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In the normal eye a watery liquid is constantly produced and drained away through tiny drainage canals. This fluid maintains a pressure within the eye that remains constant as long as the fluid drains as quickly as it is produced. electricity questions and answers pdf The normal intraocular pressure is between 10 and 20 mm Hg. Glaucoma occurs when there is a build-up of pressure within the eye due to clogged or covered over drainage canals, where the eye fluid can not drain away.

So Glaucoma is a physical condition within the eye and it is not a form of cancer or tumor, it is not infectious or contagious, it is not a danger to life itself. Glaucoma is a painless and silent disease and if it is left untreated or neglected, it will result in loss of vision and even lead to blindness. Are there different types of glaucoma?

Yes, there are many different types, but there are two major types: Chronic and Acute. Chronic open angle glaucoma (COAG) is the most common form glaucoma. In COAG the entrance to the drainage canals is open, but there is a clogging problem inside the drainage canals. The disease is slow, causes gradual loss of small patches of vision, it is a lifelong condition and responds well to medication and surgery.

Generally speaking, glaucoma cannot be cured, but it can be controlled. Once diagnosed, it requires constant, lifelong care. The major goal of glaucoma treatment is to keep the eye pressure in a range that prevents further glaucoma damage. This can be done with eye drops, pills, laser treatments and microsurgery. What advice is there for patients with glaucoma?

The retina is the thin inner lining of the eyeball. It acts like the film in a camera to "make the picture". Tiny light-sensitive cells pick up the signals of the world around us and transmit them via the optic nerve to the brain. Because of the way the light falls, the image on the retina is upside-down. Fortunately for us, however, the brain quickly re-invents the picture or else we would all be walking on our hands! Doing all the hard and vitally important work that it does, the retina needs a lot of energy from the body. Consequently it has its own little system of blood vessels which have no connections to other vessels. This means that another part of the body cannot steal the retina’s blood but conversely, when a small retinal artery is blocked, severe damage to the retina occurs as there is no blood to steal from anywhere else! When one of the small vessels or their branches becomes blocked sudden loss of vision can occur. No time should be lost in seeing your ophthalmologist because, in the case of a small artery blockage, immediate treatment can sometimes be successful. gas number Your ophthalmologist will probably also want you to undergo some systemic investigations as diseases such as high blood pressure, diabetes and others may be implicated.

Another important fact is that the little light-sensitive cells, which are divided into those that work in the dark (called rods) and those that work in the light (called cones) are constantly breaking down and re-building. When things go wrong with this system retinal degeneration occurs. The cones are mostly concentrated in the central or "bull’s eye" area (called the macula) which we use for clear vision and reading while the rods, which are more concentrated in the periphery, are needed for night vision.

An important problem affecting the macula occurs as the eye (and the patient!) ages. Slow deterioration in this area makes reading and fine close work difficult. Tiny blood vessels may develop and cause distortion of vision or even bleeding. Your ophthalmologist may recommend special photographs or laser treatment to the back of your eye. It is important to remember that the treatment is aimed at preventing further deterioration only. Unfortunately, the opposite eye may also become involved over a period of years. We call this condition Age Related Macular Degeneration. Considerable research is being done and surgical techniques being developed which may occasionally be helpful.

Inherited disorders may cause macular deterioration in much younger patients but one of the commoner degeneration’s is Retinitis Pigmentosa which, especially in the early stages, affects the rods and causes night blindness and "tunnel vision". Genetic research has helped us to identify some of the faulty genes and the race is on to find a cure.

Another serious condition which may affect the retina is retinal detachment. electric utility companies in arizona This means that the retina has come loose from the back of the eye much like wallpaper peeling of a wall! This usually happens when a tear or hole develops in the retina allowing fluid from inside the eye to seep under the retina. The first thing that the patient may notice is flashes of light or a shower of little dots called "floaters". It is important to see your ophthalmologist if you notice these symptoms, especially if you are short sighted or anyone else in your family has had a retinal detachment. The next thing that happens is that a "curtain" or shadow comes over the vision. When surgery is offered this may be a procedure involving mainly the outside of the eye or may be internal with the injection of a gas bubble or in very severe cases a special oil called silicone oil. The most important thing in the successful treatment of retinal disease is to present as early as possible to your ophthalmologist if you notice any of the symptoms we have mentioned especially if you have a family history of retinal disorders.

Whenever the light focusing system in front of the eye (mainly the cornea, also the lens) produces an image either in front of (myopic or shortsighted) or behind (hyperopic or longsighted) the retina, vision is blurred and some additional focusing system such as spectacles or contact lenses are necessary to shift the focus onto the retina.

We cannot shorten or lengthen the eyeball, but we can now alter the shape of the front of the cornea sufficiently in most cases to shift the focus (image) from it’s abnormal position to the retina, and therefore restore good vision without glasses. There is obviously some risk associated with this, so however small this risk might be, surgical approach is not considered if patients are comfortable with their glasses or their contact lenses.

