The study of myopia control (nearsightedness) is a hot field of study, particularly in China where the High Myopia – Partial Reduction Orthokeratology (HM-PRO) study was conducted. This study is the latest in an effort to find an effective means to slow or even stop the progression of nearsightedness in children. The HM-PRO study is unique in that it treated 18 highly myopic children (Rx over -5.75 D) between the ages of 8 and 11 with a combination of OrthoK lenses and glasses, and followed them for two years. The study participants were matched with a control group of 18 children, the same age and also with prescriptions over -5.75D.
In the HM-PRO study 18 participants and 18 control patients were followed for 2 years. 15 of the treatment patients and 13 control patients completed the study. After two years the treated patient’s nearsightedness increased by – 0.13D and the untreated (control) patients increased their nearsightedness by -1.00D.
Myopic progression is also measured by how much the eye grows in length (called the axial length). In this case the treated patients showed a significant reduction in progression with their axial length increasing by 0.19 mm whereas the control group’s axial length increased by 0.51 mm.
The study authors concluded that orthokeratology lenses slowed axial length elongation by 63% and reduced the prescription change by 87%. It has yet to be shown that orthokeratology lenses stop the myopic progression clearly this study, like numerous other before it, show that orthokeratology is effective in markedly slowing the progression of nearsightedness in children. At Total Eye Care we have been using reverse curve orthokeratology lenses to control myopia since 1999 and have fit hundreds of kids and adults.
Scleral lenses have been around for over 100 years. Until the new gas permeable lens materials were developed patients could only wear scleral lenses for a few hours a day. With the highly oxygen permeable lens materials now in use, patients can comfortably wear these lenses all day. Scleral lenses are most commonly used to treat eyes with irregular corneas such as keratoconus and post surgical eyes (usually following corneal transplant surgery or related to complications from refractive surgery). Another common use for scleral lenses is in the special effects industry where they are used to protect the cornea and/or to give the eye an exotic appearance.
What Is A Scleral Lens?
Scleral lenses are large contact lenses that rest on the sclera (white part of the eye) with the remainder of the lens vaulting over the cornea. Tears are trapped between the lens and the cornea allowing sclerals to treat irregular corneas. The average soft contact lens has a diameter of about 14 mm whereas scleral lenses typically have a diameter exceeding 14.5 mm.
How Are Scleral Lenses used?
At Total Eye Care Dr. Driscoll has used scleral lenses to treat many conditions such as irregular astigmatism, keratoconus, high myopia, dry eye syndrome, and complications related to LASIK and PRK. Because of their size, sclerals are quite comfortable. Patients often report the comfort being similar to that of a soft contact lens. Most patients with irregular corneas will see better with a scleral lens than with glasses.
Below is a good video that shows how scleral lenses are cared for and how to insert and remove them.
April 28-May 1, 2011: Orlando, FL —Richard A Driscoll, O.D. attended the Orthokeratology Academy of America Educational Conference. In keeping with Total Eye Care’s philosophy of providing a complete solution to their patients visual needs Dr. Driscoll has furthered his knowledge in the area of Orthokeratology a procedure where patients wear a vision retainer at night, remove the lens during the day and experience good vision all day long. Says Dr. Driscoll, “some patients simply are not surgical candidates for LASIK or PRK and want a safer alternative to refractive surgery, Orthokeratology provides that safe, effective surgical alternative.”
Current research also shows that the same vision retainers used in Ortho-K can slow myopic progression in children. Said Dr. Driscoll “parents often ask if there is anything they can do to prevent their child from becoming more nearsighted. We can now tell them that studies show Orthokeratology vision retainers significantly slow the progression of nearsightedness in children. New lens designs were also discussed at the meeting and we expect they will be shown to be even more effective. Early reports on these new lens designs will likely be presented next year.”
The keynote address, Myopia as a Public Health Concern, was given by Melbourne Hovell, Ph.D., M.P.H. The international faculty of presenters covered topics including myopia control (including soft lens technology), corneal reshaping research, safety of corneal reshaping, progressive/hyperopic Ortho-K lens designs, new corneal reshaping technologies, post LASIK lenses, Keratoconus / Ortho-K lenses, lens designs for corneal rehabilitation, corneal cross-linking and Ortho-K in China. “This is by far the most widely attended meeting on Orthokeratology and myopia control in the world. There were doctors in attendance from every continent except Antarctica” said Dr. Richard Driscoll, “controlling the progression of myopia was a central theme to the meeting.”
