What your eyes tell about your health.

It is said eyes are a window to the soul. But not many know that the eyes are a window to the health of a person. When the doctor looks inside the eye using an ophthalmoscope he is able to view the blood vessels in the retina. This is the only part of the human body where we can see even minute changes in   the blood vessels like thickening of the walls or small cholesterol crystals inside the vessels. Sometimes doctors can even diagnose diabetes, hypertension and hypercholestremia by just looking at the eye.

White Circles around the Cornea: Arcus Juvenilis.

In patients with high cholesterol levels in blood it is quite common to see white rings around the cornea. Though it may be seen in children also without any cause it is prudent to check blood cholesterol levels if all persons with arcus. 

Protruding Eyes: Proptosis.

Hyperthyroidism may cause proptosis, which may be the first sign of the condition. This may be seen only in one eye or both eyes. The ocular complications of thyroid eye disease may include corneal ulceration and visual loss. Protruding eyes can also be seen in tumors and swellings in the orbit which push the globe forwards. 

White Pupillary reflex: Leukocoria

Normally we see a red reflex from the center of the eye if we take a photo with a flash or if a light is shown into a child’s eye. If you notice a white reflex instead of red in your child’s eye you need to get the child examined immediately by an Ophthalmologist. Diseases causing white reflex include retinoblastoma, a childhood eye cancer, cataract, and infections, detachments and inflammation of the retina.

Eye Lid Drooping: Ptosis

Ptosis can be present from birth or may develop in adults. In a condition called Myasthenia Gravis the drooping may be worse after being awake longer when the individual's muscles are tired. In children if ptosis is severe enough to cause blurred vision it can lead onto amblyopia or lazy eye. It needs full evaluation and treatment at an early age. 

Red Eye

The eye can turn red in colour in several eye problems. The most common is conjunctitivitis. Conjunctivitis maybe due to infection or allergy. Inflammations of the eye like uveitis, scleritis can also make the eye red. Injury and foreign body stuck in the eye is another cause.

Transparent Iris: Albinism

This is a congenital condition of lack of pigmentation and includes the iris. Individuals with albinism have a rather transparent iris so that the red reflex is easily seen, although its colour varies from blue to brown. Most patients have deteriorating or poor vision with nystagmus. They are also at increased risk of ocular melanoma.

Light Sensitivity: Photophobia

Difficulty in looking at light can be seen in corneal abnormality like abrasions or edema and inflammation of the uvea or sclera. In these cases the eye will usually be red. In a normal looking eye photophobia can be seen in Migraine, meningitis, optic neuritis.

Night Blindness

Difficulty in night vision can be seen in under corrected myopia, advanced glaucoma or optic atrophy, retinitis pigmentosa, after pan retinal photocoagulation and some drugs. It is also seen in Vitamin A deficiency.

Mongolism: Down's syndrome

This condition involves multiple physical signs and associations. Children with Down's syndrome commonly have an upward slant to the eyes and have epicanthal folds at the inner corners of the eyes giving a Chinese appearance. They may have nystagmus or congenital cataracts and frequently have poor vision with short sight and/or squint. As they become older they are more likely to have sticky eyes, blepharitis and conjunctivitis and, in their teens and twenties, they are more at risk of developing cataracts and keratoconus.

Yellow eyes: Jaundice

Yellow colour in the eyes is seen in hepatitis and other liver disease. Increased blood serum levels of bilirubin (an orange-yellow pigment formed in the liver) gets deposited in the sclera. If you develop yellow eyes, you should have blood tests to see if you have this condition and associated liver problems.

Blue Eyes.

Normally the sclera is white in colour. Sometimes the white sclera may have a slight blue color. Blue sclera is caused by a congenitally thinner-than-normal sclera or a thinning of the sclera from disease. When the sclera thins, the color of the underlying choroidal tissue to show through it. Congenital and hereditary diseases associated with blue sclera include osteogenesis imperfecta and Marfan's syndrome. Acquired diseases such as iron deficiency anemia also can be associated with blue sclera.

A spots and floaters in your vision.

Eye floaters are due to an age-related condition called vitreous detachment. This occurs when the eye's gel-like interior liquefies and separates from the retina and forms a ring inside the eye.

Rarely a sudden onset of spots and floaters also can be caused by a serious, sight-threatening tear or detachment of the retina. If you suddenly see a shower of spots and floaters you must visit your ophthalmologist immediately.

A dark curtain coming down in your vision.

This could be caused by a retinal detachment, which occurs when the retina separates from the underlying layer of choroid. If the retina is not reattached within two weeks vision loss can be permanent and so immediate checkup is required. 

Sudden eye pain, redness, nausea and vomiting.

These symptoms can signal a sudden attack of narrow-angle glaucoma, which can permanently damage the eye's optic nerve. Immediate treatment is required to prevent permanent vision loss.

Double vision, double images or "ghost" images.

Double vision can be caused by many eye conditions. In some cases, double vision also can signal an underlying health emergency such as a stroke. If you have a sudden onset of double vision, see your eye doctor or family physician immediately.

Blurred Vision.

Sudden loss of vision is an emergency and an immediate eye checkup is required to find the cause. Blockage to blood vessels of the eye or bleeding into the eye are common causes.

A distorted central vision, including distortions such as straight lines appearing wavy. These symptoms may be caused by age related macular degeneration (AMD), a leading cause of blindness among older patients.

Cloudy and blurred eyesight with halos around lights at night. These vision changes may be due to cataracts. Cataracts tend to worsen gradually over time and are not a medical emergency. Nevertheless, as your eye's natural lens continues to cloud with aging, your vision will continue to deteriorate unless you have cataract surgery that replaces your cloudy lens with a custom intraocular lens (IOL). If you wait too long for cataract surgery, you increase your chance of complications such as glaucoma. Also, if cataract surgery is postponed too long, the cloudy lens can harden and become more difficult to remove.

