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.
