I've been sight impaired since birth due to Optic Nerve Hypoplasia. Throughout my childhood my vision was blurry... sort of like looking at the world through a fogged glass window. I was able to see objects held within a few inches from my eyes, but my distance vision was very poor. As I became a teenager I developed Diabetic Retinipathy which further deteriorated my sight.
At present I have only light perception in my right eye, and the vision in my left eye is termed "finger count"... if you hold your hand up a few inches from my eye I can count how many fingers you are holding up. I can read a large print if I hold it within an inch or so from my eye as well, and can make out photos fairly well up close, too. Anything more then a foot or so away however is vague, distorted, without detail. I can see bright colors but have difficulty discerning the difference between dark colors such as browns, blacks, dark greens, purples, blues, etc.
I access the computer using speech/magnification software. This allows me to enlarge things on the screen and also have text read to me.. I also use a V-tech, which is a closed circuit TV that enables me to read any print material (books, newspapers, magazines, etc), as well as photos, drawings, etc. The print material is placed under a camera which projects the material onto a monitor.
A picture is worth a thousand words... that's the old saying. I've created this page to offer a glimpse of what it's like to see the world through my eyes.
OPTIC NERVE HYPOPLASIA
Optic Nerve Hypoplasia (ONH) refers to the underdevelopment of the optic nerve during pregnancy. The dying back of optic nerve fibers as the child develops in utero is a natural process, and ONH may be an exaggeration of that process. ONH may occur infrequently in one eye (unilateral) but more commonly in both eyes (bilateral). ONH is not progressive, is not inherited, and cannot be cured. ONH is one of the three most common causes of visual impairment in children.
In most cases there is no known cause of ONH. All races and socio-economic groups seem to be affected by ONH.
ONH may occur by itself or along with neurological or hormonal abnormalities. Hormonal problems not apparent in early life may appear later.
People with ONH demonstrate a wide spectrum of visual function ranging from normal visual acuity to no light perception. The effect on the visual field may range from generalized loss of detailed vision in both central and peripheral fields (depressed visual fields) to subtle peripheral field loss.
A high percentage of people with ONH have associated involuntary rhythmic movements of the eye (nystagmus). In most cases, the nystagmus is associated with significant bilateral reduced visual acuity.
Depth perception may be more severe if vision loss is great.
Mild light sensitivity (photophobia) may occur.
ONH is diagnosed by direct examination of the eye by an ophthalmologist. No current laboratory or radiographic tests will establish the diagnosis. Many infants who are diagnosed with Optic Nerve Atrophy are, in fact, children with ONH. Sometimes visual functioning can be predicted from the appearance of the optic discs. However, it is very difficult to predict visual acuity on this basis alone.
VISUAL AND BEHAVIORAL CHARACTERISTICS
Vision is characterized by a lack of detail (depressed field), but this lack of detail is not comparable to the blurred reduction in vision when a person removes her glasses.
In certain cases of ONH a specific field defect occurs. The person may not be aware of people or objects in the periphery.
People with ONH may be unable to locate objects in space precisely due to a lack of depth perception.
Some people with ONH have mild photophobia. They may squint, lower their head, avoid light by turning away, or resist participating in outdoor activities.
When one eye is affected more than the other, an ophthalmologist may recommend a trial of patching the stronger eye, since the visual loss may be due to amblyopia.
Diabetes is a disease that occurs when the pancreas does not secrete enough insulin or the body is unable to process it properly. Insulin is the hormone that regulates the level of sugar (glucose) in the blood. Diabetes can affect children and adults.
How does diabetes affect the retina?
Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease’s affect on the retina is the main threat to vision. The effect of diabetes on the eye is called diabetic retinopathy.
Over time, diabetes affects the circulatory system of the retina. The earliest phase of the disease is known as background diabetic retinopathy. In this phase, the arteries in the retina become weakened and leak, forming small, dot-like hemorrhages. These leaking vessels often lead to swelling or edema in the retina and decreased vision.
The next stage is known as proliferative diabetic retinopathy. In this stage, circulation problems cause areas of the retina to become oxygen-deprived or ischemic. New, fragile, vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina. This is called neovascularization. Unfortunately, these delicate vessels hemorrhage easily. Blood may leak into the retina and vitreous, causing spots or floaters, along with decreased vision.
In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems such as retinal detachment and glaucoma.
Signs and Symptoms
The affect of diabetic retinopathy on vision varies widely, depending on the stage of the disease. Some common symptoms of diabetic retinopathy are listed below, however, diabetes may cause other eye symptoms.
Blurred vision (this is often linked to blood sugar levels
Floaters and flashes
Sudden loss of vision
Detection and Diagnosis
Diabetic patients require routine eye examinations so related eye problems can be detected and treated as early as possible. Most diabetic patients are frequently examined by an internist or endocrinologist who in turn work closely with the ophthalmologist.
The diagnosis of diabetic retinopathy is made following a detailed examination of the retina with an ophthalmoscope. Most patients with diabetic retinopathy are referred to vitreo-retinal surgeons who specialize in treating this disease.
Diabetic retinopathy is treated in many ways depending on the stage of the disease and the specific problem that requires attention. The retinal surgeon relies on several tests to monitor the progression of the disease and to make decisions for the appropriate treatment. These include: fluorescein angiography, retinal photography, and ultrasound imaging of the eye.
The abnormal growth of tiny blood vessels and the associated complication of bleeding is one of the most common problems treated by vitreo-retinal surgeons. Laser surgery called pan retinal photocoagulation (PRP) is usually the treatment of choice for this problem.
With PRP, the surgeon uses laser to destroy oxygen-deprived retinal tissue outside of the patient’s central vision. While this creates blind spots in the peripheral vision, PRP prevents the continued growth of the fragile vessels and seals the leaking ones. The goal of the treatment is to arrest the progression of the disease.
Vitrectomy is another surgery commonly needed for diabetic patients who suffer a vitreous hemorrhage (bleeding in the gel-like substance that fills the center of the eye). During a vitrectomy, the retina surgeon carefully removes blood and vitreous from the eye, and replaces it with clear salt solution (saline). At the same time, the surgeon may also gently cut strands of vitreous attached to the retina that create traction and could lead to retinal detachment or tears.
Patients with diabetes are at greater risk of developing retinal tears and detachment. Tears are often sealed with laser surgery. Retinal detachment requires surgical treatment to reattach the retina to the back of the eye. The prognosis for visual recovery is dependent on the severity of the detachment.