Extraction Without Iridectomy.-Simple extraction, as this is usually called, is practically the same as the operation already described, with the exception of removing a section of the iris. All the preliminary should be followed out in this as in any other operation, with the exception of the Atropia dilatation. The corneal incision varies somewhat, in that it is made wholly in the clear cornea in simple extraction and should involve about the upper two-fifths of the circumference of the cornea. The object of the making a more central incision in this operation is to avoid the greater tendency to incarceration and prolapse of the iris from a too peripheral incision. A free division of the capsule should be made by inserting the cystotome as before and carrying it well under the margin of the iris. The speculum may then be removed and the upper lid drawn back with the forefinger of the left hand, which at the same time may make slight pressure on the upper part of the globe. The spoon is now applied to the lower part of the cornea and pressure made directly backward until the lens is titled upon its axis and presents at the opening, when the pressure should be upward and backward, which causes an extrusion of the lens with more or less prolapse of the iris. A gentle pressure and stroking of the cornea with the spoon below, together with pressure above to open the wound, will promote the escape of the cortical substance remaining. This may be aided by irrigating the lips of the wound and the conjunctival sac with a warm, saturated solution of boracic acid, many operators recommending the irrigation of the anterior chamber at the same time. The prolapsed portion of the iris, if it has not already returned to its place, can be made to do so by gently stroking and pushing it within the lips of the wound with a smooth probe or spatula. On replacing the iris it should return to a central position and assume its circular shape; if it should not, gentle massage through the closed lid will often cause it to do so. Before applying the dressing, as already detailed, the eye should be thoroughly irrigated with the boracic acid solution and a few drops of Eserine solution may be instilled.
In the use of Eserine, Bull Trans. Amer. Ophthal. Soc., 1890, p. 578. cautions against the instillations of a strong solution of Eserine, believing that it is apt to cause iritis, and claiming that half a grain to the ounce solution, or, in some cases, even one-tenth of a grain, is sufficient to produce any desired contraction. After forty-eight hours a solution of Atropia may be instilled to prevent posterior synechiae, which are apt to follow; in other respects the after treatment in uncomplicated cases is the same as in extraction with iridectomy.
The accidents and complications liable to occur in this operation are the same as those already referred to, with the addition of prolapse of the iris, which may occur at the time of the operation or immediately afterward, before closure of the wound, and in some cases by the re-opening of the wound after having partially healed. When it occurs soon after the operations and cannot be returned to its place, it should be cut off. Prolapse may also occur later, and when it does is almost always of traumatic origin, due to some sudden movement of the patient, from coughing, lying on the operated side, from a too early examination of the eye, etc.; and when occurring later, after the wound is partially healed, it should be left undisturbed, as they generally heal with a cystoid cicatrix which in course of time flattens down, and although it causes some upward distortion of the pupil the ultimate vision may still be good. In some cases of a very large prolapse the bulging may be reduced by simply pricking, allow the aqueous to escape and apply a compress bandage.
Incarceration of the iris or anterior synechiae is an adhesion of the iris in the lips of the wound without being prolapsed through it. This accident causes considerable distortion of the pupil and may be the source of irritation to the eye. Its occurrence, how-ever, is, we believe, becoming less frequent, owing to a more general adoption of the more central corneal incision.
As previously stated, we believe the extraction without an iridectomy to be the ideal method of removing cataractous lenses; but, as it had its advantages and disadvantages, we quote from Bull (loc. cit.) a comparison of the same with the operation of extraction with iridectomy:
“1. If successful and without complication, it preserves the natural appearance of the eye-a central, circular and movable pupil.
“2. The acuteness of vision, with the astigmatism carefully corrected, is somewhat greater than after the old operation.
“3. Eccentric vision and orientation are decidedly better than by the old operation.
“4. Small particles of capsule are much less likely to be incarcerated in the wound, and thus act as foreign bodies and excite irritation.
“5.It is a shorter operation in point of time, by reason of the abscence of an iridectomy.
“6.As there is no iridectomy, there is little or no haemorrhage, and this may be considered a very decided advantage.
“The disadvantages of simple extraction are as follows:
“1.The technique of the operation is decidedly more difficult than that of the old operation. The corneal section must be larger, in order that the passage of the lens through it may be facilitated, as the presence of the iris acts as an obstacle to its exit. The section must be performed rapidly, so as to avoid the danger of the iris falling on the knife and being wounded. This rapid passage of the knife across the anterior chamber renders it difficult to make the height of the flap an even curve, particularly when the incision is entirely in the clear cornea, as it should be. The cleansing of the pupillary space and the posterior chamber is much more difficult than after the old operation.
“2. Posterior synechiae, secondary prolapse and incarceration of iris are more frequently met with than after the old operation. The two latter may be largely avoided by making the corneal section, as before stated, in the clear cornea and not in the limbus, which is too peripheral and rather favors both prolapse and incarceration of the iris.
“3.The operation is not applicable to all cases. this objection, however, may be applied to all operation.”
Aphakia-Absence of the lens is recognized by greater depth of the anterior chamber; a peculiarly black pupil and often tremulousness of the iris is present. Dilatation of the pupil will often show traces of the opaque capsule left behind. The power of accommodation is also lost. Removal of the lens in an emmetropic eye will leave a high degree of hypermetropia equal to about 11 D., and, of course, much less in a previously myopic eye. For near vision, as reading, writing, etc., a still stronger convex lens must be used. In addition to the hypermetropia, after the extraction of the lens, there is usually a certain amount of astigmatism, varying from 1 D. to 4 D., which is more often “contrary to the rule’ and which should be corrected, together with the hypermetropia. Glasses, as a rule, should never be prescribed until all signs of irritation of the eye have passed away, and are not often worn constantly at first with comfort. It is usually best to wait one or two months, at least after the operation, before prescribing permanent glasses.
Luxatio Lentis (Ectopia Lentis, Dislocation of the lens)- This condition may be either partial or complete, and may be congenital (ectopia lentis) or from disease of the eye and from traumatism. The lens may be tilted obliquely, in the vertical plane or in any direction. It may be displaced backward into the vitreous or forward into the anterior chamber, and, from injury of the sclera, it may become lodged under the conjunctiva or entirely escape from the eye. dislocation most often follows some disease where the vitreous has become fluid and the suspensory ligament, stretched and atrophied, gives way. High degrees of myopia favor this displacement, and when but partial, the border of the lens being in the pupil, there will exist two different states of refraction in the same eye, and we then may have monocular Diplopia.
SYMPTOMS- A high degree of hypermetropia is produced in emmetropic eyes; and accommodation is lost, the anterior chamber is deepened from the sinking of the iris, the pupil is small and iridodonesis or trembling of the iris is usually present. When due to disease, atrophy of the choroid and opacities of the vitreous are generally present.
DIAGNOSIS-If the edge of the lens is in the pupil it will appear with the ophthalmoscope by the direct method as a dark border and a double view of the fundus be seen, one image through the lens and the other beyond the lens. Total absence of the lens is determined by the catoptic test, which is made in a dark room with a lighted candle passed slowly before the eye, when, if the lens is present, three images should be seen-a clear, distinct, upright image from the cornea; a second, also upright, but diffused and faint image from the anterior surface of the lens, and a third, small, sharp and rather bright image. Which is inverted, from the posterior surface of the lens. If two or all of these images are seen, the lens is in place.
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.