Maria J Giraldez

• University of Santiago de Compostela

Background: The aim of the present study was to establish a cut-off value of the Lipid Layer Pattern (LLP) between participants with different subtypes of Dry Eye Disease (DED) including Deficient Dry Eye (ADDE), Evaporative Dry Eye (EDE), and Mixed Dry Eye (MDE). Methods: 240 participants diagnosed with DED according to the Tear Film and Ocular Su...

Purpose: To evaluate how Video Display Terminal (VDT) use, Contact Lens (CL) wear, and eyedrop use affect ocular surface parameters in participants with ocular discomfort and how these factors may vary across different age groups. Methods: The current cross-sectional study initially involved a total of 252 participants who completed a self-administ...

The study aimed to assess the agreement between OptoTab SERIES, alternating Cover Test, Modified Thorington test, and Von Graefe method in measuring heterophoria and accommodative convergence over accommodation (AC/A) ratio. In an initial step, heterophoria was assessed at both distance and near in a cohort of 76 healthy young volunteers using the...

Ophthalmic tacrolimus compounded formulations are usually made from the commercial intravenous presentation, which contains ethanol as a solubilizer due to the low solubility of tacrolimus. The use of cyclodextrins is presented as an alternative to ethanol, an ocular irritant excipient, to avoid its long-term irritant effects. Open-label, sequentia...

Determining the axial length (AL) of the eye is of significant interest in the management of myopia. However, the devices that allow this value to be obtained are either expensive, for example, optical biometers, or inconvenient for use in pediatric population, such is the case with ultrasound biometers. Therefore, this study aimed to develop a mat...

Background: Dry eye disease (DED) is characterized by the loss of ocular surface homeostasis with specific signs and symptoms. Studying the progression of a multifactorial disease is exceedingly challenging for researchers because several factors can influence it. The present study aims to study changes in tear meniscus height (TMH), lipid layer pa...

The present study aimed to assess the symptomatic status of Convergence Insufficiency (CI) in university students from 2018 to 2023 considering the educational environment pre- and post-COVID-19 pandemic confinements. A Convergence Insufficiency Symptom Survey (CISS) was conducted annually from 2018 to 2023, excluding 2020, in an initial group of 2...

Objective This randomised clinical trial assessed the impact on symptoms, tear film dynamics and ocular surface integrity of daily disposable silicone‐hydrogel contact lenses (CLs) over a month, paying special attention to lid wiper epitheliopathy (LWE) and its implications for CL discomfort. Methods Neophyte CL wearers ( n = 44, 21.09 ± 5.00 year...

Meibomian Glands (MG) are sebaceous glands responsible for the production of meibum, the main component of the Tear Film Lipid Layer (TFLL). The TFLL facilitates the spread of the tear film over the ocular surface, provides stability and reduces tear evaporation. Alterations in meibum composition lead to different ocular alterations like Meibomian...

The present study aimed to assess the agreement of three commercially available devices on the measurement of anterior chamber depth (ACD) with and without compensation by central corneal thickness measurement (CCT). Fifty eyes were included in an observational cross-sectional study. Participants underwent a single visit during which devices were u...

Myopia is a refractive error widely spread throughout the world, usually related to excessive axial length (AL) of the eye. This elongation could have severe consequences, even leading to blindness. However, AL varies among subjects, and it may be correlated with other anthropometric parameters. The aim of this study was to evaluate the relationshi...

(1) Background: Dry eye disease (DED) is a chronic ocular surface condition that requires precise diagnostic tools. The present study aimed to investigate the diagnostic potential of the absolute inter-eye difference (|OD-OS|) in tear meniscus height (TMH) for the detection of the presence of aqueous deficient dry eye (ADDE). (2) Methods: A sample...

Clinical relevance: Due to the long-time that wind musicians spend playing their instruments, it is important to investigate if intraocular pressure could be affected by this activity. Background: To assess the intraocular pressure fluctuations and fluctuations affecting factors in professional wind musicians while playing different tones. Methods...

