Search results for "Optometry"
showing 10 items of 812 documents
Locking Y Lateral Canthopexy as a Treatment for Dry Eye Disease Caused by Eyelid Malposition
2020
PURPOSE The signs and symptoms of dry eye disease (DED) can affect the quality of life of patients. This study analyzes whether locking Y lateral canthopexy improves patients' quality of life and in what way it does so (based on the ocular surface disease index questionnaire) and DED signs (measured by the fluorescein breakup time, tear osmolarity, Schirmer test, and corneal staining) in patients with DED caused by a eyelid malposition or impaired blink dynamics. METHODS This was a case-control study. Forty eyes of 20 patients with DED and lateral canthal disinsertion examined at the University Hospital La Ribera during a 1-year period from November 2016 to November 2017. The 40 eyes were d…
Optical quality of the diabetic eye: a review
2014
Diabetes mellitus is a metabolic disorder characterized by the presence of chronic hyperglycaemia. Several structural, morphological, and physiological changes in each of ocular component have been described in detail during the past decades. Due to these abnormalities, the diabetic patient undergoes a degradation of the retinal image by an increase of higher ocular aberrations and ocular scattering coming from mainly tear film, cornea, and crystalline lens. This review aims to provide an overview of current knowledge about the effects of diabetes mellitus in these optical phenomena and its consequence on the visual quality of the diabetic patient.
Fructose diet induced short-term impairment of cone sensitivity and gene expression in rat retina
2012
National audience; Abstract: Purpose A high fructose diet has been widely used to trigger insulin resistance in rodent; insulin resistance is one of the major risk factor for the development of type 2 diabetes. Thirty to 40% of diabetic patients develop diabetic retinopathy. In this study, we aimed to evaluate the short-term effect, at 1, 3, 5, 8 days, of a 60% fructose diet, on photoreceptor sensitivity and gene expression in the retina of Brown Norway rats. Methods: Flicker electroretinograms (8Hz) were recorded under anesthesia, from both eyes simultaneously in order to study sensitivity of photoreceptors. Then, rats were euthanized and enucleated. Retinae and posterior poles were collec…
Bleb grading by photographs versus bleb grading by slit‐lamp examination
2019
Purpose Using a bleb-grading system clinically facilitates long-term follow-up of patients with previous glaucoma surgery. Clinical evaluation of these patients can be challenging for untrained ophthalmologists. Morphological bleb configuration might influence planning of follow-up visits in glaucoma patients due to different and individual prognosis after trabeculectomy. In this study, we compared the MaBAGS (Mainz Bleb Appearance Grading System), a classification system for filtering blebs with other classification systems (MBGS/Moorfields Bleb Grading System, IBAGS/Indiana Bleb Appearance Grading Scale) in reference to usability and reliability and compare it to grading by bleb photograp…
Current Clinical Application of Microperimetry: A Review.
2018
Microperimetry (MP) is a technology that allows the study of retinal sensitivity at different foveal and parafoveal areas as well as eye fixation. It is a technique of functional evaluation, providing a direct correlation between anatomical and functional outcomes. There are a great variety of studies which evaluate the repeatability or reliability of measurements obtained with this technology and also describe and explore different clinical applications. MP has been shown to be useful in the characterization of sensory and motor conditions, such as amblyopia or nystagmus. Concerning ocular pathology, several studies have confirmed the usefulness of MP for evaluating and analyzing different…
Objective assessment of cataract: Comparison between the Lens Opacities Classification System III and a Scheimpflug camera
2015
Purpose Develop an automatic system for cataract classification using the Sirius Scheimpflug for both nuclear and cortical cataract. Methods Scheimpflug images were taken using the Sirius system in 50 patients with nuclear and/or cortical cataract (mean age 69 ± 9.2 years). The nuclear opacity (NO) and cortical opacity was graded by an ophthalmologist according to the Lens Opacities Classification System (LOCSIII) by comparing the slit-lamp image with the LOCS's standard nuclear images. A custom-made MATLAB program was used to calculate the pixel intensity value within a region of interest (ROI) of the nucleus and to calculate the percentage of opaque pixels in the cortex. Results Eighty-ni…
Effect of Phenylephrine on the Accommodative System
2016
Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil. Achieving pupil dilation (mydriasis) without affecting the accommodative ability of the eye (cycloplegia) could be useful in many clinical and research contexts. Phenylephr…
Use of digital displays and ocular surface alterations: A review.
2020
Digital display use has been accepted to be implicated as a contributing factor for dry eye disease (DED). Abnormal blinking during computer operation, including a reduced blink rate and an incomplete eyelid closure, increased palpebral fissure as consequence of high visualization angles, and meibomian gland dysfunction associated to long-term display use, are behind the increased prevalence of dry eye signs and symptoms found in digital display users. Previous research reveals significant reductions in tear volume and stability, alterations in tear film composition, including increased osmolarity, inflammatory cytokines, oxidative stress markers and reduced mucin secretion, eyelid abnormal…
Preliminary in vivo positional analysis of a posterior chamber phakic intraocular lens by optical coherence tomography and its correlation with clini…
2012
Purpose: To analyze by spectral-domain optical coherence tomography the anatomical relationship of a specific type of posterior chamber phakic intraocular lens (pIOL) implanted in cases of high to moderate myopia with the adjacent intraocular structures and to correlate it with clinical outcomes. Methods: Prospective observational case series including 18 eyes with high to moderate myopia (spherical equivalent between −5.88 and −15.75 D) of 9 patients (age range, 29–49 years) undergoing bilateral Phakic Refractive Lens (PRL, Zeiss) implantation. Postoperative visual acuity, refraction, contrast sensitivity (CS), and ocular higher order aberrations (HOA) were evaluated. Furthermore, the in v…
Validity of automated refraction after segmented refractive multifocal intraocular lens implantation
2017
Aim To evaluate the clinical utility of automated refraction (AR) and keratometry (KR) compared with subjective or manifest refraction (MR) after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X (Oculentis GmbH) refractive multifocal intraocular lens (IOL). Methods Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3mo follow-up. Results Ana…