little four eyes

Many vision issues are hereditary, which can add to the calculations families go through when deciding if and how to add to their family.  For those of us who have minor vision issues in our family, it often just means that we need to  be diligent about making sure that all of our children are monitored so that we can catch and treat any issues quickly.  But for parents with more serious vision issues, the possibility of passing along those traits is much more difficult to face.  In some cases, eye diseases can leave their children blind or with serious visual impairments.

A reader who is facing this situation recently wrote to me asking that I open a conversation about vision and genetics, especially for those who have learned that they carry hereditary visual diseases.  She and her husband first learned that both of their children have a rare eye syndrome leaving them with a long list of associated vision issues.  They then learned that both of them are carriers of a rare mutation that causes the syndrome.  They are now pursuing IVF with PGD (preimplantation genetic diagnosis – embryos are tested for mutations before they are transferred to the mother) so that they can transfer only embryos that do not carry the mutation.

For those of you whose child’s eye problems are hereditary, how has that impacted your decisions to add to your family?

I’ve recently learned about, and subsequently added some new links on the resources for parents page, and wanted to bring them to your attention.  Thanks to everyone that has suggested sites, and please, keep them coming!  If there’s a helpful website or great community out there, I want to list it.

Reference resource

• Eye Resources on the Internet – this is an extremely thorough list of Internet resources about vision compiled by the Association of Vision Science Librarians. (Thanks to Dr. Maino for posting this)

Communities for specific vision issues

• Congenital Glaucoma Network - a network for all people affected by childhood glaucoma come to share their story.  (Thanks to commenter Amy for pointing me to this network).
• Magic Foundation: Septo Optic Dysplasia (SOD)/Optic Nerve Hypoplasia – information and links to other families with children with Septo Optic Dysplasia.  (Thanks to commenter Denise for pointing me to the Magic Foundation).

Blogs by eye care professionals

• Dr Lea & Children’s Visions – Dr. Lea Hyvärinen is a Finnish pediatric ophthalmologist.  She may be most well-known by people here as the developer of the LEA symbols (the pictures of a house, an apple, a circle and a square that are commonly used as an eye chart for children).  Her blog managed by her daughter, and is so far, a way of making available her writings about children’s vision development.
• The VisionHelp Blog – VisionHelp is a blog written by a group of leading optometric vision specialists in the U.S.  They seek to increase awareness and understanding of vision treatment and vision therapy.

It took me a very long time before I could spell ophthalmologist right on the first try.  I guess one of the perks of a kid in glasses is that I can now type it quickly with no problem.  So I had to laugh when I this tweet from FakeAPStylebook (absolutely worth following if you enjoy funny tweets, it probably goes without saying that it has nothing to do with children’s eye issues):

Glasses – Check

Occlusion – Check

Surgery – Check

Prism Adaptation – Check

Hmmm… is there something related to little ones in glasses that we haven’t tried yet????   Not that I know of!  We went to the ophthalmologist on Friday due to Elliana’s eyes becoming more over corrected. (major bummer) It appears that she is reacting atypically.  As time progresses her eyes are turning in more rather than becoming straighter as traditionally happens.  She now has a Fresnel prism placed on her glasses.  My first question was, “What is that?”  I understand that it similar to the prisms used in the exams.  I asked how it is different than a lens.  It does not affect the distance at which the light focuses on the back of the eye, rather bounces light in a different way (sorry, still not sure on this.)  Googling Fresnel Prisms on glasses has me just  about as confused.  The article Management of Strabismus and Amblyopia: a Practical Guide byBy John A. Pratt-Johnson, Geraldine Tillson says that “Occasionally, a patient with an acquired esotropia and the full optical correction in place may have a much larger angle esotropia on the prism cover test than appears to be present at a casual glance…the prism estimated as needed to neutralize the deviation is inadequate and more and more prism is required.”  It sounds like this treatment is rare.  We pretty much put a stick on prism over her strong eye because it may act as an occluder.  We go back on Friday for more tests and the article says something about testing for fusion with a synoptophore or the Whorth four-dot test. None of which I know anything about.  Unfortunately, we also have to put atropine drops in both of her eyes for the next 3 days in order to get a good read on her vision this Friday.  Since she is older and more verbal about her eyes – she is NOT a happy camper and has expressed her distaste for the eye drops and has screamed all morning.  2 more mornings of drops.  Wish me luck and let me know if you know anything else about the prisms!

