[Illustration: Portrait of William Cheselden, 1688–1752. Painted by Richardson.] I. KNIFE-NEEDLE METHOD. 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). [3] Cheselden, William: Philosophical Transactions, London, 1728, xxxv, p. 451. [4] Ibid, abridged, vii, pl. v, Figures 2, 3 and 5. [5] Sharpe, Samuel: A Treatise on the Operations of Surgery, London, 1739, p. 169. [Illustration: Fig. 1.--Original case of iridotomy. Iris incised above (Cheselden).] [Illustration: Fig. 2.--Second case of iridotomy. Iris incised below (Cheselden).] [Illustration: 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[4] 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. [6] Adams, Sir William: Practical Observations on Ectropium, Artificial Pupil and Cataract, London, 1812, p. 37 et seq. [7] Guthrie, G. J.: Operative Surgery of the Eye, London, 1830, p. 428.