In conclusion let me say that the acceptance or rejection of Colonel Elliot's procedure or any other operation is not to be decided by the percentage of iritis, secondary cataract, relapses, lost eyes, etc., but by deciding whether or not his procedure in the various forms of glaucoma gives the best results, including the preservation of comfortable eyes. In other words, we are seeking not the operation that will cure every case of glaucoma but the one which is capable, in the hands of the average ophthalmic surgeon, of relieving or curing most cases of that affection.
Dr. Casey A. Wood's Paper on Operations Other than Scleral Trephining for the Relief of Glaucoma
Discussion,
Albert E. Bulson, Jr., M.D.,
Fort Wayne.
Increasing belief in Colonel Elliot's view that trephining should be the operation of choice in any form of glaucoma, makes it difficult to consider operations other than trephining in anything but a spirit of disfavor.
Until recently the decision as to the kind of operative procedure to be employed for the relief of glaucoma has depended on the form and stage of the disease, and the amount and character of the vision of the affected eye. Many operators still hold that an iridectomy is the most valuable of all operations for acute inflammatory glaucoma, and not a few hold that the operation has a decided place in the treatment of simple glaucoma. The operation is not without difficulties, and one is inclined to agree with Elliot who says that "The man who can make a 'finished iridectomy' quietly and cleanly has graduated as an ophthalmic operator." The difficulties of an iridectomy are especially pronounced in those cases in which the anterior chamber is extremely shallow and the iris is pressed against the cornea. It is in such cases that the success of the operation is increased by the addition of posterior sclerotomy and the intelligent use of miotics prior to the performance of the iridectomy. Even then the permanent results of the iridectomy will be modified in proportion to the success secured in freeing the filtration angle and opening Schlemm's canal by thorough removal of the root of the iris.
The failure of many apparently well executed iridectomies may be attributed to the fact that the iris is not removed to the extreme root, and the remaining stump is sufficient to block the drainage. This is especially apt to be the case in chronic glaucoma where the iris is adherent to the cornea, and in efforts to free the filtration angle by an iridectomy the iris is torn off in front of the adhesion and the filtration angle is not opened.
As Elliot has pointed out, iridectomy is most open to attack on the ground of safety. We have to take into account the large scleral wound made, and the fact that this lies close to the ciliary body. The sudden release of all tension and the simultaneous weakening of the supports of the lens and vitreous body create very unfavorable conditions under which to make the crucial step of the operation.
The poor results following an iridectomy in chronic glaucoma have led to the devising of many substitute operations, of which those tending to the production of a filtering scar are now preferred, and, experience shows, hold out the most hope of bringing about long continued relief. It even is considered probable that the effects of an iridectomy which brings about more or less permanent reduction in the intra-ocular pressure is due to the formation of a filtering scar which augments whatever results may have been secured in the attempt to open up the drainage into the canal of Schlemm.