Gonzalo Carracedo

Gonzalo Carracedo
Complutense University of Madrid | UCM · Department of Optics

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85
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Publications

Publications (85)
Article
Full-text available
Melatonin analogs topically administered evoke a potent tear secretagogue effect in rabbits. This route of drug administration requires high drug concentration and frequent dosing due to its reduced ocular surface retention. Therefore, contact lenses (CLs) have emerged as an alternative drug-delivery system that prolongs drug retention in the corne...
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Oral administration of cholesterol-lowering statins, HMG-CoA reductase inhibitors, is associated with beneficial effects on eye conditions. This work aims to design contact lenses (CLs) that can sustainedly deliver pravastatin and thus improve the ocular efficacy while avoiding systemic side effects of statins. Bioinspired hydrogels were prepared w...
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(1) Background: The purpose of this study was to synthesize melatonin-eluting contact lenses (CLs) and evaluate both the ocular kinetics of the released melatonin and its effect on tear volume and intraocular pressure. (2) Methods: In vitro, melatonin-eluting CLs were synthesized by using non-functionalized (HEMA) and functionalized (HEMA/APMA) mon...
Article
Given the implications of the problem of neovascularization on ocular health, as well as the growth in the number of cases, the purpose of the present study has been testing the efficacy of siRNAs (small interfering RNA) designed to silence Hypoxia Inducible Factor -1α (HIF-1α) and to demonstrate that their use stops neovascularization in a model o...
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Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity. Traditionally, the condition has been described as a noninflammatory disease; however, more recently it has been associated with ocular inflammation. Keratoconus normally de...
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(1) Background: Artemia salina is a brine shrimp containing high concentrations of dinucleotides, molecules with properties for dry eye treatment. For this reason, the purpose of the study was to evaluate the effect of the artificial tears based on an extract of Artemia salina in a rabbit dry eye model. (2) Methods: A prospective and randomized stu...
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Most irreversible blindness observed with glaucoma and retina-related ocular diseases, including age-related macular degeneration and diabetic retinopathy, have their origin in the posterior segment of the eye, making their physiopathology both complex and interconnected. In addition to the age factor, these diseases share the same mechanism disord...
Article
Purpose To evaluate comfort, visual function, and in vivo wettability after the insertion of hydrogel and silicone hydrogel contact lenses for a better understanding of how long practitioners should wait for the initial evaluation of soft contact lenses. Methods A short-term prospective, contralateral, randomized, and participant-masked study was...
Article
Significance: The performance of the Eye Refract (Luneau Technology, Chartres, France), a new instrument to perform aberrometry-based automated subjective refraction, has been previously evaluated in healthy subjects. However, its clinical implications in other ocular conditions are still unknown. Purpose: The purpose of this study was to evalua...
Article
Purpose To evaluate the changes in visual function and anterior surface aberrations during soft contact lens (SCL) wear after the instillation of hyaluronic acid (HA) eye drops with different viscosity. Methods A prospective, randomized, and participant-masked study was performed. Twenty healthy participants (25.4 ± 2.6 years) were evaluated. Hydr...
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Circadian rhythm and the molecules involved in it, such as melanopsin and melatonin, play an important role in the eye to regulate the homeostasis and even to treat some ocular conditions. As a result, many ocular pathologies like dry eye, corneal wound healing, cataracts, myopia, retinal diseases, and glaucoma are affected by this cycle. This revi...
Chapter
Nesta obra reúnem-se cerca de meia centena de textos que retratam, a partir de diferente experiências, perspetivas e olhares disciplinares, a forma como a pandemia provocada pelo vírus SARS-CoV-2 foi sentida na Universidade do Minho, a primeira universidade portuguesa a ser atingida pelos seus efeitos, a partir de 7 de março de 2020. Os contributos...
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Purpose: To compare the intersession repeatability of the Eye Refract, a new instrument to perform aberrometry-based automated subjective refraction, on healthy and keratoconus subjects. Materials and methods: A cross-sectional and randomized study was performed. A total of 64 participants were evaluated in the study, selecting one eye per parti...
Article
Significance: Scleral lenses (SLs) rest on the scleroconjunctival region, which could result in a mechanical impact in the bulbar conjunctiva that can hypothetically modify some properties of conjunctival cells. Purpose: The purpose of this study was to evaluate the differences in goblet cell density (GCD) and mucin cloud amplitude (MCA) between...
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Purpose To compare the efficacy of epithelium-off corneal collagen crosslinking (CXL) with transepithelial CXL in patients with progressive keratoconus with a follow-up of 3 years, taking into account the patients’ age and the location of the corneal ectasia. Methods In this prospective study participated 64 eyes with progressive keratoconus were...
