Laura Windsor, O.D., F.A.A.O.
Specialist in Low Vision Rehabilitation

 

 Answers Your Questions

  

Please submit your questions to Dr. Laura Windsor at drlaura@eyeassociates.com.

 

Why have I never meet in person someone with my problem?

This is a very rare condition. There are probably less than 10,000 people with it in the United States, a country of over 309,000,000.

 

Will this condition get worse? Will I loose more vision?

Achromatopsia is usually a stable condition. It is very rare for any major progression to occur. There are separate conditions called progressive cone dystrophies that appear similar to achromatopsia that can progress. These can usually be differentiated from achromatopsia by the doctor and often start at a later age than achromatopsia.
   

What can I do to improve my vision? Will eye vitamins help?

Animal studies have suggested some benefit in achromatopsia of using antioxident vitamins. We have no major human studies yet. More research is needed.

 

Is there any diet that I should follow to help my eyes?

There is no specific diet to help patients with achromatopsia, but based only on animal studies, a diet of food rich in antioxidents may be considered. More research is needed. 

 

Is there a medical or surgical treatment?

There are no current medical or surgical treatments for this disease. There are surgeries that may reduce nystagmus.

 

Will stem cells or gene therapy help?

There is current success in gene therapy to treat achromatopsia in mice and canines. This may represent the future in treatments. It holds great promise, but it will take time for this to be studied in humans. In the dog model, the best results occurred when the dog was treated within about the first year of life. See our section on genetic treatments.

 

Why does my son not like to wear the prescription the doctor prescribed in his glasses?

Not all achromats will accept their full prescription. The high hyperopia prescriptions,  found in many rod monochromats, may be more difficult for some patients to wear. These high corrections create parallax motion. Sometimes a partial correction is better and in some cases non-prescription lenses with the  correct filter may be more accepted.  Sometimes dark filters in the lenses result in the child being teased. In older children, filtered contact lenses may be helpful. 

 

I was told I am “legally blind” but I am not sure what this means?

Legal blindness is not a medical term. It was established in the 1936 Social Security Act to set a marker on the eye charts at which governmental benefits would be provided. It has traditionally been written as:  Vision in the either eye no better than 20/200 or visual field less than 20 degrees. However, in 2007 to clarify a problem created by different types of acuity charts, Social Security  changed the definition to allow legal blindness if the patient cannot read any letters on the 20/100 chart with either eye.

I have achromatopsia. Will my children have this condition?

Rod monochromatism is inherited as an autosomal recessive condition in at least three different types. This means it took one gene from each of your parents to cause the gene.Both of your parents were carriers for the condition. You as a rod monochromat would have to have a child with a person who is a carrier for the condition or another rod monochromat of the same type to have a child with rod monochromatism.  Since this condition is very rare, the chance that you and your partner or spouse is a carrier is statistically like winning the lottery two times in a row. Theoretically, it is possible but statistically it is unlikely to occur.

Though all offspring of rod monochromats will be carriers, the risk of having an offspring with rod monochromatism is so unlikely it should not be a consideration. None of our doctors have ever encountered a rod monochromat having an offspring with the same condition. 

Blue cone monochromatism (BCM) is the rarer form of achromatopsia. It is an X-linked autosomal recessive disease that occurs primarily with males. Men receive their X chromosome from their mother and can only pass that gene mutation on through their daughters. All daughters would receive the gene, but nearly always they would be carriers only. The daughter of a person with X linked BCM will have a 50% risk to pass the gene on to her children. Males receiving the affected gene will all have the disease, but females receiving the affected gene will nearly always be carriers.

 

In blue cone monochromatism, it is common to have a maternal grandfather and maternal cousins with the condition, but no children with the condition. It could present in male grandchildren.

 

Since I have rod monochromatism and one of my two brothers has it, will my children have it.

See the explanation above. In autosomal recessive diseases, both your parents had one gene for achromatopsia and one gene not causing  achromatopsia. Since it takes a gene from both parents, and each parent had a 50% chance of giving that gene to each child they have, the risk is 50%.  Thus there was a 25% risk  (50% X 50% = 25%)    with each child your parents had. In dealing with small numbers such as you and your two brothers, the odds or risk versus what we actually get can be quite variable.  Just as in flipping a coin where the odds are 50% to get either heads or tails, you could get tails three times in a row.

The fact that some of your siblings have the condition is normal for an autosomal recessive condition. It is extremely unlikely your children will be affected but each of your children will be a carrier.

Why does my child want to play outside only at night? 

The nighttime is your child’s best time for vision. The light that blinds them in the day is gone. I encourage you to do many activities with your child at night.

