Cheselden,[3] a renowned surgeon, and oculist to Her Majesty, Queen Caroline of England, first announced, in 1728, his success in making an artificial pupil by means of his knife-needle. He made his puncture back of the corneoscleral junction on the temporal side, passing the knife across the posterior chamber, and making a counter-puncture in the iris-membrane near the nasal margin. He then cut through the iris from behind forward as he withdrew the knife, the incision being carried through two-thirds of its extent. The pupillary opening thus made was a long oval slit, horizontally placed. He has reported two successful cases[4] (Figs. [1] and 2), occurring in patients who had previously undergone couching of the lens. His instrument, strange to say, was practically of the same general shape as the Hays knife-needle, but was larger, and judging from the description more clumsily constructed, as there was danger of leakage of the aqueous and sometimes of the vitreous when it was used. Its form resembled a combination of a bistoury and a sickle-shaped knife, having a sharp edge on one side, a rounded back, and an acute point. We possess two good illustrations of this knife-needle, one by Cheselden himself (Fig. [3]), and the other by his pupil, Sharpe[5] (Fig. [4]).
Fig. 1.—Original case of iridotomy. Iris incised above (Cheselden).
Fig. 2.—Second case of iridotomy. Iris incised below (Cheselden).
Fig. 3.—Original knife-needle in situ, behind the iris (Cheselden).
For more than a century the method of Cheselden seems to have been the storm center of controversy. Some doubted his veracity, others essayed his operation but failed, while a few had a moderate degree of success. Many attributed to him statements which do not appear in his published report. He says clearly that in each of his cases couching had previously been performed, and yet some have insisted that the lens was present, and must have been wounded. He also states that his incision was made from behind forward, and yet his followers, Sharpe[5] and Adams,[6] both describe the incision as being made from before backward. As Sharpe was his pupil, and presumably had seen him operate, Guthrie[7] suggests the possibility of his having made his incision both ways, the technic being practically the same.
Morand,[8] in his “Eulogy of Cheselden,” claims to have personally seen him operate “on an eye in which the iris was closed by an accident,” and gives a more detailed description which closely follows the original method. He states that Cheselden presented him with one of his knife-needles as a souvenir of the occasion. Although Morand does not record the exact date of his visit to London, he does state that it occurred during the year 1729. Huguier,[9] in his exhaustive thesis on artificial pupil, also places the date of this visit in the year 1729. This fact is important, as some writers have declared that Morand neither made the visit to London nor saw Cheselden operate, but only quoted the original account given in the Philosophical Transactions. The publication of Morand’s high encomiums in 1757 attracted renewed interest to the subject of Cheselden’s operation among men of scientific and medical attainments.
Sharpe,[5] in 1739, performed this operation in the same manner as Cheselden, except that after he had entered the knife-needle through the sclerotic he passed it through the iris and across the anterior chamber, and then incised the iris-membrane from before backward. Although he was Cheselden’s pupil, and dedicated his small volume on surgery to him, he probably did his master more harm than good, as all the objections to Cheselden’s method seemed to be based on the deprecatory remarks of Sharpe. He says, “I once performed it with tolerable success, and a few months after, the very orifice I had made contracted and brought on blindness again.” He mentions the danger of wounding the lens, the lack of success in paralytic iris with affection of the retina, the danger of iridodialysis from traction of the knife, and the possibility of failure because the incision would not enlarge sufficiently. Thirty years later (1769) he published the ninth edition of his book without recording a single additional case, but added the thought that, since extraction of the crystalline lens showed the cornea was not so vulnerable as had been believed, he would “imagine” that a larger knife might be introduced perpendicularly through the cornea and iris and a similar incision made. In his first eight editions he pictures Cheselden’s iris-knife (Fig. [4], vide p. 25), but in his ninth edition he substitutes a broad lance-knife with two edges which closely resembled the one Wenzel (vide Fig. [17]) had just introduced (1767), and which Sharpe suggests “can also be used for the extraction of the cataract.” He evidently did not have a very clear idea of the subject, and only succeeded in casting doubt and discredit on the method of Cheselden, which, judging by his own statement, he had tried but once.