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A New Test for Accommodation
NOTES, CASES, INSTRUMENTS
429
A N E W T E S T FOR ACCOMMODATION J O H N A. EGAN,
M.D.
Denver, Colorado
Fig. 2 (Wainstock). The doubletoothed forceps.
verted toward the iris. The standard instru ments are awkward and often slip off easily. The single-toothed forceps, with its flat tip, is excellent for guiding in the edge of the wound where it can easily be grasped to insert the suture. The tooth is heavy enough for firm grasping of the cornea. This singletoothed forceps is very useful in suturing the corneoscleral sections in cataracts with a minimum of ocular disturbance. The double-toothed flat forceps allows minimal corneal injury combined with max imum grasping ability. One variation of the instrument was lengthening the teeth 0.5 mm. which permitted the surgeon to grasp the cornea or sclera firmly with one hand and with the other guide the needle, held by the needle holder, directly between the lips of the forceps, with a minimal amount of ocular disturbance. 1508 David Broderick Tower
(26).
In working with the correcting cross cyl inder, and more especially when determining the amount of presbyopic add, I discovered that it could also be used as a test for ac commodation. Present practical tests utilize a line of letters, a small letter, or lines for the pa tient to view. He is expected to tell the ex aminer when such objects first become blurred as they are slowly brought toward the eye. We all have had the experience of finding that the patient, though doing his best, was answering erroneously because of the fact that it is difficult to state positively when these objects first begin to blur. In the test I am proposing, one eye be ing examined at a time, the full distance correction is worn. In front of this, a 0.25D. or 0.5D. correcting cross cylinder* is placed with its minus axis at 90 degrees. Next, a Jacques blur-point card, obtainable through your optician, is held before the eye. If the patient is not presbyopic, the horizontal and vertical lines of the black cross of the card will seem equally clear. The card is then brought slowly toward the eye until the hori zontal lines appear blacker than the vertical. At this point a Prince rule is used to measure the accommodation as in other familiar tests. If the patient is presbyopic, a + 3.0D. sph. is added to the distance correction and the measurement taken as before, the 3.0D. be ing subtracted from the result. What happens in the test is that the pa tient, who is not presbyopic in this instance, looking through the Jackson cross cylinder, accommodates, thus seeing the crossed lines on the Jacques' card equally blurred. There* A correcting cross cylinder is the same as a testing cross cylinder except that the latter has a long handle. The correcting cross cylinder has a short handle like any ordinary trial lens and fits in the trial case.
430
NOTES, CASES, INSTRUMENTS
fore, one focal line lies in front of the retina and one behind the retina. A s the card is brought closer and closer to the eye, the patient finally is unable to accommodate further and both focal lines then are forced backward. T h e posterior one then lies behind the retina and, unless the card is brought too, close to the eye, the anterior one lies on the retina making the horizontal lines clearer. (If the minus cylinder is placed at 180 degrees, the vertical lines would appear clearer.) A s mentioned before, I have found that it is difficult for patients to say exactly when a line or a letter first becomes blurred as it
is brought nearer the eye. I n the proposed test, the patient apparently can tell much more accurately when the horizontal cross lines, for instance, of the test card, become clearer than the vertical lines, T h e chief reason for this lies in the fact that the patient has two items to compare, that is, the vertical and the horizontal lines ; whereas, in the other common tests for accommodation, by the time the test object be comes a little blurred, the patient has forgotten what it looked like when it was farther from the eye and perfectly clear, 1765 Sherman
Street
(3).