Article
Purpose: The objective of this study was to evaluate the changes in the melatoninergic receptors of DBA/2J and C57BL/6J mice with the development of glaucoma. DBA/2J mice are widely used to study the physiopathology of glaucoma due to the similarities of their eyes to human eyes and the resulting similarity in the development of their pathology. I...
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Glaucoma is an optical neuropathy associated to a progressive degeneration of retinal ganglion cells with visual field loss and is the main cause of irreversible blindness in the world. The treatment has the aim to reduce intraocular pressure. The first therapy option is to instill drugs on the ocular surface. The main limitation of this is the red...
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Purpose To evaluate the preclinical efficacy of eye drops based on an extract of Artemia salina on the ocular surface of rabbits. Tear secretion, tear break-up time and corneal staining were measured. Material and methods A preclinical and short-term prospective study was performed. Twenty New Zealand white rabbits were divided into 5 groups, with...
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Purpose: To optimize a rabbit dry eye model induced by topical instillation of benzalkonium chloride (BAC), reduce the days of instillation of the original model by increasing the concentration of BAC from 0.1% to 0.2%. Materials and methods: An experimental, prospective, and randomized study was performed on 10 male New Zealand white rabbits, d...
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Purpose To evaluate the effect of a new nutritional supplement based on melatonin on the intraocular pressure (IOP) in normotensive subjects. Patients and methods A short-term prospective study was designed. Sixty-seven normotensive subjects were recruited. Patients were divided into two groups. The daily group (DG) (n = 18) was instructed to take...
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Purpose: To evaluate the agreement and repeatability between a new commercially available binocular open-field wavefront autorefractor, as part of the Eye Refract system, and a monocular closed-field wavefront autorefractor (VX110). Methods: A cross-sectional, randomized, and single-masked study was performed. Ninety-nine eyes of 99 healthy part...
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Purpose To evaluate the changes in the accommodative response and in the corneal and internal spherical aberration during 3 months of wear of orthokeratology lenses from the baseline. Methods Fifty children aged 8 to 17 were recruited for a prospective study and were fitted with orthokeratology lenses. Refraction without cycloplegia, high and low...
Article
Melatonin has been shown to enhance tear secretion associated with dinucleotide diadenosine tetraphosphate. This study investigated the isolated action of melatonin and its analogs, agomelatine, N-butanoyl-2-(2-methoxy-6H-isoindolo[2,1-a]indol-11-yl) ethanamine (IIK7), and 5-methoxycarbonylamino-N-cetyltryptamine (5-MCA-NAT) (10 µl at 100 µM), on t...
Article
Purpose: To assess the correlation between anterior corneal elevation (ACE) and anterior corneal astigmatism (ACA) obtained with two different topographers in healthy subjects at different corneal diameters. Methods: A retrospective, comparative, and observational study was conducted. Topography data from 305 patients obtained with the Oculus Pe...
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Purpose To evaluate the effect of the optical zone diameter (OZ) in orthokeratology contact lenses regarding the topographical profile in patients with high myopia (−4.00 D to −7.00 D) and to study its effect over the visual quality. Materials and Methods Twelve patients (18 eyes) were fitted with overnight orthokeratology (OrthoK) with a randomiz...
Article
Medical devices are under strict regulatory oversight worldwide and such regulations prioritise patient safety and efficacy over anything else. Contact lenses fall under the medical device category - a result of direct contact with the eye. Equally regulated are the contact lens care product solutions, which include cleaning and maintenance solutio...
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Purpose To evaluate changes in tear meniscus dynamics using optical coherence tomography (OCT) after the instillation of different concentrations of sodium hyaluronate (SH) ophthalmic solutions. Methods An experimental, double‐masked, randomized study was performed. Twenty‐three healthy subjects (16 women and seven men; mean age 23.57 ± 2.56 years...
Article
Objective: To characterize peculiarities of the corneoscleral geometry in healthy eyes. Methods: This is a prospective case series including 88 healthy eyes of 88 patients with an age ranging from 21 to 73 years. A complete ocular examination was performed with emphasis on the analysis of the corneoscleral topographic profile with the Fourier tr...
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Purpose We evaluate the efficacy of a new system of binocular refraction, mainly based on ocular aberrometry (EYER) and compare it with the traditional subjective refraction as gold standard. Methods A prospective, double blind, and transversal study was performed on 99 subjects (35 men, 64 women; mean age 37.22 ± 18.04 years; range, 7–70 years)....
Article
Objective: To evaluate changes in the anterior corneal curvature and aberrometry after scleral contact lens wear in keratoconus (KC) subjects with and without intracorneal ring segments (ICRS). Methods: Twenty-six subjects diagnosed with keratoconus were selected to participate in the study. Subjects were divided into 2 groups, those with ICRS (...
