“ If it is in excess, measures directed to bring it to the pathological norm should be instituted, but if the pressure found proves to be the pathological norm it is a bitter mistake to lower it, be the pressure what it may. ”

“ Exactly how the myotics reduce intra-ocular tension is not definitely proven. Usually it is taught that because of the myosis the base of the iris wedged in the angle of the anterior chamber is loosened and withdrawn, precisely as a fold in a coat is straightened by a tug on the fabric beneath it. Experiments, however, for example, by E. E. Henderson, have shown that the rate of filtration in an eye with artificially raised pressure is considerably larger when it is under the influence of eserin than it is when under the influence of atropin ”

“ Death of all of the perceptive elements of the retina eventually occurs. The loss of nutrition is apparently not the whole cause of blindness. Atrophy of the nerve fibers follows death of retinal neurons, but atrophy of some of the nerve fibers may be, and probably is, due to the pressure and traction exerted upon them at the margin of the disc. ”

“ Only a few years ago the literature of glaucoma was big with discussions of the comparative value of the surgical and non-surgical treatment of glaucoma, and especially of the chronic types of this disease. Now, thanks to the achievements of Lagrange, Fergus, Herbert and Elliot, the value of a filtering cicatrix, although known for a long time, has attained increased importance, due to the improvement and elaboration of operative technic, and the medical journals of the day are weighted with [Pg 62] opinions and experiences from all over the world as to these surgical measures. ”

“ It is no easy matter to determine the presence of increased venous pressure, although there are tolerably accurate instrumental technics, and yet, as Henderson points out, it is just this increased general venous pressure which is often detrimental. Therefore the perfunctory use of such drugs as nitrite of amyl and the other nitrites may not be in the least indicated when, for example, the venous pressure depends upon inability of the right heart to perform its functions, and the drug needed may, for example, be digitalis. ”

“ Wood in not having infection in a wound which remains open and unprotected for variable lengths of time is not likely to be the experience of any considerable number of operators, and probably will not always be the experience of Dr. Wood. Furthermore, the possibilities of damage by hemorrhage from the choroidal or retinal vessels, delayed formation of the anterior chamber and adhesion of the capsule of the lens to the wound, and the injurious effects of even slight trauma subsequent to the operation, including loss of vitreous, are increased by omitting the conjunctival flap. ”

“ You have two possibilities for the production of glaucoma with sinus disease: A toxic factor due to poisons being carried into the eye; and second, interference with a proper blood supply to the eye through compression of the efferent or afferent blood vessels supplying the eye from edema of the tissues about the eye consequent upon the sinus infection. Either is associated with the production of substances which increase the hydration capacity of the ocular colloids. ”

“ It is hard successfully to maintain in a patient with chronic glaucoma what I may call an eserin life, just as it is hard to maintain in a person with an enlarged prostate a catheter life and escape infection, resulting, if it occurs, in the one instance in a difficult and stubborn conjunctivitis, and in the other in a cystitis. Still, we are obliged to use myotics, and the way to employ them to the patients' best advantage, I have ventured to repeat in spite of the universal familiarity with the methods. ”

“ Trephining is an operation which can be performed by any surgeon who is used to ophthalmic manipulations, and who has good sight. It is essential that he should work in a good light. The necessary technique can be acquired from a written description. It is not for a moment necessary that the surgeon who wishes to learn trephining should see the originator of the operation at work. If, however, he feels diffident at undertaking the procedure until [Pg 110] he has seen it done by another, there are many centers in this country where the operation is now being successfully performed. ”

“ In cases of high tension, even a simple sclerectomy will allow ample filtration, owing to the gaping of the wound, while in cases without elevation of the tension, sclerectomy will be quite ineffectual. Lagrange therefore proposes the following rules of procedure: (a) If [Pg 131] tensions is normal to +1, do sclerectomy without iridectomy, the amount of sclera excised being inversely proportionate to the degree of hypertension. (b) If tension is +1 to +3, do sclerotomy-iridectomy, the iridectomy being added to avoid entanglement of the iris. ”

“ I believe that eserin irritation is most successfully avoided, not by preparations of the myotics in combination with the antiseptics, for example, tricresol, which has been so much advocated, but by ordering very small quantities of the solution, insisting that it shall be frequently renewed and sterilized at each preparation, and that a half an hour after its instillation, during the day time at least, the eye shall be thoroughly flushed with some mild antiseptic solution, for example, boric acid and sodium chlorid. ”

“ The central fact to be borne in mind is, if the physiological pressure is vascular in origin and nature, the pathological pressure must likewise be derived from the same source.
Sclerosis of the meshwork of the iris angle is the predisposing factor because it hinders free access of aqueous into the venous sinus of Schlemm. Sclerosis alone, however, will not cause glaucoma so long as access to the iris veins can keep the intra-ocular pressure at the intra-venous level, and, too, as long as the exciting cause is absent. ”

