Post-operative astigmatism control by selective suture removal.

Fifty eyes in 50 patients with > 2.5 dioptres (D) of with-the-rule astigmatism (refraction) following uncomplicated extracapsular cataract extraction were recruited for this prospective study. Selected single sutures were removed and both the amount of astigmatic loss and the change in axis were measured at intervals. After removal of the first suture the mean astigmatic loss at 1 week was 2.9 D by keratometry and the mean change in the axis was 23 degrees (74% occurred within the first hour). The astigmatic loss was greater with subsequent suture removal. Timing of suture removal (before or after 8 weeks) and the amount of initial post-operative astigmatism (more than or less than 5 D) had a minimal effect on the total astigmatic loss. We suggest selective single suture removal can be performed safely at 5-6 weeks post-operatively with removal of a second suture, if necessary, in the steepest axis after 1 hour. The prescription of spectacles should be delayed for 1 week after the final suture has been removed.