Eye Disorders - Introduction

Sight is the most important of the five main senses. Your eyes tell you much more than your other senses do, and the part of the brain that deals with sight is far larger than the parts that deal with the other senses.

The eye is a complex, intricate, and fairly delicate structure . Each eyeball is a sphere about 25 mm (1 in) in diameter. Three concentric layers of tissue cover the eyeball. The tough outermost layer is the sclera, which is visible as the white of the eye. Its exposed surface at the front of the eye has a transparent covering, the conjunctiva, which also lines the inner surface of the eyelids. At the front of the eye, the sclera and conjunctiva join the cornea, a dome-shaped structure sometimes called the “window” of the eye.

Beneath the sclera is the choroid, a layer rich in blood vessels that supply the eye tissues with oxygen and nutrients. Toward the front of the eye, this layer thickens to form the ciliary body. From the front of the ciliary body extends a circular area of fibers, the iris, which varies in color from person to person and determines eye-color. In the center of the iris is an opening, the pupil, which looks like a black disc. Through this opening, light enters the eye. The amount of light is controlled by the contraction or dilation (widening) of the pupil. This adjustment is regulated by the muscles of the iris.

Immediately behind the iris and pupil is a transparent elastic body, the crystalline lens, which is attached to the ciliary body. Muscles thicken or narrow the lens, enabling the eye to focus on objects at varying distances. The space between the cornea and the lens is filled with a watery substance called aqueous humor. Behind the lens is a jelly-like substance called the vitreous humor, which makes up the bulk of the eyeball.

The innermost layer, the retina, lines the rear three­quarters of the eyeball. The retina includes a layer of light-sensitive nerve cells that are called the rods and cones because of their shapes. Light passes through the pupil and lens to the retina in such a way as to form an upside-down image of whatever you are looking at. The rods are very sensitive to light intensity and enable you to see in dim light. The cones detect color and fine detail.

There are 125 million rods and 7 million cones in each eye. Between them, the rods and cones transform the sensations of color, form and light intensity that they receive into nerve impulses. These impulses are then transmitted along retinal nerve fibers to the optic nerve, a stalk-like collection of nerves that connect the rear of the retina to the brain. The brain interprets the impulses received from each eye, reverses the images, and integrates them into one three-dimensional image.

The eye disorders covered in this section are dealt with in four groups. The first consists of errors of refraction such as problems of nearsightedness and farsightedness. The second group is concerned with disorders of those parts of the eye that you can see, mainly the eyelids, eyelashes, sclera, iris and lens. The third group deals with two forms of glaucoma, a disease that arises from a problem with drainage of aqueous humor. The final group is concerned with disorders that affect the structures in the inner layer of the eye, including the retina and its blood supply. The muscles and other tissues that surround the eyeball in its bony socket, which is known as the orbit, are also covered in this section.

Bone Tumor - How to Cope up with Bone Tumor?

What do doctors call this condition?

Sarcoma of the bone, bone cancer, primary malignant bone tumor

What is this condition?

Most bone tumors are caused by the spread of cancer from another part of the body (secondary tumors).

Tumors that originate in the bones themselves (primary tumors) are rare, accounting for less than 1 % of all malignant tumors. Primary tumors are more common in young males, but may affect individuals between ages 35 and 60 as well.

What causes it?

The causes of a primary malignant bone tumor are unknown. Some researchers suspect that the tumor arises in areas of rapid body growth because children and young adults with such tumors seem to be much taller than average. Additional theories point to heredity, trauma, and excessive radiation therapy.

What are its symptoms?

Bone pain is the most common symptom of a primary malignant bone tumor. Often more intense at night, the pain isn’t usually associated with movement. It’s dull and usually localized, although it may be referred from the hip or spine and result in weakness or a limp.

Another common sign is a mass or tumor. The tumor site may be tender and swollen; the tumor itself often can be felt. Fractures are common. In late stages, the person may have a fever, impaired mobility, and physical wasting and malnutrition.

How is it diagnosed?

A biopsy is essential for confirming a primary malignant bone tumor. Bone X-rays, radioisotope bone scans, and CAT scans show tumor size.

How is it treated?

Surgical removal of the tumor is the preferred treatment. This may be combined with preoperative chemotherapy using drugs such as doxorubicin, vincristine, cyclophosphamide, cisplatin, and dacarbazine administered through the arteries to the long bones of the legs. In some instances, radical surgery such as amputation is necessary.

Ovarian Cysts – Remedies for the Treatment ofOvarian Cysts

What is this condition?

