PURPOSE To assess the efficacy and safety of topography-guided photorefractive keratectomy (PRK) for keratoconus and to estimate the subsequent risk of progression. METHODS This is a retrospective follow-up study. Between 1998 and 2013, 28 eyes of 23 patients (age 17-60) with grade 1-3 keratoconus received topography-guided PRK. Corrected-distance visual acuity (CDVA), keratometry, pachymetry...

PURPOSE To assess the prophylactic effect of preoperative application of topical diclofenac on postoperative pain control in patients having photorefractive keratectomy (PRK). SETTING Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. DESIGN Randomized masked clinical trial. METHODS In this paired-eye study, patients having bilateral PRK received 1 drop of diclofena...

PURPOSE To analyze the risk factors associated with a series of ectasia cases following photorefractive keratectomy (PRK) and all published cases. METHODS In a retrospective study on post-PRK ectasia patients, 9 eyes of 7 patients were included, in addition to 20 eyes of 13 patients from the literature. Risk of post-PRK ectasia was calculated using the ectasia risk score system (ERSS) for las...

Photorefractive keratectomy (PRK) represents a therapeutic option to remodel corneal stroma and to compensate refractive errors, which involves inflammatory and/or regenerative processes. In this context, the modulation of cytokines/chemokines in the conjunctival sac fluid and their role in the maintenance of the corneal microenvironment during the healing process upon refractive procedures has...

Laser in situ keratomileusis (LASIK) is the most frequently performed corneal refractive procedure. Despite technological improvements, residual postoperative refractive errors are still an issue that needs to be dealt with, especially when they interfere with the patient ́s quality of life. Retreatment after LASIK is commonly performed by lifting the flap created during the first operation foll...

PURPOSE To compare corneal reepithelialization, pain scores, ocular discomfort, and tear production after photorefractive keratectomy (PRK) and butterfly laser epithelial keratomileusis (LASEK). METHODS This prospective, randomized, double-masked study comprised 102 eyes of 51 patients who underwent laser refractive surgery. Each patient was randomized to have one eye operated on with PRK and...

Purpose. To assess near visual acuity in a presbyopic age group following hyperopic photorefractive keratectomy (PRK). Setting. Private practice in Siena, Italy. Methods. In this retrospective single-surgeon comparative study, PRK with mitomycin C was performed to correct hyperopia using Bausch & Lomb 217z laser for 120 eyes of 60 patients in the presbyopic age group (mean spherical equivalent ...

In darkened leaves the Calvin cycle enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) form a regulatory multi-enzyme complex with the small chloroplast protein CP12. GAPDH also forms a high molecular weight regulatory mono-enzyme complex. Given that there are different reports as to the number and subunit composition of these complexes and that enzyme regula...

PURPOSE To determine whether the nerve fiber analyzer GDx with the new variable corneal compensation (VCC) device allows measurements of retinal nerve fiber layer parameters independent from birefringence changes of the cornea after photorefractive keratectomy (PRK). METHODS Retinal nerve fiber layers of 32 eyes in 32 myopic patients undergoing PRK were analyzed using the GDx-VCC. Photorefrac...