Comparison Of Three Anterior Segment Imaging Systems For Anterior Chamber Measurements Needed For Sizing Of Posterior Chamber Phakic Iol

Phakic posterior chamber lenses comes in different sizes. To avoid excessive vaulting of the IOL or contact of the IOL with the crystalline lens a good prediction of the sulcus diameter is crucial. Several formulae have been developed, with the most accurate ones needing measurements of the anterior chamber characteristics such as the angle-to-angle distance (ATA) and the spur-to-spur distance (STS).

Purpose: Aim of this study is to compare three anterior segment imaging devices concerning their measurements of the aforementioned structures (ATA, STS, WTW).

Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria

In this prospective study, 63 eyes of 63 patients with an axial length of longer than 25.5mm without ocular comorbidities apart from cataracts were included. All patients underwent measurements in a random fashion with four anterior segment OCT devices (Casia2, Tomey; Anterion, Heidelberg Engineering; MS-39, CSO). To assess repeatability, each patient was measured three times with each device.

Preliminary results are available. The mean arithmetic difference between Anterion and Casia2 for ATA was -0.03 ± 0.35 mm, for WTW was 0.59 ± 0.38 mm, and for AQD (aqueous chamber depth) was 0.02 ± 0.22 mm. The mean arithmetic difference between Anterion and MS-39 in STS was 0.58 ± 0.59 mm, and between Casia and MS-39 0.31 ±0.54 mm.  Final results will be presented.

A good repeatability for all variables was found for all anterior segment OCT devices included. A good correlation was found between Anterion and Casia2 and Anterion and MS-39 measurements, respectively.