Maintaining a healthy balance of tear production, preservation, and elimination is crucial for proper eye function. Tear osmolarity and its variations have been suggested as reliable indicators for diagnosing high-prevalence pathologies such as Dry Eye Disease (DED). It is important to note that in most methods used to estimate tear osmolarity, the...

Background: Inter-eye variability is a recognized characteristic of Dry Eye Disease (DED) and has been proposed as a diagnostic indicator in clinical practice. This study aimed to assess the diagnostic potential of the absolute difference between eyes in three key diagnostic tests recommended by the Tear Film and Ocular Surface Society Dry Eye Work...

Background: Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in several tissues and organs causing, among others, severe eye symptoms. The high instability of cysteamine eye drops makes it difficult to develop formulations with an acceptable shelf life to be prepared in hospital pharmacy departments. Previ...

Objectives To compare the values of central corneal thickness, anterior chamber depth (ACD), lens thickness (LT), vitreous length (VL), axial length (AL), and corneal-compensated intraocular pressure performed with and without contact lenses (CL). Methods Forty volunteer participants (16 men and 24 women, 24.2±2.9 years) were recruited. In a singl...

Background: Due to the increasing use of contact lenses (CL) and the interest in ocular and body size relationships, this study aimed to compare measurements from two biometers (contact ultrasonic EchoScan US-800 and non-contact optical Lenstar LS900) with and without CL and to explore the relationship between ocular and body biometric parameters....

Purpose: The present study aimed to analyse the variation in the status of untreated Dry Eye Disease (DED) participants over 4-, 6-, and 8-year periods. Methods: Prospective participants previously diagnosed with DED by a medical doctor were contacted for an ocular examination visit. Participants were recruited following three groups for 4-, 6-, an...

Purpose The possible variability in diagnostic test results is a statistical feature of dry eye disease patients. The clinician should consider tear film variations over time since the timing of tear film measurements is important for proper diagnosis. The purpose of the present study was to analyze the inter-week variation of osmolarity measuremen...

Purpose: to evaluate rheumatoid arthritis (RA) as a potential risk factor for the development of aqueous deficient dry eye (ADDE) compared to evaporative dry eye (EDE). Study Design: The study design was observational and cross-sectional. Methods: Two hundred volunteer participants with dry eye disease (DED) were recruited based on the TFOS DEWS II...

Purpose To determine if the Meibomian Gland (MG) secretion quality is associated with symptoms of ocular discomfort, hours of Video Display Terminals (VDT) use, eyelid margin abnormalities, conjunctival hyperemia, and Meibomian Gland Loss Area (MGLA) in a sample of university students. Methods An online survey that included an Ocular Surface Disea...

A decrease of the Tear Meniscus Height (TMH) has been proposed as a useful indicator for Aqueous Deficient Dry Eye (ADDE) categorization. The present study aimed to calculate a TMH cut-off criterion for the categorization or severity assessment of ADDE with the Tearscope. 200 participants with a previous Dry Eye Disease (DED) diagnosis according to...

Purpose: To compare the values of central corneal thickness (CCT), the anterior chamber depth (ACD) and the axial length (AL) on measurements performed with and without contact lenses (CL) in healthy subjects. ACD was measured with two different devices (Visionix 120+ and EchoScan US-800) and the values were also compared between them. Material and...

Purpose: The aim of the present study was to state a relationship between the meibomian gland loss area (MGLA), eyelid hyperemia and meibomian gland (MG) orifices plugging in a sample of university students. Material and methods: A total of 74 participants were recruited. Meibography images were obtained with the OCULUS® Keratograph 5M and MGLA was...

Purpose: Anaglyphs, Vectograms and Cheiroscopes are visual therapy materials based on red/green, polarized, or black/white targes that used similar but slightly different images for each eye to train fusion and vergence skills. This study aimed to analyse the differences in the results obtained on those devices on participants with low, normal, or...

