Comparative Evaluation of Anterior Segment Optical Coherence Tomography, Ultrasound Biomicroscopy, and Intraocular Pressure Changes After Panretinal Photocoagulation by Pascal and Conventional Laser. Retina. 2020;40:537-545. [PMID: 30531420 DOI: 10.1097/iae.0000000000002400]

Comparison of measurements of anterior chamber angle via anterior segment optical coherence tomography and ultrasound biomicroscopy

BACKGROUND

Glaucoma is an irreversible optic neuropathy with the loss of visual field and decrease of vision. The variable clinical manifestations may result in differential diagnostic difficulties. The early screening and diagnosis of glaucoma are currently experiencing a demand for anterior segment analysis tools that can gather more information with one short measurement. Therefore, we analyzed the agreement, difference, and correlation of chamber angle parameters such as angel opening distance at 500 μm (AOD500) and trabeculo-iris space area at 500 μm² (TISA500) measured by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM).

AIM

To compare the differences, correlation, and agreement in measuring AOD500 and TISA500 by AS-OCT and UBM.

METHODS

Both AS-OCT and UBM were performed to measure AOD500 and TISA500 in 45 subjects (72 eyes). All subjects without glaucoma were collected from October 2015 to August 2016 at the Ophthalmology Department of the Fourth Affiliated Hospital of China Medical University. Data of the two groups (AOD500 and TISA500) were compared by nonparametric tests. Pearson correlative analysis and Bland–Altman analysis were used to compare the correlation and agreement.

RESULTS

There were no significant differences between AS-OCT and UBM in measuring AOD500 (P1 = 0.110, P2 = 0.633, P3 = 0.078, and P4 = 0.474) and TISA500 (P1 = 0.584, P2 = 0.889, P3 = 0.297, and P4 = 0.550) of the four quadrants of the anterior chamber angle. There was a high correlation in measuring AOD500 (r1 = 0.562, r2 = 0.671, r3 = 0.635, and r4 = 0.720; P < 0.001) and TISA500 (r1 = 0.584, r2 = 0.889, r3 = 0.297, and r4 = 0.550; P < 0.001). There was a good agreement in measuring AOD500 and TISA500 by the two modalities.

CONCLUSION

There is a high correlation and agreement between AOD500 and TISA500 measurements by AS-OCT and UBM. They are interchangeable under some circumstances. AS-OCT proves to be a better early screening tool for glaucoma.