0000000000087819
AUTHOR
Miguel J. Maldonado
showing 6 related works from this author
Precision of a commercial hartmann-shack aberrometer: limits of total wavefront laser vision correction.
2012
Purpose To assess the intrasession and intersession precision of higher-order aberrations (HOAs) measured using a commercial Hartmann-Shack wavefront sensor (Zywave; Bausch & Lomb) in refractive surgery candidates. Design Prospective, experimental study of a device. Methods To analyze intrasession repeatability, 1 experienced examiner measured 30 healthy eyes 5 times successively. To study intersession reproducibility, the same clinician obtained measurements from another 30 eyes in 2 consecutive sessions at the same time of day 1 week apart. Results For intrasession repeatability, excellent intraclass correlation coefficients (ICCs) were obtained for total ocular aberrations, total HOAs, a…
Direct Objective Quantification of Corneal Haze after Excimer Laser Photorefractive Keratectomy for High Myopia
1996
Purpose: The purpose of the study is to measure regional distribution differences in corneal haze after excimer laser photorefractive keratectomy for high myopia. Methods: The authors developed computerized gradient edge detectors with which were analyzed digitized anterior slit-lamp photographs of 40 eyes, an average of 21.0 plus or minus 14.5 weeks after photorefractive keratectomy for high myopia (−6 to −22 diopters). A treated area and an adjacent untreated area on the anterior corneal surface, each containing six regions, were quantified, and the difference was correlated with various parameters. Results: Mean differences between scarred and clear areas for haze grade 0.5, 1.0, 2.0, 3.…
Goldmann Applanation Tonometry Using Sterile Disposable Silicone Tonometer Shields
1996
Abstract Purpose: Placement of a sterile single-use cover over the tonometer tip may be a convenient and safe alternative method to repeated chemical disinfection. This study was undertaken to evaluate the accuracy and performance of Goldmann applanation tonometry using a sterile disposable silicone tonometer shield over the biprism tip. Methods: The same investigator measured intraocular pressure in 120 eyes with and without the shield. The eyes were tested randomly first with either the uncovered or the covered tonometer to control for the possible effects of repeated tonometry influencing measurement differences. Readings were recorded independently in a masked fashion. Results: The intr…
Long-term Results of Combined Cataract, IOL and Glaucoma Surgery
1994
OBJECTIVE: To determine the long-term intraocular pressure (IOP) control in patients that had undergone combined extracapsular cataract extraction (ECCE), lens implant and glaucoma surgery and compare the results obtained by the longer and shorter follow-up groups. STUDY DESIGN: Retrospective study of postoperative results with a minimum follow-up of one year, maximum of 10 years and a mean of 33.1 months. SETTING: Department of Opthalmology, ‘La Fe’ University Hospital. Department of Surgery of Valencia School of Medicine, Valencia, Spain. PATIENTS: Ninety-five eyes examined of 72 patients presenting coexisting cataract and glaucoma who underwent combined surgery in the last 11 years. MAIN…
Combined procedure for glaucoma and cataract: A retrospective study
1994
Abstract To ascertain the long-term effects of a triple procedure in the case of coexisting cataract and glaucoma, we did a retrospective study of 93 eyes that had cataract extraction, IOL implantation, and trabeculectomy within a ten-year period. Mean follow-up was 32.4 ± 21.9 months. Mean postoperative intraocular pressure (IOP) was significantly lower than preoperatively, even though fewer medications were being used. One year after surgery, 60% of eyes had a best corrected visual acuity of 20/40 or better with an average improvement of 3.8 Snellen lines. Patients who had had surgery four or more years before the study had the highest percentage of eyes with an IOP exceeding 22 mm Hg. Th…
Reproducibility of digital image analysis for measuring corneal haze after myopic photorefractive keratectomy.
1997
Purpose To evaluate the usefulness of digital image analysis for quantifying corneal haze by determining the reproducibility of its measurements at the corneal plane. Methods In a prospective study, 20 randomly selected eyes that had undergone myopic photorefractive keratectomy were photographed focusing the slit beam on their anterior corneal surface. Each photograph was examined using computer image analysis techniques that detect the edge of the reticular pattern of the image. Quantification of the difference between two areas, treated and adjacent untreated cornea, each containing 3,750 pixels with a resolution of 256 gray levels, was performed. Intra-analyzer variation was determined b…