Purpose The present study aimed to determine the relationship of non-modifiable (rheumatoid arthritis, thyroid diseases, and arterial hypertension) and modifiable risk factors (diuretics, antidepressants, or anxiolytics tranquilizers) with the different Dry Eye Disease (DED) diagnostics in a sample adjusted by antihistamines intake. Methods A tota...

Purpose Clinicians play a key role in prescribing contact lenses that best suited for fitting which materials had an impact on ocular surface parameters. The present study aimed to evaluate the impact on symptomatology, tear film dynamics and ocular surface integrity of a silicone-hydrogel (Somofilcon-A) and a hydrogel (Omafilcon-A) lens before and...

Objective: Distinguish between EDE severity levels by analysing the MGLA, conjunctival hyperemia and corneal staining. Methods: One hundred participants were recruited based on OSDI, TO, TFBUT, TMH, and LLP to be categorised as healthy (Group 1) or EDE (Group 2). Group 2 was divided into Group 2A (mild symptoms), 2B (moderate), and 2C (severe)....

The measurement of tear film osmolarity has been suggested as a gold standard in the diagnosis of dry eye. Many tear film physiological variables oscillate during the day. This review summarises current clinical knowledge regarding diurnal osmolarity variation in the tear film. A critical analysis is presented in respect of of sample size and chara...

Significance: Tear film instability has been recognized as one key mechanism on dry eye disease. There is a need for new instruments, methods, or protocols to improve the repeatability and reproducibility of the tear film stability to facilitate its clinical evaluation use as a rapid and reliable primary diagnostic test. Purpose: The present pil...

Clinical relevance: Variation with time in the tear film parameters should be considered by the clinician since the time when measurements are made can influence proper diagnosis. Background: A hallmark of dry eye is an unstable tear film associated with variability in objective daily measures. The purpose of the present study was to evaluate the i...

Purpose The physical properties of contact lens care solutions and Eye Drops (ED) may affect initial comfort and dry eye symptomatology in contact lens wearers, although these properties are not always provided by manufacturers. The present study aimed to measure and compare the osmolality and pH of commercially available contact lens care solution...

Purpose: To analyze whether inter-eye osmo larity differences were related to dry eye symptomatology. Methods: A total of 135 participants were randomly recruited from those who visited in the Optometry Clinic of the Optometry Faculty (Universidade de Santiago de Compostela). In a single scheduled session after the recruitment, Ocular Surface Di...

Background Hyperosmolarity of tear fluid has been recognised as a common feature of all types of dry eye disease. This study was designed to assess the inter‐session reproducibility of a freezing point depression osmometer (Fiske 110) as the most common and precise way of measuring osmolality, by using two different volumes of tear samples on healt...

Purpose: To evaluate the relationship between meibometry with both ocular symptoms and tear film stability by: (1) to find out whether meibometry is able to differentiate between dry eye symptomatic and asymptomatic subjects classified by standardized dry eye questionnaires (OSDI and McMonnies), and (2) to assess the clinical relationship between...

Objective: The sudden increase of blood flow in the bulbar conjunctiva, known as hyperemia, is associated to a red hue of variable intensity. Experts measure hyperemia using levels in a grading scale, a procedure that is subjective, non-repeatable and time consuming, thus creating a need for its automatisation. However, the task is far from straig...

Background and objectives: Dry eye disease is a public health problem, whose multifactorial etiology challenges clinicians and researchers making necessary the collaboration between different experts and centers. The evaluation of the interference patterns observed in the tear film lipid layer is a common clinical test used for dry eye diagnosis....

Purpose: Different values of the lower tear meniscus height (TMH) can be obtained depending on the method and technique of measurement employed. The aim of this study was to analyse the interobserver variability of a method for measuring TMH by using an open source software. Material and methods: On a group of 176 subjects, two videos of the cen...

