive error is a candidate to wear contact lenses. Developments such as astigmatic contacts, multifocal contacts, and hybrid (rigid center / soft periphery) contact lens designs along with the introduction and the tremendous growth in the use of single use daily disposable contacts has made one form or another of contact lenses something to consider for almost everyone. Today’s CLs are healthier, more comfortable and provide better vision than ever before. CLs have the advantage of superior peripheral vision, more natural vision “sensation” and obvious advantages for demanding physical activities. With contemporary contact lens materials and designs we have successfully addressed issues that limited many people in the past such as concerns of poor comfort due to dryness, contact lens vision instability and contact lens induced complications associated with over-wear and over-use of lenses. Your eye doctor should always present contact lens options to you regardless if you ask or not. So often patients think that they can’t wear contacts, so it does become the responsibility of your doctor to inform and educate you about CL alternatives.
contact lens vision correction options
Combination of Glasses and Contact Lenses
So how do you decide if you should be a contact lens wearer or a glasses wearer? Who said you have to? The two vision correction options are not mutually exclusive; in fact they are quite synergistic. All contact lens wearers should have an excellent pair of glasses to use. Contacts may be more cosmetically acceptable to many, they may be much better for various physical activities such as sports, however there are many times when glasses may be preferred such as at the end of a long day of contact lens wear, first thing in the morning before inserting your CLs, or on those days you just don’t want to bother with your CLs or simply prefer the look of your glasses for some situations. Today even the person who predominantly wears glasses can consider part time contact lens wear. Single use daily disposable (DD) CLs are the perfect option for such an individual. DD CLs are now even available in astigmatism and multifocal designs!

Refractive Surgery
Refractive surgery is also developing and is more effective and safer today than ever before. An experienced and skilled eye doctor is in the best position to consult with you in order to determine if you are an excellent candidate for the various refractive surgical options available. Again, having refractive surgery does not always eliminate your need for glasses or contact lenses. Although that would be the optimal outcome, many patients still use glasses and contact lenses after having refractive surgery. Typically the glasses and contact lenses are far less strong and are used significantly less often than prior to surgery. Some patients need them due to complications of surgery while others need them when outcomes did not perfectly correct vision and of course refractive surgery does not stop eyes from changing over the years, so many patients who had successful refractive surgery may experience vision changes years after surgery that require the use of glasses, contacts or both.

Irregular Refractive Error Options

Specialty Contact Lenses
Next let’s talk about choices in vision correction for those with irregular corneas and other conditions that are termed “medically necessary” vision correction cases. Individuals with irregular corneas such as those with keratoconus or post LASIK or other refractive surgery induced ectasias often require contact lenses that in essence “mask” the irregularity of the cornea. In the past this equated with the fitting of rigid corneal contact lenses, however today many other alternatives can be considered such as the fitting of scleral large diameter gas permeable contacts, hybrid CLs designed for irregular corneas and even combination systems of soft lenses with corneal gas permeable lenses (called “tandem” or “piggyback” CL systems). These CL alternatives provide advantages such as improved comfort, improved eye health response by limiting contact lens to cornea bearing, and improved contact lens positioning and stability which positively impacts visual performance.

Combination of Contact Lenses With Glasses
It should be clearly stated that spectacle lens alternatives still can have a significant role in the treatment of individuals with irregular corneas. Often glasses can be prescribed that provide adequate vision if even for part time and limited applications. While less severe cases may perform quite well with glasses as their primary modality of vision correction. Your doctor may need to modify the power of your glasses prescription in order for you to adapt to wearing glasses, however even a modified prescription power can frequently allow for some degree of visual function and allow for the ability to reduce the number of contact lens wearing hours during the day.

Surgical Procedures
Application of certain surgical and medical procedures such as intra-corneal ring segments (Intacs TM) or corneal collagen cross linking (CXL) for corneal irregularity can often help these patients in various ways and may allow for perhaps a less complex contact lens application or easier adaptation and improved function with glasses. Management of these diseases and conditions is quite complex and requires the expertise of doctors with extensive experience. Your doctor, if appropriately skilled and experienced can provide you with all of the required information and education so that you both can jointly decide on the best vision correction options for you.

In conclusion, patients today have numerous options for their vision correction. These options each have advantages and disadvantages but in most cases can be utilized synergistically. The role that your eye care professional plays in consultation and education of the vision correction alternatives applicable to you cannot be over stated. Vision is a precious gift and you should experience the highest quality of visual performance possible.

