Abstract
Purpose: :
To evaluate changes in anterior segment morphology pre and post laser peripheral iridotomy (LPI) using three-dimensional cornea and anterior segment optical coherence tomography (CASIA; Tomey Corp.,Aichi,Japan).
Methods: :
A total of 15 eyes from 13 primary angle closure patients were evaluated using CASIA. The participants comprised 5 males and 8 females. The mean age was 65.1 ± 9.4 years old (mean ± standard deviation). Intra ocular pressure (IOP) was 36.6 ± 21.1 mmHg. CASIA measurements were performed pre and post LPI. Using a 1.3 µm light source, and swept-source technology,CASIA creates three-dimensional images of the anterior segment including angle recess in 0.3 to 2.2 seconds. The measurement parameters were anterior chamber depth (ACD), anterior segment volume (ACV), trabecular-iris contact length (TICL), iris convexity (IC), and the volume of the iridotomized area.
Results: :
The IOP after LPI was 14.9 ± 6.41 mmHg. ACD and ACV significantly increased from 1.76 ± 0.19 mm and 70.7 ± 13.7 mm3 before LPI to 1.84 ± 0.21 mm and 99.5 ± 17.1 mm3 after LPI (P = 0.016 and < 0.001, paired t-test, respectively). TICL and IC significantly decreased from 0.54 ± 0.10 mm and 0.36 ± 0.01 mm before LPI to 0.037 ± 0.10 mm and 0.043 ± 0.003 mm after LPI (P < 0.001, both). The volume of iridotomized area was 0.13 ± 0.06 mm3.
Conclusions: :
CASIA non-invasively revealed three-dimensional changes in the anterior segment anatomy and calculated ACV. LPI significantly increases ACV and reduces anterior bowing of the iris.
Keywords: imaging/image analysis: clinical • laser • anterior segment