Blind spots in your field of view, accompanied by eye floaters and unexplained blurred vision. If you have diabetes, these vision problems may be due to the onset of diabetic retinopathy. Regular eye exams are essential for diabetics, particularly if you are over age 60. By evaluating the condition of your retina, your eye doctor can provide valuable information to your general physician about the control and severity of your diabetes.

Itchy, watery eyes

These signs and symptoms are most commonly due to dry eye syndrome. Dry eyes usually are more of a nuisance than a sight-threatening condition. But symptoms can be severe, particularly as you grow older and your body produces fewer tears or your tear chemistry changes. Consult your eye care practitioner for advice about remedies, which may include over-the-counter or prescription eye drops.

Visual Fields.

The visual field is the portion of the subject's surroundings that can be seen at any one time. The field of vision can give an idea about many eye problems. Eye diseases can affect the fields of vision in characteristic patterns.

Central field loss

·         Age-related macular degeneration.

·         Optic neuropathy.

·         Leber's optic atrophy.

·         Macular holes.

·         Cone dystrophies

·         Retinal artery occlusion.

Peripheral field loss

·         Glaucoma

·         Retinal detachment.

·         Retinitis pigmentosa.

·         Chorioretinitis.

·         Branch retinal artery occlusion

Hemi anopia: One half of vision lost.

Depending on the part of the brain affected the filed loss will have characteristic diagnostic patterns.

·         Brain tumors

·         Stroke

Eye in Systemic Illness

The following conditions affect the eye to an extent that they may first present through their ocular manifestations, or their ocular manifestations are likely to be significant in confirming the diagnosis.

Diabetes mellitus

Diabetes maybe diagnosed for the first time on a routine eye examination. Diabetes affects small blood vessels and can be particularly destructive in the eye. Reduced blood supply due to narrowing of blood vessels causes hypoxic damage to the tissues of the eye, particularly the retina. Diabetes can cause of early cataracts, due to excess glucose interfering with the metabolism of the crystalline lens.

The blood vessels of the retina can be seen directly using an ophthalmoscope. Similar changes may be seen in the blood vessels of the kidney and heart and hence by looking at the eye we can even predict the health of the kidneys and heart.

Hypertension

An Ophthalmologist maybe able to diagnose hypertension by just looking into the eye. Hypertension can cause the blood vessels to become narrow. Severe retinal changes are normally associated with a diastolic pressure >110 mm Hg and/or a systolic pressure of systolic pressure of >220 mm Hg.

Complications of hypertensive retinopathy include optic neuropathy and central vein or artery occlusions. These can cause defective vision.

Connective tissue disorders

Those disorders which particularly affect joints can also inflame the eye, causing red eye (scleritis or uveitis). Connective tissue disorders include: Rheumatoid arthritis, SLE, Ankylosing spondylitis, Ulcerative colitis. These can be associated with Uveitis, papilledema, dry eye, episcleritis or scleritis, eyelid tightening and telangiectasia. Retinal vasculitis may cause sudden unilateral transient or permanent visual loss.

Multiple sclerosis

Often the first nerve to be affected by the acute demyelination of multiple sclerosis (MS) is the optic nerve, causing optic neuritis. Optic neuritis causes marked diminution of vision which may spontaneously recover. These patients require MRI evaluation and neurology consultation.

Toxoplasmosis

This is an infection by Toxoplasma Gondi which is transmitted from cats. It causes retinochoroiditis. Active infection in the eye is more common when there is an immune deficiency such as AIDS, or after transplant. Prompt treatment is required to prevent permanent blindness.

Eye conditions and their associations

Cataracts

Most cataracts are age-related but they may be associated with underlying conditions. They are more common in patients with diabetes and Down's syndrome. They may be associated with steroid use, hormone deficiencies, previous eye trauma, congenital rubella and some congenital conditions. 

Uveitis

Most cases of uveitis do not have a definitive cause. In some cases they may be associated with systemic diseases like inflammatory disorders such as rheumatoid arthritis, infections like tuberculosis and with infestations like toxoplasmosis.  Uveitis might be expected in any disease process which has the capacity to affect joints, given that the eye is a modified joint. 

Central retinal vein occlusion

Central retinal vein occlusion (CRVO) is associated with hypertension, diabetes, smoking, hyperlipidemia, hyper viscosity states, glaucoma, thrombophilia and vasculitis.

Central retinal artery occlusion

Central retinal artery occlusion (CRAO) should prompt a search for a source of atherosclerosis, emboli or inflammatory causes. It is a common presenting feature of carotid artery stenosis.

Amaurosis fugax

Amaurosis fugax is a transient obscuration of vision. It is due to short duration ischemia caused by emboli, thrombus vasospasm, or hematological problems. It is also seen in carotid artery stenosis.

Pupillary abnormalities

The size of the pupil can be affected by diseases like Horner's syndrome, use of cocaine, some eye drops and cranial nerve palsies.

Abnormal eye movements

Abnormal eye movements and squints are found in many conditions affecting the cranial nerves or their corresponding brainstem nuclei. These include cerebrovascular accidents, aneurysms and diabetes. Transient paralysis of cranial nerves III, IV or VI may occur during ophthalmoplegic migraines and may go on for days or weeks. These are rare and recovery is full.

Preventing Age-Related Eye Problems

Of course it's far preferable to prevent age-related eye problems than to try to minimize their impact on your vision after they have begun. You can reduce your risk of developing serious eye problems later in life by maintaining a healthy lifestyle and having routine eye exams. Eye vitamins and good nutrition also may reduce your risk of certain eye problems.