The effect of lens removal on patients with angle closure

Poster Details

First Author: P.Good UK

Co Author(s):    A. Mandolas   I. Masood   R. Siddiqi        

Abstract Details

Purpose:

To use Ultrabiomicroscopy (UBM) in order to evaluate the biometric changes in the anterior segment following clear lens extraction in patients with chronic angle closure.

Setting:

The Academic Unit of the Birmingham and Midland Eye Centre

Methods:

Fifteen patients (12 females, 3 males; age range 56-83 years) with chronic angle closure as identified by Gonioscopy underwent UBM examination of the anterior segment using an Aviso (Quantel Medical) 50 MHz Linear Probe. Measurements were made axially and of all 4 quadrants. Mean Anterior Chamber (AC) depth, Angle opening distance (AOD), Trabecular iris segment area (TISA), and Lens vault (LV) were measured before and after lensectomy. None of the patients had cllinically significant cataracts, and none had undergone laser peripheral iridotomy. Following UBM examination 8 patients were found to have a pupil block mechanism, 7 with a lenticular mechanism, 6 with plateau iris, and 6 with a mixed mechanism. Statistical analysis was made with Analysis Of Variance.

Results:

Before surgery All patients had at least 180 degrees of angle closure whereas after surgery all 15 patients had at least 270 degrees of open angles. The mean AC depth was 2.11 mm (sd 0.2 mm) before surgery and 3.42 mm (sd 0.4 mm) after surgery. The mean AOD was measured at 72 microns (sd 6.5 microns) before surgery and 573 microns (sd 45 microns) after surgery. Mean TISA was measured at 0.12 mm squared (sd 0.02) before surgery and 0.68 mm squared (sd 0.05) after surgery. The Mean LV was measured at 1.45 mm (sd 0.12) before surgery, and 0.26 mm (sd 0.05) after surgery. All of these values show a statistically highly significant change after surgery.

Conclusions:

This study shows that clear lens extraction is a very effective treatment for chronic angle closure with all of the 15 patients in this study achieving at least 275 degrees of open angles and an approximate 8 fold increase in angle opening distance. This was true of patients with pupil block, lenticular, plateau iris or mixed mechanisms. FINANCIAL DISCLOSURE?: No