Background: This study was designed to examine diurnal variations in tear film break-up time (BUT) and maximum blink interval (MBI) and to assess two different ways of calculating these variables on video recordings of the BUT test interpreted with the help of especially designed software. The repeatability of interpreting BUT video recordings was...

Purpose: The purpose of this study was to examine the precision and accuracy of the Fiske 110 Osmolarity System under different protocols to determine the possible applications of this device in tear film research and clinical practice. Methods: Three separate studies were performed. In the first, Fiske 110 measurements were made on undiluted and d...

The purpose of this study was to examine the precision and accuracy of the Fiske 110 Osmolarity System under different protocols to determine the possible applications of this device in tear film research and clinical practice. Three separate studies were performed. In the first, Fiske 110 measurements were made on undiluted and diluted (1:1, 1:4,...

Dry eye syndrome is a common disorder of the tear film which affects a remarkable percentage of the population, impacting on quality of life. The study of the tear film stability is essential for the dry eye characterisation. The Break-Up Time (BUT) is a clinical test which computes the time the first tear film break-up appears. Besides the time, b...

Purpose: To evaluate the effect of conditioned medium from human uterine cervical stem cells (CM-hUCESCs) on corneal epithelial healing in a rat model of dry eye after alkaline corneal epithelial ulcer. We also tested the bactericidal effect of CM-hUCESCs. Methods: Dry eye was induced in rats by extraocular lacrimal gland excision, and corneal u...

Dry eye syndrome is a common disorder of the tear film which affects a remarkable percentage of the population. The Break-Up Time (BUT) is a clinical test used for the diagnosis of this disease, which computes the time the first tear film break-up appears. This work describes a fully automatic methodology to compute the BUT measurement and evaluate...

Purpose: The lipid layer plays a major role in limiting evaporation of the tear film. Based on interference phenomena, there is a test directed to lipid layer pattern (LLP) evaluation, but is affected by subjective interpretation of the patterns. The aim of this study is to compare the LLP evaluation between two experienced observers on a group of...

Purpose: To examine the relationship between tear meniscus height (TMH) and subjective meniscus grading (subjective tear meniscus [TM]) with tear osmolarity. Methods: Tear osmolarity measurements (using TearLab) and digital images of the TM were obtained in 177 consecutive patients undergoing an eye examination at our optometry clinic (Universid...

The present paper aims to assess the effect of lotrafilcon A contact lenses (CL) in situ on intraocular pressure (IOP) measurement performed with three portable tonometers (ICare, Tonopen and Perkins). This cross-sectional study included thirty young healthy subjects. Intraocular pressure measurements without CL were performed first, followed by IO...

Dry eye syndrome (DES) is a common disorder of the tear film, affecting a significant percentage of the population. The Non Invasive Break-Up Time (NIBUT) is a clinical test used for the diagnosis of DES. In this work, we propose a methodology for the semi-automatic computation of the NIBUT test. We tested our methodology on a dataset composed of 1...

Purpose: The lipid layer plays a major role in limiting evaporation of the tear film. Based on interference phenomena, there is a test directed to lipid layer pattern (LLP) evaluation, but is affected by subjective interpretation of the patterns. The aim of this study is to compare the LLP evaluation between two experienced observers on a group of...

Tear film breakup time (BUT) test only examines the first break in the tear film, but subsequent tear film events are not monitored. We present a method of measuring the area of breakup after the appearance of the first breakup by using open source software. Furthermore, the speed of the rupture was determined. 84 subjects participated in the study...

To measure different parameters of lower tear meniscus height (TMH) by using photography with open software of measurement. TMH was addressed from lower eyelid to the top of the meniscus (absolute TMH) and to the brightest meniscus reflex (reflex TMH). 121 young healthy subjects were included in the study. The lower tear meniscus was videotaped by...

The purpose of this study is to establish the procedure of acquisition and evaluate the Lipid layer pattern (LLP) by Tearscope in order to enhance this useful technique. To aid this purpose, we present a new broad LLP images database (included in a web application called Pli-marker) The tear film lipid layer was examined using a Tearscope-plus (Kee...

