What Are Scleral Contact Lenses?

In the beginning…of contact lenses…there were scleral lenses…only.

In the year 1887 a great gift was given to the world of sufferers of distorted vision resulting from corneal tissue that was irregular in shape from disease or trauma.
scleral lenses

The contact lens was invented nearly simultaneously by physicians working separately in Germany and in France. Working from drawings of Leonardo da Vinci (1508) and ideas of the British astronomer Sir John Herschel (1828), August Müller and separately Adolph Fick and Eugene Kalt blew glass shells to fit the outer eye and to some extent remedy their visual difficulties. These lenses rested on the conjunctiva of the eye above the sclera or white of the eye and were thus the first scleral contact lenses — the first contact lenses of any sort.

What are Scleral Contact Lenses?

The design and manufacture of scleral lenses has been a story of technological development significant for improvement in comfort, material, and affinity for the ocular surface.

For many years the lenses were partially molded and partially ground from the material of which hard contact lenses are made: PMMA (poly-methyl methacrylate) known as Plexiglas or Perspex. To form these lenses, like tooth implants, a plaster cast is made from a negative mold prepared from dental impression putty. The plastic would be heated and given the shape of the fitting surface of the lens from the plaster cast and then the power and edge curves would be ground onto the outside surface of the lens. Later came preformed trial sets not unfamiliar to those which we use today.

The current generation of scleral lens fitting began sometime in the last fifteen years with the mating of advanced corneal topography measurements, computer driven lathes and the observations of some very clever contact lens scientists. Proprietary designs of scleral lenses offering a variety of diameters, fitting philosophies, and multiple parameters are filling the gaps contact lens specialists have been wrestling with using smaller corneal contact lens designs for decades with less than optimal results. Most recently a firm has begun manufacturing lenses with a 3-D printer from an image generated from the eye. One eye…one lens, the lens is meant to fit like a fingerprint.

When discussing contact lens treatment, experts are experts because they agree that, any sort, size, or design of lens will have both positive and negative effects on the eyes and the tissues surrounding them. While it is true that many of the fitting and comfort issues confronted with corneal lenses of any size and design can be managed well with scleral designs, the scleral lens can also be difficult for some patients; for some eyes; for some conditions.

From the outset the larger size of the today’s scleral lens provides comfort on par with soft contact lenses for exactly the same reason: their size. Also, like soft contact lenses the scleral will not move around on the surface of the eye allowing the wearer a much more relaxed contact lens experience — there is no necessity to balance small corneal lenses between tense eyelids – vision can be enjoyed in any direction of gaze. The lenses will not fall off the eye and the increased size is a clear plus in finding a dropped contact lens.

On the other hand the quality of vision gained with scleral lenses specifically in cases of distorted corneae is far more comparable to that achievable with corneal GP lenses than with soft contact lenses in most cases.

Over the years my keratoconus patients have benefited from a series of contact lens breakthroughs that have variously improved the quality of their vision, their comfort with contact lenses, or in some other way the health of their eyes. Some years ago I “re-invented” the piggy-back system of contact lens wear which I summarized in 2008 in an article published in the Contact Lens Spectrum. Piggy-backers would place their vision restoring firm contact lens on top of a disposable daily wear lens of minimal focusing power. The soft lens would reduce the sensation of the firm lens while in many cases preventing the contact lens from abrading the cornea. More recently I have been successfully moving patients to scleral lenses because there is certainly less bother (only one lens per eye) and far less worry over corneal abrasions as the lens rests on the conjunctiva over the sclera and maintains a fluid cushion over the cornea itself.

Scleral lenses are finding their place in the world of contact lens fitting primarily to remedy vision problems from very irregular or otherwise damaged corneae both those caused by developing disease and trauma through injury or surgery. More and more, these lenses are requested by patients with normal eyes who want to enjoy the benefits provided by these lenses while participating in sports or other activities.

Scleral lenses are renowned for their greater comfort. In many cases a correctly fitted lens can be worn for many waking hours. Many patients have found that they benefit from exchanging the fluid from the reservoir from time to time throughout the day. The fluid that fills the lens-cornea space is sterile, non-preserved normal saline or in some cases saline with a non-preserved tear substitute added when needed for improved comfort.

A proper care regimen for scleral lenses is not different from that for any other contact lens manufactured from a firm oxygen permeable material. The lenses require cleaning upon removal, soaking in a recommended solution appropriate to the material of the lens and a periodic treatment to remove protein deposits. Of course, the exact care specifications will vary from patient to patient according to the evaluation of their contact lens specialist.

