Tobacco Amblyopia results from the excessive use of tobacco, either by smoking or chewing. And also occasionally from the absorption of dust in tobacco factories. Smokers of shag and
strong tobacco mixtures or cigars suffer most. Cigarette and beedi smokers are affected often. In many cases there is also over- indulgence in alcohol. The patients are usually 35 to 50 years of age, may have smoked excessively for years with impunity, the attack coinciding with some intercurrent cause -debility or digestive disturbance.
Various substances have been regarded as the toxic agent, but a potent factor may be poisoning with the cyanide in tobacco smoke associated with a deficiency of vitamin B12.
The patient complains of increased fogginess of vision, usually least marked in the evening and in a dull light. Central vision is greatly diminished, so that reading and near work become difficult; although the condition is bilateral, one eye is usually more affected. Patient finds very difficult in bright sunlight.
On examination, one can find the peculiar bad smell of tobacco, trembling of hands. Except for the diminution ofvision, in all other respects eye would be almost normal. After dilating pupil and examining the retina in detail also, one cannot find any significant changes. The only test which helps to diagnose the disease correctly is the visual fieldexamination. The purpose of doing this examination is to know whether all the parts of the retina are equally sensitive to
light, and also to find out the non – seeing areas.
Pathologically the condition is due to degeneration of the ganglion cells of the retina, particularly of the central areas where the cells show vacuolation and Nissl degeneration. Since the central area is affected, patient feels the fogginess of vision. Initially it may not pose much problem
for the patient,but if it persists, the patient may become almost blind, because he would not be able to see the central objects because of the central blindness.Therefore the disease has to be diagnosed in the earlier stages, so that the proper treatment can be instituted and the blindness can be halted.
Treatment consists of abstention from or severely curtailing the use of tobacco and alcohol. If this is done the prognosisis eventually good although the visual improvement may not be evident for a period of some months. Improvements may be hastened by large doses of vitamin B preparations (B1 and particularly B12 ).It is unfortunate that most of the time our patients fail to follow this strict regimen and slowly start smoking as well as drinking, with the result that they would
land up in their old misery.
Smokers should note that not only they are more prone for the respiratory diseases and heart problems but also they may lose their precious eyesight partially or fully and should make serious efforts to give up smoking.