OPHTHALMIC MINIATURE
You choose for the operation, a clear serene day; and fixing the Patient in a chair, opposite a well-lightened window, place yourself in another fronting him, which for this purpose, should be a little more elevated than his. Apply over the sound eye, some soft linen compresses, and then bind up the Eye, with a band or hand kerchief, round the Head, which will prevent the other eye, from rouling, as also save the Patient from some anxiety, in knowing when, and how you go on. Having enjoined strict silence, to the spectators and assistants, give the Patient an oblique position: that is, if it be the Right Eye, you are to work on, let that side project a little more towards you, than the other, by which you make your incision freer. Nevertheless I would not recommend this position, to be used, indiscriminately; for a good deal depends on the form of the Eye, and the Operator must always prefer that posture, to his Patient, which gives himself the greatest ease and com mand. Let the lids be separated, by an assistant, and then the Surgeon holding the handle of the needle, between two fore-fingers and the thumb, with the black Line, of the handle, fronting him, pierces the Cornea transparens, just at the border of the Sclerotica, in the inferior middle part of the Eye, or at its lateral external angle, for the choice is no way material. The quantity of 'the instrument, that has entered the Cornea, will determine whether it is thoroughly pervaded, or no; it being in a Human Eye, but about τΑ Line: but a more exact Rule, is the spurting out of the aqueous humour, which sometimes flies in your face, at other times, drib bles down the cheek, according to the pressure on the Cornea, and breath of the incision. The convex part of the needle faces the Iris, and with its sides you gently dilate the Orifice, and then you remove your needle, and introduce the blade of your scissors, and dilate the Cornea, at its border, on both sides, till you have a fair view of the Pupilla which is done, by turning up the part of the Cornea, which has been dilated: you now introduce thro' the Pupilla, the Iris Needle, and dilate . the Chrystalin Capsula, which being done, by a gentle pressure, on the inferior part of the Eye, you press out the Christalin: return the inverted part of the Cornea, and apply to the Eye, soft linen compresses, moistened in water, in which a little Saffron has been infused, and animated with a fourth part Brandy. Let the Patient be confined to a dark room, without much fire, and kept to a low diet, for three or four days—let him also, in this time avoid lying on either side, but rather, if possible, sleep in a perpendicular posture; at least, let his head be elevated, and cause him to lye on his back. "A critical analysis of the new operation for a cataract," Mr. O'Halloran of Limerick, 1750.
429
A N E W T E S T FOR ACCOMMODATION J O H N A. EGAN,
M.D.
Denver, Colorado
Fig. 2 (Wainstock). The doubletoothed forceps.
verted toward the iris. The standard instru ments are awkward and often slip off easily. The single-toothed forceps, with its flat tip, is excellent for guiding in the edge of the wound where it can easily be grasped to insert the suture. The tooth is heavy enough for firm grasping of the cornea. This singletoothed forceps is very useful in suturing the corneoscleral sections in cataracts with a minimum of ocular disturbance. The double-toothed flat forceps allows minimal corneal injury combined with max imum grasping ability. One variation of the instrument was lengthening the teeth 0.5 mm. which permitted the surgeon to grasp the cornea or sclera firmly with one hand and with the other guide the needle, held by the needle holder, directly between the lips of the forceps, with a minimal amount of ocular disturbance. 1508 David Broderick Tower
(26).
In working with the correcting cross cyl inder, and more especially when determining the amount of presbyopic add, I discovered that it could also be used as a test for ac commodation. Present practical tests utilize a line of letters, a small letter, or lines for the pa tient to view. He is expected to tell the ex aminer when such objects first become blurred as they are slowly brought toward the eye. We all have had the experience of finding that the patient, though doing his best, was answering erroneously because of the fact that it is difficult to state positively when these objects first begin to blur. In the test I am proposing, one eye be ing examined at a time, the full distance correction is worn. In front of this, a 0.25D. or 0.5D. correcting cross cylinder* is placed with its minus axis at 90 degrees. Next, a Jacques blur-point card, obtainable through your optician, is held before the eye. If the patient is not presbyopic, the horizontal and vertical lines of the black cross of the card will seem equally clear. The card is then brought slowly toward the eye until the hori zontal lines appear blacker than the vertical. At this point a Prince rule is used to measure the accommodation as in other familiar tests. If the patient is presbyopic, a + 3.0D. sph. is added to the distance correction and the measurement taken as before, the 3.0D. be ing subtracted from the result. What happens in the test is that the pa tient, who is not presbyopic in this instance, looking through the Jackson cross cylinder, accommodates, thus seeing the crossed lines on the Jacques' card equally blurred. There* A correcting cross cylinder is the same as a testing cross cylinder except that the latter has a long handle. The correcting cross cylinder has a short handle like any ordinary trial lens and fits in the trial case.