Just like any lens modality, the fitting requires expertise. Many who fit and dispense contact lenses rely on boxed soft lenses for their patients. When corneae become distorted those lenses will hardly fill the need. Greater expertise is required to fit rigid corneal lenses needed for these more problematic surfaces. The decision of the corneal lens expert to move on to the world of larger lenses is not of the same magnitude as that from boxes to corneal GP lenses. The investment is more a matter of time spent in discussion with the manufacturer’s fitting consultants, some reading, a webinar or two and keeping up to date with the lens designs that are available.

I was not among the first to use the current generation of scleral lenses, but when the opportunity knocked some years ago, I realized the importance of this form of contact lens and I believe I have positively influenced the quality of life of many of my patients.

5/28/15

Bezalel Schendowich - scleral lensesBezalel Schendowich, OD
Medical Advisory Board of the National Keratoconus Foundation
Fellow of the International Association of Contact Lens Educators
Clinical Supervisor & Specialty Contact Lens Fitter, Sha’are Zedek Medical Center, Jerusalem, Israel

Proper Contact Lens Care Provides Best Vision, Comfort and Ocular Health

9/18/14

Proper contact lens care is essential for the best contact lens wearing experience. Mr. Ward, Director of the Emory Contact Lens Service has shared some valuable information about taking care of your contact lens in the article below. On Tuesday join us for additional tips for people who wear contact lenses and wear cosmetics.contact lens case - proper contact lens care

Contact lenses provide alternatives to spectacles, and contact lens wearers report better peripheral vision, depth perception and overall vision quality. Contact lenses can correct near-sightedness, far-sightedness, astigmatism and even correct the need for reading glasses. They are also used to manage some ocular surface diseases.

Contact lenses fall into two basic material types: soft contact lenses (SCL) and rigid gas-permeable (GP) lenses. Soft lenses account for the great majority of the contact lens market. GP lenses require more precise fitting and are often used as specialty devices to correct high prescriptions and/or to manage various ocular disorders and may require longer lens-adaptation time. Regardless of lens type, careful attention to lens care instructions can provide good vision and life-long lens wearing comfort.
Proper lens care depends on the lens type, wearing schedule and other factors. Single-use or daily-disposable soft lenses are prescribed to be worn once and discarded. This is theoretically the safest lens wearing modality in that no lens cleaning, lens care or storage case is required for this modality. Other daily wear soft lenses may be replaced every 2 weeks, monthly or by other schedule. Any and all lenses that are removed each day must be cleaned and disinfected prior to their reuse. Your eye care practitioner should provide specific instructions relative to your lens wear and care needs. General lens care instructions and Dos and Don’ts are bullet-listed below.

A word of caution –
Contact lens wear is quite safe as long as proper lens and storage case care are followed. However, improper lens wear and care can put the lens wearer at risk for serious consequences. Sight-threatening microbial keratitis (corneal ulcer) is the most significant adverse event associated with contact lens wear and is largely preventable. The contact lens storage case is the most likely potential reservoir for contact lens related ocular infections. Therefore, lens storage case care should be high on the list of important lens wearing instructions. Contact lens cases are not meant to be family heirlooms; cases should be replaced regularly, at least every 1-3 months.

The Bullet List of Contact Lens Care Recommendations

  • Hand washing: Always wash your hands before handling contact lenses. Use mild, basic soap and avoid antibacterial, deodorant, fragranced or moisturizing liquid soaps (many liquid soaps have moisturizers that can contaminate your contacts from handling).
  • Cleaning, rinsing, and disinfecting: Digital cleaning (rubbing the lens with your finger in your palm) removes dirt and debris and prepares the lens surfaces for disinfection. Rub & rinse thoroughly, even if the product is labeled “No Rub”. Lens storage solutions contain chemicals that inhibit or kill potentially dangerous microorganisms while the lenses are soaked overnight.
    • Contact lenses should be cleaned when removed from the eye.
    • Do not re-use old solution or “top-off” the liquid in the lens storage case. Empty the storage case daily and always use fresh solution.
    • Do not use lens care products beyond their expiration dates. Discard opened bottles after 28 days.
    • Do not allow the tip of the solution bottle to come in contact with any surface, and keep the bottle tightly closed when not in use.
    • Do not transfer contact lens solution into smaller travel-size containers.
  • Keep your contact lens storage case clean (inside and out).
    • All lens storage cases should be emptied, rinsed, wiped, and air-dried between uses.
    • Keep the contact lens case clean and replace it regularly, every one to three months.
    • Do not use cracked or damaged lens storage cases.
    • Take care to remove residual solution from surfaces of lens case and solution bottles.

