Abstract
Purpose: :
The MIPH-EADS Eye&Health Study is an epidemiological study within the staff of a European aerospace company with the goal to monitor ocular and systemic risk factors of work-related health conditions. The purpose of the reported subset is to determine the geometry of the anterior chamber angle by use of a spectral-domain OCT and to establish quantitative correlations between the width of the angle, the refraction and intraocular pressure.
Methods: :
Out of 4617 eyes (2309 subjects) those with refractive errors of +3 diopters (D) were identified by refraction measurement (KR-8800, Topcon Inc., Japan) and examined using the anterior segment mode of a spectral-domain 3D OCT-2000 (Topcon Inc., Japan). Non-contact tonometry was performed (CT-80, Topcon Inc., Japan). As reference group we had 108 eyes of 54 emmetropic subjects (+/- 0.5 D). Previous ocular surgery was exclusion criterion. Width of the chamber angle was determined by using newly developed and validated semi-automated software tools and statistical analysis (Pearson correlation, ANOVA, regression analysis) was performed using SPSS 18.0 (Chicago, USA).
Results: :
In this study, 668 eyes of 398 persons were included. Valid chamber angle OCT measurements could be obtained from 60 (72.3%) hyperopic and 412 (76.5 %) myopic eyes meeting the inclusion criteria. Mean hyperopic refraction was +4.7 D (+3 D - +8.75 D), mean myopic refraction was -5.9 D (-4 D - -14.75 D). The mean width of the chamber angle was 30.7° (13.5° - 45.6°, SD 7.4°) in the hyperopic group, 40.7° (19.3° - 66.0°, SD 8.2°) in the myopic group and 36.4° (21.1° - 51.8°, SD 6.7°) in the reference group. Correlation was highly significant (p<0.001) between refractive error and the aperture of the chamber angle as measured from OCT. Validation coefficients were between 0.88 and 0.95.
Conclusions: :
Our results highlight the correlation between refraction and aperture of the angle in hyperopia and myopia as determined by OCT-2000. The understanding of this relationship may be helpful in using OCT technology as a diagnostic tool in risk assessment of narrow angle situations.
Keywords: anterior chamber • clinical (human) or epidemiologic studies: risk factor assessment • imaging/image analysis: non-clinical