2/26/15


Barry Eiden OD, FAAOS. Barry Eiden, OD, FAAO
Medical Director, North Suburban Vision Consultants, Ltd.
NSCV Blog: www.nsvc.com/blog
President and Founder, International Keratoconus Academy of Eye Care Professionals

Understanding and Treating Corneal Scratches and Abrasions

Corneal Scratches and Abrasions

Call it a scratch, an abrasion or erosion; no matter how you describe it or what the cause, damage to the cornea most always causes pain.

So what exactly is the cornea and why can even a small scratch hurt so much? The cornea is the clear dome at the very the front of the eye. Its primary job is to surface the tears and with them, focus light into the eye. It then passes through the crystalline lens and on to the retina where it is transformed into electrical impulses that are ultimately transformed by the brain into sight.

Because vision is so essential for survival and the cornea so critical to seeing, it is among the most richly innervated and exquisitely sensitive of all tissues. Even the smallest piece of dust that finds its way into the eye and touches the cornea can cause significant discomfort, irritation and copious tearing in an attempt to wash it away. A healthy cornea is transparent and consists of several layers that give the cornea its smooth dome like shape. The outermost layer, the epithelium, is designed to break away to protect the delicate deeper layers if scratched or abraded.
cornea layers - corneal scratches and abrasions

Looking For the Cause

The most common causes of corneal scratches are accidents. Tiny infant fingers and fingernails are a common cause of abrasions in young parents, tree branches are a frequent source of abrasions in hikers and lovers of the outdoors, and makeup brushes are a typical cause in women. Scratches can also be caused by foreign objects that get into the eye and then work their way on to the inside of the upper lid – causing a scratch that occurs with each blink. That’s why its important to carefully investigate the cause of every corneal scratch.

A scratch pr abrasion usually produces near instantaneous pain and tearing as the eye tries to wash away the irritant. Light sensitivity soon follows and can be so intense that the eye can involuntarily shut. This is actually nature’s way of “patching” the eye to facilitate healing.

To confirm you have a scratched cornea, a doctor or other health care professional will often apply a wetted fluorescein strip to the inside lid or white of the eye. Fluorescein is a dye that glows bright green when exposed to black light. The dye is absorbed by damaged areas, clearly showing the area if the scratch or abrasion.

Getting On the Mend

The good news is that most scratches will rapidly heal on their own, especially smaller and more superficial ones. The confocal microscope, a high tech device that provides extreme magnification views of living tissue, has been used to observe corneal healing in real time. The video captures are breathtaking as individual corneal cells can be seen literally stretching over each other to mend and seal the corneal surface.

If an abrasion is larger or deeper it may require patching to help healing. The traditional eye patch applied with tape to keep the eye shut has largely been replaced by the bandage contact lens which is far more comfortable and allows some vision and easier observation during follow up examination. It also allows medication to be applied if needed. Because there is a risk of infection whenever the outer boundaries of the body are breached, topical antibiotics are often used as a precaution in treating scratches of the cornea and ocular surface.

Most commonly the cornea heals quickly and completely, but not always. In rare cases damaged areas of the cornea may not heal fully, leaving the outer layers of the cornea susceptible to coming off again for no apparent reason. This is thought to be more common after scratches caused by organic material such as a tree branch. Called recurrent corneal erosions, they often occur during sleep waking the person with a sudden sharp pain and excessive tearing. There are a variety of treatments for recurrent corneal erosion.

Conclusion

Most people will sooner or later experience a scratched cornea. Most scratches will be minor and will resolve with minimal treatment. However, some can be serious and have significant consequences. The best way to avoid problems is to be aware that they can occur and take measures to protect the eyes in situations where the risk of eye trauma is higher. This includes: wearing safety glasses while working with power tools, or sports where eye contact is possible. This includes cycling and sport shooting.

Be aware of active infants with little fingers that seem to have a magnetic attraction of their parents eyes. If you use eye makeup, leave enough time to properly apply it without rushing and potentially scratching your cornea in the process.

Finally, if you experience a scratched cornea and the pain doesn’t rapidly abate, see an eyecare specialist. Urgent care centers are fine for most things, but when it comes to the eyes finding a knowledgeable eye care professional is wise.

