Abstract
Purpose :
To evaluate the clinical outcomes and corneal higher order aberrations (HOA), 6 months after implantation of Intacs,® followed by corneal collagen cross-linking (CXL) therapy for keratoconus.
Methods :
Patients were enrolled as part of a prospective, randomized, controlled clinical trial, and were randomized to one of two groups: Intacs placement, immediately followed by CXL during the same session, or Intacs placement followed by crosslinking 3 months later. This study was a secondary analysis performed on the changes of total, trephoil 0, trephoil 30, coma 0, coma 90, and spherical higher order aberrations, 6 months after combination therapy (Pentacam,Oculus Inc, USA). The data was compared using a paired two tailed t test (significant, P<0.05).
Results :
Sixty two eyes (62 patients) underwent cobination therapy. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), maximum keratometry (Kmax), IS ratio (IS), and the point of maximum flattening(Kflat) all improved 6 months after therapy [( UDVA-0.2+/-0.31p<0.01), ( CDVA-0.1+/-0.2,p<0.01),(Kmax-3.2D+/-3.1D,p<0.01),(IS-5.1D+/-6.4D, p<0.01), (Kflat-7.9D+/-4.3D)]. Preoperative total, trephoil 0, trephoil 30, coma 0, coma 90, and spherical aberrations (root mean square) were 4.0+/-1.9, 0.6+/-0.5, 0.5+/-0.5, 1.1+/-0.9, 3.2+/-1.8, and 0.9+/-0.9, respectively. Total, coma 0, and coma 90 HOAs significantly improved by 1.2+/-0.7(p<0.01), 0.37 +/-0.54(p<0.01), and 1.6+/-1.1(P<0.01), respectively. Trephoil 0, trephoil 30, and spherical aberrations changed by 0.01+/-0.6, 0.2+/-0.9, and 0.1+/-0.5, respectively. However, these changes failed to reach statistical significance (ptrephoil 0=0.9, ptrephoil 30=0.2, pspherical=0.1). The improvement in total HOAs correlated with flattening of Kmax and the point of maximum flattening [(rKmax= 0.3,p=0.03), rflat=0.4,p<0.01)]. The improvement of coma 90 was correlated with the Kflat alone (p=0.3,p=0.01).
Conclusions :
UDVA, CDVA, Kmax, IS, and the Kflat improved, 6 months after Intacs and CXL therapy. Total, horzontal coma, and vertical coma higher order aberrations improved during this same time period as well. The Kflat significantly correlated with the improvement of both total and vertical coma HOAs. Flattening of Kmax correlated with the improvement of total HOAs, at 6 months, as well.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.