A number of different diseases can cause retinitis pigmentosa of the eyes. These diseases can occur as a side effect of a common physical disorder or simply develop as a result of genetics. It is estimated that one in every 4,000 Americans suffers from the effects of retinitis pigmentosa.
Causes of Retinitis Pigmentosa from Disease
The most common causes of retinitis pigmentosa are easily controlled by lifestyle choices and drug therapy. Usually, this is a result of high blood pressure and is considered one of the primary reasons to control a person's blood pressure. Hypertension will cause hemorrhaging in the retina, ultimately resulting in the development of the disease. Those suffering from diabetes can also develop retinitis pigmentosa. Diabetes can cause aneurysms along the retina, which results in blindness.
Other eye disorders can commonly result in the development of this disease. Glaucomas and macular degeneration often cause retinitis pigmentosa due to changes in the eye or the development of scar tissue. Also, conditions that result in alterations to pigmentation of the eye have also been found to result in this disorder.
Genetic Causes of Retinitis Pigmentosa
Geneticists have identified at least 100 genes that can cause the development of retinitis pigmentosa. These genes are heterogeneous, meaning they appear to come from different sources within each person's genetic code. However, each of these sources results in varying degrees of the disorder with symptoms ranging widely in severity.
According to scientists, roughly 10 to 25 percent of the genetic linkage comes from dominant genes, while 15 to 20 percent are recessive. Likewise, only five to ten percent are linked to the X chromosome. Oddly, roughly half of those affected have no prior family medical history of retinitis pigmentosa. Also, the disease seems to impact those with hearing loss at a large level, with approximately 30 percent of all patients exhibiting both symptoms.
Above: Close up of retinitis pigmentosa; supplied by Christian Hamel at Creative Commons; http://upload.wikimedia.org/wikipedia/commons/4/49/Fundus_of_patient_with_retinitis_pigmentosa%2C_mid_stage.jpg
Identifying Retinitis Pigmentosa
Those suffering from retinitis pigmentosa can be most readily identified by the symptoms. The field of vision shrinks, a person develops a difficulty reading or seeing detailed images and occasionally becomes clumsy.
Optometrists can use a variety of different testing mechanisms to test for retinitis pigmentosa. These include a simple eye chart test, examination of the retina or by conducting an ultrasound on the eye's internal structure itself.
Symptoms and Treatment of Retinitis Pigmentosa
Specifically, retinas pigmentosa causes the destruction of the rod and cone interaction in the eye. Cell death, otherwise known as apoptosis, occurs within the photoreceptors of the rod or cones, causing a loss in night vision at the minimum and full blindness in acute patients.
Treatment for this disorder is limited based on the level of scientific research available. Doctors are limited to analyzing the age and history of the patient and make a determination of how long the disease will take to fully manifest. The main source of treatment is simply protecting the retina using sunglasses with UV protection.