In all these cases the foreign particles, whether crystals or otherwise, are usually the retrogressive changes of senescence proclaiming that the forces which make for degeneration are more potent than those which make for regeneration.
But urates are not found in the eye, even though the patient is gouty. On the other hand, both in gouty joints and in other similarly affected parts of the body we find a deposition of urate of soda.
Gouty Diathesis.—From the days of Sydenham—himself a martyr to gout—diathesis has been a name to conjure with, and an all-sufficient diagnosis. In the podagrous patient any intercurrent disorder, any inexplicable ache or pain, was ascribed to gout, and patient and doctor were alike satisfied. “Tempora mutantur,” but still we are prone to call morbid conditions gouty when they occur in gouty people.
If we accept the theory that gout is due to an excess of uric acid in the blood, the view which I have expressed elsewhere[48] that gout does not cause iritis is directly challenged. For if it be granted that a sudden outpouring of so non-toxic an acid causes an acute inflammation—for instance, in the synovia of the great toe—why should not our faith incline us to go further and find in this malevolent, though bland, acid a source of inflammation affecting the fibro-muscular meshwork of the iris?
If, however, we adopt the infective theory, then the association of the uratic deposits no longer dominates our creed—we view them as mere clinkers and by-products erupted from the furnace.
The infective theory of gout also lends plausibility to an association with iritis, for this latter is a disease of infective origin. For the intimate relationship of all forms of asthenic arthritis with iritis is of very frequent occurrence, but is practically never seen in the more sthenic arthritides: rheumatic fever, acute gout and traumatic arthritis.
Nearly fifty years ago Jonathan Hutchinson drew up a “Report on the Forms of Eye Disease which occur in connection with Rheumatism and Gout.”[49]
At the present day it is not easy to differentiate his 117 cases according to modern classification, but he includes gout, rheumatism, rheumatic arthritis, etc. The differential diagnosis between gout and rheumatism was simplified by the creation of a mule—“rheumatic gout”—and upon its back were packed the doubtful cases.
Hutchinson’s views regarding the essential difference between gout and rheumatism are crystallised in his statement that in rheumatism there is an arthritic susceptibility to weather, in gout an arthritic susceptibility to diet.
Osteoarthritis also seems to have been included as one of the gouty diseases, probably because post-mortem examination revealed uratic deposits in the disorganised cartilage. This, however, would appear to be an epi-phenomenon, and must not be allowed to obscure the essential distinction between true gout and osteoarthritis. It is a sign of articular disorganisation of long standing, and is the homologue of the similar deposition of crystals, etc., already referred to as occurring in the eye as the result of chronic disease therein.