2/10/15

AArthur B. Epstein, OD, FAAO
co-founder of Phoenix Eye Care
and the Dry Eye Center of Arizona
Fellow of the American Academy of Optometry
American Board of Certification in Medical Optometry
Chief Medical Editor of Optometric Physician™

Understanding Ocular Herpes

Ocular herpes is caused by the type 1 herpes simplex virus, and is a common, recurrent viral infection affecting the eyes. This type of herpes virus can cause inflammation and scarring of the cornea. Herpes of the eye can be transmitted through close contact with an infected person whose virus is active.
ocular herpes
The National Eye Institute (NEI) says an estimated 400,000 Americans have experienced some form of ocular herpes, with close to 50,000 new and recurring cases occurring each year, ranging from a simple infection to a condition that can possibly cause blindness. There are several forms of eye herpes:

  • Herpes keratitis is the most common form of eye herpes and is a viral corneal infection. Ocular herpes in this form generally affects only the top layer which is called the epithelium, of the cornea, and usually heals without scarring.
  • Stromal keratitis occurs when the infection goes deeper into the layers of the cornea. This can lead to scarring, loss of vision and, occasionally, blindness. Although the condition is rare, the NEI reports that stromal keratitis is the leading cause of corneal scarring that subsequently causes blindness in the United States.
  • Iridocyclitis is a serious form of eye herpes where the iris and surrounding tissues inside the eye become inflamed, causing severe sensitivity to light, blurred vision, pain and redness.

Treatment for eye herpes depends on where the infection is located in the eye – in the corneal epithelium, corneal stroma, or iris, etc.

Some ocular herpes treatments could aggravate the outbreak and therefore should be considered on a case-by-case basis.

If the corneal infection is only superficial, it can normally be alleviated by using antiviral eye drops or ointments, or oral antiviral pills over a two to three week period. In some patients, both drops/ointments and pills are used. Steroid drops can help decrease inflammation and prevent corneal scarring when the infection appears deeper in the corneal layers. Steroid drops are almost always used in conjunction with and simultaneously with antiviral drops. For those relatively few eyes where, despite the best of treatment, the virus has caused vision-impairing scars, corneal transplantation surgery is often a highly successful solution.

Although eye herpes has no cure, treatment can help control outbreaks. Studies are underway to determine better methods for managing the disease.

1/27/15


Susan DeRemerSusan DeRemer
Vice President of Development
Discovery Eye Foundation

Imagination and KC

Imagination is a powerful thing. It can take you to great heights or take you into a downward spiral. I know. It’s done both to me. Thirty years ago I was diagnosed with keratoconus (KC) in both eyes. Then, I wasn’t sure what it was all about and my imagination took over spinning out all kinds of scenarios. Was I going to go totally blind? Would I be able to continue working? Would I still be able to drive? Was I scared then? Yes!

Imagination and KC
Over the years I’ve been through many of the ups and downs KC’ers face – uncomfortable lenses, vision changes, cornea abrasions, the piggyback system and pushing the limits of lens wear-time. The KC in my left eye deteriorated and a cornea transplant was the only option left. In the early 80s, my surgeon performed the transplant while listening to tracks from Michael Jackson’s album, Thriller. The transplant gave me the vision I needed stay in the workforce. I travelled for business, spent hours in front of a computer, belonged to a bowling league, walked on a glacier, climbed a fraction of the Great Wall, shed inhibitions in an acting class, answered crisis hotline calls, took “artsy” out-of-focus photos and gazed into the innocent, perfect eyes of my grandsons.

Everything wasn’t all rosy. There were highs and lows throughout those years because my other eye with KC kept going downhill before it stabilized. I still encountered all those difficulties KC contact lens wearers face when lenses are critical to functioning. But, I never let KC take over my life. Sometimes after I tried something new, I had to concede that vision challenges lessened the enjoyment and I labeled it “not for me” and moved on to something else.
Juror 1389 - Imagination and KC
I’m retired now and am sixty-nine. Now, my transplant cornea has filamentary keratitis and chronic dry eye so wearing a RGP lens is out. I’m at 20/200 in that eye but am still thankful for the good vision years. My other eye fluctuates between 20/50-60 with a RGP lens but comfortable wear-time is down to 3-4 hrs. Old anxieties have resurfaced. I live alone. Is driving my golf cart over? What am I going to do? “Explore your options,” my inner voiced commanded. So, I tackled the worst-case scenario first – what if I can’t wear any kind of lenses even scleral? I researched tools and services available to those with all kinds of vision problems. I visited the Southeastern Guide Dog Campus in Palmetto, FL in the US and learned all about Seeing Eye guide dogs. They’re amazing! My doctor started conversations about scleral lenses but that got put on hold.

