| Objective: Primary angle-closure glaucoma (PACG) is the most common type of glaucoma in China, which pathogenesis is associated with the ocular anatomy. Lowe measured the ocular anatomy of glaucoma patients in 1970. In 1990 Ultrasound biomicroscope devised by Pavlin turned up, which can provide high-resolution of anterior segment of eye and explore the posterior chamber. Recently 20MHz ultrasound was applied in clinic with the advantage of overall anterior segment of eye. A large number of work has been done on the anatomy of PACG eyes, but index by internet indicate the absence of variable frequency ultrasonic measurement of pre-clinical acute PACG eyes.This study measure some parameters of these patients with standardized A scan, 20MHz B mode Ultrasound, Ultrasound biomicroscope and mathematics model, comparing with the normal subjects, then analyze: the characteristics of ocular anatomic parameters; measurement of iris configuration in quantity; correlation between theses parameters and age, axial length. It provides some new parameters to study ocular anatomy.Material and methods: 1. subjects: Normal subjects: 63 eyes, age 40-70,divided averagely into three groups according to patient age ,all subjects is executed uniform eye examination to exclude ocular diseases and refractive error. Pre-clinical acute PACG subjects: 63 eyes, age 40-70,divided into three groups averagely, all subjects is executed uniform eye examination to meet the diagnostic criteria of pre-clinical acute PACG and exclude other ocular diseases and refractive error. There is 21 persons in every subgroup and 1 : 2 is the male-to-female ratio. 2. methods: Lens thickness and axial length is measured by using BVI-Cine Scan S5.03 A-scan ultrasound. Sclera-lens angle is measured by using 20MHz B-scan. The parameters of anterior segment of eyes are measured by using Model P40 Ultrasound-4-biomicroscope. Results:1 .Comparison between pre-clinical acute PACG subjects and normal ones: these differences are significant statistically on central anterior chamber depth, axial length, lens thickness, lens relative location, trabecular-iris angle, angle-opening distance at 500 micro, angle recess area, iris-ciliary process angle, sclera-lens angle, iris-lens angle, iris curvature, iris-lens contact distance and iris-zonule distance. Other parameters including iris-ciliary process angle, ciliary process thickness, iris root thickness and posterior chamber area, are no difference. The pre-clinical acute PACG eyes have shallower anterior chamber, shorter axial length, thicker lens thickness, forward lens relative location, shallower trabecular-iris angle, forward revolving and thinner ciliary body, increased iris-lens contact distance and iris bombe, so anterior chamber is crowding. Ciliary sulcus and poster chamber area are same in both groups, but the whole posterior chamber moving forward in glaucomatous one.2. Age-related, there is no change on lens relative location, trabecular-iris angle angle-opening distance at 500 micro, angle recess area, iris-ciliary process angle, sclera-lens angle and iris-lens angle in both groups. Age-related, thicker lens thickness, increased iris-lens contact distance and shallower anterior chamber exist, but the former change in same degree in both groups.3.Comparison between age subgroups: statistic difference occur among three age subgroups on central anterior chamber depth, trabecular-iris angle, angle-opening distance at 500 micro, angle recess area, iris-ciliary process angle, sclera- lens angle, Lens thickness, Len thickness, lens relative location, iris-lens contact distance and iris curvature. Between 40~ subgroups, The difference in axial length is not significant, reversely other subgroups.4. Iris curvature is 98.363?7.289um~1 in normal eyes, which is 190.429?5.308jj,m"' in the pre-clinical acute PACG eyes. Age-related, increased iris-5-curvature exists in glaucomatous eyes.5.In normal eyes, lens thickness is inversely and lens position central anterior chamber depth directly with axial length...
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