“ A normal, or even a low arterial blood pressure is sufficiently above the normal intra-ocular pressure to furnish a source of increased fluid in the eye. Increased arterial pressure has been found in a large proportion of cases of glaucoma; and may be necessary to the production of the highest intra-ocular tension. A sudden relaxation of the arterial walls, that would permit the arterial blood pressure to make itself felt in the eye, might cause an important rise of intra-ocular tension and may be a factor in the etiology of acute attacks. ”

“ Anaesthesia of the cornea develops, due to pressure on the nerve fibers that are distributed to the epithelium, the compression probably occurring along the course of the long ciliary nerves, from which the corneal nerves are derived, as they pass between the choroid and the unyielding sclera (Collins & Mayou) .
In advanced cases of glaucoma after the congestive period has subsided the cornea becomes somewhat condensed, the lymph spaces contracted; a condition of sclerosis obtains. Alteration in the shape of the cornea occurs only rarely in adult life. ”

“ A reservoir with a free outlet can only fill during a flood; and then quickly empties itself again. The outflow channels in the normal eye provide for carrying away of the waste products of such an active nutrition, that it is hard to think they will become inadequate in glaucoma until there has been a marked decrease from their normal capacity. Priestley Smith has pointed out that the glaucomatous eye softens more slowly than the normal eye after enucleation, in spite of the fact that a greater force is operating to drive fluid out of the eye. ”

“ After needling the lens in young people I have seen a rise of intra-ocular tension to 50 and 60 mm., maintained for many days, with considerable general deep hyperemia, and soreness of the globe, followed by gradual return to normal tension, and no permanent impairment of vision or the visual field.
One other type may be mentioned. That of an elderly patient with marked vascular disease, often renal involvement, and distinctly impaired nutrition. There may be renal retinitis or retinal hemorrhages. The case may easily become one of hemorrhagic glaucoma. It may run a very chronic course. ”

“ Should the blood pressure be very high, paracentesis, for example, would apparently not be the proper procedure, and the resulting difference produced between the blood pressure and the eye tension would cause a rapid reformation of fluid with higher specific gravity and higher osmotic coefficient. ”

“ Another method of reducing the intra-ocular tension is by the suction method, which consists in the use of certain cups from which the air is exhausted by means of a suction apparatus. Domec uses an elliptical eye cup, the concave margins of which fit closely about the globe. The air is exhausted with each respiration of the patient and from 50 to 200 tractions are made at each sitting. ”

“ In other words, it is often necessary from the general standpoint that a certain amount of plus pressure shall remain if the patient's general well-being is to be maintained. There must always be a differential diagnosis between plus pressure and what may be called over plus pressure. ”

“ Cases of simple glaucoma do run their course of many years to complete blindness, or to death, without exacerbations, inflammation, or characteristic pain. In such cases the intra-ocular tension does not rise suddenly; and it may be little or not at all elevated above the usual normal limit.
For nine years I have watched the progress of such a glaucoma in a man now aged 87, with slow development of glaucomatous cupping of the optic disc, now more than 3 D. deep. The tension has never been noted at more than Plus T (?) , and when taken with the tonometer varied from 9 to 32 mm. ”

“ Where the iris tissue lies in contact with the cornea, the stroma of the iris almost totally disappears. In some cases the iris becomes totally adherent to the cornea.
Ciliary Body and Chorioid. In acute glaucoma there is congestion of the entire uveal tract, the congestion partaking more of a venous stasis than of an active or arterial congestion. The vessels of the [Pg 46] ciliary process, which are larger and more tortuous in adults of advanced years than in the young, become enormously distended, causing almost complete obliteration of the perilental space. ”

“ There seems to be a special liability to glaucoma among those residing at high altitudes, best explained by nerve influence. The frequency of glaucoma among Jews may be due to a small cornea, as suggested by Priestley Smith; but it is quite as reasonable to connect it with a racial excitability or nervous instability. More definite knowledge of the nervous mechanism concerned in the regulation of intra-ocular pressure and the production of glaucoma is much needed. ”

“ The arrangement of the arteries at the disc, passing out as they do from the nasal side, of necessity make the vessels that pass to the temporal part of the retina longest and of less caliber. These vessels and their terminals are first to suffer marked diminution in size; death of the perceptive elements supplied with nutrition by these vessels follows. For this reason the nasal part of the field of vision is more often the first to disappear. In [Pg 49] congestive (inflammatory) glaucoma, the typical field of vision shows most marked contraction on the nasal side. ”