Anterior segment imaging: Fourier-domain optical coherence tomography versus time-domain optical coherence tomography

Abstract

Purpose: To compare anterior segment measurements and morphology of 2 optical coherence tomography (OCT) systems.

Setting: Department of Ophthalmology, District Railway Hospital, and the Nursing Department and Social Medical Issues, Health Care Division, Silesian Medical University, Katowice, Poland.

Methods: In normal eyes and in eyes with corneal and trabecular-iris angle disorders, the central corneal thickness (CCT), trabecular-iris angle, and angle-opening distance at the nasal and temporal angles were measured 3 times during 1 visit using the Visante time-domain OCT system and the RTVue-100 Fourier-domain corneal anterior module OCT system. Anterior segment morphology was assessed and compared.

Results: Fifty-four eyes were evaluated. The mean values (+/-SD) by time-domain OCT and Fourier-domain OCT were, respectively, automatic CCT, 535 +/- 33.07 microm and 538 +/- 31.82 microm; manual CCT, 545 +/- 30.91 microm and 542 +/- 30.57 microm; nasal trabecular-iris angle, 34.7 +/- 9.5 degrees and 35.2 +/- 8.9 degrees; temporal trabecular-iris angle, 35.3 +/- 8.5 degrees and 35.5 +/- 9 degrees; nasal angle-opening distance, 435 +/- 95 microm and 444 +/- 98 microm; and temporal angle-opening distance, 443 +/- 103 microm and 452 +/- 99 microm. There was no significant difference between mean values, and they were highly correlated. On morphologic analysis, time-domain OCT had lower resolution; however, all anterior chamber structures were visible on 1 image. Fourier-domain OCT provided precise information about small areas of the anterior chamber.

Conclusion: Fourier-domain OCT provided accurate anterior eye segment measurements that agreed with those obtained with time-domain OCT.