Article
Purpose: To evaluate the changes in the corneal thickness, anterior chamber depth and posterior corneal curvature and aberrations after scleral lens wear in keratoconus patients with and without intrastromal corneal ring segments (ICRS). Methods: Twenty-six keratoconus subjects (36.95 ± 8.95 years) were evaluated after 8 h of scleral lens wear....
Article
Purpose: To evaluate the differences in corneo-scleral topographic profile between healthy and keratoconus eyes, and their potential diagnostic ability for keratoconus detection. Methods: Prospective comparative study including 21 keratoconic eyes (11 patients) and 88 healthy eyes (88 patients). In all cases, a complete eye exam was performed in...
Article
Purpose: To analyze the variation in vertical coma and the rest of ocular aberrations before and after fitting prismatic soft contact lenses (PSCL). Methods: Thirty-seven eyes of 20 healthy subjects (24.30±2.03 years) were evaluated to analyze the variation in ocular wavefront aberrations before and after fitting PSCL of different base-down pris...
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Introduction: Dry eye disease (DED), defined as a multifactorial disease of tears and ocular surface, results in symptoms of discomfort, ocular irritation, visual disturbance and tear film instability. This syndrome is accompanied of ocular surface inflammation and it is produced by a deficient activity of the lacrimal functional unit. In addition,...
Article
Objective: To study the influence of soft contact lens (SCL) central thickness and material in keratoconus on visual function after intracorneal ring segment (ICRS) surgery. Methods: A pilot, experimental, prospective, cross-sectional and double-blind study was performed. Fourteen keratoconus patients with age range of 34.75±9.22years (7 males a...
Article
Objective: To compare, in terms of efficacy, the differences between the use of saline solution and a viscous artificial tear to fill the lens during the first month of orthokeratology wear. Methods: A pilot, double-masked, crossed, randomized, and prospective study was conducted. In this study, 20 subjects (14 males and 6 females) with a mean a...
Article
Purpose: The aim of this study was to evaluate the ability to uptake and to deliver diquafosol from commercial contact lenses (CLs) and its effect on tear secretion. Methods: For both in vitro and in vivo experiments, two commercial silicone hydrogel (Si-Hy) CLs (comfilcon A and balafilcon A) were used. The CLs were soaked overnight for 12 h in...
Article
Diadenosine tetraphosphate abbreviated Ap4A is a naturally occurring dinucleotide, which is present in most of the ocular fluids. Due to its intrinsic resistance to enzyme degradation compared to mononucleotides, this molecule can exhibit profound actions on ocular tissues, including the ocular surface, ciliary body, trabecular meshwork, and probab...
Article
Background: The aim was to evaluate the turbidity and thickness of the post-lens tear layer and its effect on visual quality in patients with keratoconus after the beginning of lens wear and before lens removal at the end of eight hours. Methods: Twenty-six patients with keratoconus (aged 36.95 ± 8.95 years) participated voluntarily in the study...
Article
Purpose: To study the levels of melatonin in the aqueous humour of normotensive and hypertensive intraocular pressure (IOP) patients and to compare them to an animal model of glaucoma. Methods: A total of 37 eyes of 37 patients who underwent cataract surgery were included in the study and were divided into normotensive patients, with IOP below 2...
Article
Purpose: Based on the relationship between keratoconus and dry eye, the aim of this study was to evaluate changes in signs and symptoms of dry eye in keratoconus patients before and after intrastromal corneal ring surgery. Methods: Fifteen keratoconus patients were enrolled in Fundación Jiménez-Díaz of Madrid and University Clinic of Optometry of t...
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Article
Dinucleoside polyphosphates comprises a group of dinucleotides formed by two nucleosides linked by a variable number of phosphates, abbreviated NpnN (where n represents the number of phosphates). These compounds are naturally occurring substances present in tears, aqueous humour and in the retina. As the consequence of their presence, these dinucle...
Article
Purpose: To evaluate the signs and symptoms of dry eye and dinucleotide secretion in tears of keratoconus patients (KC) and the potential effect of rigid gas permeable (RGP) contact lens wear. Methods: Twenty-three KC patients and forty control subjects were enrolled in this study. Signs of dry eye including tear volume, tear stability and corne...
Article
Objective: To evaluate the ocular surface temperature using an infrared thermography camera before and after wearing scleral lens in patients with keratoconus and correlate these results with the tear production and stability. Methods: A pilot, experimental, short-term study has been performed. Twenty-six patients with keratoconus (36.95±8.95 ye...
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Objective: To evaluate the differences between goblet cell density (GCD) and symptomatology after one month of orthokeratology lens wear. Methods: A pilot, short-term study was conducted. Twenty-two subjects (29.7±7.0 years old) participated voluntarily in the study. Subjects were divided into two groups: habitual silicone hydrogel contact lens...