President Dr. Cary Herzberg had the pleasure of announcing the inception of the new International Academy of Orthokeratology(IAO). The IAO brings together Ortho-K organizations from the United States (OAA) as well as Europe and Asia. This international organization will support, promote and advance corneal reshaping worldwide through quality education and research presentations at meetings held around the world.
A few times during the life of The Eye Doc Blog I’ve been approached by numerous merchandisers to review or place banner ads promoting pinhole glasses. This begs the question do pinhole glasses work? The simple answer is it will make the image a little clearer and much darker. Comparing the vision from pinhole glasses to that attained by prescription lenses is like comparing your vision at midday versus 20 minutes after the sun sets. OK, maybe pinhole glasses aren’t that good. Pinhole glasses however do have a valuable purpose.
How Do Pinhole Glasses Work
First let’s discuss how prescription lenses focus light on the eye. Prescription lenses focus light on the fovea (the most sensitive part of the retina where we have our best visual acuity) by taking all of light that is entering the eye and focusing it at one point, on the fovea. The further the light is from the center of the pupil the more it most be focused to allow us to see clearly. Light that enters the pupil at the center does not have to be focused at all. This is how pinhole glasses work. Pinhole glasses block out all of the light in the periphery that must be focused in order to hit the fovea and allows in only the light that enters directly into the center of the pupil and thus does not need to be focused.
Do Pinhole Glasses Serve Any Purpose
Pinhole glasses are used in a doctor’s office to see if a patient, presenting with a red eye, for instance, can see better if she was wearing her glasses. As an example, a new patient presents to an eye doctor’s office with a red eye. After we have asked them the typical questions to provide some history about her red eye we want to see how well she is seeing. Often, a patient with a red eye was driven to the office by someone else and didn’t bring their glasses. After we check their vision we see that they have 20/80 vision in their red eye. Now the question becomes is their poor vision due to not wearing their glasses or is there another cause? Enter pinhole glasses, or more likely a pinhole occluder (a paddle with lots of little holes in it). We recheck our patient’s vision while she is looking through all of those little holes and lo and behold her vision through the pinhole glasses is 20/30. It’s still not 20/20, however we now have an additional degree of comfort that if she was wearing her glasses her vision would be normal. A pinhole is used to see if the vision is likely to improve with glasses.
So there you have it. Pinhole glasses, while certainly not a substitute for prescription eyewear, do serve a purpose as a screening tool for refractive conditions.
Total Eye Care unveiled OrthoKDoctor.com a new website designed to answer patient questions about Orthokeratology, a safe and effective alternative to refractive surgery
Orthokeratology is known by numerous terms, the most common of which are Gentle Vision Shaping System, OrthoK, Corneal Refractive Therapy and Overnight Vision Correction. Total Eye Care introduces the new website OrthoKDoctor.com to inform patients about this exciting technology.
“Orthokeratology is a safe and gentle method where contact lenses temporarily reshape the cornea while a patient sleeps. The beauty of OrthoK is that it is temporary. As long as a patient wears a retainer lens the effect remains, much like wearing a retainer after orthodontic braces are removed” says Dr. Richard Driscoll, clinical director at Total Eye Care. Read more…….
As parents we often think that our son or daughter has good vision and therefore does not need an eye exam. Common misperceptions of why eye exams in children are not important include, my son doesn’t complain of blurry vision, my child’s grades are good, or the parents have good vision therefore the kids probably do too.
School screening don’t qualify as an eye exam. While an essential part of protecting the visual and physical health of our children, school screenings were never intended to replace a professional eye exam. School screenings prevent children from “falling between the cracks” and are best used to supplement regular eye care. Read more about safeguarding our children’s vision.
The March issue of Ophthalmology cites an eight year Swedish study of 30,000 women comparing the cataract surgery rate for women that have used hormone replacement therapy and those that have not. Birgitta E. Lindblad, MD, the lead author of the study, stated that “if future studies confirm the associations we found, increased risk for cataract removal should be added to the list of potential negative HRT outcomes.”
The rate of cataract surgery in the study was up to 18% higher in women that were using HRT, that rate corresponded with how long the patient had been using HRT. It was also noted that alcohol greatly increased the cataract removal rate with the study showing a 42% higher rate in women using HRT and having more than one alcoholic drink per day over those that were not using HRT.
The study also noted that when the body produces estrogen it prevents cataract formation, however supplemental estrogen medication does not react entirely the same way in the body and increases cataract formation.
Good Morning America reports that the American Academy of Ophthalmology states 90% of patients achieve 20/20 vision following laser vision correction. What the AAO report does not address is that 20/20 does not mean that the patients have a good quality of visual acuity. The Good Morning America Video (video at the end) interviews both satisfied and unsatisfied patients. Some patients complain of a worsening of their dry eye symptoms, halos or shadows, glare or starbursting, poor night vision, reduced contrast or simply uncorrectable blurry vision. The vast majority of the patients that have had LASIK or PRK are happy with the result. However, laser vision correction is not reversible and some of the resultant problems from refractive surgery are not resolvable.