High tear fluid osmolarity is a feature common to all types of dry eye. This study was designed to establish the accuracy of two osmometers, a freezing point depression osmometer (Fiske 110) and an electrical impedance osmometer (TearLab™) by using standard samples. To assess the accuracy of the measurements provided by the two instruments we used...

: The lipid layer of the tear film limits evaporation during the interblink interval and also affects tear stability. This study was designed to validate a new software application designed to characterize the tear film lipid layer through texture and color pattern recognition. : Using the Tearscope-plus (slit-lamp magnification ×200), the lipid la...

Background: Non-contact Tonopachy NT-530P (Nidek Co., LTD) provides intraocular pressure (IOP) and central corneal thickness (CCT) measurements. This study assesses the reliability and repeatability of its IOP measurements in young healthy adult subjects. Methods: IOP was determined in the right eye of 64 healthy patients using Tonopachy followe...

Dry eye syndrome is a common disorder of the tear film, affecting a significant percentage of the population. The Break-Up Time (BUT) is a clinical test used for the diagnosis of this disease. In this research, it is proposed an automatic methodology to evaluate the BUT test. This methodology locates the different measurement areas from a video of...

The recently developed noncontact tonopachymeter Tonopachy NT-530 P provides intraocular pressure values corrected for central corneal thickness (CCT). The purpose of this study was to assess the accuracy and repeatability of its CCT measurements. The CCT measurements were obtained in 64 right eyes of 64 young healthy subjects using the Orbscan cor...

Dry eye syndrome is a common disorder of the tear film, affecting a significant percentage of the population. The Break-Up Time (BUT) is a clinical test used for the diagnosis of this disease. In this work, we propose several improvements for the automatic computation of the BUT measure that solve the limitations of previous approaches. In particul...

Purpose: White light optical profiling (WLOP), no usually applied to contact lenses (CL), is a well-established technique for non-contact measurement of surface topography over large areas at moderate lateral and high vertical resolution (sub-nanometer). The aim of this study is to analyze surface properties of five hydrogel CL evaluating represent...

Purpose: Average roughness (Ra) is generally used to quantify roughness; however it makes no distinction between spikes and troughs. Shape parameters as kurtosis (Rku) and skewness (Rsk) serve to distinguish between two profiles with the same Ra. They have been reported in many biomedical fields, but they were no applied to contact lenses before. T...

Purpose: The lipid layer of the tear film limits evaporation during the inter-blink interval and also affects tear stability. This study was designed to validate a new software application designed to characterize the tear film lipid layer through texture and colour pattern recognition. Methods: Using the Tearscope-plus (slit lamp magnification 200...

This study was designed to qualitatively and quantitatively characterize the surface morphology of four unworn conventional hydrogel contact lenses (omafilcon, hioxifilcon, nelfilcon A, and ocufilcon B) and two silicone-hydrogel contact lenses (senofilcon A and comfilcon A) without surface treatment. Surface roughness was assessed using atomic forc...

Purpose To assess the accuracy and repeatability of intraocular pressure (IOP) measurements obtained with the Canon TX-10™ noncontact tonometer (NCT), using the Goldmann applanation tonometer (GAT) as the gold standard. Methods Seventy-three young healthy subjects were enrolled in the study. Central corneal thickness (CCT) was obtained with Orbsca...

The aim of this study was to characterize, qualitatively and quantitatively, the surface morphology of four unworn conventional hydrogel contact lenses (Omafilcon, Hioxifilcon-based, Nefilcon A and Ocufilcon B) by White Light Optical Profiling (WLOP). WLOP is an ideal technique for sampling larger areas as well as for higher measurement speed compa...

This study was designed to assess whether hydrogel contact lens (CL) surface hydrophobicity and roughness affect Staphylococcus epidermidis adhesion. Bacterial adhesion experiments were performed on two unworn silicone hydrogel and three unworn conventional hydrogel CLs using the S.epidermidis strain CECT 4184. Microbial colonization was assessed b...