Article
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Purpose: To evaluate the ocular surface temperature (OST) using an infrared thermography camera in Sjögren Syndrome (SS) patients compared with healthy subjects and correlate these results with the dry eye symptomatology, tear volume, stability and matrix metalloproteinase 9 (MMP-9) concentrations. Methods: Twelve patients of primary SS (46.64 ± 13...
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Purpose . To compare the ocular surface symptoms and signs in an adult population of silicone-hydrogel (Si-Hy) contact lens (CL) wearers with another modality of CL wear, overnight orthokeratology (OK). Materials and Methods . This was a prospective and comparative study in which 31 myopic subjects were fitted with the same Si-Hy CL and 23 underwen...
Article
Purpose: To evaluate the most important signs of dry eye, such as osmolarity, inflammation, and diadenosine tetraphosphate (Ap4A) concentration before and after wearing scleral lenses for 8 h in keratoconus patients. Methods: A pilot, experimental, short-term study involved 26 keratoconus patients (average age, 36.95 ± 8.95 years). They voluntar...
Article
Dry eye disease affects a substantial segment of the word population with increasing frequency. It is a multifactorial disease of the ocular surface and tear film, which causes ocular discomfort, visual disturbances, and tear instability with potential damage to the cornea and conjunctiva. Because of its multifactorial etiology, the use of differen...
Article
Background The aim was to evaluate the visual performance achieved with a new multifocal hybrid contact lens and to compare it with that obtained with two other currently available multifocal soft contact lenses.Methods This pilot prospective comparative study comprised a total of 16 presbyopic eyes of eight patients ranging in age from 43 to 58 ye...
Article
To describe the stabilization of early adult-onset myopia in three university students after initiating orthokeratology treatment with corneal refractive therapy contact lenses. Three Caucasian early adult-onset progressing myopic subjects (1 male, 2 females) were fitted with corneal refractive therapy lenses to correct myopia between -1.50 and -2....
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Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers. Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central cornea...
Article
To evaluate neophyte contact lens wearers' fitting to rigid gas permeable (RGP) contact lenses in terms of wearing time, tear volume, stability, corneal staining, and subjective ratings, over a 1-month period of time. Twenty-two young healthy subjects were enrolled for wearing RGP on a daily wear basis. The participants included in this study never...
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The purpose of this study was to evaluate the effect of orthokeratology for different degrees of myopia correction in the relative location of tangential (FT) and sagittal (FS) power errors across the central 70° of the visual field in the horizontal meridian. Thirty-four right eyes of 34 patients with a mean age of 25.2 ± 6.4 years were fitted wit...
Article
Abstract Purpose: To compare signs and symptoms of dry eye in keratoconus (KC) patients versus healthy subjects. Methods: A total of 15 KC patients (KC group, n = 15 eyes) and 16 healthy subjects (control group, 16 eyes) were enrolled in this study. The Schirmer I test with no anesthetic, tear break-up time (TBUT), corneal staining characteristics,...
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PurposeTo quantify diadenosine polyphosphate levels in tears of congenital aniridia patients to estimate the ocular surface changes associated with congenital aniridia compared to normal individuals.Methods Fifteen patients diagnosed with congenital aniridia and a control group of forty volunteers were studied. Tears were collected to quantify the...
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Purpose: We have investigated the effect of melatonin and its analogues on rabbit corneal epithelial wound healing. Methods: New Zealand rabbits were anaesthetised and wounds were made by placing Whatman paper discs soaked in n-heptanol on the cornea. Melatonin and analogues (all 10 nmol) were instilled. Wound diameter was measured every 2 hours...
Article
To compare the clinical performance of the Clearkone hybrid contact lens for the treatment of keratoconus against the habitual contact lens of the patients. A total of 33 eyes from 18 patients were fitted with the Clearkone. High- and low-contrast visual acuity (HCVA and LCVA), central corneal thickness (CCT), and contrast sensitivity acuity (CSF)...
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Objetivo Evaluar el posible uso de las lentes de contacto blandas (LC) para mejorar la función secretagoga del diadenosín tetrafosfato (Ap4A), de cara a promover la secreción lagrimal. Métodos Se utilizaron dos lentes de contacto convencionales de hidrogel (Omafilcon A y Ocufilcon D) y dos lentes de contacto de hidrogel de silicona (SiH) (Comfilco...
Article
Purpose: To study the concentrations of diadenosine polyphosphates in the ocular surface after PRK and LASIK. Methods: Sixty-one patients (30 males and 31 females) with ages ranging from 20 to 63 (34.04 ± 9.13 years) were recruited in Balear Institute of Ophthalmology, Palma de Mallorca, Spain. LASIK was performed in 92 eyes of 46 patients and P...