Abstract
Purpose:
To measure the anterior chamber angle width with OCT and analyze its relationship with the morphometric variables of the eye in a normal population.
Methods:
Prospective study of one eye from 320 consecutive healthy patients. We examined the patients with Pentacam ®, IOL Master ®, and RTVue ® (Optovue, California, USA) anterior segment Fourier Domain OCT (AS-OCT). Images were obtained under standard light conditions, and when the signal strength intensity was greater than 30. Parameters evaluated: age, sex, IOP, refractive error, axial length, pupil diameter and pachymetry. . Anterior chamber (AC) parameters examined were: depth, volume and diameter. Angle parameters: nasal and temporal width measured in degrees, angle opening distance (AOD), trabecular iris space area (TISA) and iris thickness; length, thickness and area of the trabecular meshwork (TM). Pearson correlation analysis was performed to study the correlation between the AC angle and the rest of the variables.
Results:
19 patients (6%) were excluded because the angle width could not be measured due to low image quality. The mean values of the population were: age: 45 ± 14.2 years (range 19 to 84), IOP: 15.92 ± 3.8 mmHg (range 8 to 26.4), sphere: -0.4 ± 2.79 diopters (range -6.25 to 6.5), axial length: 23.91 ± 1.51 mm (range 20.03 to 29.14), AC depth: 3.42 ± 0.43 mm (range 2.45 to 4.38), AC diameter: 11.93 ± 0.39 mm (range 11 to 13), iris thickness: 412.6 ± 88.88 microns (range 195 to 910), pupil diameter 2.96 ± 0.62 (1.71 to 5.51). The mean temporal angle width was 38.8 ± 12.7 degrees (range 14.5 to 78.2), AOD: 587.18 ± 261.65 microns, (range 64 to 1440), TISA: 0.201 ±0.093 mm2 (range 0.027 to 0.519). We found a correlation between the angle and the depth of the AC (r = 0.76), with the axial length (r = 0.68), with the spherical refractive error (r = -0.68), with age (R = -0.60), and weakly with the IOP (r = -0.17). Cited correlations were statistically significant (p <0.05%).
Conclusions:
SA Fourier Domain OCT enabled us to analyze and measure the chamber angle in 94% of eyes. We found a strong correlation between the angle width and depth of the AC, spherical refractive error and age, and weak with the IOP.
Keywords: 420 anterior chamber •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)