The eye examination. When you have an eye examination it is not just a matter of testing your eyesight. We set aside 30 minutes for each examination to give plenty of time to carry out a thorough investigation of your sight and the health of your eyes. The examination will start with a chat about your sight and the reason for your visit. You may be having problems with your vision, or it may simply be an annual check-up, but it important for the optician to know about any changes that you have noticed with your sight. So whether it is a problem with your distance or near vision, with headaches or sudden changes like flashes or floaters tell the optician as much as you can about anything that may be of concern to you. You will be asked about your general health and any medication you may be taking - this is important because there are several types of medication that can have side effects that cause changes to the tissue in the eye. You will also be asked whether there is any family history of eye problems, as there are several eye diseases that have a genetic element. Once we know the reason for the visit your vision will be checked with and without your glasses (if you have any). Then the optician will carry an examination with a torch called a retinoscope. This may need the room to be darkened. Once the light has been shone into your eyes, different lenses will be placed in the special trial frame so the optician can find out how well your eyes are focussing without you having to answer any questions. Once both eyes have been checked with the retinoscope, the optician will have a good idea what glasses will suit you best, but the power of the lenses will be refined by asking you to look at different charts (some with letters and others with red and green backgrounds or patterns of circles or dots) and compare different lenses to find out the best combination of lenses will give you the clearest and most comfortable vision. The eyes will normally be tested one at a time, and once the readings have been taken for each eye your binocular vision will be tested to ensure that the eyes are working as unit. Sometimes patients experience double vision and this can sometimes led to special lenses called prisms being incorporated into the spectacles. The distance vision is usually checked first, and once that has been done your near vision will also be assessed to see if you will need a different strength lens for near work. Usually once a person reaches their mid-forties they will start to find close work more difficult. It is not uncommon to require a slightly different prescription for computer work compared to normal reading, due to the fact that the computer screen is further away from your eyes than the position that a book or newspaper is normally held. The next part of the eye examination is to check the health of the eyes. This will be done using another special torch called an ophthalmoscope. This enables the optician to check for the presence of eye disease such as cataract or glaucoma. Finally any patient over the age of 40 will normally have the pressure of the eyes measured, and sometimes the peripheral vision will also be assessed. We will then be in a position to give advice on whether or not new glasses are necessary and if there are issues with your eyes that require further investigation with an ophthalmologist at the Royal Gwent Hospital Eye Department. Glaucoma Glaucoma is a disease that causes damage to the optic nerve at the point it leaves the eye. There are several types of glaucoma, the most common being chronic or simple glaucoma. Glaucoma usually occurs when the pressure in the eye becomes too high, and the increased pressure then damages the optic nerve. The pressure is maintained by a fluid called aqueous humour, which is basically filtered blood. The aqueous is produced in a small organ called the ciliary body at the base of the back of the iris, it flows through the pupil and then drains out in the angle between the cornea and the front of the iris. So long as the fluid production is balanced by the drainage then there is no problem, but if too much aqueous is produced or the drainage system does not work properly then the pressure can build up and glaucoma can result. This process usually takes a long time (months to years), hence the condition is called chronic glaucoma, meaning it has taken a long time. People suffering from chronic glaucoma are usually prescribed drops to reduce the pressure, and this prevents further damage to the optic nerve. The drops need to be used continually, because they do not cure the glaucoma they only control it. There are several factors that increase your risk of glaucoma: your age: chronic glaucoma becomes much more common as we get older. It is uncommon below the age of 40 but this type of glaucoma affects one per cent of people aged over 40. About five per cent of people over the age of 65 have primary open angle glaucoma your race: if you are of African origin you are more at risk of chronic glaucoma. It is also more likely to develop at an earlier age and be more severe family: you are at a higher risk of developing glaucoma if you have a close relative who has chronic glaucoma short sight: if you are very short sighted you have a higher risk of developing chronic glaucoma diabetes: if you have diabetes you have an increased risk of developing chronic glaucoma. Chronic glaucoma is normally painless and since it causes damage to the peripheral vision first it can go unnoticed until it is quite advanced. So if you are in one of the groups that increases your risk of the disease it is important to have regular eye examinations so that it can be detected as early as possible. There are 3 tests your optician will use to check for the presence of glaucoma. 1. Measuring the pressure of the eye. This is called tonometry, there are several types of of instrument for measuring pressure (they are called tonometers), some require drops to anaesthetise the front of the eye, and others can be used without drops. 2. Examining the optic nerve. When your optician examines your eyes the condition of the optic nerve will be assessed, and measurements recorded with your notes. If the condition of the nerve changes over time, it can indicate the presence of glaucoma. 3. Measuring your field of vision. Glaucoma is known to affect certain parts of the peripheral vision first, then the damage progresses to affect more and more of the things you can see. Using a visual field analyser your peripheral can be checked and any signs of damage from glaucoma can be detected. This usually involves looking at a screen and being asked to count lights as they flash in different parts of the screen. This test is always done one eye ata time. If your optician suspects that glaucoma may be present in one of your eyes, you will be referred to an ophthalmologist at the Royal Gwent Hospital so that further tests can be done and any necessary treatment prescribed. Other less common types of glaucoma are: acute glaucoma, which occurs when the pressure raises very quickly – it is very painful and needs urgent medical attention to prevent blindness secondary glaucoma, which occurs as a result of another condition, such as trauma, iritis or untreated cataract congenital glaucoma, which happens when a newborn baby has glaucoma while it is developing in the womb Cataract Cataract is a condition that affects the lens inside the eye. The lens should be clear, so that light can be focussed properly on the retina. When a cataract is present the lens becomes cloudy and this prevents