Abstract
Purpose: :
To compare ocular higher order aberrations induced by CRT® to those produced by LASIK surgery for patients with comparable levels of myopia, who were evaluated over the same period of time with the same aberrometer.
Methods: :
A retrospective chart review of 11 subjects who utilized CRT® lenses for myopic correction and 12 subjects who underwent LASIK surgery for correction of low to moderate level myopia was performed. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), manifest refraction, and optical higher order aberration readings were recorded before and one month after treatment for each subject.
Results: :
The CRT® treatment group consisted of 11 subjects (4 men, 7 women) with a mean age of 29.1 ± 5.2 (range: 23-40 years), while the LASIK treatment group consisted of 12 subjects (3 men, 9 women) with a mean age of 39.2 ± 12.0 (range: 23-60 years). Manifest refraction statistically significantly decreased from -2.81 D ± 1.05 D at baseline to -0.77 D ± 0.64 D following CRT® treatment for one month (p<0.0001) and from -3.11 D ± 1.21 D at baseline to -0.43 D ± 0.27 D one month post-LASIK surgery (p<0.0001)Both CRT® and LASIK exhibited no statistically significant changes in total HOA for 4mm pupil sizes but did induce statistically significant increases in total HOA for 6mm pupil sizes. CRT® and LASIK both exhibited statistically similar factors of change for total HOA and coma-like HOA for 6mm pupils. CRT®, however, did demonstrate a statistically significant greater factor of increase in spherical-like HOA for 6mm pupils (p=0.01).
Conclusions: :
CRT® and LASIK surgery could effectively correct myopia while significantly increasing the HOA for 6mm pupils. Comparison of the two treatments showed that both increased HOA to a statistically similar degree, with the exception of spherical-like aberrations, which were statistically significantly greater after CRT® than after LASIK. Future clinical trials should be conducted to determine whether the significant difference between CRT® and LASIK treatments with respect to their induction of HOA is clinically significant.
Keywords: refractive surgery: optical quality • imaging/image analysis: clinical • cornea: clinical science