“Watch out where you’re going,” Jim shouted to his friend.
The warning came just in time to alert Jack to stop before he walked into the utility pole.
“I never saw the pole,” Jack said, but he dismissed this scare and forgot about it. That is until a few evenings later, when he walked right into the corner of the garage.
“What happened to you?” his mother asked as she helped clean his face.
Listening to her son, she made an important decision. A few days later Jack sat in the exam chair in their eye doctor’s office.
The doctor studied Jack’s eyes, then turned to the boy’s mother and said he was sure Jack had retinitis pigmentosa.
Jack and his parents are composite characters made up from the experiences of several people I’ve known through the years who’ve been diagnosed with the vision disorder and parents who’ve raised children who have it.
The disorder, affecting at least 100,000 people in the United States, is a group of inherited conditions in which the rods in the retina slowly degenerate and change the way light is seen. The cones also may be affected, distorting color vision.
It causes a progressive loss of night vision, peripheral vision and general visual sharpness. As the disease progresses, tunnel vision may occur. Some people may experience total blindness although most will retain a little eyesight.
Although its exact cause is unknown, retinitis pigmentosa is believed to be caused by mutations in several different genes. In most cases, the disorder is linked to a recessive gene inherited from both parents.
But mutations in dominant genes and genes on the X-chromosome have also been linked to some cases, especially in those with no family history of the disease.
The condition can also show up as part of other syndromes, such as Bassen-Kornzweig disease or Kearns-Sayre syndrome, and may be associated in those with near-sightedness, cataracts, degenerative vitreous conditions and inherited hearing loss.
The first symptom of retinitis pigmentosa is usually diminished night vision or difficulty to see in dimly lit or dark places. Vision often deteriorates more in adolescence or early adulthood.
Because it is believed to be a genetic disorder it cannot be prevented. Early diagnosis is essential for successful treatment and for planning its expected progression.
The ophthalmologist or optometrist can diagnose the disease with an ophthalmoscope, which looks at the inside of the eye through the pupil. In a normal eye the fundus will be orange, but in those with retinitis pigmentosa there will be brown or black blotches.
Although the ophthalmoscope is still widely used, advanced technology such as peripheral retinal mapping allows for earlier diagnosis by identifying “bone spienli” pigment deposits in the extreme periphery.
To confirm the diagnosis, an electroretinogram may be used to measure electrical activity in the retina. People with the disease have lower activity levels.
There are currently no medical or surgical procedures for retinitis pigmentosa and no known cure, but experimental treatments may slow the disease’s progression.
Preliminary trials have been promising in the use of dilatiazem, a commonly prescribed heart medication, and in large doses of vitamins A and E. However, excess amount of these nutrients can cause side effects and must be used under a doctor’s supervision.
Protecting the eyes from sunlight and eye patching also may be recommended. Low-vision aids such as magnifying and telescopic lenses can help compensate for diminished eyesight.
Although Jack’s parents were distraught, they vowed to do their best for their son.
They would not baby him or allow him to grow up helpless. He would be allowed to play with other children with few restrictions.
And they would ensure he had regular appointments with his eye doctor. Though his vision might decrease, Jack would still enjoy his life.
Parents of children with eye problems or diminished eyesight need to allow their children to enjoy normal activities; they should not be so protective that the child is unable to develop his full potential.
Ernie Jones, a registered nurse who retired due to vision loss, can be reached at 529-9252 or at firstname.lastname@example.org.