Ovarian cysts are usually noncancerous sacs that contain fluid or semisolid material. Although these cysts are usually small and pro­duce no symptoms, they require thorough investigation to be sure they’re not cancerous. Common types of ovarian cysts include follicular cysts, lutein cysts, and those associated with polycystic ovarian disease.

Ovarian cysts can develop any time between puberty and menopause, including during pregnancy. Some lutein cysts occur infrequently during early pregnancy. The prognosis for noncancerous ovarian cysts is excellent.

What causes them?

Follicular cysts are typically small and arise from follicles that have malfunctioned during the menstrual cycle. When such cysts persist into menopause, they secrete excessive amounts of estrogen in response to the hypersecretion of follicle-stimulating hormone and luteinizing hormone that normally occurs during menopause.

Granulosa-lutein cysts, which occur within the corpus luteum, are functional, nonneoplastic enlargements of the ovaries, caused by excessive accumulation of blood during the bleeding phase of the menstrual cycle. Theca-lutein cysts are commonly bilateral and filled with clear, straw-colored fluid; they’re often associated with other types of ovarian tumors or hormone therapy.

Polycystic ovarian disease is part of the Stein-Leventhal syndrome and stems from endocrine abnormalities.

What are the symptoms?

Small ovarian cysts (such as follicular cysts) usually don’t produce symptoms unless twisting or rupture causes abdominal tenderness, distention, and rigidity. Large or multiple cysts may induce mild pelvic discomfort, low back pain, painful intercourse, or abnormal uterine bleeding secondary to a disturbed ovulatory pattern. Ovarian cysts that become twisted cause acute abdominal pain similar to that of appendicitis.

Granulosa-lutein cysts that appear early in pregnancy may grow as large as 2 to 2½ inches (5 to 6 centimeters) in diameter and produce discomfort on one side of the pelvis and, if rupture occurs, massive one-sided bleeding within the abdomen. In nonpregnant women, these cysts may cause delayed menstruation, followed by prolonged or irregular bleeding. Polycystic ovarian disease may also produce secondary absence of menstruation, diminished menstrual flow, or infertility.

How are they diagnosed?

Generally, the doctor diagnoses ovarian cysts based on the woman’s signs and symptoms. A physical exam and lab tests may also help detect certain types of cysts.

Visualization of the ovary through ultrasound, laparoscopy, or surgery (often for another condition) confirms ovarian cysts.

How are they treated?

Follicular cysts generally don’t require treatment because they tend to disappear spontaneously within 60 days. However, if they interfere with daily activities, Clomid taken orally for 5 days or progesterone given intramuscularly (also for 5 days) reestablishes the ovarian hormonal cycle and induces ovulation. Oral contraceptives may also accelerate involution of functional cysts (including both types of lutein cysts and follicular cysts).

Treatment for granulosa-lutein cysts that occur during pregnancy is symptomatic because these cysts diminish during the third trimester and rarely require surgery. Theca-lutein cysts disappear spontaneously after elimination of hydatidiform mole or choriocarcinoma, or discontinuation of human chorionic gonadotropin or Clomid therapy.

Treatment of polycystic ovarian disease may include the administration of such drugs as Clomid to induce ovulation, Depo-Provera for 10 days of every month for the woman who doesn’t want to become pregnant, or low-dose oral contraceptives for the woman who needs reliable contraception. Surgery may be necessary to remove a persistent or suspicious ovarian cyst.

What can a woman who’s had ovarian cyst surgery do?

You’ll be advised to increase your activities at home gradually­preferably over 4 to 6 weeks. Abstain from intercourse and use tampons and douches during this period.

Leukemia – Treatment for Curing it Fast and Effectively

Leukemia is a cancer of white blood cells. Normally the number of white blood cells that are produced equals the number that die off as part of the natural process of cell turnover in the body. This keeps the total number of white blood cells constant. In leukemia, white blood cells often multiply at an increased rate. It is also significant that the cancerous cells tend to live longer than normal white blood cells. Thus the number of abnormal cells increases, either gradually or rapidly, and this causes an over accumulation of leukemic cells throughout the body. These cells often interfere with the functions of various organs. And, because the cells are abnormal, they do not cope effectively with infectious agents that the normal white blood cells help to eliminate from the body.

There are two main types of leukemia, which affect different types of white blood cells. Lymphocytic leukemia is a malignancy of lymphocytes and/or the cells from which they originate. Myelogenous (or granulocytic) leukemia is a cancer of the cells from which granulocytes originate. Both of these leukemias may be acute or chronic. Acute lymphocytic leukemia mainly affects children; it is discussed elsewhere .