A New Method of treating Glaucoma, based on recent researches into its Pathology

Abstract

THIS little brochure is written by a Cambridge graduate who has devoted considerable time and attention to the study of diseases of the eye, and who has devised a new and very serviceable form of ophthalmoscope. The proposition he endeavours to establish is “that the ordinary method of treatment for glaucoma by iridectomy, though highly successful in acute forms of the disease, is nevertheless both uncertain and unsatisfactory in the chronic condition of glaucoma.” The truth of this proposition all those who have had large experience in the performance of operations on the eye will freely admit: the reason is less easy to give. Dr. Johnson describes the lymphatic system of the eye, and adduces evidence to show that the aqueous humour is secreted by the ciliary processes and posterior surface of the iris, whilst it is drained off by the canal of Fontana, and the meshwork at the corneo-iridal angle. Any circumstance obliterating this angle is apt to induce glaucoma. It is certainly not due to swellings of the lens, since Brailey has shown that the lens is smaller in the glaucomatous than in the normal eye, but Dr. Johnson thinks that acute glaucoma may be referred to swelling and inflammation of the ciliary processes, whilst in chronic glaucoma there are slow and gradual changes in the ciliary body and in the lesions around the angle of the anterior chamber, which in his opinion explains the different effects of iridectomy in cases of acute and chronic glaucoma. Dr. Johnson then proceeds to describe an operation which he terms scleral paracentesis, and describes as new, but which we have seen performed both by Mr. Hancock and by Mr. Power many years ago. In point of fact, Mr. Hancock's operation was a scleral para-centesis, and his view, which is not altogether incorrect, and was based on observation, was that in glaucoma a circumcorneal depression could be seen which he imagined to be due to the ciliary muscle, and his section, made with the same instrument recommended by Dr. Johnson, namely, a Wenzel's double-edged knife, was made through the sclera with the object of dividing the ciliary muscle; and the excellent results obtained in some cases show clearly that the escape of the vitreous which followed the incision, accompanied, when the anterior chamber was opened, by the aqueous humour, was quite enough to afford relief to all the symptoms and to restore vision, even if the spasm of the ciliary muscle was quite imaginary. We do not, however, wish to deprive Dr. Johnson of the credit of having thought out this method of procedure, though he may rest assured that he will meet with many cases of chronic glaucoma that will derive no benefit from scleral paracentesis, and that he will have to be careful in promising success from his operation in such cases.

A New Method of treating Glaucoma, based on recent researches into its Pathology.

By Geo. Lindsay Johnson (H. K. Lewis, 1884.)