Screening for Narrow Angles in the Japanese Population Using Scanning Peripheral Anterior Chamber Depth Analyzer

Abstract

Additional information is available at the end of the chapter http://dx.doi.org/10.5772/54556 . IntroductionPrimary chronic angle-closure glaucoma P"CG is a leading cause of blindness, and has particularly high prevalence rate in East "sia [ -]. The Handan Eye Study [ ] reported that the standardized prevalence of P"CG is . %, and two thirds of those with P"CG were blind in at least one eye. Many cases of P"CG are asymptomatic and often present with severe visual field loss at the first visit. The severe visual impairment from P"CG is related to the insidious development of the disease. [ ] Primary angle closure suspect P"CS is characterized by narrow or occludable angles without raised intraocular pressure IOP or glaucomatous optic neuropathy. Primary angle closure P"C is the eyes with narrow angles and the appositional closure, peripheral anterior synechiae P"S and/or raised IOP but without glaucomatous optic neuropathy. P"CG is defined as the case of P"C with glaucomatous optic neuropathy. It has been estimated that % of the eyes with P"CS progress to P"C and . % progress from P"C to P"CG over -years [ ]. Prophylactic laser iridotomy LI is the first-line treatment for narrow angles, and may stop the progression of the angle closure process and prevent development of P"CG. However, LI is less effective in controlling IOP if optic nerve damage with P"S has already occurred [ ]."ssessment of angle width is essential for the diagnosis and managing angle closure [ -]. Currently, the golden standard for angle assessment has been indirect visualization by