Why? I was in the middle of a huge project. My imagination was taking me to great heights in this project. I was at the critical stages of writing a novel. It required my full attention. Fitting sessions and lens adjustment time would derail my momentum or even force me to take a detour off my route to my destination of having my novel catalogued in Books in Print. I didn’t need high functional vision to imagine scenes and characters. What I did need was a soft contact to act as a bandage to alleviate the pain of filamentary keratitis in my left eye. The soft lens worked! I published Juror 1389 – Dorsie Raines Renninger! Did vision challenges hinder me? Yes, at times. But, I pushed on and worked with what vision I had. I adapted – I bumped up MS Word font size way beyond 200%. I set an alarm clock to signal a stop after two hours of screen time. I removed my RGP lens and took eye-soothing breaks. I used various colors of paper for my research subjects so I could find notes easily. Thera® Tears were constant buddies. And, I asked for help! I formed a 1389 project team with good vision. They read. They highlighted mistakes to correct. I’m 100% certain any reader of Juror 1389 would never guess the author had vision challenges. Why would they? It’s of no importance to them. They’re only interested in what my imagination produced – a good story, a good read.

My message to all KCers is this – KC is a life altering condition not a life threatening condition. Don’t let keratoconus threaten your life or how you live it. Make these two words your mantra – Accept and Adapt. Make peace with what vision you have or will have. Accept it. Move on. Move towards being the best you can be in spite how out-of-focus the world looks to you. Life is not perfectly focused for anyone! Adapt – seek out tools and invent ways to change how you do things. Discover “what works” for you. Learn to ask for help. And remember, imagination is powerful. It has crisp, clear vision. It’s always there. Use it to visualize anything you want or what kind of life you want to live.

1/22/15


Gerry Tickler - Imagination and KCGerry Trickle
Author, web content and greeting card verse writer
She is now working on her next novel – learn more at: www.gttrickle.com

Cataract Surgery and Keratoconus

1/8/15

The eye works like a camera, specifically a digital camera. There is the front lens of the camera (cornea), the aperture (iris), the film (retina), and a cable to take the image to the brain (optic nerve). This “camera” also has an additional lens – the natural crystalline lens, which lies behind iris. This natural lens is flexible when we are young, allowing us to focus at distance then instantaneously up close. Around age 40-45, this natural lens starts to stiffen, necessitating the need for reading glasses for most people. This stiffening is the beginning of the aging process that eventually leads to formation of a cataract. We refer to the lens as a cataract when it becomes sufficiently cloudy to affect ones quality of vision.cataract surgery and keratoconus-Cataract diagram In general, cataract surgery is one of the safest and most successful of all surgeries performed. The basics of cataract surgery in eyes with keratoconus is very similar to non-keratoconic eyes.

Keratoconus (KC) affects this “camera” by causing the front lens (cornea) to bulge. This causes the optics to be distorted. In many cases, this can be corrected for with hard contact lenses (CL) or spectacles; in other cases a corneal transplant may be necessary. When it comes time for cataract surgery in the setting of KC, there are several factors that need to be considered.

Corneal Stability
The first thing to be considered is the stability of your cornea. In general, KC progresses more in your late teens to early twenties, and then stabilizes with age. A very exciting treatment for KC is collagen crosslinking. This treatment is meant to stiffen the cornea to prevent instability that is inherent to KC. This treatment promises to stop the progression of KC at a young age. Fortunately, with age, the cornea naturally crosslinks and stiffens, therefore when it comes time for cataract surgery, there is little chance of the progression of KC. Your doctor needs to choose the appropriate intraocular lens (IOL) to refocus your eye after surgery. Two of the most important factors in IOL selection are the length of your eye and the shape of your cornea. Long term CL wear can mold your cornea. It is important to assure that you stay out of your CLs long enough for your cornea to reach its natural shape. Depending on how long you have worn your CLs, it may take several months for the cornea to stabilize. This time can be challenging as your vision will be suboptimal (because you can’t wear CLs), and will be changing (as your cornea reaches its natural shape). When your cornea does stabilize, it is important to determine whether the topography (shape) is regular or irregular. This “regularity” is also known as astigmatism. If the astigmatism is regular, light is focused as a line – generally, this distortion can be fixed with glasses. However, if the astigmatism is irregular, light cannot be focused with glasses, and hard CLs are needed to provide optimal focusing. If you have had a corneal transplant, I generally recommend all your sutures to be removed to allow your new cornea to reach its natural shape.

