Accommodative insufficiency (AI) involves the inability of the eye to focus properly on an object.
Accommodative insufficiency is a sensory motor anomaly of the visual system that is characterized by an inability to focus or sustain focus at near, demonstrated clinically by an insufficient amplitude of accommodation based on age-expected norms. The American Optometric Association defines accommodative insufficiency as occurring when the amplitude of accommodation is lower than expected for the patient’s age and is not due to sclerosis of the crystalline lens. Symptoms begin almost simultaneously with an increase in near work demand. The inability to focus on near targets or to sustain clear vision for a period of time, diplopia, asthenopia, and difficulty reading with headache are the most frequent patient complaints.
Scheiman et al in a study that included 2,023 pediatric patients found 19.7% to suffer from a binocular or accommodative dysfunction. This was broken down further into convergence excess (7.1%), convergence insufficiency (4.6%), accommodative insufficiency (2%) and accommodative excess (1.8%).
Typically, there are a few different causes of accommodative insufficiency. Children who have had poor health overall and suffered from illnesses such as a severe flu bug, glandular fever, or chronic fatigue can develop weak focus. It can also be a side effect of some medications or visual stress. Children who are not able to develop good focusing stamina are prone to accommodative insufficiency.
Accommodative insufficiency is commonly present in people with convergence insufficiency. An understanding of the close association between accommodative function and convergence is important. When patients accommodate, convergence occurs, and when they converge they also accommodate. This relationship can be quantified by the AC/A (Accommodative Convergence/Accommodation) and CA/C (Convergence Accommodative/Convergence) ratios, respectively. Accommodative and convergence insufficiency typically present at the same time, a likely result of a neurological link. The rate of co-morbidity has been shown to increase with the severity of the convergence insufficiency.
Symptoms of Accommodative Insufficiency begin almost simultaneously with an increase in near work demand. It is common as school age children encounter more desk work and when the font size on worksheets and in text books gets smaller. Many parents note that the amount of near work that children perform on a daily basis has increased ten-fold from when the parents were young. Students are expected to do more near work and at a more demanding level than ever before. Research has shown that some children, especially under the age of 8, often do not report any symptoms of Accommodative Insufficiency.
The symptoms of accommodative insufficiency are known to include blurred vision, fatigue, headaches, motion sickness, double vision, and lack of concentration. Accommodative insufficiency is most commonly detected in school-aged children. This is when it becomes apparent that a child is having a problem focusing on certain tasks, such as reading, writing, or copying from the blackboard. However, accommodative insufficiency is often mistaken for a learning disability or attention deficit disorder when, in fact, it’s a vision impairment that is causing the child trouble. In turn, poor school performance can be another warning sign.
Accommodative Insufficiency in children has the potential of being misdiagnosed as ADHD/ADD or learning disability. Of note, it has also been found that Accommodation can be altered significantly by medications such as Adderall, Ritalin, Concerta and Dexedrine. This is why it is paramount to the overall binocular vision of the person to be seen by a developmental optometrist.
There are also several systemic findings associated with accommodative dysfunction. They can include neurasthenia (a condition characterized by general lassitude, irritability, lack of concentration, worry, and hypochondria), emotional factors, toxic conditions, dental caries or infection, as well as endocrine disturbances, anemia, and hypertension.
Several management options are available for Accommodative Insufficiency including plus lenses for near and optometric vision therapy.
A pediatric optometrist should be consulted if accommodative insufficiency is suspected in a child to determine the proper course of treatment to take. A child may simply need to start wearing reading glasses, or the doctor might find it necessary for them to undergo vision therapy. This is meant to teach the brain the right cues for focusing.
Accommodative insufficiency can be an extremely frustrating condition for children to deal with, especially when it comes to focusing in the classroom and on schoolwork.
Accommodative Insufficiency - Info