Central scotoma
Scotoma is a visual field defect which results in formation of black spots with no vision. A black spot or blind spot in the center of vision then it is central scotoma. It can be bilateral and unilateral as well.
Onset
The central scotoma can be unilateral or bilateral. If the scotoma is due to some macular diseases then definitely retina is involved in it. This can further be confirmed by macular OCT. Optical coherence topography is an imaging technique commonly used to evaluate the condition of layers of retina. These scans are very helpful to detect the eye problems that are causing the formation of central scotoma.
If the formation of central scotoma is not due to retina then most of the time the differential diagnosis is optic disc. The unilateral scotoma is usually due to
How to diagnose the causes
The ophthalmologists generally recommend OCT and MRI of head and orbit. If the central scotoma is bilateral then its causes are usually systemic which occur due to toxic and nutritional causes.
Causes of formation of central scotoma
Macular degeneration
In macular degeneration which occurs in late stage of life generally after 50 years. Macula is the central portion of retina sensitive to light and helps for the central vision and fine details. In dry type of AMD the onset of central vision loss is slow and gradual while vision loss is more intense in wet AMD. It occurs due to age, cardiovascular diseases, obesity, alcohol consumption, diabetic retinopathy, hypertension and smoking etc. the degeneration in the macula result in the formation of central scotoma.
Strokes
Stroke occurs due to rupturing of blood vessel in the brain. The parts of brain are associated with the vision. Hence a stroke can cause vision loss. Central scotoma is one of the specific types of visual field loss in response to a stroke. The visual field affects should also be addressed along with motor and systemic side effects. The visual field loss can be restored if addressed and diagnosed properly.
Tumors
The tumors of brain and optic nerve insert pressure on the blood vessels and nerves which result in decrease or blurring of vision and then vision loss due to damage to macula in result of tumor formation. The blood supply to macula can be compromised which result in the degeneration of macular cells resulting in vision loss and formation of scotoma.
Scars and lesions
The scars of macula and retina and lesions of optic nerve can result in visual field defect resulting in the formation of blind spot. They cause ischemia to retina which causes degeneration of retina. The ischemia can also result in neovascularization of retina.
Alcohol consumption
Alcohol consumption has become a thing of concern. It not only causes systemic diseases but also affects the visual organ of the body. Its uncontrolled consumption cause toxic nutritional amblyopia and neuropathy as well. It induces deficiency of folate and B12 vitamins which are very important for papillomacular bundle.
How to diagnose central scotoma
Patients come with the complain of
The central scotoma occurs right in the center of eye. It generally affects the daily activities on a larger scale. The people find it difficult or impossible to recognize things which come in the center of visual fields. However they see best at the periphery or when they tilt their eyes. Following tests are helpful for the diagnosis
- The confrontation test
- Amsler grid tests
- Perimetry
- Serological tests for systemic complications
Treatment for central scotoma
Most of the time central scotoma is fixed. We cannot treat them with glasses, contact lenses and surgeries. Doctors generally recommend low vision therapies and aids. Low vision therapy helps these patients to live with this central vision loss by making lifetime adjustments and routine modifications. This counseling of such patients is very helpful.
If the scotoma occurs due to minor stroke or migraine then it generally resolves completely with in few hours.
Founder of EyesMatterMost- an optometry student who loves talking about eyes. I tend to cover topics related to optometry, ophthalmology, eye health, eyecare, eye cosmetics and everything in between. This website is a medium to educate my readers everything related to eyes.