Global InformationVan Herick technique information
The Van Herick technique is an eye examination method used to determine the size of the anterior chamber angle of the eye.
Glaucoma is currently the principal cause of irreversible blindness in the world.[1] Therefore, The Van Herick technique is pertinent to the interests of all eye care practitioners as it permits for a quick and simple screening alternative to the conventional Gonioscopy examination.[2] It should not however, be used as a replacement for the gonioscopy examination but rather be used as a means of refuting or confirming the results of a gonioscopy examination.[3]
The Van Herick's technique has become the most commonly used qualitative method of assessing the size of the anterior chamber angle (ACA). Whereby, it involves comparing the depth of the peripheral anterior chamber to the thickness of the cornea, when a narrow beam is shone within the limbus at a 60°angle.[4] The anterior chamber drainage angle is then graded as a ratio between the peripheral anterior chamber depth and corneal thickness (AC : C ratio) [5] or expressed traditionally as a fraction [6] to provide the Van Herick's result. Grading can also be obtained by distinguishing the structures visible upon observation. Each visible structure correlates to a Van Herick grade which can then be expressed a fraction.
- ^ Foster, P. J. (2001). "Advances in the understanding of primary angle-closure as a cause of glaucomatous optic neuropathy". Community Eye Health. 14 (39): 37–39. PMC 1705931. PMID 17491924.
- ^ Gispets, J.; Cardona, G.; Verdú, M.; Tomàs, N. (2013). "Sources of variability of the van Herick technique for anterior angle estimation" (PDF). Clinical and Experimental Optometry. 97 (2): 147–151. doi:10.1111/cxo.12094. PMID 23909926.
- ^ The University of Iowa. 2015. Introduction – van herick. Retrieved from http://www.gonioscopy.org/index.php?option=com_k2&view=item&layout=item&id=118&Itemid=679
- ^ McDonnell, C. 2010. Assessment of the anterior chamber angle and depth. Retrieved from http://www.metropolia.fi/fileadmin/user_upload/Liiketoimintapalvelut/Sosiaali-_ja_terveysala/Optikoiden_DG-koulutuksen_materiaalit/Assessment_of_the_anterior_angle_of_the_eye.pdf
- ^ Leung, Myra; Kang, Sammie Soo Ok; Turuwhenua, Jason; Jacobs, Robert (2012). "Effects of illumination and observation angle on the van Herick procedure". Clinical and Experimental Optometry. 95 (1): 72–77. doi:10.1111/j.1444-0938.2011.00646.x. PMID 21995506. S2CID 12957229.
- ^ Dabasia, P, L., Edgar, D, F., & Lawrenson, J, G. (2013). Methods of measurement of the anterior chamber angle part. Optometry in Practise 14(2), 147-154. Retrieved from http://www.optometryinpractice.org/filemanager/root/site_assets/documents/14-4/Ant_Cham_Pt2_C-34448.pdf