Different values of the lower tear meniscus height (TMH) can be obtained depending on the method and technique of measurement employed. This study aimed to assess (1) differences between the absolute (TMH-A), reflex (TMH-R) and fluorescein (TMH-F) lower tear meniscus heights, (2) differences between the central (TMH-R), nasal (TMH-RN) and temporal...

The aim of this study was to establish the relationship between OST, tear film stability as assessed by NIBUT and subjective evaluation of the lipid layer thickness in a young, asymptomatic, sample group (N=29). Non-invasive tear break-up time (NIBUT) and tear lipid layer structure were evaluated through a slit-lamp mounted Tearscope Plus. A self-c...

To study the effect of 1 drop of combined topical anaesthesia (tetracaine 0.1% and oxybuprocaine 0.4%) on central corneal thickness (CCT) values and at 2.5 mm from the corneal centre in nasal, temporal, superior and inferior hemi meridians, monitored by Orbscan over a period of 16 minutes. The corneal thickness of 12 right eyes of 12 young healthy...

Objective: To study the effect of 1 drop of combined topical anaesthesia (tetracaine 0.1% and oxybuprocaine 0.4%) on central corneal thickness (CCT) values and at 2.5 mm from the corneal centre in nasal, temporal, superior and inferior hemi meridians, monitored by Orbscan over a period of 16 minutes. Materials and methods: The corneal thickness of...

Objetivo: Determinar la relacion entre los diferentes componentes opticos oculares y la emetropizacion en funcion de la longitud axial (LA). Metodos: Participaron 109 jovenes universitarios divididos en cinco grupos segun el error refractivo: emetropes, hipermetropes, miopes bajos, miopes moderados y miopes altos. La medida de los parametros intrao...

To report the relationship between different optical ocular components and the influence of axial length on emmetropization. 109 young university students, divided into five groups, were enrolled in this study: emmetropes, hyperopes, low myopes, moderate myopes and high myopes. Intraocular parameters and topographic corneal analyses were performed...

Objective: Corneal topography and thickness has clinical importance in contact lens fitting and refractive surgery, however repeated measurement of corneal thickness and curvature is complicated by the natural phenomenon of diurnal variation. Our aim was determine diurnal variations of central and paracentral corneal thickness and curvature over a...

Corneal topography and thickness has clinical importance in contact lens fitting and refractive surgery, however repeated measurement of corneal thickness and curvature is complicated by the natural phenomenon of diurnal variation. Our aim was determine diurnal variations of central and paracentral corneal thickness and curvature over a period of t...

The purpose of this study was to assess the accuracy of the ICare tonometer, using the Perkins applanation tonometer (AT) as the reference, in a sample population being treated with travaprost 0.004% for glaucoma. Twenty-eight consecutive patients with open-angle glaucoma or ocular hypertension who had been receiving travaprost 0.004% to control el...

Objective: Corneal topography and thickness has clinical importance in contact lens fitting and refractive surgery, however repeated measurement of corneal thickness and curvature is complicated by the natural phenomenon of diurnal variation. Our aim was determine diurnal variations of central and paracentral corneal thickness and curvature over a...

The TGDc-01 "PRA" (Ryazan State Instrument, Ryazan, Russia) tonometer is a new portable small-sized tonometer that measures intraocular pressure (IOP) through the eyelid. The purpose of this study is to assess the repeatability of the TGDc-01 IOP measurements by comparing them against those obtained with Goldmann tonometer and with those from Perki...

To determine the relevance of the different ocular optical components in the refractive state of young adults, paying special attention to the corneal topography represented by the asphericity value. Corneal topographies and ultrasonic biometries were obtained from 109 university students with different refractive errors (spherical equivalent range...