Other Dos and Don’ts

  • Do not wear your lenses during water activities (swimming, hot tubs, showering, etc).
  • Soft contact lenses should not be rinsed with or stored in water. Soft lenses will change size and shape if exposed to water.
  • Do not put your lenses in your mouth.
  • Do not use saline solution or re-wetting drops in an attempt to disinfect lenses. Neither is capable of disinfecting contact lenses.
  • Wear and replace contact lenses according to the prescribed schedule.
  • Follow the specific contact lens cleaning and storage guidelines from your eye care professional.
  • Do not change lens care products without first checking with your eye care practitioner.
  • Spare rigid (GP) lenses should be stored dry for long term storage { clean, rinse, dry}. New or dry-stored GP lenses should be re-cleaned and disinfected prior to lens wear.
  • Do not store soft lenses in the storage case for an extended period of time. “Spare” soft contact lenses should be new and stored in their original and unopened packaging.
  • Do not sleep in your contact lenses unless specifically approved to do so by your eye care practitioner.

For information from the Centers for Disease Control and Prevention, see:
www.cdc.gov/contactlenses/
www.cdc.gov/contactlenses/cdc-at-work.html

Michael Ward - proper contact lens careMichael A. Ward, MMSc, FAAO
Director, Emory Contact Lens Service
Emory University School of Medicine

 

Treatment Options For Children

8/19/14

Here is part two in Buddy Russell’s series; this one focusing on contact lenses as a treatment option for children.

We Are Not Born With Good Vision

The human visual system at birth is poorly developed, but rapidly becomes the remarkable combination of nerve tissue, muscles and optics that provide us with the sense of vision. Those babies born with “perfect” eyes have only the opportunity to develop normal vision. The information processed by the eyes is sent directly to the brain and is interpreted as vision.Toddler looking through glasses - treatment options for children During the first few weeks, the child sees shapes, lines and space between objects. The child’s visible world is most usable within 8-14 inches of his/her eyes. During this time, the eyes may appear to wander. After about a month or so, the normal child’s eyes will appear more coordinated and they start to show more interest in looking at objects. It is usually in the third month that a child who has normal eyes can fix and follow on a near object. The growth of the eye is a dynamic process, influenced by genetics and the environment.
Early detection of any eye problem is key to treating the disorder. The prevalence of vision problems in children is higher than you might think. For example:

  • 1 in 10 children are at risk from undiagnosed vision problems
  • 1 in 25 will develop strabismus
  • 1 in 30 will be affected by amblyopia
  • 1 in 33 will show significant refractive error
  • 1 in 100 will exhibit evidence of eye disease
  • 1 in 20,000 children have retinoblastoma

As a result of his granddaughter and her eye problem, former President Jimmy Carter initiated a program in 2002 called InfantSEE. This program allows children to have an eye exam at a very young age at no charge to the family. Participating eye doctors provide a more thorough exam than the busy pediatrician. As a result, there is a greater opportunity to detect and treat eye disorders that may otherwise go undetected.

“Have to” Contact Lenses

Fitting pediatric patients is not usually about routine visits and patients who want to wear contact lenses. It is about critical and often urgent situations and patients who have to wear contact lenses. The more common medical indications for contact lenses can be categorized into three groups; anisometropia, irregular corneal astigmatism and “large” refractive errors.

Anisometropia

One of the more common conditions potentially leading to a permanent loss of vision in a young patient is anisometropia. This difference in the refractive errors of the two eyes can lead to suppression of the less clear image. As a result of the non-focused eye, the brain of a young patient simply turns off the blurred eye. Early detection is key to successful treatment. Following the diagnosis of this problem being present, simply correcting the refractive error may be enough. However, it has been reported that as little as one diopter difference between the two eyes corrected with spectacles and the resultant anisokonia, can lead to foveal suppression impacting stereopsis and depth perception. The use of a contact lens or contact lenses alters the effective image size due to the vertex distance being zero compared to either the magnification or minification of the image size due to the vertex distance with spectacles. One of the most severe examples of this condition would be a child with a unilateral congenital cataract and managed with spectacles postoperatively.

