The first step in the operation itself is the securing of the eyelids. This is usually done with a small spring speculum, which gently holds the lids open without in any way pressing on the eye.
The removal of the cataract can be achieved in a number of ways, the aim being to clear all the opacity from the pupil of the eye. Basically, there are two methods either of which may be used: Read the rest of this entry »
At one time almost all intraocular surgery was performed under a local anaesthetic. For two reasons local anaesthesia is used much less commonly today. First, the whole science of general anaesthesia has greatly advanced and the likelihood of coughing has been considerably reduced. Second, methods of repairing the cataract wound are now better than they used to be. Coughing and sneezing after the operation consequently constitute less of a threat than formerly. Read the rest of this entry »
Until the advent of contact lenses or intraocular lens implants spectacles were the only means of achieving a finely focused image on the retina after a cataract operation. Although in many cases this is most satisfactory, there are limitations to such correction. At first some patients find that wearing thick cataract glasses causes a number of problems which arise from magnification of the image, distortion in the peripheral part of vision, and some limitation of the field of clear vision.
These all result from the spectacle lens itself rather than from the operation. Read the rest of this entry »
In an ideal world the best way to restore an eye to normal would be to replace the cataractous lens with a clear one of the same power lying in the position from which the original lens was removed.
At the Oxford Ophthalmological Congress the eye surgeon Harold Ridley reported the results of eight operations that he had performed to insert a Perspex lens. He thus founded a completely new branch of ophthalmic surgery. Ridley had treated many ocular injuries suffered by members of the Royal Air Force during World War II. Aircraft windshields (made of Perspex) had shattered after explosions or the impact of bullets, and Perspex fragments had penetrated the eyes of plane crews. Ridley had noticed how inert Perspex was in the eye and how little inflammation it caused. Read the rest of this entry »
For the first two weeks or so of the immediate postoperative period vigorous activity is discouraged. Stooping, lifting heavy objects, sneezing or coughing, and any very violent physical effort should be avoided. Any activity that makes the patient feel that his collar is too tight or that his neck is swelling should be stopped because movements which cause congestion in the head also provoke an increase in pressure within the eye. Until the wound is properly healed this could lead to its leaking, to haemorrhage, to poor healing, and, in the worst event, to loss of the eye. After two weeks, however, the surgical wound should be well healed. At the routine outpatient visit which should be made at this time, the state of healing will be assessed by the surgeon, who will tell the patient what physical activities may be undertaken. Read the rest of this entry »
Where cataract is due to abnormal body metabolism, then treatment of the metabolic disorder can sometimes prevent development of cataract, or even reverse cataract where cataract has begun. Diabetes mellitus is a good example of this. Otherwise metabolic cataract can be treated by conventional methods. It should be said at once that in most countries of the world eye-drops and medicines of ill-founded clinical value, and rarely backed by any sound medical trials, are still available. Read the rest of this entry »
The retina, then, is a nerve pad dependent upon a complex network of support systems. One of these support systems is a supply of blood, for it is in the blood that many of the essential nutrients are carried from one part of the body to another. Therefore the eye, and more particularly the retina, is or can be affected by deficiencies in other organs. The retina is in fact fed by blood systems both in front and behind, and many blood diseases can have a deleterious effect on retinal functions; and both systems are sufficiently intricate and fine to be hypersensitive to abnormalities in the blood. However, since the variations and permutations of retinal degeneracy are enormous it is sometimes very difficult to diagnose its cause. It is always possible to describe what one sees as being wrong with a decayed retina, but even after many specialized tests it can still be impossible to say with any accuracy what is the precise cause. This has seriously hampered the treatment of some retinal conditions. Where the cause of a disease is known it is always much easier to prescribe a cure, or at least medication that will halt or slow down what is usually a progressive condition. Read the rest of this entry »
The retinae are the sensory parts of the eyes, and to all intents and purposes may be regarded as a part of the brain. At the embryonic stage the developing brain very early on grows two buds which will become the eyes. This brain tissue gradually transforms into the light-sensitive retinae, or receptor organs. In the young foetus the buds lie just below the skin surface. The forward part of the eye tissue then invaginates to form the crystal lens of the eye, while the skin forms the cornea, or front lens of the eye. Slowly each bud is extended away from the brain, until it is only attached to the brain by a stalk, or optic nerve. Read the rest of this entry »
The greater the ophthalmologist’s knowledge of general disorders, the more help he will be in their diagnosis, or at least in making a wise referral. And this applies as much to nervous disorders as it does to diseases in the blood. The central nervous system is necessarily and intimately connected with the eye and vision, which are therefore affected by nerve and brain abnormalities. Read the rest of this entry »
The eye has its natural protective mechanisms. The lids, for example, protect the front of the eye from dust, wind and objects coming towards the face. They also protect the eye from excessive light. The eye itself is set in its bony cavity: the orbit. In the orbit there are some soft fatty tissues which act as a cushion, permitting the eye to sustain a light blow without injury. Nevertheless the eyes are vulnerable. The eye will be injured, often severely, by fast-flying hard objects, and also by some gases and solutions. It is easy to incapacitate a human being, either temporarily or permanently, by spraying irritant solutions onto the face, and such methods have been widely used by criminals, police and the armed services. Read the rest of this entry »