I’m reposting this comment from Stacy in hopes that others will have information for her. -Ann Z

I have a 15 month old son, Ethan, and we just had our first visit with a pediatric ophthalmologist. I feel very disappointed, frustrated and scared after this appointment. We took our son to the ophthalmologist because his left eye turns in. I was not terribly worried because I had amblyopia as a child and anticipated that at the most we would be patching our son’s eye. The eye doctor told us that Ethan’s right eye has 20/20 vision, but his left eye is extremely nearsighted and that he had something called “myelinated retinal nerve fibers.” The eye doctor told us we would need to patch his right eye and that he would need to wear glasses with a Rx of -8.5 in the left lens. He told us we could “read up” on these myelinated retinal nerve fibers as it is a rare condition. He also said that with patching and glasses (6-8 hours a day) that a reasonable vision expectation for Ethan would possibly be 20/50. I feel lost. All I can find on “myelinated retinal nerve fibers” are medical journals full of jargon that I do not understand!!! I’m still unclear as to what Ethan’s actual diagnosis is or how long we will need to patch and wear glasses. All I know is that I am to return in 2 months to check his vision again. We are seeking a second opinion. But has anyone been told their child has “myelinated retinal nerve fibers?” Any help would be soo appreciated! I feel defeated.

Edited on 26-Jan-10 to correct the errors that Dr. Bonilla-Warford pointed out (thanks Nate!) – Ann Z

Glasses prescriptions can be confusing – lots of numbers and abbreviations that aren’t necessarily easy to figure out, or at least, they weren’t when I first tried to understand Zoe’s prescription.  And in fact, I thought I understood what all the numbers meant, but after doing more research for this post, I found it to be far more complex than I’d originally thought. (On that note, if any eye doctor types read this and catch any mistakes, please, please let me know and I’ll correct them – thanks Nate!).

Before we get too far into what a prescription is, I thought it might be worthwhile to mention what a prescription isn’t.   It will not tell you:

• what your child’s diagnosis is.  You can tell whether glasses will correct for nearsightedness or farsightedness, but that doesn’t tell you what the cause of the vision problem is.
• if your child has amblyopia, it will not tell you what his or her actual visual acuity is.
• if your child has strabismus, it will not tell you how much his or her eyes are turning in or out.
• how well your child’s eyes work together, and whether or not he or she has stereoscopic vision.
• how advanced your child’s cataracts or glaucoma is, and how that affects their vision.
• anything that is not related to how glasses or contacts should be made in order to correct your child’s refractive errors (that is, due to the shape of the eye not being able to focus light correctly).

Okay, so back to the eyeglasses prescription then, and what it can tell you.  Prescriptions have a lot of different components, and I’ve seen them written a number of different ways, but they do have common elements at the core.  I’ll go into more detail on each piece, but I tried to put together something of a “cheat sheet” here:

Which eye are we talking about?

Since we’re nearly always looking at prescriptions for two eyes, you’ll nearly always see two sets of numbers, one for the left eye, and one for the right.  I’ve seen some prescriptions that label them “left” and “right” or “l” and “r”, which even I can figure out on my own.  But more often, I’ve seen “O.D.” and “O.S.”.  These are abbreviations for the Latin words for left eye and right eye.  For the record:

• O.D. : right eye
• O.S. : left eye
• O.U. (which I’ve never seen before, but found this information so figured I’d include it) : both eyes

Sphere

Sphere, often abbreviated as “sph” is the spherical refractive error, or nearsightedness or farsightedness.  It’s pretty much what I think of when I think of an eye glasses prescription.  Then again, I’ve never really had to deal with astigmatism (for me or Zoe).  The first part of this number will be a plus or minus sign:

• + : farsighted, or longsighted prescription: hyperopia.
• - : nearsighted, or shortsighted prescription: myopia.
• 0, Pl, or Plano : no error

How bad is the spherical prescription?

