Distribution of Anterior Chamber Angle Width and Correlation With Age, Refraction, and Anterior Chamber Depth—The Gutenberg Health Study

Abstract

PURPOSE.Scheimpflug imaging allows quantitative analysis of the width of the anterior chamber angle. We report the population-based distribution of the anterior chamber angle width using this noncontact imaging technique and investigate associated factors. METHODS.A population-based cross-sectional study was carried out in Germany. A comprehensive ophthalmologic examination including refraction, biometry, and Scheimpflug imaging was performed. Automated measurement of the anterior chamber angle was performed in each anterior chamber quadrant. Exclusion criteria were previous ocular surgery or inadequate image quality. Association analyses were carried out to determine independently associated systemic and ocular factors for anterior chamber angle width using a generalized estimating equation model. RESULTS.A total of 3014 subjects (48% female) with a mean age of 58.6 6 10.4 years were included in this study. The mean anterior chamber angle width was 32.68 6 5.58. Statistical analysis revealed an independent association between a smaller anterior chamber angle and female sex, higher age, and more hyperopic refraction. When including biometric parameters, shallow anterior chamber depth, shorter axial length, higher central corneal thickness, and lower corneal power were independently associated with a narrower mean anterior chamber angle width.CONCLUSIONS. These parameters are considered risk factors for angle-closure glaucoma.Keywords: Scheimpflug photography, epidemiology, anterior chamber angle, refraction, anterior chamber depth A nterior chamber angle and depth have been identified as an important risk factor for angle-closure glaucoma 1 and progression of open-angle glaucoma.2 For almost a century, gonioscopy has been used to semiquantitatively analyze anterior chamber angle width. [3][4][5] More recently, quantitative imaging modalities including ultrasound biomicroscopy, optical coherence tomography, and Scheimpflug imaging have been developed. [6][7][8] In contrast to ultrasound biomicroscopy, optical coherence tomography and Scheimpflug imaging offer noncontact imaging of the anterior segment and make these methods attractive for patients and doctors alike. 9 To interpret measurements from Scheimpflug imaging and to integrate the results into a clinical context, it is important to know the distribution of anterior chamber angle width and to understand associations with clinical factors. The underlying idea is that a narrower anterior chamber angle width is associated with clinically suspicious risk factors for acute angle closure, namely female sex, older age, hyperopic refraction, shorter axial length, and thicker crystalline lens.Hence, the focus of this study is to derive normative values of the anterior chamber angle width. Using Scheimpflug imaging we investigate, for the first time, correlations between anterior chamber angle width and systemic and ocular parameters in a very large population-based setting. MATERIALS AND METHODSThe Gutenberg Health Study (GHS) is a prospective, populationbased, obs...

Ocular biometry, refraction and time spent outdoors during daylight in Irish schoolchildren

“…Further analysis of anterior chamber depth in the Irish population merits investigation due to the association between shallow anterior chambers with angle closure glaucoma. 28 Longer anterior chamber depth was associated with a more myopic SER in this study; this could be due to longer eyes having deeper anterior chambers although the resultant refractive effect of a longer anterior chamber is toward a less myopic SER. 27 The relationship between the axial length/corneal radius ratio and SER was linear and negatively associated with SER in the current study.…”

“…As anterior chamber depth was not measured prior to cycloplegia in this study, findings are likely to overestimate anterior chamber depth in the natural state. Further analysis of anterior chamber depth in the Irish population merits investigation due to the association between shallow anterior chambers with angle closure glaucoma . Longer anterior chamber depth was associated with a more myopic SER in this study; this could be due to longer eyes having deeper anterior chambers although the resultant refractive effect of a longer anterior chamber is toward a less myopic SER …”

Steeper Iris Conicity Is Related to a Shallower Anterior Chamber: The Gutenberg Health Study

“…While several studies investigated anterior chamber angle width using Scheimpflug imaging, AS-OCT, or ultrasound biomicroscopy [ 14 – 19 ], little is known about the iris position in the anterior segment. The anterior chamber angle is formed by the posterior corneal surface and the peripheral anterior iris surface and therefore a close association between a steeper forward inclination of the iris profile and a smaller anterior chamber angle may appear likely.…”

“…Similarly, iris conicity was not associated with central corneal thickness which is known to be linked with anterior chamber angle aperture [ 19 , 24 ]. These findings indicate that iris conicity follows other rules than the mere chamber angle.…”

Cluster analysis reveals patterns of age‐related change in anterior chamber depth for gender and ethnicity: clinical implications

“…As expected, increased hyperopic spherical equivalent refractive error was associated with a shallower anterior chamber depth, as per previous studies. 17,18,28 . Interestingly, the effect appeared greatest in the female Caucasian group within the present study, which suggests an interaction with gender and ethnicity, the former of which was also suggested by Foster et al 50 However, the overall coefficients of determination were low, suggesting that refractive error only played a small role in accounting for chamber depth in the present cohort.…”