CONGENITAL GLAUCOMA
Ultrasonography plays a key role in the management of congenital glaucoma. A B-scan ultrasonogram can be performed during an examination under anesthesia if one or both eyes have significant corneal cloudiness precluding proper posterior segment examination. It is important to detect retinal detachment or intraocular tumor (retinoblastoma) before performing a goniotomy or trabeculotomy for congenital glaucoma. Uncontrolled intraocular pressure in the neonate and infant causes a progressive enlargement of the entire globe, not just the progressive optic disc cupping seen in adults. A progressive increase in ocular myopia may be seen and can be monitored by retinoscopy. Monitoring axial length by serial A-scan ultrasonography can be valuable in assessing increases in axial length that may suggest progression and lack of intraocular pressure control.
THE FUTURE
Recent improvements in UBM technology have increased the quality of images obtained. Optical coherence tomography (OCT), with its ability to image the optic disc and to measure retinal nerve fiber layer thickness, has impacted the management of glaucoma significantly. Recently, anterior segment OCT has been used to assess anterior chamber angle and other clinical conditions.14 Unlike UBM, anterior segment OCT imaging is a noncontact test. Anterior segment OCT is similar to UBM in quantitative anterior chamber angle measurement for the detection and management of narrow angles.15 Because anterior segment OCT is light based, penetration of the iris pigment epithelium is poor, making UBM preferable for imaging events in the posterior chamber.
REFERENCES
1.Pavlin CJ, Harasiewicz K, Foster FS. Ultrasound biomicroscopy of anterior segment structures in normal and glaucomatous eyes. Am J Ophthalmol 1992;113(4):381–9.
2.Pavlin CJ, Harasiewicz K, Sherar MD, et al. Clinical use of ultrasound biomicroscopy. Ophthalmology 1991;98(3):287–95.
Glaucoma 215
3.He M, Friedman DS, Ge J, et al. Laser peripheral iridotomy in eyes with narrow drainage angles: ultrasound biomicroscopy outcomes. The Liwan Eye Study. Ophthalmology 2007;114(8):1513–9.
4.Barkana Y, Dorairaj SK, Gerber Y, et al. Agreement between gonioscopy and ultrasound biomicroscopy
in detecting iridotrabecular apposition. Arch Ophthalmol 2007;125(10):1331–5.
5. Forbes M. Gonioscopy with corneal indentation. A method for distinguishing between appositional closure and synechial closure. Arch Ophthalmol 1966;76(4):488–92.
6.Friedman DS, Gazzard G, Foster P, et al. Ultrasonographic biomicroscopy, Scheimpflug photography, and novel provocative tests in contralateral eyes of Chinese patients initially seen with acute angle closure. Arch Ophthalmol 2003;121(5):633–42.
7.Pavlin CJ, Harasiewicz K, Foster FS. An ultrasound biomicroscopic dark-room provocative test. Ophthalmic Surg 1995;26(3):253–5.
8.Sakai H, Morine-Shinjyo S, Shinzato M, et al. Uveal effusion in primary angle-closure glaucoma. Ophthalmology 2005;112(3):413–9.
9.Pavlin CJ, Ritch R, Foster FS. Ultrasound biomicroscopy in plateau iris syndrome. Am J Ophthalmol 1992;113(4):390–5.
10.Pavlin CJ, Harasiewicz K, Foster FS. Posterior iris bowing in pigmentary dispersion syndrome caused by accommodation. Am J Ophthalmol 1994;118(1): 114–6.
11.Pavlin CJ, Macken P, Trope GE, et al. Accommodation and iridotomy in the pigment dispersion syndrome. Ophthalmic Surg Lasers 1996;27(2): 113–20.
12.Carassa RG, Bettin P, Fiori M, et al. Nd:YAG laser iridotomy in pigment dispersion syndrome: an ultrasound biomicroscopic study. Br J Ophthalmol 1998; 82(2):150–3.
13.Yamamoto T, Sakuma T, Kitazawa Y. An ultrasound biomicroscopic study of filtering blebs after mitomycin C trabeculectomy. Ophthalmology 1995;102(12): 1770–6.
14.Radhakrishnan S, See J, Smith SD, et al. Reproducibility of anterior chamber angle measurements obtained with anterior segment optical coherence tomography. Invest Ophthalmol Vis Sci 2007;48(8): 3683–8.
15.Radhakrishnan S, Goldsmith J, Huang D, et al. Comparison of optical coherence tomography and ultrasound biomicroscopy for detection of narrow anterior chamber angles. Arch Ophthalmol 2005; 123(8):1053–9.