Posterior keratometry changes after steep axis phacoemulsification: a prospective study.

Purpose: To measure changes in posterior corneal curvature after steep axis phacoemulsification and investigate the possibility of its effect on SIA.

Methods

This was a prospective longitudinal study on 60 consecutive eyes of age-related cataract with regular astigmatism and absence of co-morbidities undergoing uneventful cataract surgeries with main incision at steep meridian. Preoperative and 4 weeks postoperative measurements of anterior and posterior corneal curvatures using Scheimpflug based corneal topographer were performed. Posterior corneal curvature was assessed at 3, 5- and 7-mm diameters.

Results

The study found a statistically significant change in posterior corneal K1, K2 and mean astigmatism in all zones (3, 5 and 7 mm) at 4 weeks postoperative, when compared to preoperative readings.

Conclusion

Posterior keratometry is likely to be an important determinant of Surgically Induced Astigmatism (SIA) and should be factored in for refractive cataract surgery.