Rapid suture management of post-keratoplasty astigmatism

Post-keratoplasty astigmatism is managed by topography-guided suture removal. This can take several weeks until satisfactory reduction in astigmatism is achieved. This study aimed to assess whether topography performed 30-40 min after the removal of the first pair of sutures would predict the next set of sutures requiring removal.

A prospective study of 20 consecutive penetrating keratoplasty patients was carried out. Topography guided suture removal in the steep meridian was carried out. Topography was repeated after 30-40 min and 4-6 weeks later. The tight sutures requiring removal were identified for each occasion and compared. The difference was considered insignificant if the axes of sutures requiring removal was <22.5 degrees. Paired t-test and chi (2) were performed for statistical analysis.

In 85% of individuals, the 30-40 min topography gave an accurate indication of the next pair of sutures requiring removal. The difference in mean astigmatism at 30-40 min post suture removal (4.37+/-2.08 D) and at 4-6 weeks (4.24+1.97 D) was not significant (P=0.150). However, the difference between vector-corrected change of topographic astigmatism at 30-40 min after suture removal and at 4-6 weeks (1.72 D) was significant (P<0.001). Improved best-corrected visual acuity was seen in 50% of patients.

This study showed that corneal topography performed 30-40 min after suture removal can identify the next set of sutures requiring removal. This can be used as a guide to remove more sutures at the same visit, thereby expediting post-keratoplasty visual rehabilitation and reducing the number of follow-up visits.