Abstract
Abstract: :
Purpose: To investigate the influence of patient age, preoperative corneal thickness and K on the amount of myopic induction after conductive keratoplasty (CK) . Methods: Fourteen eyes of 14 patients who are over 40 years of age with hyperopia and meet CK criteria were enrolled into our prospective study. The first group of eyes (8 eyes) had 24–spot treatment and the second group (6 eyes) had 32–spot treatment. Pre– and postoperative measurements performed include manifest and cycloplegic refraction, Orbscan IIz topography and pachymetry. Postoperative measurements were performed at 3 and 6 months. Results: The average patient age is 55.7±7.0(range 47 to 66 years). Mean preoperative spherical equivalent refraction is +0.46±0.35(range 0 to +1.38 D). Mean preoperative corneal thickness is 571.9±47.7 µm(range 500 to 629 µm). Mean preoperative simulated K reading is 42.0±1.4(range 39.0 to 44.7). The average amount of myopia induction in the 24 spot treatment group is –1.17±0.54 D(range –0.25 to –1.88 D) and the 32 spot treatment group is 1.04±0.42 D(range 0 to –1.88 D) Within each treatment group having the same number of treatment spots: (1) The amount of myopic induction after CK decreases with increasing of age (R=0.72);(2) Preoperative corneal thickness and K reading do not correlate with the amount of myopic induction after CK(R=0.13 and R=0.117, respectively). Conclusions: Increasing age tends to diminish myopic induction by CK while preoperative corneal thickness and K reading do not appear to affect CK effect.
Keywords: refractive surgery • aging • topography