Purchase this article with an account.
S. Roters, G. Welsandt, H. Mietz, G.K. Krieglstein; In vivo Quantification of Anterior Segment Dimensions in Normal and Glaucomatous Eyes With Ultrasound Biomicroscopy . Invest. Ophthalmol. Vis. Sci. 2005;46(13):151.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Background: Several types of glaucoma are caused by anatomical abnormalities of the anterior segment. We performed 50 MHz ultrasound high resolution images in different types of glaucoma to analyze the potential of this non–invasive technique to detect new diagnostic criteria. Methods: 243 eyes of 243 glaucoma patients with primary open angle glaucoma, PEX–glaucoma, pigment dispersion syndrome, dysgenetic glaucoma, pupillary block and ciliary block glaucoma, plateau iris syndrome, neovascular glaucoma, steroid induced glaucoma, traumatic glaucoma and glaucoma after cataract surgery were examined. A total of 14 different measurement points within the anterior chamber were taken and were correlated with the slit lamp and gonioscopic findings. 52 patients without ocular abnormalities were examined as a control group. Results: The average measurements of patients with POAG, PEX–glaucoma and steroid induced glaucoma were not significantly different from normal subjects. The most sensitive parameter was the anterior chamber angle with significant deepening in pigment dispersion syndrome (p=8.80 E–17), dysgenetic glaucoma (p=8.13 E–05), glaucoma after trauma (p=0.02) and in case of pseudophakic and aphakic glaucoma (p=0.002). In cases of angle closure glaucoma [pupillary block (p=5.63 E–12), ciliary block (p=2.31 E–07)] and neovascular glaucoma (p=0.02) we found a significant narrowing of anterior chamber angle. Patients with angle–closure glaucoma showed the greatest anatomic variability of the 14 measurement points with significant deviations from the control group in 12 of them. Further sensitive parameters were the sclera–iris–distance at a distance of 250 µm from the scleral spur and the sclera–iris–angle. Discussion: Ultrasound biomicroscopy is capable to show the structures of the anterior segment that are relevant to glaucoma and provides a platform for exact measurements. This technique does not represent a diagnostic tool in case of glaucoma because the geometric dimensions in normal eyes do not significantly differ from the main groups of glaucoma (primary open angle and PEX glaucomatous eyes). Only in cases of angle closure glaucoma, neovascular glaucoma with a narrow anterior chamber angle, pigmentary –, dysgenetic –, traumatic –, aphakic –, and pseudophacic glaucoma with a wide anterior chamber angle most of the measurements were statistically different. The potential of ultrasound biomicroscopy to asses the dimensions of the posterior chamber and ciliary body rotation are relevant in the improvement of specific diagnosis of different types of glaucoma.
This PDF is available to Subscribers Only