This survey collects the theoretical results in the area of pseudo RungeKutta methods (PRK ) for ordinary differential equations and it is a vehicle for a current bibliography from 1966 to 2002. PRK methods require fewer functional evaluations than Runge-Kutta methods of the same order. Byrne and Lambert (1966-1967 ) was the first who considered PRK methods in significative forms. Afterwards Co...

Aim of this paper is to compare the visual outcome in supervised PRK and LASIK surgery. Materials and methods used are Retrospective review of cases performed with Technolas 217 Z platform between July 1, 2009 and June 30, 2010. Inclusion criteria were spherical equivalent of -0.50 to -09.50 diopters (D), refractive mean astigmatic error of -3.00 D, intention to provide full distance correction...

We prospectively compared visual and refractive outcomes in patients with high myopia and myopic astigmatism after small-incision lenticule extraction (SMILE) and photorefractive keratetctomy (PRK) with mitomycin C. Sixty-six eyes of 33 patients (mean age, 29.7 ± 5.6 years) were included (SMILE: 34 eyes, PRK 32 eyes). Preoperatively, no significant difference was noted in manifest spherical equ...

This study computes the gradient of a function numerical solutions ordinary differential equations (ODEs) with respect to initial condition. The adjoint method approximately by solving corresponding system numerically. In this context, Sanz-Serna [SIAM Rev., 58 (2016), pp. 3–33] showed that when value problem is solved Runge–Kutta (RK) method, can be exactly computed applying an appropriate RK ...

BACKGROUND The purpose of this study was to evaluate the effects of laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) on corneal biomechanical properties. METHODS We used the ocular response analyzer to measure corneal hysteresis (CH) and corneal resistance factor (CRF) before and after refractive surgery. RESULTS In all, 230 eyes underwent LASIK and 115 ey...

AIMS/BACKGROUND Since wound healing processes are known to be more rapid in those who are young, it was decided to examine the effect of patient age on refractive outcome of photorefractive keratectomy (PRK). METHODS The records of 599 eyes that had undergone PRK were studied retrospectively. The eyes were categorised by baseline myopia and patient age. Spherical equivalent and corneal haze w...

WAVEFRONT-guided photorefractive keratectomy (PRK) induces fewer higher-order aberrations than wavefrontguided LASIK, while the latter induces fewer higher order aberrations than conventional or optimised LASIK, suggest the preliminary results of two new studies presented at the XXIII Congress of the ESCRS. “In my practice, I employ wavefront guided technology in every patient that is eligible,...

BACKGROUND Tetracaine and proparacaine are two of the most commonly used medications for providing topical anesthesia in laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). These agents have not been previously compared in a prospective manner to determine their efficacy in these settings. METHODS This prospective, single-masked, randomized study comprised 256 eyes fro...

PURPOSE To determine whether photorefractive keratectomy (PRK) has a significant effect on optic nerve head (ONH) parameters and peripapillary retinal nerve fiber layer (RNFL) thickness measured by the Heidelberg Retina Tomograph 3 (Heidelberg Engineering GmbH, Heidelberg, Germany) in eyes with low to moderate myopia. METHODS This prospective, interventional case series, includes 43 consecuti...

PURPOSE To evaluate epithelial healing and visual outcome after laser-assisted subepithelial keratectomy (LASEK) without alcohol de-epithelialization and to compare this technique to photorefractive keratectomy (PRK) in myopia. METHODS In a series of 1953 patients undergoing bilateral myopic PRK, an epithelial flap could be obtained by manual de-epithelialization in the left eye of 56 patient...