IOL Selection
The second thing to be considered is the type of IOL. IOLs allow your doctor to refocus the optics of your eye after surgery. In many cases, the correct choice of IOL may decrease your dependence on glasses or CLs. There are several factors that are important when considering the correct IOL for a keratoconic patient. The amount and regularity of your astigmatism plays a very significant role in IOL selection. In general, there are four types of IOLs available in the US – monofocal, toric, pseudo-accomodating, and multifocal. In general I do not recommend multifocal IOLs in patients with KC. These IOLs allow for spectacle independence by spitting the light energy for distance and near, however, with an aberrated cornea (which is what happens in KC), these IOLs do not fare well. If there is a low amount of regular astigmatism or irregular astigmatism, your best bet is a monofocal IOL. This is the “standard” IOL that is covered by your health insurance. If you have higher amounts of astigmatism that your doctor determines is mostly regular, you may benefit from a toric (astigmatism-correcting) IOL. These IOLs can significant improve your uncorrected vision and really decrease your dependence on glasses. It is important to realize that monofocal and toric IOLs only correct vision at one distance. With a monofocal IOL you still can wear a CL to fine-tune your vision, however, with a toric IOL, in general you will need glasses for any residual error. There is a pseudo-accomodating toric IOL available, and this may be a good option if you are trying to decrease your dependence on glasses and correct some of your astigmatism. These IOLs are relatively new to the US market.

If You Had A Corneal Transplant
In the setting of a corneal transplant many of the same factors need to be considered – stability of the graft, choice of IOL, etc. In addition, the health of the graft has to be judged. Prior to cataract surgery in my patients with corneal transplants, I make sure to remove all of their sutures and give the cornea time to stabilize (just as if they were a CTL wearer). If you are a CL wearer, the same rule of being out of the TL until the topography is stable applies. The health of a transplant needs to be established prior to undergoing cataract surgery. The cornea has five main layers to it –cataract surgery and keratoconus-corneal structure the back layer (inside) is called the endothelium. This layer is responsible for “pumping” fluid out of the cornea, allowing it to stay clear. In all eyes there is a loss of endothelium cells with cataract surgery. I generally perform a “specular microscopy,” which allows me to visualize and quantify the corneal endothelium prior to surgery. This allows me to risk stratify you before your surgery. It is important to realize that corneal transplants have a lifespan and may have to be repeated in the future.

Keep in mind, there is some uncertainty in biometry (the process of selecting an IOL) in all eyes – this error can be higher in keratoconic eyes. This highlights why assuring stability is important. Equally important is picking the correct IOL for your situation. Also, keep in mind that I have discussed generalities in this article. Your individual case could be different. This is a conversation best left between you and your surgeon. In general, cataract surgery and keratoconus or a corneal transplant can be a very safe and effective way in restoring vision.

Sam Garg, MDSumit (Sam) Garg, MD
Interim Chair of Clinical Ophthalmology and Medical Director
Gavin Herbert Eye Institute at the University of California, Irvine

Can Keratoconus Progression Be Predicted?

12/9/14

This article on keratoconus progression is from the National Keratoconus Foundation’s monthly e-update. To receive this valuable source of KC information to your inbox, you can subscribe here.

Neutrophil-to-lymphocyte (NLR) ratio is a new potential predictor of systemic inflammation in several diseases. The aimed of this study, conducted by a group of researchers in Turkey, was to evaluate NLR ratio in patients with keratoconus.
research keratoconus progression
The study included 54 patients with keratoconus and 25 age- and sex-matched control subjects. All participants underwent a detailed ophthalmological examination and corneal topography. The KC patients were divided into progressive and non-progressive keratoconus groups on the basis of topographic parameters. Serum samples were obtained from all subjects, and the NLR ratio was calculated.
The study authors reported that the NLR ratio was 3.27 ± 1.37 in the progressive keratoconus group versus 1.87 ± 0.39 and 1.87 ± 0.52 in the non-progressive and control groups, respectively (p<0.01). They also observed that there was a positive correlation between the NLR ratio and progression (p<0.05). In the receiver-operating characteristic analysis, an NLR ratio ? 2.24 predicted the presence of progression with 79% sensitivity and 81% specificity.

The NLR ratio is a simple and inexpensive marker of systemic inflammation. The NLR ratio was found to be higher in patients with progressive keratoconus than in the non-progressive group and controls.

SOURCE: Neutrophil-to-lymphocyte ratio may predict progression in patients with keratoconus. By Karaca EE1, Ozmen MC, Ekici F, Yüksel E, Türko?lu Z.
Cornea. 2014;33(11):1168–1173.

CathyW headshotCatherine Warren, RN
Executive Director
National Keratoconus Foundation
A program of the Discovery Eye Foundation