 

Why does my child have congenital achromatopsia? Did we do something wrong?

No! These are genetic diseases. It is not related to any behavior, medication, or drugs! 

 

Why do my child’s eyes seem to shake?

Sensory nystagmus is often the first sign that a child has a vision problem. It is typical in nearly all children with impaired vision from early age. On first onset, it requires careful medical workup usually with a pediatric ophthalmologist to rule out various causes of vision loss that produce nystagmus. It is also commonly seen is other congenital vision disorders including albinism.

 

When my child's eyes shake from the nystagmus, does he see the world shaking?

 

No! In nystagmus that begins in early childhood, the child will not see the world shaking. In the onset of nystagmus in later life such as head injury,  oscillopsia, the sense the world is moving can occur.

 

I did not detect my child's eye shaking until three months of age. Did I miss early signs of this problem?

No! The nystagmus associated with achromatopsias usually appears about age 3 - 4 months. The aversion to light also begins in this time period.

 

The shaking of the eyes seem to change. Why does it change?

Stress, illness, direction of gaze of the eyes and converging the eyes to read all my affect the speed amplitude and type of nystagmus. When nystagmus increases, the visual acuity may decrease slightly at that time.

Why does my child seems to tilt her head slightly to on side? 

Many patients with nystagmus have a null point, a position of the head and eyes that slows the nystagmus and thus improves the vision. You should encourage the child to assume their preferred position to see well. Be sure other caregivers, teachers and relatives understand this.

My child sometimes seem to look slightly away from what he is  supposed to be looking at?

Some achromats may shift their fixation slightly to the side to place the image on the area they see better rather than right on the center of the eye. This is called eccentric fixation. It is not the same as the null position.  It can slightly improve vision. In most achromats, owing to their mild vision loss, it is usually only a slight shift.

How can I help my child see better?

We have provided an extensive list of ideas to aid parents. The first step is getting the diagnosis and then you need to see the low vision specialist. Controlling light is the first most important step. You must create a world where light and glare are controlled so your child can thrive intellectually and emotionally. See our section on Children's Vision.

 

Can achromats drive?

Not all achromats can become drivers.  Some blue cone monochromats, who have less visual impairment may drive with only eyewear and the proper filters.

Today, with the development of new soft filtered contact lenses to better control glare and modern bioptic systems, more and more achromats may have the opportunity to become bioptic drivers. Our doctors have been leaders in developing different levels of filters to aid these patients and in the fitting of bioptic drivers. You can find more about driving on this site in our section, "Driving Issues" and you can visit our other website dedicated to bioptic driving at www.BiopticDrivingUSA.com.  Driving also depends on the state or country that you live in.  About 80% of the USA states allow bioptic driving in some form.

 

Will dark red lenses help me? 

Rod monochromats have primarily rod photoreceptor functioning and lack all or nearly all cone function. Thus the achromat must see with the rod cells, which are normally bleached out by bright light. Red filters allow only lower energy red light pass to the retina. Thus the rod cells are not bleached and the patient can function better in normal light.  If red filters do not work for you, you may either not have the right darkness of red or you may be an incomplete achromat for whom solid red filters block too much vision. In the latter case, a different color filter may be a better option.

 

Is red the only color that works?

Other colors can work but may be slightly less efficient in sparing rods from bleaching out. We often use brown/amber filters in our contact lenses to improve cosmetics. In incomplete achromats, the color of the filters selected must not block any of the patient's residual color vision. 

For example, blue cone monochromats may have some blue and yellow color function that would be blocked by solid dark red filter. In these patients, we may use magenta filters created from both red and blue dyes that allow both blue and red to pass through to the retina. The red helps the rods function in bright light and the blue provides signal to the remaining blue cones.

Do the red contact lenses work better than tinted glasses?

Achromats are quite variable. We have patients wearing both contact lenses and glasses, but with the exception of children too young to fit with filtered contact lenses, the vast majority of our patients find the glare control is dramatically improved with the correct filtered contact lenses.

All patients with or without filtered contact lenses, should still wear sunglasses outside owing to the difference in brightness from inside to outside bright sunshine can be on the order of 350 to 2500 times more light energy.

 

When can a child be fit with filtered contact lenses?

This is always a difficult question to answer. The benefit of the contacts is great, but the handling of lenses can be an issue and the ability of the child to report discomfort can be an issue. The answer depends also on the parents, especially their ability to handle the contacts lenses. We know from our experience that by age nine many children handle contacts quite well. Younger children must be looked at on a case-by-case basis. The child's maturity and motivation should be considered as well. Many young children do fine with red or magenta filtered eyewear until they reach an age where cosmetic appearance becomes more important.