Options available to patients that are not happy with their surgical result, of course depend on the symptom. Some of the options available to patients are:
Post Surgical Contact Lenses
These special contact lenses are available as soft contacts, as gas permeable lenses and as a combination soft/gas permeable. Post refractive surgery contact lenses are usually used when a patients vision can not be corrected by additional surgery, glasses or regular contact lenses because their corneal surface has become slightly irregular or distorted. The symptoms may include, blurry vision, halos and shadows.
Dry Eye Syndrome
The most common complaint following refractive surgery is dry eyes. Most often the dryness improves two to six months following surgery. Ocular dryness can also cause blurry vision. Should the dryness not improve there are numerous solutions to improve patient comfort and it is worth seeking help from an eye doctor that is familiar with treating dry eye syndrome.
Glare and Poor Night Vision
Often glare, halos and night vision problems are due to large pupils and/or uncorrected refractive error. Night driving glasses will usually help patients that are still a little nearsighted following refractive surgery. Treating the glare is little more difficult. Glare often improves with time, however a medication called Alphagan has been known to improve night glare symptoms by causing the pupil to constrict slightly. Alphagan may contribute to the ocular dryness, however.
Know Your Vision Correction Options
LASIK and PRK are good procedures and can greatly improve one’s quality of life. Prior to taking the refractive surgery plunge patients should thoroughly research their options. In an upcoming article I’ll cover the alternatives to refractive surgery.
At Total Eye Care we offer all of the refractive surgery and non surgical vision correction options available and we pride ourselves on giving our patients an objective opinion of all of their choices. It is important for our patients to be well educated on the pros and cons of each option so that they can make an informed decision.
Check out the video below from the Good Morning America’s investigation on LASIK, it offers a balanced report on refractive surgery.
In December 2009 we covered the results of a recent study Myopia Increasing Rapidly in The US Population. Recently National Public Radio’s Medical Detectives interviewed, Dr Susan Vitale, principle author of the study “1994-2004 National Health and Nutrition Examination Survey” and Dr. Don Mutti, an expert in myopia. It’s a good listen and only a little over 3 minutes.
The rate of nearsightedness in the US has increased by over 66% in the past 30 years says a study published in the December 2009 issue of Archives of Ophthalmology
A 66% increase in myopia is a huge change over a 30 year period. The new study tried to simulate the testing methods of the original 1972 study on nearsightedness in the US population. The 1971-1972 National Health and Nutrition Examination Survey found that 25% of the US population between the ages of 12 and 54 were nearsighted vs the 1994-2004 National Health and Nutrition Examination Survey’s finding of 41.6%. Increased nearsightedness was noted regardless of age, sex, race or education.
The authors concluded that it would be beneficial to identify behavioral risk factors that cause increased myopia. If risk factors for increasing myopia are identified we may be able to slow the progression.
The big question is “what caused this increased nearsightedness in the US population”? As eye doctors we are often asked what causes nearsightedness and the usual answer is that that we believe nearsightedness is a combination of genetics and environmental influences. In the last 30 years our society has become much more near centric. People spend hours glued to their computer monitors at work and home. Kids spend more time at near now then ever before with computer games, hand held games etc.
Numerous recent studies have shown that orthokeratology contact lenses can greatly slow the progression of nearsightedness
Finding ways to slow or halt the progression of myopia has been a longstanding subject of study in eyecare. The process of using special contact lenses to reshape the front part of a patient’s eye to prevent the progression of nearsightedness and to allow the patient to see without glasses is called orthokeratology. There are a number of different names for orthokeratology, orthoK, corneal molding, corneal reshaping and corneal refractive therapy are some of the most common names.
Almost a year ago the study, Controlling Astigmatism & Nearsightedness in Developing Youth (CANDY) showed that orthokeratology contact lenses reduced the progression of nearsightedness in kids between 9 and 16. The authors of the CANDY study found that the amount myopia in children that did not wear the overnight Corneal Refractive Therapy lenses increased at a rate of .37D per year while those children wearing the lenses progressed at only .03 diopters per year.
Another study, Corneal Reshaping and Myopia Progression published in the British Journal of Ophthalmology, conducted at the Ohio State University College of Optometry found that the eyes of the children wearing overnight orthokeratology lenses increased in length at a markedly slower rate than the studies’ non ortho-K lens wearers.