The number is in “diopters” but we don’t need to know too much about that (read about it on Wikipedia here), it’s a measure of how much the curvature of the eye  is off from normal.  Basically, the higher the number (ignoring the plus or minus), the worse the prescription.

Myopia (-)

• 0.00 to -3.00 : mild myopia
• -3.00 to -6.00 : moderate myopia
• -6.00 and higher : high myopia

Hyperopia (+)

• 0.00 to +2.25 : mild hyperopia
• +2.25 to +5.00 : moderate hyperopia
• +5.00 and higher : high hyperopia

Cylinder

Cylinder is the measure of astigmatism.  Astigmatism is when there’s an irregular shape to the cornea, often described as a football shape.  It causes blurriness at any distance.  There are two measurements that go along with astigmatism, the first, cylinder, is a measure of how severe the astigmatism is.

How bad is the cylinder prescription?

Like the spherical error, the cylinder number is measured in diopters.  The thing you want to pay attention to is the number.  It may be written as a plus or a minus, but that doesn’t actually make any difference in how bad the prescription is, ophthalmologists use a “+”, optometrists use a “-” (see Dr. Bonilla-Warford’s comment for more explanation of that).   The higher the number after the plus or minus, the more severe the astigmatism.

• 0.00 to 1.00 : mild astigmatism
• 1.00 to 2.00 : moderate astigmatism
• 2.00 to 3.00 : severe astigmatism
• 3.00 and higher : extreme astigmatism

Axis

The axis tells you which way the astigmatism is oriented on your child’s eye

If you think of astigmatism as a football shape, it makes sense that the football might be turned any direction.  The axis number then, tells you the orientation of the astigmatism.  The number is in degrees, it doesn’t have anything to do with how severe the astigmatism is, just how it is situated on your child’s eye.

Add

If your child needs bifocals, you will likely see a number here.  This tells you how the prescription should be changed for close up.  Let’s say your child has a regular glasses prescription of +3.00, if the add number is +1.00, then the near distance prescription will be +3.00 + 1.00, which equals +4.00 (3+1=4).  In the same vein, if your child is nearsighted, say -4.00, but has an add of +2.00, then the  near distance part of the bifocals will have a prescription of -4.00 + 2.00, which equals -2.00.

Sometimes, you don’t have an “Add” part of the prescription, and instead you’ll just see a prescriptions for distance vision and a separate prescription for near vision.

But what does that mean for how my child sees?

If you’re wondering what your child’s prescription means in terms of how they can see, there are a couple of places online where you can plug them in to see how blurry things appear.  Keep in mind that an eyeglasses prescription is not the final word in how well a child sees.  For instance, it will not tell you how your child’s weak eye is seeing if your child has amblyopia, or how your child might be seeing if he or she has cataracts or glaucoma.

Online vision simulators:

• Eyeland Web Tools – this site has one tool for myopia, and a different one for hyperopia, and one for astigmatism.  All three show you a scene that you might see while driving a car.  So hopefully not a scene that your child would necessarily see, but it still helped me visualize how the world might look with Zoe’s prescription.  Simulates prescriptions from +9 to -9 for the spherical error, and up to -8 for the astigmatism.
• Eli Billauer’s blur simulator – I’ve mentioned this site before on Little Four Eyes.  Enter your child’s prescription (sphere, cylinder and axis) for each eye, and it will show you two Snellen charts (the one’s with the big E at the top), one for each eye, that simulates how your child might see it.  Simulates prescriptions from +5 to -5 for the spherical error and +5 to -5 for astigmatism.
• Wolfram Alpha- this is a weird search engine that tries to answer your questions, and calculate equations that you enter.  You can enter your child’s eyeglasses prescription, and it will give you information about it, including a simulation of looking at the Snellen chart, and the far or near point for clear vision.  You will only see the Snellen chart if the simulator thinks one of the lines would be visible, which is +2.5 to -2.5.   You need to enter the prescription this way:

  OD +4.25 cyl 0.5 x 90

  (the number after the “x” is the axis for astigmatism, you can leave off the astigmatism numbers if they don’t apply).

