Posters

Quantitative anterior segment ultrasound biomicroscopy (AS-UBM) and Lenstar interferometry before and after cataract surgery

Poster Details

First Author: P. Fedor UNITED STATES

Co Author(s):                        

Abstract Details

Purpose:

To evaluate the quantitative biometry of the anterior segment and the position of the lens/IOL in myopic and hyperopic patients before and after cataract surgery using new method of Quantitative anterior segment ultrasound biomicroscopy (AS-UBM) and Lenstar interferometry. Effective lens position (ELP) is currently the most important source of error in prediction of refractive outcome after cataract surgery. A new system of quantitative analysis of the anterior segment was developed to describe the anterior segment anatomy. Measurements obtained from UBM were compared with established standard measurements of immersion ultrasound (IMM) and Lenstar interferometry (LS).

Setting:

Anterior segment private practice

Methods:

This is a retrospective non-randomized study comprising 50 eyes. Inclusion criteria were patients with UBM exams before and after cataract surgery of sufficient quality for quantitative analysis. A new system of quantitative analysis of the anterior segment was developed to describe the anterior segment anatomy. Measurements obtained from ultrasound biomicroscopy were compared with measurements obtained by immersion ultrasound (IMM) and Lenstar interferometry (LS). Group with axial length of less than 23.5 mm was compared with eyes with axial length of more than 23.5 mm, as well as a subgroup of short eyes with axial length of less than 22.00 mm.

Results:

Thirty eyes obtained Lenstar anterior chamber (AC) measurements preoperatively as well as immersion ultrasound A-scan and UBM. The Lenstar AC was 2.78 +/-0.49 mm, the IMM-AC was 2.94 +/-0.52 mm, with a correlation coefficient of 0.96. The UBM-AC was 2.97 +/-0.52 mm with a correlation coefficient of 0.97 with a Lenstar AC. The posterior shift ofciliary body depth (CBD) in hyperopic group was 0.37 +/-0.2 mm as compared to 0.24 +/-0.19 mm in myopic group. In the subgroup of 9 patients with high hyperopia the posterior shift of CBD was 0.43 +/-0.2 mm.

Conclusions:

In summary we confirm that AS-UBM is suitable for quantitative analysis of the anterior segment. It has good correlation of the preoperative ACD and LT with immersion ultrasound and Lenstar values, with correlation coefficients in the range of 0.96 - 0.98. The Lenstar measurement of ACD and LT (although not AL) are approximately 0.15 mm shorter as compared to both immersion and UBM measurements. Our study shows with direct imaging of the ciliary body that the apex of the ciliary body moves posterior after cataract surgery and this effect is more pronounced in hyperopic/shorter as compared to myopic/longer eyes.

Financial Disclosure:

NONE