The course above described refers to the ordinary senile or hard cataract, occurring in individuals upward of thirty-five years of age. All cataracts occurring under this age are of the soft variety, the course of which will be referred to later under the different varieties.
CAUSES.-Senile cataract often occurs in its incipiency in young people from twenty to thirty years of age, and for this reason the term simplex would be preferable to senile. Schoen
Archiv Ophthal., vol. xvii., 3, 1889. says that “three-fourths of the total number of cataractous eyes are hypermetropic or astigmatic.” The strain from uncorrected refractive errors, we believe, bears a very important part in the causation of cataract.
Sugar in the urine has been found in about one per cent. of cataract cases. The urine should, therefore, always be examined, and especially when cataract is met with in young persons. Albumin has also been found in the urine. Cataract has been seen in persons suffering from epilepsy and other convulsions, also after meningitis, cutaneous diseases, etc. It is also frequently found in those working in excessive heat and light, as in glass- blowers. Heredity appears to bear a very important relation to its occurrence, as examples of its transmission have frequently been reported.
In countries subject to epidemics of ergotism, cataract has been frequently found associated with it. Animals poisoned with Naphthalin have developed cataract. Cataract is often secondary to inflammatory affections of the eye, especially of the iris, ciliary body and choroid, in glaucoma and detachment of the retina. Traumatism is also a frequent cause, and may be either from a direct injury of the lens or from concussion.
Varieties of Cataract.-The description already given may be considered as applying in a general way to all forms of cataract, the most typical type of which is the simple or senile cataract. The classification of cataracts met with in different works is most confusing, as by different authorities they will be classed according to their anatomical location, their consistency, their color, whether primary or secondary, partial or complete, senile or congenital, etc. The following table, taken from De Schweinitz, Diseases of the Eye, 1892, p. 386. gives a resume of the various classifications.
Anatomically 1. Lenticular.
2. Capsular.
3. Capsulo-lenticular.
1. Senile (a) Cortical = General.
(b) Nuclear 2. Juvenile or congenital {(a).Complete {Complete.
{Congenital.
{ Lamellar, or zonular {(b). Partial {Pyramidal, or polar.
Clinically.. 3. Complicated or secondary {Anterior polar cataract.
{Posterior polar cataract. {Complete cataract.
4. Traumatic.
5. After cataract.
The clinical classifications are perhaps most frequently employed, and as the description already given applies to the first clinical sub-division, i.e., senile cataract, we will refer briefly to some of the other varieties.
Complete Congenital Cataract involves all the layers of the lens and is a rare form of cataract, frequently accompanied by nystagmus. In this the lens is soft, densely opaque and either of a white or bluish-white color. There is also often an opacity of the capsule as well, and this form of cataract is apt, in course of time, to undergo degeneration, becoming shriveled up, membranous or calcareous. There may be a dislocation of the lens from degenerative changes of the zonule of Zinn.
The cause of this variety of cataract has been variously attributed to heredity and disturbances of nutrition in intra- uterine life. If, however, it has become calcareous or membranous, extraction should be made as in senile cataract.
Cataracta Lamellaris or Cataracta Zonularis is a congenital opacity involving only a portion of the lens, and, as its name implies, affects only one or more lamellae between the nucleus and the cortex, forming an opaque layer surrounding the clear nucleus of the lens. Microscopical examination of this form of cataract has but rarely been made, and hence the description given by Beselin Archiv. Ophthal., vol. xvii., 3, 1888. is of much value. He concludes, ” that a chemical alteration in the subsequent nucleus, brought about by a change in the nutrition of the part, attending rhachitis, is the primary factor. This change is followed by a general contraction of the affected part, which causes the formation of fissures between this part and the normally developed, unaffected, cortical layers of lens substance. A granular deposit takes place in the tissue plasma collected in the fissures and at the same time the neighboring lens-fibres take on a form of granular degeneration. In the majority of cases lamellar cataract is present in both eyes, although it does occur in but one.” It is supposed that the opaque layers are the outer layers of the lens during the period when the nutrition is disturbed by rachitis, later, after the disappearance of the rachitis, normal transparent lens substance is again deposited, forming the transparent external layers.
