Paralytic myosis occurs in spinal lesions above the dorsal vertebrae, in general paralysis of the insane, and is a prognostic sign of general paralysis approaching when it follows the dilated pupil of acute mania and may be due to a paralysis of the cervical sympathetic from injury.
Spinal myosis is nearly always bilateral and may be preceded or accompanied by atrophy of the optic nerve and contraction of the field of vision. This form of myosis is seen in tabes dorsalis, and, from the peculiarity of the contraction of the pupil, it is called the Argyll Robertson pupil, as he first called attention to it in 1869. In this, the pupil is contracted, and, while not responding at all or very feebly to light, responds actively to convergence and is always indicative of a serious central lesion.
Contraction of the pupil unassociated with more serious disturbance is of rare occurrence; the cause, therefore, usually demands our attention. Atropine instilled into the eye may be employed, though it generally gives only temporary relief.
Jaborandi and Physostigma ven. are especially recommended for this condition, though various remedies which produces contraction of the pupil may be thought of.
Hippus.- Is a spasmodic pupillary movement irrespective of light or accommodation. There is an alternate contraction and dilation of pupil which may occur in nystagmus, in multiple sclerosis, acute meningitis, after epileptic attacks, in hysterical spasms, etc.
Iridodonesis.- Tremulousness of the iris is dependent upon loss of support of the iris and is usually the result of a partial or total dislocation or absence of the lens. It may also occur in hydrophthalmus, or when there is an increased amount of fluid in the posterior chamber. There is nothing to be done for
it.
Iridoncosis.- Atrophy of the iris is the result of inflammation, usually a chronic parenchymatous iritis, and sometimes occurs after perforation of the cornea where the anterior synechiae have kept up the inflammation. It consists of a fatty degeneration.
Hypaemia.- Blood in the anterior chamber is usually of traumatic origin, although may be spontaneous, as a result of some intra-ocular inflammation, as iritis. It may be but slight, or sufficient to entirely fill the anterior chamber, and is usually rapidly absorbed by the application of a compress-bandage and the internal administration of Arnica, Aurum, Hamamelis or Ledum.
Iridodialysis.- a separation of the iris from its peripheral attachment is usually traumatic, as from a blow on the eye, which spreads the cornea at the corneo-scleral junction, causing a separation, or from operation, as in iridectomy.
Coloboma Iridis.- Congenital absence, due to an arrest of development of a part of the iris, of either one or both eyes, is not uncommon. It is usually complicated with other congenital anomalies, especially of the choroid, or may be of the lens, or optic nerve, or in microphthalmos. It may extend to the periphery or not, and is usually downward, or downward and inward, and may be of various shapes. Pollak Archiv. Ophthal., vol. xx., p. 410, 1891. reports three cases and gives the literature upon coloboma of the iris.
Irideraemia (Aniridia).- Absence of the iris may be total or partial, but it is usually total and in both eyes. When complete, we may be able to see the ciliary processes, unless small or atrophied. The lens usually becomes opaque, vision is decreased and nystagmus often accompanies it. Stenopaic glasses may improve.
Membrane Pupillaris Persistans consists of the presence of two or three fibres running across the pupil which are attached on the anterior surface of the iris and external to the sphincter. During the greater part of intra-uterine life the pupillary membrane stretches across the pupil, and in normal eyes it remains permanent after birth only in that part which covers the iris, whose endothelial layer it becomes; but occasionally small shreds will remain and are called persistent pupillary membrane.
Heterochroma is the term applied to variations in the color of the iris. In one eye the iris may be black or brown and in the other blue, or the two colors may exist different sections of the same iris.
Corectopia, an anomalous position of the pupils; Diplokoria, double pupil, and Polycoria, many pupils, are all congenital anomalies which are sometimes met with.
Operations on the Iris – Iridectomy.- This operations, consisting in the excision of a portion of the iris, is the one most frequently made for both therapeutic and optical measures. It is indicated for therapeutic purposes in glaucoma, staphyloma, posterior synechiae and sometimes may be of value in obstinate cases of recurrent iritis, or in keratitis with deep ulceration or hypopyon. It is also indicated in tumors of the iris or for foreign bodies in the iris and is frequently performed preliminary to cataract extraction. For optical purposes it may be indicated in opacity of the cornea, occlusion of the pupil, central opacity or dislocation of the lens and in cataract extraction. Iridectomy, when made for visual purposes, should of course be made where there is the least opacity of the cornea and lens, preferable below and a little to the inner side, if possible. When made of therapeutical purposes it is preferably above, that the upper lid may cover the deformity as much as possible. The size of the iridectomy, when made for optical purposes, should be small and large when made as a therapeutical measure.
The instruments needed for this operation are a speculum (see Fig. 49), fixation forceps (see Fog.50), an angular or straight keratome (Figs. 67 and 68), or Graefe cataract knife; either curved or straight iris forceps (Figs. 69 and 70) and a pair of iris scissors (Fig.71). Cocaine anaesthesia is usually sufficient in all cases, excepting, possibly, in glaucoma or an especially nervous subject, when a general anaesthetic should be administered. The eyelids are kept open with the speculum and the eye steadied by a firm hold with the fixation forceps directly opposite the point at which the incision is to be made. The keratome is then inserted in the sclerotic at the corneo-scleral margin (except when made for therapeutical purposes, when it would be from one to two mm. from the edge of the cornea) obliquely and in such a direction that, if continued, it would wound the iris and lens; but, as soon as the point is seen in the anterior chamber, the handle is depressed so as to bring the blade into a plane anterior and parallel to that of the iris and the blade is pushed forward into the anterior chamber until an external wound of sufficient size has been attained. The keratome is now to be slowly withdrawn, with its apex toward the cornea and well away form the iris and lens. The aqueous escapes with the withdrawal of the knife and should be allowed to pass off slowly. The iris forceps are now entered, closed, into the anterior chamber, opened, and the iris seized near its pupillary edge, drawn out and cut off by an assistant at one cut of the scissors, or, as some prefer, drawing it to one side of the wound and partially snip it off and then drawn to the other angle, where the excision is completed (Figs. 72 and 73). Care should be taken to see that the cut edges of the iris go back into place, if not they may be pushed in with a hard rubber spoon, as none of the iris should be allowed to remain in the wound. The eye is then closed and a compress bandage applied.
The Accidents from Iridectomy are first, from an injury of the lens by the keratome. This is a very serious accident which will be followed by partial or complete cataract and possible glaucoma from swelling of the lens. Sometimes the keratome will enter the layers of the cornea instead of the anterior chamber when this is discovered, the instrument should be withdrawn and a fresh incision made. Haemorrhage into the anterior chamber, if occurring after the excision of the iris, requires no attention, as it will be rapidly absorbed, and if it occurs before the iris is cut, the blood can usually be made to flow out by depressing the edge of the wound. Haemorrhage into the fundus of the eye is apt to occur during iridectomy for glaucoma and is of serious import. It results from a too rapid escape of the aqueous on the withdrawal of the keratome.
Iridotomy (Iritomy) consists in the formation of an artificial pupil by simple incision of the iris. It is only occasionally adopted, and that in cases of absence of the lens, when the pupil is closed and the iris adherent to the lens- capsule, as may sometimes occur after cataract operation, where the iris has been put on the stretch by being drawn upward by the cicatrix. It is best made after De Wecker’s method,- a vertical incision about 3 mm. long is made in the cornea about the same distance from its margin with a keratome. De Wecker’s forceps- scissors are then entered, close, point of one is forced through the iris, by closing the blades the tightly stretched iris-fibres are cut through and from their retraction a central clear pupil is formed.
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.