Of a cataract.
Now a humour concretes under the twoὑαλοειδὴς. coats, where I mentioned the void space to be, either from a disease, or a blow; and being gradually indurated, it obstructs the interior faculty of vision. There are several species of this malady, some of which are curable, and others not. For if the cataract be small, immoveable, of the colour of sea-water, or burnished iron, and leaves some sense of light on its sides, there remains hope. If it is large, if the black part of the eye, losing its natural appearance, is changed into some other, if the cataract be of the colour of wax[(11)], or gold; if it slides and moves to and fro, it is scarcely ever cured. And for the most part, the more severe the disease, or the greater the pains of the head, or the more violent the blow has been, which gave rise to it, so much the worse it is. Neither is old age a proper time of life for a cure; which without an additional disease causes a dimness of sight: nor even childhood; but the middle age betwixt these. Neither is a very small eye, nor one, that is hollow, fit for this operation. And there is also a certain maturity of the cataract itself: wherefore we must wait till it seems to be no longer fluid, but to have concreted with a certain degree of hardness.
Before the operation, the patient must use a spare diet, drink water for three days, the day immediately preceding take nothing at all. After this preparation he must be set in a light place, in a seat facing the light, and the physician must sit opposite to the patient on a seat a little higher; an assistant behind taking hold of the patient’s head, and keeping it immoveable; for the sight may be lost for ever by a slight motion. Moreover the eye itself, that is to be cured, must be rendered more fixed by laying wool upon the other, and tying it on. The operation must be performed on the left eye by the right hand, and on the right by the left hand. Then the needle sharp pointed[(12)], but by no means too slender, is to be applied, and must be thrust in, but in a straight direction, through the two coats, in the middle part betwixt the black of the eye and the external angle opposite to the middle of the cataract, care being taken to wound no vein. And it must not be introduced with timidity[(13)] neither, because it comes into a void space. A person of very moderate skill cannot but know when it arrives there; for there is no resistance to the needle: when we reach it, the needle must be turned upon the cataract, and gently moved up and down there, and by degrees work the cataract downward below the pupil; when it has past the pupil, it must be prest down with a considerable force, that it may settle in the inferior part. If it remain there, the operation is compleated. If it rises again, it must be more cut with the same needle, and divided into several pieces; which when separate, are both more easily lodged, and give less obstruction. After this the needle must be brought out in a straight direction, and the white of an egg spread upon wool must be applied, and over that something to prevent an inflammation, and then the eye be bound up.
Afterwards there is a necessity for rest, abstinence, mild unctuous medicines, and food (which it is soon enough to give on the day following) at first liquid, that the jaws may not be too much employed, then when the inflammation is gone, such as was directed in wounds. To which we must add this rule, that the patient’s drink be water for a pretty long time.
Of a flux of gum.
I have already treated of a flux of thin gum, which infests the eyes, so far as the cure depends upon medicines. I now come to these cases, that require manual operation. Now we observe that some people’s eyes never grow dry, but are always moistened with a thin humour; which circumstance occasions a constant asperity, and from slight causes excites inflammations, and lippitudes, and in fine renders a person uneasy all his life. And this disorder in some no remedy can relieve; in others it is curable. Which difference ought first of all to be known, that we may relieve the one, and not meddle with the other.
And in the first place, it is in vain to attempt the operation in those, who have this disorder from their infancy, because it will certainly continue to their dying day. Secondly, it is needless, where the discharge is not great, but acrid; because they are not assisted by a manual operation, but are brought to a sound state by medicines, and a proper diet for generating a thicker phlegm. Broad heads also are hardly susceptible of the remedy. Then it makes a difference whether the gum be discharged by the veins, that lye between the skull and the skin, or by those between the membrane of the brain and the skull: for the former moisten the eyes by the temples; the others by the way of those membranes, that go from the eyes to the brain. Now a remedy may be applied to those veins, that discharge above the bone, but not to those below the bone[(14)]. Neither can relief be given, where the discharge comes from both places; because when one part is relieved, nevertheless the other remains disordered.
The source of the disorder is discovered by this method. After shaving the head, such medicines, as stop the gum in a lippitude, ought to be laid on from the eye-brows as far as the top of the head: if the eyes begin to be dry, it appears that they are moistened by those veins, which are under the skin: if the moisture is not diminished, it is manifest it descends from below the bone: if a humour still flows[(15)], but in less quantity, the disorder is from both. In most patients however the complaint is found to be derived from the superior veins; and therefore the greater number may be relieved. And this is very well known, not only in Greece, but amongst other nations too: so that no part of medicine has been more clearly explained in any country.
Some practitioners in Greece cut the skin of the head in nine lines; two straight ones in the occiput, one transverse above these; then two above the ears, one also transverse betwixt them; and lastly three straight ones between the top of the head and the forehead. Others drew these incisions in a straight direction from the top of the head to the temples; and discovering from the motion of the jaws the origins of the muscles, made gentle incisions in the skin above these, and separating their lips by means of blunt hooks, they inserted lint in such a manner, as to prevent the edges of the skin from uniting, and to cause flesh to sprout up in the middle, which might bind those veins, from whence the humour passes to the eyes. Others again have drawn a line with ink from the middle of one ear to the middle of the other, and another line from the nose to the crown of the head; and where these lines met, made an incision with a knife; and after the effusion of blood, cauterized the bone in that part. And notwithstanding this, they also applied the actual cautery to the rising veins both in the temples, and betwixt the forehead and crown of the head.
It is a common method of cure to cauterize the veins in the temples, which indeed are generally turgid in this kind of disorder; but that they may be more inflated and show themselves better, the neck must first be tied pretty strait. And the veins must be cauterized with small and blunt irons; till the flux of gum upon the eyes stop: for that is a sign the passages are blocked up, by which the humour was conveyed.