430
NOTES, CASES, INSTRUMENTS
fore, one focal line lies in front of the retina and one behind the retina. A s the card is brought closer and closer to the eye, the patient finally is unable to accommodate further and both focal lines then are forced backward. T h e posterior one then lies behind the retina and, unless the card is brought too, close to the eye, the anterior one lies on the retina making the horizontal lines clearer. (If the minus cylinder is placed at 180 degrees, the vertical lines would appear clearer.) A s mentioned before, I have found that it is difficult for patients to say exactly when a line or a letter first becomes blurred as it
is brought nearer the eye. I n the proposed test, the patient apparently can tell much more accurately when the horizontal cross lines, for instance, of the test card, become clearer than the vertical lines, T h e chief reason for this lies in the fact that the patient has two items to compare, that is, the vertical and the horizontal lines ; whereas, in the other common tests for accommodation, by the time the test object be comes a little blurred, the patient has forgotten what it looked like when it was farther from the eye and perfectly clear, 1765 Sherman
Street
(3).
OPHTHALMIC MINIATURE
You choose for the operation, a clear serene day; and fixing the Patient in a chair, opposite a well-lightened window, place yourself in another fronting him, which for this purpose, should be a little more elevated than his. Apply over the sound eye, some soft linen compresses, and then bind up the Eye, with a band or hand kerchief, round the Head, which will prevent the other eye, from rouling, as also save the Patient from some anxiety, in knowing when, and how you go on. Having enjoined strict silence, to the spectators and assistants, give the Patient an oblique position: that is, if it be the Right Eye, you are to work on, let that side project a little more towards you, than the other, by which you make your incision freer. Nevertheless I would not recommend this position, to be used, indiscriminately; for a good deal depends on the form of the Eye, and the Operator must always prefer that posture, to his Patient, which gives himself the greatest ease and com mand. Let the lids be separated, by an assistant, and then the Surgeon holding the handle of the needle, between two fore-fingers and the thumb, with the black Line, of the handle, fronting him, pierces the Cornea transparens, just at the border of the Sclerotica, in the inferior middle part of the Eye, or at its lateral external angle, for the choice is no way material. The quantity of 'the instrument, that has entered the Cornea, will determine whether it is thoroughly pervaded, or no; it being in a Human Eye, but about τΑ Line: but a more exact Rule, is the spurting out of the aqueous humour, which sometimes flies in your face, at other times, drib bles down the cheek, according to the pressure on the Cornea, and breath of the incision. The convex part of the needle faces the Iris, and with its sides you gently dilate the Orifice, and then you remove your needle, and introduce the blade of your scissors, and dilate the Cornea, at its border, on both sides, till you have a fair view of the Pupilla which is done, by turning up the part of the Cornea, which has been dilated: you now introduce thro' the Pupilla, the Iris Needle, and dilate . the Chrystalin Capsula, which being done, by a gentle pressure, on the inferior part of the Eye, you press out the Christalin: return the inverted part of the Cornea, and apply to the Eye, soft linen compresses, moistened in water, in which a little Saffron has been infused, and animated with a fourth part Brandy. Let the Patient be confined to a dark room, without much fire, and kept to a low diet, for three or four days—let him also, in this time avoid lying on either side, but rather, if possible, sleep in a perpendicular posture; at least, let his head be elevated, and cause him to lye on his back. "A critical analysis of the new operation for a cataract," Mr. O'Halloran of Limerick, 1750.