CATARACT is an opacity of the crystalline lens or of its capsule.
You will all agree to this, but you will say that the expression is too vague and loose, because there are lenticular opacities which are not cataract. Nevertheless I think it is sufficiently definite for practical purposes. I do not admit that all intra-lenticular changes resulting in opacity must show themselves unyielding to treatment in order to be called cataract; such a limitation is not true to nature, and is not in consonance with the history of the world in general medical, surgical and ophthalmological literature.
However, I come before you to give some ideas of my own, and as one seeking instruction from you. I want to ask you, whether the day has not dawned for an earnest effort to get at the true nature of cataract, and ascertain whether we must fold our hands impotently in its presence till it is like a ripe kernel in its shell ready to be enucleated, or whether we should fix our diagnosis as early as possible, to the end that our patients may have the benefit of our scientific therapeutics, and reasonably look for retardation, amelioration, or even complete cure of that which threatens to shut out the light of day from them.
The True Nature of Cataract.
It is necessary to a right understanding of the subject that we have a clear conception of the essential nature of cataract, not merely as a pathological entity in a given cadre, but from a microcosmic standpoint: from the point of view of the entire economy.
Cataract is a general disease, i.e., the opaque state of the lens is most frequently only a local expression of a general state.
To me an opaque lens existing by itself in an otherwise healthy-body is inconceivable, except from trauma, or from mal- development, or from obstructed nutrition; but given a normally developed lens, not mechanically or chemically injured, it cannot of itself become opaque unless from some other part of the organism. It is barely possible to have a sclerosis of the lens and a supple elastic condition of the other parts of the economy. In a word the sclerotic change in the lens is of a piece with the state of the other tissues of the same individual at the same time.
If this be granted, then cataract is a constitutional state, and our remedial measures must be directed to the constitution, and they should be taken at the earliest stages and continued for a long time, for chronic disease can only be cured by chronic treatment.
I was very much gratified to read in the last edition of Professor Angell’s work, A Treatise on Diseases of the Eye, 6th edition, 1882, that ophthalmologists are beginning to take a broader view of the pathology of cataract. This eminent colleague says (p. 270): “Recently, investigations, chiefly by Michel, in regard to the influence of the general circulation upon the nutrition of the eye, go very far to prove that cataract is generally caused by sclerosis of the carotid arteries. Thus in the course of ten months fifty-three cases of cataract observed showed a sclerosis of the carotid in every case. In some, where one eye only was affected, there was sclerosis of the carotid in the same side only, or it was more highly developed in that side, while in double cataract the opacity of the lens was most advanced on the side corresponding to that in which the sclerosis of the carotid was greatest. In addition to the sclerosis there was also in some of the cases an enlargement of the thyroid gland. The ages of the patient varied from eight to eighty-one years.”
Here I must object not to this statement in itself, but to the way in which Professor Angell puts it.
It is hardly correct to say that because sclerosis of the carotid accompanies cataract that, therefore, the lenticular opacity is secondary to the sclerosed carotid. I submit that cataract is itself a sclerosis of the lens, and that the hardened condition of lens and carotid is merely common to both, though the carotid may possibly degenerate first. I quite agree with Dr. Angell that it is not probable that every case of cataract will show a sclerosis of the carotid, and that there may be senile marasmus, or a feebleness of the circulation after exhaustive disease, or congenital insufficiency of the arterial circulation, or abnormal growths pressing on the carotids-all and any of them as causes of cataract.
Some of the most frequent causes of cataract are, in my opinion, gout, rheumatism, rheumatic gout and syphilis, and here what benefits the gout or rheumatism will tend to better the cataract.
But my limits will not admit of my dealing with all the causes of cataract, and I therefore propose to confine myself more particularly to three that have hitherto been brought before the profession, and to which I attach very great importance. I refer to
and (c) Hard Water.
I have watched cataract cases with great care for some years, and I am prepared to maintain that the most frequent causes of cataract are the use of much salt, or of much sugar, or of hard water; very frequently we find all the three causes operating at the same time in the same individual.
Before proceeding allow me to say that I do not propose to exclude any of the other causes of cataract -no, I merely confine myself to these three as emanating from my own experience, and because I wish to call your very special attention to them. Then first as to.
Salt-Eating as a Cause of Cataract.
I lately published a little treatise entitled, Super salinity of the Blood, an Acceleration of Senility and a Cause of Cataract, and in it I claim to have proved that an excess of salt acts as a positive cause of cataract.
The proof that salt will cause cataract in the lower animals has long been given, and it has been my object, in the little work just cited, to show that not a few of the cases of cataract that we meet with are more or less due to the fact that the patients had been in the habit of partaking of too much salt with their food, or in their food, or perhaps even as a saline mineral water.
It will not be needful that, I go over much of the ground again here, as I shall not have time, but I may just give the conclusions to which I have arrived, and a few points that lead up to them.
According to the experiments of Kunde, we find that certain of the lower animals to which salt has been administered, at once get cataract. Kunde’s experiments were confirmed by other observers. Subsequently Kunde says: “(Ueber Wasser entziehung und Bildung voruebergehender Kartarakte, 1857), if you take a frog weighing 30 grammes, and give it a 0.2-0.4 dose of salt, either under the skin or in the rectum, you will, in a short time, observe a bulging out of the cornea, with an increase of the aqueous humor, and sooner or later, an opacity of the lens, which will begin, sometimes anteriorly and at other times posteriorly. This opacity increases in proportion as the animal gets weaker, and attains to such a degree at last, that the lens takes on a light ash-gray appearance.”
And again: “Two grammes of rock-salt was introduced into the stomach of a young cat, and it killed her in three hours, but the lens had turned opaque before death.”
Kunde repeated the experiment many times, but always with the same result, the lens became opaque.
Here, then, we find that common salt administered to the lower animals, causes a development of cataract in them.
In his experiments Kunde was aided and controlled by Kolliker, Virchow, H. Muller and Von Graefe. His experiments have been repeated by Kohnhorn, in Germany, by Weir Mitchell in America, and by B.W. Richardson, in England, and amply confirmed.
I hope you will pardon my going over the ground so well known to you all, but I want to bring out very prominently this importance fact, that the common salt of our tables is a ready producer of cataract.
In my little treatise “Supersalinity of the Blood,” etc., I take up this idea, and endeavour to show that not a few of the cases of cataract that come before us, have their origin in the excessive use of salt.
When too much salt is ingested, the blood becomes supersaline; when the blood is supersaline, its specific gravity is raised, and the lens is deprived of its natural condition as a transparent body,-in fact, it becomes opaque. If this condition of the blood continue for any lengthened period the lens must necessarily degenerate, and the cataractous state becomes permanent. I have shown that very many cataractous patients are fond of salt, and I submit that the salt must, in not a few instances, be held responsible for the dried up, sclerosed state of the lens and other tissues of the body.
The physiological effect of salt upon our bodies is to dry up, to deprive of water, to harden, and hence salt makes us thirsty. This is, I hold, with Kunde, the essentiality of its action, Weir Mitchell and Richardson to the contrary notwithstanding.
Let us now pass on to the next cause of cataract, viz., to
The Use of Sugar as a Cause of Cataract.
The experiments of Weir Mitchell, as set forth in a paper in the American Journal of the Medical Sciences, for January, 1860, show that not only salt, but also sugar can cause cataract. I have not read this paper myself, but only know it from Richardson’s references to it. Hence I must refer to the experiments of Richardson that were undertaken to the same end, and gave a like result, i.e., sugar causes an opacity of the crystalline lens.