The vision is more or less affected, depending upon the density of the opacity and the amount of lens involved. The patients hold objects very close to the eyes and are commonly thought to be near-sighted, and true myopia may exist. With the ophthalmoscope there is seen a sharply defined opacity in the axis of the lens which is generally circular and more or less dense; the periphery of the lens is usually perfectly clear. The darkness of the opacity is greater near the edge than the center, and this aids in the diagnosis because a solid cataract with the nucleus involved would be densest at the centre. Occasionally opaque dentations are seen projecting into the transparent periphery from the margin of the opacity. Lamellar cataract usually affects both eyes. A history of convulsions, as pointed out by Arlt, is frequently found in these cases. In addition to rickets, scrofula or hereditary syphilis is often determinable as a constitutional cause and is frequently evidenced by an examination of the teeth, which appear irregular, notched and broken. Lamellar cataract, as a rule, remains stationary, though not invariably so.
Treatment of this form of cataract is usually by iridectomy, which should be made when, upon dilatation of the pupil, with the refractive error, if any corrected, the vision is improved, as by displacing the pupil the transparent portion of the lens is used and clearer vision results. Discission or removal of the lens may be made when the vision is less than one-third of the normal, when opaque spots extend into the transparent periphery beyond the layers involved indicating a tendency to form a complete cataract and when there seems no likelihood of improving the vision by an iridectomy.
Cataract Polaris Anterior or Cataracta Pyramidalis may be simply a minute white dot upon the capsule of the lens, or a larger, dense, chalky-white, circular patch involving both the capsule and the substance of the lens for a short distance immediately beneath. It often seems to stands out in front in a pyramidal form. The condition is sometimes congenital, and, if so, usually in both eyes. In these cases it may be the result of imperfect closure of the capsule, or possibly from the remains of the pupillary membrane. More frequently, however, the opacity occurs after birth from a central perforating ulcer of the cornea, as in ophthalmia neonatorum; the lens is thrown forward in contact with the cornea upon escape of the aqueous, a plug of lymph is thrown out, closing up the perforation, and as the aqueous reforms the lens is pressed back, carrying with it a little mass of lymph attached to its capsule. In these cases a central opacity of the cornea may frequently be seen by the oblique illumination. This form of cataract is always stationary.
Cataract Polaris Posterior is the term applied to a glistening, white, round opacity of the posterior pole of the lens or its capsule. In its congenital form it is due to some remains or imperfect absorption of the hyaloid artery. When acquired it is usually the result of a disease of the choroid, vitreous or retina causing malnutrition of the lens. Opacities in the vitreous are usually determinable, and often lesions of the fundus may be discovered with the ophthalmoscope. The opacity is seen to move but very slightly upon movement of the eye because of its position at about the centre of rotation. The opacity in itself does not cause a very great loss of vision, but the patients see poorly on account of the lesions further back. This form of opacity may remain stationary for a long time, but in the end the lens usually grows more opaque.
Cataracta Traumatica is an opacity of the lens due to injury, and as a rule the whole substance of the lens becomes opaque. The traumatism may be a direct injury to the capsule of the lens, as in penetrating substances, which, by lacerating the capsule, permits the aqueous to come into contact with the substance of the lens, causing it to swell and become opaque. Absorption sometimes results, but in other cases the swelling of the lens will set up either glaucoma, iritis or cyclitis. A blow upon the eye may also cause an opacity of the lens by the force of the concussion, rupturing either the anterior or posterior capsule, and in some cases it may possibly occur without any rupture of the capsule. Cataract usually forms very rapidly within a few days, after the admission of aqueous to the lens substance and results from the action of the sodium chloride of the aqueous upon the globulin of the lens substance. The younger the patient the more rapid is the swelling and absorption and the danger of increased tension and inflammation is less. The older the patient the greater is the danger of glaucomatous symptoms. In an extensive rupture of the capsule some of lens substance escapes into the anterior chamber where it swells up, breaks down and becomes absorbed. In some cases of slight laceration of the capsule there is formed a limited opacity, which may disappear, remain stationary or increase.
Professor of Ophthalmology in the College of the New York Ophthalmic Hospital; Surgeon to the New York Ophthalmic Hospital. Visiting Oculist to the Laura Franklin Free Hospital for Children; Ex-President American Homoeopathic Ophthalmological, Otological and Laryngological Society. First Vice-President American Institute of Homoeopathy : President Homoeopathic Medical Society of the State of New York ; Editor Homoeopathic Eye. Ear and Throat Journal : Associate Editor. Department of Ophthalmology, North American Journal of Homoeopathy, etc.