Irregular Corneal Astigmatism

Whether acquired or congenital, the presence of irregular corneal astigmatism of the anterior curve of the cornea is best managed with a contact lens. This condition is to be considered urgent if the patient is of a young age. The eye may forever loose the opportunity to be corrected as the resultant amblyopia develops over a short period of time. By neutralizing the corneal irregularities with a contact lens, the eye of a young child will hopefully gain enough vision improvement to avoid the potential permanent loss.
Obviously, patching the better eye may also be necessary if the treated eye’s vision is not as correctable as the unaffected eye. The length of time the child is to be patched is to be determined by the pediatric ophthalmologist or optometrist, as this area of treatment is sometimes controversial. The factors that are considered include the level of vision obtained, age of the child and the condition of the other eye.

Large Refractive Errors

The optics of spectacle correction in high powers have inherent properties that include distortion, prismatic effect and minification / magnification. For instance, the decrease in image size when one views an object through high minus spectacles may result in less vision. This decrease in image size may impact the opportunity to fully develop normal vision in a young child. The smaller image size that is due to the vertex distance of spectacles may be better managed with a contact lens that has a vertex distance of zero thus providing a larger image. This larger image size often increases best-corrected vision.

“Fitting” the Caregiver

Arguably, the most important factor with young children having a good outcome is the parents / caregivers. The technical challenges that exist in these cases are secondary to the ability the fitter must possess to effectively explain and train the person or persons that will take care of the child outside of the office. They must be your partner in the child’s treatment. They must understand the urgency of the situation, they must understand the seriousness of the problem, they must be trained to properly apply, remove and care for the lens / lenses, they must also follow any and all instructions concerning the child. Many of these parents struggle with feelings of nervousness, guilt and sadness. My strategy is to be sensitive to their feelings but not let them feel sorry for themselves too long as the clock is ticking. I provide verbal instructions, written instructions, videos, my email address and a 24-hour phone number. I welcome the caregiver to ask any question at any time. I do my best to let them know that I do care and that I want them and their child to be successful. I am tough on them. There is no good excuse not to do as I have instructed them to do.

When the child and the parent / caregiver are convinced that I am confident in my ability and they know that I do care, the partnership develops as we walk the path together. I want the child to know that they are coming to see me. I want them to know I will reward their cooperation with all phases of the visit. This positive reinforcement may be in the form of a piece of candy, a small toy or just a sticker when the child allows me to see their eye, measure their cornea or intraocular pressure or they just tell me what they can see. Kids love to please us just like they love to please their parents. Reward them for it. Whether you consider this approach bribery or positive reinforcement, it works.

Buddy Russell - pediatric contact lensesBuddy Russell, FCLSA, COMT
Associate, Specialty Contact Lens Service
Emory University Eye Center

Pediatric Contact Lenses

8/14/14

Because August is Children’s Eye Health Month we are pleased to present a four-part series on pediatric vision issues and contact lenses by Buddy Russell, FCLSA, COMT. With over thirty years experience fitting contact lenses, Buddy is currently an associate of the specialty contact lens service at Emory University Eye Center in Atlanta, Georgia. Buddy is a clinical instructor in Emory’s Ophthalmic Technology Program and teaches students and ophthalmology resident’s contact lens technology. 

Child refractive exam - pediatric contact lensesHe is a licensed dispensing optician, a Fellow member of CLSA and has been certified by JCAHPO as a Certified Ophthalmic Medical Technologist. He lectures at national and international meetings on contact lens related topics. Buddy has written articles for a number of publications, two chapters for CLSA’s advanced training manual and is a peer reviewer for the Cornea publication. He is also a contributing editor for CLSA’s Eyewitness journal. His current areas of research include pediatric aphakia and keratoconus. He joined the faculty at TVCI in 2006.

The first article will examine that pediatric contact lenses for children go beyond vision correction, the second will explore lenses as a treatment option, the third will look at a variety pediatric eye conditions and the final post will discuss the contact lens fitting challenges you face when you work with children.

Introduction

Working with the pediatric patient and their caregivers / family can be challenging, rewarding, fun, and yet sometimes frustrating. Many of these cases often include factors that are unique to the young patient. In addition to the technical challenges of obtaining the objective data, the fear of uncertainty is often present. The uncertainty of the unknown can either paralyze you or motivate you to step up and simply do what must be done.

