BACKGROUND We report the case of an 81-year-old woman with a history of radial keratotomy 9 years prior who developed endophthalmitis without preceding keratitis 4 days after uneventful photorefractive keratectomy surgery. This case report utilized clinical examination and microbacterial laboratory findings. FINDINGS Diagnosis of bacterial endophthalmitis was made via clinical examination and...

Background Photorefractive keratectomy (PRK) is at risk of serious complications such as corneal ectasia, which can reduce corrected distance visual acuity. The rate of complications of PRK is higher in patients with atypical topography. Objective To determine the outcomes of photorefractive keratectomy in patients with atypical topography. Methods This cross-sectional study was done in 201...

PURPOSE To examine the physiological optics of photorefractive corneal surgery and to study the effect on glare production of the optical zone diameter. METHODS An optical analysis computer program was used to generate rays that define the edge of the optical zone for any given pupil size and glare-free field. RESULTS The optical zone diameter must be based on the postoperative corneal curv...

BACKGROUND A return toward toward photorefractive keratectomy has occurred due to better corneal stability and fewer corneal flap complications; however, pain remains a major drawback of the procedure. Currently, clinical pain control measures focus on the administration of pain medications, which may delay corneal epithelial healing and has, occasionally, led to serious corneal toxicity. OBJ...

Laser technology is used in many basic and clinical disciplines and specialties, and it has played an important role in promoting the development of ophthalmology, especially corneal refractive surgery. We provide an overview of the evolution of laser technology for use in refractive and other ophthalmologic surgeries, mainly focusing on two types of lasers and their applications. First, we dis...

PURPOSE To describe the laboratory findings in patients with infectious keratitis, who underwent refractive surgery, correlating the surgical procedure and the time of infection manifestation, and the results of culture and smears. METHODS The previous samples were obtained from patients submitted to radial keratotomy (RK), photorefractive keratectomy (PRK) and laser in situ keratomileusis (L...

Propagation of incoherently soliton pairs in photorefractive crystals under steady-state conditions is studied. These soliton states can be generated when the two mutually incoherent optical beams with the same polarization and wavelength incident on the biased photorefractive crystal. Such soliton pairs can exist in bright-bright, dark-dark, gray-gray as well as in bright-dark types. In this p...

Over the years, mitomycin C has been used by refractive surgeons to prophylactically decrease haze after surface ablation procedures and therapeutically in the treatment of preexisting haze. Development of mitomycin C treatments has had a significant role in the revival of surface ablation techniques. We reviewed the literature regarding mechanism of action of mitomycin C, its role in modulatin...

We present experimental evidence demonstrating that the photorefractive-index change responsible for the formation of photorefractive spatial screening solitons and coherent collisions between them is primarily isotropic in nature, even though the photorefractive medium is inherently anisotropic.