General EYE ADVICE

Recommendations:

(i) Regular eye examinations are particularly important form middle age onwards. Some relatively common serious eye diseases are not symptomatic in their early stages. In order to prevent the progression of these eye diseases, it is essential to have regular eye examinations. Examples of such diseases are glaucoma and diabetic eye disease in which an affected person may lose most of his/her sight before becoming aware of having an eye problem. It is especially important to have regular eye examinations if you have a family history of a certain eye condition. A good example again is glaucoma. As familial glaucoma can appear from an earlier age than usual, regular eye examinations should begin from the teenage years if there is a family history of glaucoma.

It is also important to realise that several important and commonly occurring systemic diseases, such as high blood pressure and diabetes, are not uncommonly associated with subtle or pronounced eye changes. The author has encountered numerous cases of undiagnosed systemic disease in the course of providing routine eye examinations. For these reasons, one should have regular eye examinations even if one does not need to change their glasses or if one decides to wear ready-made spectacles that are sold at department stores etc.    

(ii) Presbyopia occurs almost universally with age, to varying degrees. Many people remark that they become more reliant on glasses after wearing a correction for their presbyopia. This is because the eyes are less stressed when wearing glasses and they are allowed to become more long-sighted. On the other hand, deliberately avoiding a correction for presbyopia necessitates greater muscular tension within the eye. This can lead to either the appearance of astigmatism (of the against- the-rule type, see Part IIA) or short-sightedness.

I have found that many people prefer to have the full correction, which gives them the most clear and comfortable vision and do not mind a greater reliance on glasses. Other people prefer to avoid using glasses and make greater efforts in focusing. These people will be less reliant on glasses, however, they experience more eyestrain symptoms (tired eyes etc). They also have more difficulties in adjusting to spectacles, especially when they are used for distance. Excessive straining of the eyes may be associated with more permanent eye health problems.

When the best possible vision and comfort is required, the full recommended near correction is the best option. It is preferable to make the spectacles in such a way as to allow for regular shifting of the focus into the distance. This need only be for a couple of seconds and is effective in preventing eyestrain. Bifocals or single vision lenses in a look-over frame are ideal for this purpose.

Practicing good vision habits will help prevent eyestrain and consequent effects on the eyes. Refer to Appendix I for details. VDU users may refer to Part II (C): hints on eye usage with computers for detailed discussion and appropriate recommendations related to VDU use.

(iii)Glaucoma

(a)Glaucoma related to increased pressure.

If upon examining the eyes, the health professional finds a mildly increased pressure in the eyes which does not require medical treatment, it is wise to consider the possible causes of the increased eye pressure. This may help to prevent a possible further increase in eye pressure leading to glaucoma. If there are no obvious general health problems that need to be attended to, and the eye care professional cannot find any causes within the eye for the increased eye pressure, there are several factors that need to be considered.

As nervous stress is considered to be a major contributing factor, a concerted effort in finding ways to reduce emotional stress would be strongly recommended. Exercise is an important life style factor that needs to be considered. Treadmill walking has been found to reduce eye pressure by as much as 30%. Daily outdoor walking can only be of even greater benefit as this would also help to reduce stress. Caffeine intake can increase the eye pressures and thus it is important to try to limit or eliminate coffee drinking if possible. If an excessive amount of continuous close work is carried out, it would be important to ensure that it is performed with regular shifting of the focus say every five to ten minutes. Further details on appropriate eye use are given in Appendix I. Obesity, excessive salt or fluid intake and high blood pressure may also lead to raised eye pressure and need to be controlled.

The life-style changes suggested above can also be implemented when your eyecare practitioner prescribes anti-glaucoma medication. This is usually in the form of eye drops. If drops are prescribed, they should be used as directed to obtain maximum benefit and prevent loss of sight. Ask your practitioner to show you an appropriate method of instilling the eye drops to ensure they get into the eye. After instilling the drops, close your eyes for a few minutes and press the inner corner of your eye with your index finger to prevent escape of medication into the nostril. Wait at least ten minutes between instilling different drops to ensure adequate penetration of the drops. Care must be taken to prevent contamination of the bottle by contact with eyelashes, lids, skin or the tears in the eye.

(b) Normal Tension Glaucoma.

The primary cause of nerve damage in normal tension glaucoma is thought to be poor blood flow at the optic disc. The factors that are involved in reducing blood flow are not clearly understood. Thus there are not any widely accepted medications or other treatments for normal tension glaucoma. However, it has been shown that in these patients, it is particularly important to bring the eye pressures down to the perfectly optimal reading of 15mmHg or less. This is because there is already a problem with blood flow, and even a slightly raised pressure may further decrease the blood flow in some patients.

As smoking is known to affect the health of blood vessels and thus blood circulation, it is advisable that smoking be limited or stopped. Exercise improves blood flow and should be encouraged. The blood pressure should be regularly checked to ensure that it does not fall significantly below the normal levels. This applies especially to those who are on anti-hypertensive (blood pressure lowering) drugs. Betaxolol (Betoptic) is a drug that appears to be of particular use in normal tension glaucoma as it helps to increase blood flow at the optic disc. This is done by the dilating effect that Betoptic has on the small blood vessels and by the drug's other action of reducing the eye pressure.

It is suspected that vasospasm (abnormal muscle contraction leading to narrowing of tiny blood vessels) may be an important cause of reduced blood flow at the optic disc and thus of normal tension glaucoma. It may thus be of benefit to try to reduce nervous stress as it is often implicated in other cases of vasospasm such as migraine. It has been shown that migraine sufferers have an increased risk of glaucoma compared to the normal population. Finally, it has been suggested that certain foods are beneficial to blood flow and health of nervous tissue in the eye. These foods include blueberry and cod liver oil.

(iv)Diabetic Eye Disease

The most important factor to consider in trying to prevent progression of diabetic eye disease is the general health and strict control of blood sugar levels. Stress reduction the appropriate diet and adequate exercise are the key factors to consider in controlling diabetes. All those factors that affect blood flow such as smoking should be optimised. Regular eye examinations as recommended for each particular individual by their eye care practitioner, are essential in order to detect serious damage to the retina. If this damage is detected early enough, laser treatment can be successfully applied in most cases to prevent more serious loss of vision.

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