Eye Movements Reveal Reading Impairments in Schizophrenia

A study of eye movements in schizophrenia patients provides new evidence of impaired reading fluency in individuals with the mental illness.

The findings, by researchers at McGill University in Montreal, could open avenues to earlier detection and intervention for people with the illness.

While schizophrenia patients are known to have abnormalities in language and in eye movements, until recently reading ability was believed to be unaffected. That is because most previous studies examined reading in schizophrenia using single-word reading tests, the McGill researchers conclude. Such tests aren't sensitive to problems in reading fluency, which is affected by the context in which words appear and by eye movements that shift attention from one word to the next.

The McGill study, led by Ph.D. candidate Veronica Whitford and psychology professors Debra Titone and Gillian A. O'Driscoll, monitored how people move their eyes as they read simple sentences. The results, which were first published online last year, appear in the February issue of the Journal of Experimental Psychology: General.

eye movement measures provide clear and objective indicators of how hard people are working as they read. For example, when struggling with a difficult sentence, people generally make smaller eye movements, spend more time looking at each word, and spend more time re-reading words. They also have more difficulty attending to upcoming words, so they plan their eye movements less efficiently.

The McGill study, which involved 20 schizophrenia outpatients and 16 non-psychiatric participants, showed that reading patterns in people with schizophrenia differed in several important ways from healthy participants matched for gender, age, and family social status. People with schizophrenia read more slowly, generated smaller eye movements, spent more time processing individual words, and spent more time re-reading. In addition, people with schizophrenia were less efficient at processing upcoming words to facilitate reading.

The researchers evaluated factors that could contribute to the problems in reading fluency among the schizophrenia outpatients -- specifically, their ability to parse words into sound components and their ability to skillfully control eye movements in non-reading contexts. Both factors were found to contribute to the reading deficits.

"Our findings suggest that measures of reading difficulty, combined with other information such as family history, may help detect people in the early stages of schizophrenia -- and thereby enable earlier intervention," Whitford says.

Moreover, fluent reading is a crucial life skill, and in people with schizophrenia, there is a strong relationship between reading skill and the extent to which they can function independently, the researchers note. "Improving reading through intervention in people with schizophrenia may be important to improving their ability to function in society," Titone adds.


Article republished from http://www.sciencedaily.com/releases/2013/02/130219121451.htm

Vitreous Detachment

What is vitreous detachment?

Most of the eye's interior is filled with vitreous, a gel-like substance that helps the eye maintain a round shape. There are millions of fine fibers intertwined within the vitreous that are attached to the surface of the retina, the eye's light-sensitive tissue. As we age, the vitreous slowly shrinks, and these fine fibers pull on the retinal surface. Usually the fibers break, allowing the vitreous to separate and shrink from the retina. This is avitreous detachment.
In most cases, a vitreous detachment, also known as a posterior vitreous detachment, is not sight-threatening and requires no treatment.

Risk Factors

Who is at risk for vitreous detachment?

A vitreous detachment is a common condition that usually affects people over age 50, and is very common after age 80. People who are nearsighted are also at increased risk. Those who have a vitreous detachment in one eye are likely to have one in the other, although it may not happen until years later.

Symptoms and Detection

What are the symptoms of vitreous detachment?

As the vitreous shrinks, it becomes somewhat stringy, and the strands can cast tiny shadows on the retina that you may notice as floaters, which appear as little "cobwebs" or specks that seem to float about in your field of vision. If you try to look at these shadows they appear to quickly dart out of the way.
One symptom of a vitreous detachment is a small but sudden increase in the number of new floaters. This increase in floaters may be accompanied by flashes of light (lightning streaks) in your peripheral, or side, vision. In most cases, either you will not notice a vitreous detachment, or you will find it merely annoying because of the increase in floaters.

How is vitreous detachment detected?

The only way to diagnose the cause of the problem is by a comprehensive dilated eye examination. If the vitreous detachment has led to a macular hole or detached retina, early treatment can help prevent loss of vision.

Treatment

How does vitreous detachment affect vision?

Although a vitreous detachment does not threaten sight, once in a while some of the vitreous fibers pull so hard on the retina that they create amacular hole to or lead to a retinal detachment. Both of these conditions are sight-threatening and should be treated immediately.
If left untreated, a macular hole or detached retina can lead to permanent vision loss in the affected eye. Those who experience a sudden increase in floaters or an increase in flashes of light in peripheral vision should have an eye care professional examine their eyes as soon as possible.
Article republished from http://www.nei.nih.gov/health/vitreous/vitreous.asp#a

What Is Orthokeratology?

What Is Orthokeratology?

In the most basic of terms Accelerated Overnight Orthokeratology or Ortho-k is the science of changing the curvature or shape of the cornea to change how light is focused on the retina at the back of one's eye.

Think of the cornea as the eye's equivalent of a watch crystal. It is a clear, dome shaped structure that overlies the colored iris. Its tissue is most similar to clear, wet skin; and like skin it is very pliable. Because the cornea separates the eye from air and the rest of the outside world and because it has a curvature that bends light towards the back of the eye, it is responsible for most of the eye's corrective power and contributes to various conditions such as nearsightedness (myopia), farsightedness (hyperopia), and the blur of astigmatism.

When you choose Ortho-k a few key tests must be performed. Chief among these tests is the determination that your eyes are healthy. The Orthokeratologist will examine the retina and also the health of the outside of the eye. The other key procedure is the mapping of your cornea. To do this an instrument called a Topographer is used. Just like a topographical map of a camping area show hills, plains, and valleys; the topography of the eye shows your doctor exactly how your cornea is shaped. The information from your corneal mapping plus the size of your cornea and the prescription needed to correct your vision are all used to design the retainer lenses (corneal molds) needed to create the Ortho-k effect.

On the day you pick up your Ortho-k retainer lenses you will be instructed in how to insert, remove, and take care your vision retainers. The fit of your retainers will be evaluated and you will be scheduled to be seen after your first night of wear. On day 1, your doctor will re-evaluate your fit and newly corrected vision and another mapping of your cornea will be performed.

Throughout your initial fitting period, your Orthokeratologist will monitor your corneal health and the effectiveness of treatment. At certain times your retainer lens fit may be modified to achieve your goals.

Orthokeratology can produce results in a surprisingly short period of time. The length of treatment to achieve your goals can vary from patient to patient. Factors which can affect the speed of treatment include:

1. your initial prescription
2. corneal rigidity
3. tear quality and quantity
4. your expectations.

We advise patients that they may need to use their retainers every night to maintain their newly corrected vision although some patients are able to vary their wearing time to once every two to four nights. The reason for this is due to the flexibility of your cornea.