Melissa from Children’s Hospital Boston’s pediatric blog, Thrive, wrote about a baby undergoing a new surgical procedure, called keratoprosthesis to replace her damaged cornea with an artificial one.  It’s an interesting story with a hopeful ending.  I have to say, writing this blog has given me a new appreciation for vision, and how fragile it can be, and some of the amazing advances in medicine.  I feel like I’m forever learning more and more (that’s a good thing).

In Tami’s story, her daughter Lilly passed the vision screening that their school system required for kindergarten, but was found to have amblyopia at an eye exam at an ophthalmologists   (read the whole story) .  As I was looking in to this, I was surprised to learn that this isn’t all that uncommon.  Children can and do pass the quick vision screenings at their doctors or at school, when in fact, they do have vision problems that need to be treated.  In the United States, most states require some vision screening before a child starts school (though 16 states have no requirement at all), only 3 states require a comprehensive eye exam.  I’d love to hear from readers in other countries about whether they have any vision screenings or exams that are required of children before they start school.

What’s the difference between a vision screening and a comprehensive eye exam?  A comprehensive eye exam is performed by an opthalmologist or optometrist and includes a visual acuity test using one eye, and then the other, cover testing, and then dilating drops and retinoscopy (if you’re reading this because your child wears glasses, this would be the very familiar eye exam).  The screenings, on the other hand, vary from place to place, but most typically involve reading an eye chart or vision acuity cards, though some use refractors that measure the refractive error of the eye without dilating the eye first.  Screenings may be done by pediatricians, school nurses, technicians or trained lay persons.  There is no question that the full comprehensive eye exam is necessary to get the complete picture of a someone’s vision needs.  The question is whether a screening can identify kids with vision issues and get them to an eye exam to figure out exactly what treatment is needed.

The Report of the National Commission of Vision and Health on Children’s Vision that was released this summer does a nice job of compiling and explaining studies that have been done to compare vision screenings to vision exams (the report is here, start on page 9 for the section on screenings and exams).  Vision in Preschoolers, or VIP, is one such study, conducted in 2001-2004, by the National Eye Institute, which compared 11 vision screening tests to see which were the most accurate.  The three best tests still missed more than 30% of kids with vision problems (though they did identify 90% of children with the most severe vision problems).

At least one study cited in the report found that the additional cost of having all children go through a comprehensive eye exam is easily offset by the increase in the number of children whose amblyopia could be detected earlier and treated successfully, compared with the numbers detected and treated with a vision screening program (full text of that study is here).

I know that I’m preaching to the choir here at Little Four Eyes, but please encourage friends and family to have their children’s vision checked out at a full eye exam, rather than relying on vision screenings.  Programs such as InfantSEE (at infantSEE.org) provide exams at no cost for infants, and many insurance programs cover comprehensive eye exams once a year or once every two years.

Tami sent me this story about her experiences in getting her daughter diagnosed.  I have more to write about the importance of vision exams over vision screenings, but there is so much good advice in this story, that I wanted to publish it on its own.  -Ann Z

My daughter, Lilly, turned 5 in June. During her annual check up we were sent to the optometrist’s office to read the eye chart. That is the only thing that is required by our school system for kindergarten entrance. There was no specific line for her to stand on, the lady just told us to stand in an approximate spot about 4 feet from the chart and read as many lines as possible with both eyes. Next she was told to cover her left eye with her hand and read as many lines as possible. Then the same with the right eye covered. We were handed a slip of paper saying she had 20/20 vision.

I knew our health insurance covered one eye exam a year as long as we saw an ophthalmologist. We don’t have vision insurance and I have been wearing corrective lenses since I was 10 so I always take advantage of that. I had also taken Lilly in before she started preschool when she was 3. He didn’t find any problems at that time. Her preschool also had the Lion’s club in doing eye checks and there were not problems found.

I had an exam already scheduled for her the next week after her annual pediatrician’s exam (June 30th). I figured it was a good idea to get her in before she started kindergarten, just to be sure there were no problems.

After going back to the office she sat in the exam chair and was told by the nurse to read the chart with both eyes, no problem. Then the dr came in. He had her read the chart with both eyes, no problem at all. Then asked her to cover her left eye with the plastic thing, no problem. Next he told her to cover her right eye, she sat there for a moment, then started moving the plastic thing and cheating. I could tell the dr was getting annoyed by it so I went over and covered her eye. To my complete shock, she could not read it! Not even the top line. My heart sank. How could I not know that my baby couldn’t see out of one eye?

