[Imaging of the anterior eye chamber with optical coherence tomography].

BACKGROUND

Optical coherence tomography (OCT) represents a high-resolution diagnostic method which can be used to precisely image the anterior eye segment. Further developments in scanning technology and data evaluation allowed to visualize the entire anterior eye segment in one image, and the purpose of this study was to clinically evaluate this new system.

PATIENTS AND METHODS

The studied OCT system was adapted to a slit-lamp and allowed us to image the anterior segment with an axial resolution of 10 microm at a scanning rate of 200 Hz with a depth of 7 mm and a maximal width of 15 mm. In selected cases the clinical value of anterior segment OCT was assessed. The reproducibility and level of agreement of anterior chamber depth measurements were assessed during the preoperative examination in 49 cataract surgery patients and compared to ultrasound (US) biometry (10 MHz).

RESULTS

The studied anterior segment OCT allowed the cross-sectional imaging of the entire anterior eye segment. Changes of the anterior chamber before and after cataract surgery or surgical iridectomy were visualised. Furthermore, the findings of the anterior chamber after implantation of an iris-fixated intraocular lens (IOL) and an iris prosthetic system could be assessed. The reproducibility of the anterior chamber depth measurement was +/- 22 microm (OCT) and +/- 76 microm (US). The mean difference between optical and acoustic values was 1 microm (0.03 % p = 0.921) and the limits of agreement (95 % confidence interval) were 260 microm (8.58 %).

CONCLUSIONS

The anterior segment OCT proved to be a helpful diagnostic method. The cross-sectional visualisation of the entire anterior chamber allowed us to assess important values for the implantation of iris-fixated IOL and other changes after surgical procedures. The resolution and reproducibility were higher than for conventional ultrasound biometry.