What Is Central Scotoma?
Central scotoma is a condition that coincides with central visual fixation. It is considered to be the most damaging condition as routine precision and reading work require the central part of the vision. The condition suggests a lesion between the optic nerve and optic chiasma. It can be seen in many different ways in a person. For instance, some people can see it as a gray spot, distorted and blurred vision. Central scotoma can be a little more frustrating because only the central part of the vision is affected, not the peripheral, making day-to-day life even more difficult.
The macula is located behind the retina, which plays an essential role in central vision. Due to the degeneration of the macula, the cells are deprived of oxygen and nutrients. As a result, waste products build up there. In the other scenario, the leaky blood vessels grow more, which causes further degeneration of the cone cells of the macula. The sharp and middle parts of the macula have degeneration, due to which straight vision is impaired.
What Are the Types of Central Scotoma?
There are the following types of central scotoma:
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Relative Scotomas: The eyesight is limited to bright and large objects. A person has difficulties seeing dim and small objects.
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Absolute Scotomas: Despite any light intensity, the vision is compromised.
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Positive Scotomas: Due to retinal defects, a person has a black spot in front of the eye during vision.
What Are the Causes of Central Scotoma?
The following are the etiological factors associated with central scotoma:
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Multiple Sclerosis: Multiple Sclerosis is known to be the etiology behind uni or bilateral scotoma.
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Methyl Alcohol: This is the reason behind the symmetrical bilateral scotoma.
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Deficiencies: Vitamin B-12 nutritional deficiencies.
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Vascular Lesions: This can be the cause of unilateral scotoma.
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Glaucoma: Glaucoma can be the reason behind off-center scotoma.
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Macular Degeneration: It is the most common cause behind central scotoma, which causes disorders related to the optic nerve or retina.
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Nerve Damage: This can cause damage to the retina, which in turn disables the visual message-sending ability to the brain.
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Eye Infection: Eye infections that cause complications, such as the formation of scar tissues, strokes, or tumors can be the reason behind this condition.
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Traumatic Brain Injuries: Traumatic brain injuries may affect the optic nerve or leave scar tissues or blood clots, this can be the reason behind this condition.
What Are the Signs and Symptoms of Central Scotoma?
The followings are the signs and symptoms associated with central scotoma:
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Central vision is compromised.
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Migraines.
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Blurred vision in the central part.
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Gray or black spot in the central part of the vision.
How to Diagnose Central Scotoma?
The diagnosis of the scotomas starts by checking for any nerve damage or retina or optic nerve involvement in cognition. Once the cause behind this condition is determined, the management of scotoma gives better results. There are the following diagnostic methods used for evaluating the causes behind central scotoma:
A Fundus Examination: The fundus is the only location of the eye where the vasculature is visual to examine. This examination is used to check for any type of nerve damage, tear to detachment, or glaucoma in patients. Mydriatic eye drops are used in the patient’s eye to dilate the pupil for examination. After that, depending on the requirement, direct, indirect, or slit-lamp examination is done.
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Direct Examination: During this type of examination, the patient will be sitting in a chair comfortably. The lights in the examination room will be off, and the doctor will be sitting across from the patient with an ophthalmoscope to examine the eye. The doctor may ask to change the direction of the eye while the patient will be examined with the instrument with a light and several different lenses (ophthalmoscope).
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Indirect Examination: This examination allows the ophthalmologist to have a clear and detailed look at the structures located at the back of the eye. During this procedure, the patient will be in a reclined position. The doctor will be examining each eye with a lens and headgear with the light on it. Additionally, in some cases, the doctor may use a blunt probe to apply gentle pressure on the eye.
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A Slit Lamp Examination: It is an examination done with a microscope that is attached to the light. This is called a slit lamp. This is used for close and precise examination of the back of an eye.
A Visual Field Test: This type of test is also known as the Humphry visual test. It examines the severity of the central as well as peripheral vision using spots of light. During this test, the patient is asked to place his head and chin on the resting part of the instrument and fix his vision on the central fixation point in the large bowl-sized instrument. This test measures the non-mobile stimulus in the static perimeter. Every time a patient sees the stimulus, he is asked to press the green button on the remote control given to him. The stimuli may be different in size and light intensity. This test continues until it reaches 50 percent of the stimulus intensity or until the threshold.
How to Manage Central Scotoma?
Central scotoma cannot be treated with surgery or glasses. An ophthalmologist may suggest the following support for the condition:
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The phone or keypads with a larger number to see clearly.
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If a person has to work on a computer screen, the doctor may recommend using an anti-glare screen.
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It is very difficult to see numbers on the wall clock, so using a talking clock would be a great help.
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For reading, the audiobook is recommended.
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Change the setting on the digital screen to magnify the text size.
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Magnifying glasses or hand-held magnifying glasses also can be very useful.
Conclusion
Central scotoma is a condition that causes many other complications in daily life as it directly affects the central vision of the eyes. The condition should be closely monitored along with the management of the other health-related complications associated with it. Also, the use of supporting aids can be a great help in managing the condition. Lastly, patients with this condition should regularly go for follow-ups.