Laser in-situ keratomileusis, or LASIK, is considered safe and effective for patients with low to high myopia (up to +-10 diopter of shortsightedness), with or without astigmatism, and low to moderate hyperopia (up to +- 3 diopter of farsightedness). The ophthalmologist uses an automated microkeratome to cut a thin, hinged layer in the cornea, called a flap. The flap is then laid back and the surgeon uses an excimer laser beam to flatten the underlying cornea by vaporising a thin layer of tissue. la gastronomia The flap is gently put back in place. The cornea heals without any stitches.

You need to be screened and assessed by your local Ophthalmologist. Your eye surgeon will be able to give you a good idea whether you are a possible candidate. The procedure, as well as advantages and disadvantages will be discussed with you. You will need to remove soft contact lenses five days before this assessment, and hard contact lenses at least two weeks before the assessment.

With this method the laser beam is applied directly to the surface of the cornea, after the thin superficial layer of cells has been wiped off. After the laser resculpturing of the cornea is done, it takes a day or two to heal and it can be uncomfortable during this period. The healing process sometimes leads to regression (some refractive error returns) or to scarring.

In cases of severe refractive errors exceeding the safety limits for Excimer laser surgery, you might be advised by your eye surgeon to have a phakic lens implanted. This is a special "contact lens" designed for permanent implanting into the eye, after which "fine tuning" of the refractive error will be done with the Excimer laser. The advantages and disadvantages of this procedure will be discussed with you. This method is only advised in patients under 40 years of age, who do not require reading glasses yet.

Are you always searching for your reading glasses? Have you ever wished that there were a solution to this problem? When you are in front of the television your glasses are either in the bedroom, kitchen, car or even at the office. With the development of technology there is an operation available which could eliminate this problem and make the "old" eye as good as new.

Reading problems will start to occur at the age of about 40 years and affects just about everybody after 45. When the eyes are focusing close up, the lens changes its shape. The diameter increases and light rays are focused on the retina. As we get older the lens grows and when the space are too limited to adjust its shape, reading problems start to occur.

The recovery process depends on the age of the patient. Persons under the age of 50 will recover quicker than those over 50. gas monkey monster truck hellcat It can take up to six months and requires a lot of exercise. This can be compared to a broken arm or leg. When the plaster of paris is removed the bone is tin and the muscles are weak. The muscles need to regain their strength as soon as there are sufficient space available for the lens to change its shape while reading. gas jockey Who qualifies for this operation?

The implants are done under general anaesthetics and the patient goes home that same day. You will have to come for a one-day, a week, a month and a three-month follow-up after the operation. Only one eye is done at a time. In some cases it will only be necessary to do one eye. Some patients will be able to function effectively if the dominant eye is done first. What are the dangers involved?

As with any other operation there is always the risk of infection. To prevent this the operation is performed under sterile conditions in theatre. It is possible that the arches may move which will reduce the effectiveness of the procedure. This can be corrected by repositioning the arches under anaesthetic. There are even a small percentage of cases where the eye has rejected the arches. This seldom happens, but is possible. What can I expect immediately after the operation?

The dull opacified cornea can however be transplanted with a new cornea, thus restoring the vision of the patient, whether he be a young child, an adult or an old person. 9gag nsfw The operation is performed by highly trained ophthalmic surgeons using the latest micro surgical techniques. Hospitalization is however often no longer than a day or two. The success of such grafts are more than all other forms of organ transplantation; a more than 90% chance of the new cornea retaining its clarity.

There is however in South Africa a tremendous shortage of corneal donors. It has been estimated that there are more than 20 000 blind South Africans whose sight could be restores with a corneal graft. It is thus essential that the general public become more aware of corneal grafting and agree to donate their corneas or the corneas of their diseased relatives for grafting. Corneas from donors of all ages are used. Usually only the cornea is removed from the deceased and donating a cornea is thus not a disfiguring procedure.

In the early 1970’s Dr Parma, then the Director of Heraldry, and I enjoyed lunch together in Cape Town. I explained that Ophthalmology was in need of a Coat of Arms which could be taken through to the future and which will be exclusive to our Society. After much effort, thought, research and modifications, a Coat of Arms was designed, which proved to be heraldically correct and registerable with the College of Heraldry in Pretoria, and acceptable to O.S.S.A.

The Shield or escutcheon, may be divided by quarterings. Its dexter (=right) side is seen from the Knight’s aspect. Decoration on the Base, that is, below the quartering, is known as the Charge. The Shield supports the Wreath which, in turn, supports the Crest. Mantling fills the background and the motto is usually below, the so-called Achievement.

Zeus, the king of the Gods, assumed human form in the disguise of a boy and fell in love with Lo, the daughter of the River God. Hera, Zeus’ wife, suspected his infidelity and followed him to his trysting place in a beautiful grove. Aware of her approach, Zeus caused a dense mist to fall and changed Lo into a white heifer which Hera then commanded him to give her as a present. She instructed the god Argus, who had 100 eyes, 50% of which remained ever awake, to guard the heifer. electricity lesson plans for 5th grade Zeus summoned his son Hermes to release Lo. Hermes borrowed Pan’s pipes and played to Argus until he fell asleep at which stage he cut his head off. Hera, in commemoration of Argus’s death, had his eyes transferred on to the tail of a peacock.