Relationships between ocular dimensions and the effects of provocative tests. Water drinking. Homatropine eye drops. Water drinking and homatropine eye drops.

Weekers, Lavergne, and Prijot (1958), Davenport (I959), and Perkins and Jay (I960) have all commented on a high incidence of myopia in open-angle glaucoma. Abdalla and Hamdi (1970) showed that myopic eyes have higher ocular tensions than emmetropic eyes in most age groups. The findings of Tomlinson and Phillips (1970) agreed with this, but showed that ocular tension correlated more closely with the axial length of the eye (i.e. high axial length was associated with higher ocular tension than low axial length) than with the refraction. Tomlinson and Phillips (I969) have reported a correlation between high cup-to-disc area ratio and high axial length of the eye. Armaly (I969) has suggested that the cup/ disc ratio may be a factor determining the susceptibility of eyes with high intraocular pressure to visual field defects. A tendency to high ocular tension and large cup/disc ratio in eyes of long axial length miay partly explain the high prevalence of open-angle glaucoma in myopic eyes. A very clear association between shallowness of the anterior chamber and closed-angle glaucoma is known (Rosengren, 193I; Tornquist, I956; Lowe, I969). In open-angle glaucoma also, a shallower than normal anterior chamber has been observed (Rosengren, 193I; Tornquist and Broden, I958; Tomlinson and Leighton, in preparation, i.e. unpublished data).