ABSTRACT This study aimed to critically review the literature regarding the magnitude, orientation, and correlation between anterior, posterior, and total corneal astigmatism, as well as their clinical implications in normal eyes, in patients with keratoconus, and in individuals evaluated in the context of refractive surgery. An integrative literature review was conducted, with a systematic search of studies published between 2010 and 2025. Observational studies that assessed corneal astigmatism using Scheimpflug tomography in healthy eyes, eyes with keratoconus, or eyes evaluated […]

ABSTRACT This report aimed to evaluate the evolution of topography, astigmatism, and visual acuity in eyes with keratoconus that underwent intra-stromal ring implant surgery. The report compared these results with those of contralateral, non-operated eyes. The goal was to confirm whether the intra-stromal ring implant surgery could also slow the progression of the disease. Four cases of young and adult patients who underwent corneal ring implant surgery in one eye were analyzed, with clinical and topographic follow-up for up to […]

ABSTRACT Purpose: To evaluate the visual, topographic, and refractive outcomes of the implantation of asymmetric segments (AS) of the ICRS intracorneal ring in eyes with keratoconus and irregular/asymmetric astigmatism (phenotypes type 2 Duck and 3 Snowman by morphological classification of Fernandez-Vega/Alfonso Keratoconus). Methods: Prospective clinical study including 60 patients (60 eyes) with keratoconus who underwent implantation of the Kearing ICRS selected and implanted according to the Mediphacos nomogram () with femtosecond laser. Preoperative and postoperative evaluations included uncorrected visual acuity, […]

ABSTRACT Purpose: To retrospectively analyze the changes in corneal keratometry and astigmatism after intrastromal ring surgery, comparing the use of one long arch segment versus two traditional arc length segments. Methods: A cross-sectional study obtained data from 94 eyes of patients diagnosed with keratoconus that underwent surgical treatment with corneal ring implant. They were divided into two groups according to the type of implant received: one long-arch segment (Group A) or two traditional segments (Group B), both 250 microns thick. […]

ABSTRACT Objective: To retrospectively evaluate the influence of intracorneal ring thickness on reduction of corneal astigmatism in patients with keratoconus. Methods: From a database of 2,033 eyes submitted to corneal ring implant surgery, a sample of 90 eyes with similar keratometry and astigmatism characteristics was selected. All eyes in this study received two segments of traditional arc length of approximately 160°, with varying thicknesses: Group A received two segments of 150 µm; Group B received two segments of 200 µm, […]

Abstract Objective: To determine the factors associated with refractive defects in an urban population of the Peruvian Andes. Methods: A cross-sectional analytical study of secondary data analysis was performed, using all the records of the patients who attended the ophthalmological consultation between January and May 2015, the variables of type of ametropia (astigmatism, myopia and hyperopia), Sex, age, occupation and place of residence of the patients. P values, prevalence ratios and 95% confidence intervals were obtained using generalized linear models. […]

Abstract Objective: To evaluate the astigmatism induced by cataract surgery through the phacoemulsification (PHACO) technique guided by the VERION® surgical planner, in an ophthalmological service of Paraná. Methods: This is an observational study with retrospective individualized evaluation of medical records, analyzing 37 eyes of 20 patients who underwent cataract surgery using the PHACO technique using VERION® and non-toric intraocular lens implantation at the Hospital de Olhos de Cascavel – PR in May 2016. Results: Within our sample of 37 eyes […]

Objetivo: Relatar a prevalência e analisar os padrões de astigmatismo corneano em candidatos à cirurgia de catarata. Métodos: Os pesquisadores examinaram 2136 olhos de 1204 pacientes a cirurgia de catarata de 1 de janeiro a 31 de dezembro de 2016. Todos os candidatos foram avaliados com interferometria de coerência parcial (IOLMaster). Os resultados foram analisados estatisticamente em relação às variáveis qualitativa e quantitativa. Resultados: A média de idade dos pacientes foi de 71,9 anos, com predomínio do sexo feminino. A […]