The Definition May Vary

The definition of pediatric contact lens fitting can be different to different people. The fitter who works with the occasional twelve-year-old neophyte wearer will define pediatric fitting different from the person that works with babies on a routine basis. Pediatrics is generally defined as a branch of medical care that deals with infants, children and adolescents. The word pediatrics is derived from two Greek words (pais = child and iatros = healer), which means healer of children. Are you a “healer of children” or do you tend to feel better about someone else assuming the challenge and responsibility? This article will discuss some of the conditions, contact lens indications, fitting techniques and challenges that are present with the young patient.

Refractive Indications

What age is “appropriate “ to fit a contact lens on a child? In the absence of a medical indication, Jeff Walline, OD and his colleagues have addressed the answer to this question in the published literature. In addition, the American Academy of Optometry published a position paper in 2004 that stated that by the age of eight, a child was able to handle contact lenses and assume some degree of responsibility. We are all aware that not all eight year olds are capable of dealing with contact lenses. For that matter, not all eighteen year olds are mature enough to assume responsibility for anything. Some of the concerns that a contact lens practitioner may have in fitting these young children include the risk of safety to the child’s health, too much chair time, physical limitations, lack of hygiene, and lack of maturity. These are all legitimate concerns when you consider the child can see well with spectacles.

What does the literature reveal concerning these questions and concerns? Are the answers there?

CLIP Study

The Contact Lens In Pediatrics study compared 169 neophyte wearers in two age groups (children age 8-12 and teens age 13-17) over a period of three months. The summary of the clinical findings in the publication is that adverse events was low and the younger children took a little longer to train application and removal of the contact lenses. The more impressive outcomes from this study was determined by a tool used more frequently in child psychology referred to as the Pediatric Refractive Error Profile (PREP) survey. The PREP survey is a clinically validated quality of life instrument to assess how a child “sees” him or herself. This 26-question survey revealed that contact lenses improved the child’s self image in regards to their appearance, increased confidence in themselves while participating in activities and overall satisfaction of their form of vision correction. These findings were consistent in both age groups. More than 80% of both age groups found contact lenses easy to clean and take care of as all participants were fitted with 2-week disposable soft lenses and used a multipurpose disinfection care system.

The ACHIEVE Study

The Adolescent and Child Health Initiative to Encourage Vision Empowerment (ACHIEVE) were published in 2009. Jeff Walline, OD and his colleagues designed this study to find out the effects that glasses and contacts had on the self-perception of the child. This study examined 484 myopic children 8-11 years. The participants were randomized to spectacles (n=237) or contact lenses (n=247) and followed for three years. The children were evaluated at baseline, 1 month and every 6 months for three years by a validated psychology tool for self-perception referred to as the Self-Perception Profile for Children (SPPC). The SPPC instrument allows a 4 point self-assessment in 6 categories; scholastic competence, social acceptance, athletic competence, physical appearance, behavioral conduct and global self-worth. The participants revealed the most dramatic areas of improvement with contact lenses compared to spectacles in the areas of physical appearance, athletic competence, scholastic competence and social acceptance. Similar to the low occurrence of adverse events with contact lens wear found in the CLIP study, over the three year period there were only 13 adverse events among 9 subjects. In addition, the ACHIEVE study found very similar rates of myopic progression in both groups of patients over the three year period (1.08D spectacle group and 1.27D contact lens group).
What can we conclude from these two studies?

One is that we are in a position to not only help a young person see but we are also in a position to do it safely and assist the child by instilling more confidence in themselves at a young age that may impact them as they mature into an adult who feels good about themselves. Young children are accustomed to following rules. When properly trained, these same young patients may grow into some of the most compliant patients that we have in our practice. There are some practical considerations for prescribing contact lenses to the younger patient. Mary Lou French, O.D. has stated the three M’s are important for success; Maturity (good hygiene, good communication skills, signs of responsibility), Motivation (why do they want contacts? Does the child want them or just the mom or dad? Are they active in activities where freedom from spectacles is important?), Mom (is the mom / dad / older sibling willing to help?). Don’t let age be the deciding factor. Consider your position as one that may positively impact the young patient in how they “see” and feel about themselves.

Buddy Russell - pediatric contact lensesBuddy Russell, FCLSA, COMT
Associate, Specialty Contact Lens Service
Emory University Eye Center