Next the dr put dilating drops in and asked us to wait in the hall for a few minutes. When we went back in he did all the usual things optometrists and ophthalmologists do with adults. Looking into her eyes, changing lenses to find the right prescription the reading the charts again.

Sadly this dr was not very good about explaining her situation. He told me she had good vision in the right and bad vision in the left along with an astigmatism. She would need glasses and I would need to put atropine drops in the good eye every day. That was about it. As soon as I left the office I was on the phone leaving a message with a friend who’s daughter also wears glasses, just to get  some general information from her such as a good place to buy glasses.

After a night of stewing, not sleeping and worrying about how we were going to pay for all of this with no vision insurance I talked to the nurse and she informed me that it was called Amblyopia and that our health insurance would probably pay for it. So, I called the insurance company, they told me that yes it was a medical diagnosis so insurance would pay for exams, but not glasses. I find that crazy. If you break a bone your insurance pays for getting a cast put on!

I was talking to the mother of one of Lilly’s t-ball teammates. Her daughter had amblyopia also and they had a wonderful pediatric specialist that they really liked in another city about 45 minutes away. I decided we’d go back for her re-check the next month and see what the dr said.

A month later (August 6) we had to go back for a re-check. After reading the eye chart and looking at her eyes he tells us that she’s had tremendous improvement and we could stop the drops, continue wearing the glasses and come back in a year.

After all that I had read on the internet, I didn’t like what I heard. So I called the specialist I had been told about, and actually had heard his name from a few other people too. It was hard to get an appointment (September 6) and I had to take Lilly out of school for half the day, but I had no choice unless I wanted to wait until January.

I am totally sold on the pediatric ophthalmologist! When we were called back into the exam room the assistant asked us what brought us there and I explained everything up until that point. That place is fantastic. What a difference going to a place that is geared toward children! The staff is so much more patient and they have so many tricks to making the kids cooperate. In the first room Lilly read the eye chart with her glasses on and the lady took her glasses for a bit to check them. Then she dilated both her eyes and sent her into the waiting room filled with toys and a Disney movie playing.

After a few minutes we were sent into a different room to wait for the dr. When he came in he asked us to again tell him the story of what brought us to his office. He seemed very irritated by us being told that everything was fine after a month. He told us that treating amblyopia can take many months and even years to treat. He did all the same things as the other dr, but he was much more patient with her and had the tools to get her to cooperate for him, such as animals and movies to draw her attention.

At the end of the exam he told us that she definitely needed to return to treatment and gave us the option of doing the drops again or try patching. She also needed new lenses in her glasses, a stronger prescription for the bad eye. He told us that if the drops didn’t make enough improvement we would have to start patching and also warned us that it was possible that she would need surgery if the the patching didn’t work. He asked if we had ever noticed the lazy eye , which we hadn’t, so he made her eye drift off so we could see what was going on. He was also very thorough about telling us all about the condition, such as most of the time children have it from birth and how often it goes undiagnosed. He waited to see if we had any more questions for him before he left too. Nothing is worse than a dr that darts out of the room before you have a moment to think about things.

I walked out of that office feeling much better about the situation than I ever had. I will NEVER deal with someone who is not a pediatric specialist for anything again. The original dr is a good dr for me, but not for her!

We go back next month (November 5th) to see if she’s improving with the drops.

I just read a fantastic post over at Christopher’s Eyes that I wanted to pass along. Christopher is three, and has congenital glaucoma, which means many, many appointments to check his eye pressure.  For young kids, this means an exam under anesthesia (EUA), which is a huge production requiring a trip to a hospital and a lot of preparation, because the child will be put under anesthesia.  Most doctors will say that EUA’s are needed until a child is at least 6 because no child will sit still enough for the adult pressure checks.  Christopher’s Dad talks in great detail about  the process they went through to help Christopher feel comfortable at the doctor’s office, and to understand what was going on, and to sit still for successful eye pressure checks at the doctor.

Even if your child won’t need an EUA, the post is a good one for thinking about compassionate and helpful ways to help your child feel comfortable in exams or with unfamiliar procedures.