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

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 μm and 538 ± 31.82 μm; manual CCT, 545 ± 30.91 μm and 542 ± 30.57 μm; 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 μm and 444 ± 98 μm; and temporal angle-opening distance, 443 ± 103 μm and 452 ± 99 μm. 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.