Changes in Keratometric Values and Higher-Order Aberrations in Hydrogel Corneal Inlay Implantation
Purpose
The purpose of this study is analyzing surgically induced refractive change (SIRC) and the change of the high-order aberration after Raindrop corneal inlay insertion and finding the principle that Raindrop corrects presbyopia.
Methods
The Raindrop corneal inlay (ReVision Optics, Inc.) was implanted on the corneal stromal bed beneath a keratotomy flap in 11 nondominant eyes of 11 patients. Simulated K, true net power (TNP), equivalent K-reading (EKR) were provided by Pentacam (Oculus) Scheimpflug rotating camera and the change of keratometric values were compared with surgically induced refractive change (SIRC) measured by subjective refraction. Corneal high-order aberrations were also measured.
Results
The change of spherical equivalent refraction was a 1.03 diopter(D) myopic shift. The changes of TNP and EKR at central cornea (3 mm) produced more dioptric power than SIRC. (1.61D, p<0.01 / 2.17D, p<0.01) The EKR changes at 4.5 mm zone and 5.0 mm zone did not produce statistically significant difference with SIRC. (1.22 D,p=0.05 / 1.01 D,p=0.73) Only spherical aberration showed statistically significant difference in analysis in changes of high-order aberrations and the amount of SA change was -0.43 ± 0.12 microns.
Conclusion
Both the keratometry in the peripheral cornea and the refractive spherical equivalent show a myopic refractive shift in response to the inlay effect. The Raindrop corneal inlay corrects presbyopia via increasing negative spherical aberration.