Objetivos: Determinación de la relevancia de diferentes componentes ópticos oculares en el estado refractivo de adultos jóvenes, con especial atención a la topografía corneal representada por el valor de asfericidad. Sujetos y métodos: Las topografías corneales y biometrías ultrasónicas fueron obtenidas en 109 estudiantes universitarios con diversa...

Determination of the role of the axial length/corneal radius ratio (AL/CR) in the refractive state and investigation of its relationship with the ocular optical components: AL, CR, anterior chamber depth (ACD), crystalline lens thickness (CT) and vitreous chamber depth (VCD). The RE (right eye) of 193 University students 22.27 (SD 3.24) years, with...

Objetivo: Determinación del papel de la ratio longitud axial/radio corneal (LA/RC) en el estado refractivo e investigación de su relación con los componentes ópticos oculares: LA, RC, profundidad de cámara anterior (PCA), espesor del cristalino (EC) y profundidad de cámara vítrea (PCV). Métodos: Se ha examinado el ojo derecho (OD) en 193 estudiante...

It is important to know how well the surface topography can be measured with current devices for corneal topographic analysis. There are several applications that need an accurate and precise method to measure corneal shape and variations, such as the effect of contact lens wear and the different refractive surgery techniques. The aim of this study...

This article compares measurements of corneal thickness obtained with the Orbscan Topography System with those obtained with the ultrasonic pachymeter, when used to measure central-comeal thickness in normal subjects. Slit-scan topography (Orbscan II system, version 3.0, Bausch & Lomb, Rochester, NY) and ultrasonic pachymetry (Ophthasonic A-Scan/ P...

Purpose. This article compares measurements of corneal thickness obtained with the Orbscan Topography System with those obtained with the ultrasonic pachymeter, when used to measure central-corneal thickness in normal subjects. Methods. Slit-scan topography (Orbscan II system, version 3.0, Bausch & Lomb, Rochester, NY) and ultrasonic pachymetry (Op...

We investigated the effect of high Dk daily wear rigid gas permeable contact lenses on corneal topography. Eight young myopic subjects wore hard contact lenses for 21 days. Corneal topography was monitored using the EyeSys system. It was measured every day during the next 21 days after the fitting. We recorded the corneal radius of curvature at 16...

In this study we compare three different keratometric methods normally used in contact lens fitting to assesses the effect of contact lenses on corneal curvature. Measurements were obtained from 100 normal eyes using a Javal ophthalmometer, an Nidek autokeratometer, and Corneal Analysis System (EyeSys) to compare the keratometric readings obtained...

Central and peripheral corneal thickness has been used increasingly to obtain information about physiologic and clinical conditions of the cornea. In this study, a new method based on ultrasonic pachometry for topographical corneal thickness measurement is described. Results suggest that the technique is reliable for clinical determination of globa...

Central corneal thickness of both eyes of 18 normal subjects was measured in a study comparing a Haag-Streit optical pachometer and an ultrasonic pachometer (Teknar Ophthasonic, preset velocity 1630 m/sec). All subjects were awake for 3 hours before measurements to reduce swelling of the cornea from overnight eye closure. Reliability was assessed b...

Astigmatism and corneal power were established by a triple procedure in a study at 100 eyes at 50 young subjects using the Helmholtz keratometer, Javal ophthalmometer and Eye Sys corneal analysis system. Mean keratometric astigmatism was significantly different between the three instruments. The average central corneal power was significantly diffe...

BACKGROUND. Patients with dense ocular media disorders retain the ability to project or point to an intense source of light. Using this response capability and high luminance points of light as stimuli, Vernier judgments (a hyperacuity test) can be made by these patients, even without the presence of a "window" through a leucoma, cataract, or bleed...

With certain (but not all) vernier acuity (VeA) stimulus displays observers exhibit no or slight performance decrements with aging. Because three-point VeA test displays are much more easily applied experimentally and clinically, we examined visual performance on this task as a function of age. Ages of groups tested ranged from 20 to 70+ years (som...