Many key cellular functions, such as cell motility and cellular differentiation are mediated by Rho-associated protein kinases (ROCKs). Numerous studies have been conducted to examine the ROCK signal transduction pathways involved in these motile and contractile events with the aid of pharmacological inhibitors such as Y-27632. However the molecular mechanism of action of Y-27632 has not been f...

AIM To evaluate the effect of topical vitamin A supplementation on corneal re-epithelialization time, postoperative pain, visual acuity, and haze following photorefractive keratectomy (PRK). PATIENTS AND METHODS This prospective study included 32 patients. For each patient, one eye was randomized to the vitamin A group and the fellow eye to the non-vitamin A group (control group). Eyes in the...

The chloroplast enzyme phosphoribulokinase (PRK; EC 2.7.1.19) is part of the Calvin cycle (reductive pentose phosphate pathway) responsible for CO(2) fixation in photosynthetic organisms. In green algae and vascular plants, this enzyme is light regulated via reversible reduction by reduced thioredoxin. We have sequenced and characterized the gene of the PRK from the marine diatom Odontella sine...

PURPOSE To evaluate possible changes of the ocular rigidity coefficient in vivo after photorefractive keratectomy (PRK) in a series of rabbit eyes, using an invasive ocular rigidity measurement device. METHODS Sixteen eyes of 8 rabbits were used in this study. One eye from each rabbit underwent PRK for -10.00 diopters (D) in a 5-mm optical zone (92 microm) while the fellow eye served as the c...

PURPOSE To determine the accuracy of Pentacam Scheimpflug system Holladay equivalent keratometry (K) readings (EKRs) in calculating intraocular lens (IOL) power after corneal refractive surgery, including laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and radial keratotomy (RK). SETTING Jules Stein Eye Institute, David Geffen School of Medicine at University of Calif...

PURPOSE To compare the corneal power measurements obtained using different topographic instruments after myopic photorefractive keratectomy (PRK). METHODS Patients with myopia who were candidates for corneal refractive surgery were sequentially included. Pre-PRK and six months post-PRK corneal powers were measured using Javal manual keratometer, Orbscan II, Galilei, Tomey TMS4, and EyeSys 200...

PURPOSE To characterize the velocity of epithelial migration after photorefractive keratectomy (PRK) with 3 different corneal ablation patterns. SETTING Department of Ophthalmology, Catholic University of Rome, Rome, Italy. METHODS Fifteen patients (30 eyes) with mild to moderate myopia and with simple to compound myopic astigmatism were enrolled for this study. The surgical procedure consi...

BACKGROUND/AIMS Epithelial debridement for photorefractive keratectomy (PRK) is associated with pain, slower visual recovery, and may be aetiological in haze production. The aim of this study was to assess the clinical results of a new technique involving raising and replacing of an epithelial flap in photorefractive keratectomy. METHODS A prospective, non-randomised, comparative, paired eye ...

PURPOSE To investigate the optical quality of the anterior cornea during a 6-year follow-up after photorefractive keratectomy (PRK) for myopia. METHODS Forty-nine patients (98 eyes) underwent PRK using an excimer laser platform. Patients were subdivided into three groups according to their preoperative spherical equivalent refraction and amount of cylinder component: the low-myopia, the high-...

PURPOSE To quantify optical and biomechanical properties of the feline cornea before and after photorefractive keratectomy (PRK) and assess the relative contribution of different biological factors to refractive outcome. SETTING Department of Ophthalmology, University of Rochester, Rochester, New York, USA. METHODS Adult cats had 6.0 diopter (D) myopic or 4.0 D hyperopic PRK over 6.0 or 8.0...