The following hypothesis is based upon Fischer's edema theory of glaucoma and the relation of the circulation of the eye and orbit and that of the nose and the accessory sinuses, the minute anatomy of which is not as yet thoroughly understood. However, sufficient work has been done to make it appear that the lymph channels which drain the eyes and orbits empty into the same main channel as do those which drain the sinuses. Admitted for sake of argument that such is the case, then disease either acute or chronic of one or more of the sinuses with the accompanying inflammatory reaction, congestion and stasis, will cause an increased amount of fluid to be taken care of by the lymph channels draining these sinuses. This will in turn cause flooding of the common lymph channel, producing a stagnation in the flow of fluid from the orbits and eyes at the junction with the main channel, with backing up of the fluid within these channels and retention of the waste products within the orbits and eyes; thus will be brought about conditions most favorable (to quote from Fischer's theory of glaucoma) "to an abnormal production or accumulation of acid in the eye. In consequence of this abnormal acid content the hydration capacity of the ocular colloids is raised and glaucoma results, not because water is pushed into the ocular colloids, but because these suffer changes which make them suck in water from any available source." This hypothesis also might suggest why the subconjunctival injection of sodium citrate in addition to alkalinizing the ocular contents, may be effective in reducing tension, _i. e._, the amount of fluid injected beneath conjunctiva may overcome the stagnation in the lymph passages, flush out these channels and improve ocular elimination. Fischer in a personal letter says: "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." If such is the case why could not the existence of pyorrhea and blind abscesses about the roots of the teeth be the source of the toxic factors mentioned by Fischer? Hence the suggested association of the dental surgeon with the ophthalmologist in these cases of apparently idiopathic increased intra-ocular tension. It would be well to state here a cursory examination of the mouth will not discover root abscesses any more than such examination will discover non-suppurative sinus disease. A careful examination of each tooth together with radiograms of the entire maxilla are absolutely essential to determine their presence or absence. Trephining for Glaucoma BY ROBERT HENRY ELLIOT, M.D.,