the light forming a clear image on the retina, leading to hazy vision. Cataract cannot be treated with lasers but always requires surgery to remove the cloudy lens. The surgeon will then replace the lens that has been removed with a new artificial one. Before the operation several measurements will be taken so the new lens should give you clear vision even if you needed very strong glasses beforehand. Many people have slight cataracts in their eyes and have no real problems, in these cases treatment is not needed. However if the cataract starts to cause problems with your eyesight, such as hazy vision or increased sensitivity to light, then you will be referred to an ophthalmologist to be assessed for treatment. Cataracts quite commonly affect both eyes, but the eye with the worst vision would usually be treated first, with the second eye being operated on a few months later. It is very rare to have both eyes operated on at the same time. Macular degeneration Macular degeneration is the name for a group of conditions which affect the central vision. The macular is a tiny area of the retina, and it used for seeing detail. The most common type is called Age Related Macular Degeneration (ARMD) and, as its name suggests, it is a disease that affects older people. Even though ARMD causes problems with your central vision, it does not lead to total loss of sight and is not painful. ARMD affects the vision you use when you're looking directly at something, for example when you're reading, looking at photos or watching television. It may make this central vision distorted or blurry and, over a period of time, it may cause a blank patch in the centre of your vision. The exact cause of ARMD is not certain. But there are known to be several factors that increase the risk of a person developing it: Age: ARMD develops as people grow older and is most often seen in people over the age of 65, although it can develop in people who are in their forties and fifties Gender: more women have ARMD than men, probably because women tend to live longer than men. Genes: some genes have been identified which seem to be linked to the development of ARMD in some people. This has been discovered by looking at families with more than one member who has ARMD, but not all ARMD is thought to be inherited Smoking: smoking greatly increases your risk of developing ARMD. Studies also show that stopping smoking can reduce your risk of developing ARMD Sunlight: some studies suggest that exposure to high levels of sunlight (particularly the UV light contained in sunlight) throughout your life may increase your risk of developing AMD. Wearing sunglasses to protect your eyes from the UV light in sunlight is a good idea for everyone throughout their life What you eat: a number of studies have looked at diet as a risk factor for someone developing ARMD. At the moment there isn't agreement on how much of a risk factor diet is. There is some evidence that vitamins A, C and E and zinc may help to slow the progression of ARMD in people who already have the condition. There are two main categories of ARMD: Dry ARMD. The most common form of ARMD is the dry type. This type of ARMD occurs over a long period of time, so the vision changes slowly and patients have time to adapt to the deterioration in their sight. Unfortunately there is no treatment for dry ARMD, however there is some evidence that high doses of vitamin A, C, E and the minerals zinc and copper when taken together may help slow down the progression of dry AMD, particularly if someone already has changes to their vision because of AMD in one eye. There are a number of vitamin products available which have been designed for people with dry AMD and you can usually buy these over the counter from your pharmacist. However, there is no evidence that taking high doses of these vitamins can prevent you developing AMD in the first place. A balanced with plenty of fresh fruit and vegetables is good for your general health and may also help your eye health. Wet ARMD Wet ARMD only affects 10-15% of patients with ARMD. Wet ARMD is caused by new blood vessels growing beneath the macular; these new blood vessels are very weak and tend to leak very easily which causes bleeding and swelling in the macula. Unlike the dry type wet ARMD can cause very sudden changes to your vision, with distortion being very common. For example someone who suddenly notices that a straight line (like a lamp-post or door frame) appears to have a kink in it, especially if the kink moves as you look along the straight line, is likely to have wet ARMD and should have an eye examination urgently. The other big difference between the wet and dry types of the disease is that the wet type can sometimes be treated if it is caught early enough and the vision has not become too bad. If your optician thinks you have wet ARMD that may benefit from treatment you will be referred to the Eye Department at the Royal Gwent Hospital as an emergency, and you will normally be seen by an ophthalmologist with a couple of days. At the hospital you will undergo further examination and if the condition is suitable for treatment you will have a course of Lucentis injections. Lucentis is a drug that prevents the formation of the new blood vessels, so it can help to stop the leaking and the swelling at the macula. Both types of ARMD lead to loss of central vision. This can be very disconcerting and make everyday activities such as reading and watching TV difficult. This is why it is very important to have regular eye examinations, and to call the practice immediately if you notice any sudden changes to your eyesight. Low Vision Service Eye problems become much more common as we age, and with people living longer now than ever before there will inevitably be some people who will have problems with their vision that cannot be helped sufficiently with a normal pair of spectacles. For this reason the practice provides a Low Vision Service for people who cannot achieve a good standard of vision due to eye disease. Your optician will advise you if are eligible to assessed for low vision devices, and you will booked in for an hour long appointment, where a thorough investigation of your visual problems and requirements will be carried and you will be shown the different types of device that can help improve your vision. These range from super strength reading glasses, to hand magnifiers, illuminated magnifiers, electronic magnifiers and telescopic devices to help improve your distance vision. As part of the Welsh Low Vision Service any device that helps to improve your vision can be supplied free of charge. You will be given full instructions on how to use the device(s) and follow- up checks ensure that if there any problems using them we can iron them out. Domiciliary Visits With the ageing population there are increasing numbers of patients who find it difficult to get to the practice for their regular eye examinations. To overcome this problem we provide a home visiting service for any patients who cannot get to the practice without someone else helping them. Modern technology means that most of the instrumentation used during the eye examination is now portable, and with a computer based eye chart a comprehensive examination can be provided in the home. We can carry out diabetic screening and measure the pressure of the eye in the home, and provide a good selection of frames too. If you feel you would benefit from a home visit contact the practice and we can arrange to come at a time that suits you.
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