Does frontalis sling surgery for congenital ptosis change the corneal topography and refractive characteristics postoperatively?

Abstract

Purpose: To evaluate the effect of frontalis sling surgery for congenital ptosis on corneal curvature and refractive status. Methods: Prospective study of 60 eyes of 48 patients with severe simple congenital ptosis who underwent surgical correction by frontalis sling surgery. Assessment was done pre-operatively and at 1 week, 1 month, 3 months post-operatively by computerized topographer (Shipp Nippon, CT 1000), IOL master (Carl Zeiss, 500), autorefractometer (Unicos URK-800) and AS-OCT (Cirrus HD-OCT). The results were statistically evaluated to analyze any change in visual acuity, refractive status, keratometry, astigmatism and central corneal thickness (CCT). Results: Three months post-operatively, significant reduction of cylindrical power by −0.358 D was observed by refraction with corresponding improvement of mean BCVA by 0.24±0.04 logMAR. Corneal topography showed reduction in astigmatism by −0.47±0.95 D; however, the average keratometry did not undergo a significant change. The mean values of astigmatism by IOL master and topographer were comparable. There was significant steepening of the previously flatter meridian (horizontal meridian, in 63.3% patients) while the steeper meridian remained relatively unchanged. A greater reduction in astigmatism was noticed in children in the age group of 5–10 years. Conclusion: Ptosis surgery modifies the corneal curvature, restoring corneal symmetry and reducing astigmatism; thus changing the refractive status of the patient, which needs to be addressed post-operatively to improve the quality of vision. Children with severe ptosis may benefit from being operated at an early age to achieve better astigmatic reduction.