AIM: To observe intraocular pressure(IOP)and anterior chamber of healthy subjects by use of miotic in darkroom provocative test.

METHODS: Series of cases were prospectively analyzed. Thirty healthy cases(60 eyes)aged 25～35 years-old were the objects of study. All tests were performed from 10:00 a.m.～12:00 a.m. All subjects were sitted 1h in the chairs opposite to let head bend down at the back of chair for 1h in the first test. IOP and anterior segment paramater were measured by Pentacam before and after darkroom provocative test. The second test was repeated by use of pilocarpine as the above, and the data was compared with that of the previous test.

RESULTS:IOP was increased significantly than before(P=0.000), pupil size(P=0.000), anterior chamber volume reduced(P=0.008)and anterior chamber angle was widened(P=0.017)which were significant difference in the first test. But central anterior chamber depth was not siginificant(P=0.261). IOP, anterior segment volume, anterior chamber angle and central anterior chamber depth were significant difference(P=0.000)in the second test. But there was no siginificant dfifference for pupil size(P=0.193). By use of pilocarpine anterior chamber volume(P=0.002), anterior chamber angle, central anterior chamber depth and pupil size were significant difference(P=0.000). IOP was not siginificant(P=0.21).

CONCLUSION:Reduced anterior chamber volume and narrowed anterior chamber angle are the basis of positive darkroom provocative test. Pilocarpine can make anterior chamber angle widened and make it possible to decrease IOP. Physician should take pupil size into account when measure anterior segment paramater by Pentacam.