Antonio Ferreras

University of Zaragoza, Caesaraugusta, Aragon, Spain

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Publications (119)173.07 Total impact

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    ABSTRACT: To compare the diagnostic performance of different segmentations of the nerve fiber layer (NFL) thickness measurements using an artificial neural network and to define the optimal number of sectors with best diagnostic ability for glaucoma diagnosis.
    Journal of glaucoma. 07/2014;
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    ABSTRACT: Objective: To compare the 3-year outcomes of two different dosing regimens used for wet age-related macular degeneration patients treated exclusively with ranibizumab. Methods: A Treat and extend (TAE) dosing group (n=30) and a treat and observe (TAO) dosing group (n=30) were retrospectively recorded. Survival rates (SR) based on visual acuity (VA) outcomes were calculated and analyzed. The central retinal thickness measured with spectral domain (SD) optical coherence tomography (OCT) and number of intravitreal injections performed in both groups were also compared. Results: At 36 months, Kaplan-Meier SRs were 90.9% for TAE and 89.7% for TAO (loss<0.3 units logMAR). VA improved in 42.4% and 24.1%, while 33.4% and 62.1% remained stable for TAE and TAO groups, respectively. No final VA differences were found between both therapeutic strategies (p>0.05, log-rank test). No differences were found in the final number of injections received: 20.31±6.6 in TAE group vs. 18.41 ± 7.1 in TAO group (p=0.19). Conclusions: Both approaches showed similar number of injections and visual outcomes.
    Clinical and Experimental Ophthalmology 02/2014; 5. · 1.96 Impact Factor
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    ABSTRACT: Purpose/methods To present the neuro-ophthalmology examination in 5 spastic ataxia of Charlevoix-Saguenay (ARSACS) patients showing significant increases in retinal nerve fiber layer (RNFL) thickness. Results/conclusions All patients showed abnormal visual fields, normal optic discs with increased visibility of RNFL in color stereo-photographs, normal examination with Heidelberg Retina Tomography instrument, and moderate to markedly increased RNFL thickness in Cirrus Optical Coherence Tomography evaluation (average thickness: 119 to 220 microns). We found evidence that RNFL hypertrophy may be an alternative funduscopic finding to the hypermyelinated retinal fibers in previous reports. A revision of ARSACS diagnostic criteria, particularly with regard to retinal alterations, is necessary.
    Archivos de la Sociedad Espanola de Oftalmologia 01/2014; 89(5):207–211.
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    ABSTRACT: Objective. To evaluate the relationship between spectral-domain optical coherence tomography (OCT) and standard automated perimetry (SAP) in healthy and glaucoma individuals. Methods. The sample comprised 338 individuals divided into 2 groups according to intraocular pressure and visual field outcomes. All participants underwent a reliable SAP and imaging of the optic nerve head with the Cirrus OCT. Pearson correlations were calculated between threshold sensitivity values of SAP (converted to linear scale) and OCT parameters. Results. Mean age did not differ between the control and glaucoma groups (59.55 ± 9.7 years and 61.05 ± 9.4 years, resp.; P = 0.15). Significant differences were found for the threshold sensitivities at each of the 52 points evaluated with SAP (P < 0.001) and the peripapillary retinal nerve fiber layer (RNFL) thicknesses, except at 3 and 9 clock-hour positions between both groups. Mild to moderate correlations (ranging between 0.286 and 0.593; P < 0.001) were observed between SAP and most OCT parameters in the glaucoma group. The strongest correlations were found between the inferior RNFL thickness and the superior hemifield points. The healthy group showed lower and weaker correlations than the glaucoma group. Conclusions. Peripapillary RNFL thickness measured with Cirrus OCT showed mild to moderate correlations with SAP in glaucoma patients.
    BioMed Research International 01/2014; 2014:514948. · 2.88 Impact Factor
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    ABSTRACT: Objective. To compare the equivalent optic nerve head (OHN) parameters obtained with confocal scanning laser ophthalmoscopy (HRT3) and spectral-domain optical coherence tomography (OCT) in healthy and glaucoma patients. Methods. One hundred and eighty-two consecutive healthy subjects and 156 patients with open-angle glaucoma were divided into 2 groups according to intraocular pressure and visual field outcomes. All participants underwent imaging of the ONH with the HRT3 and the Cirrus OCT. The ONH parameters and the receiver operating characteristic (ROC) curves were compared between both groups. Results. Mean age did not differ between the normal and glaucoma groups (59.55 ± 9.7 years and 61.05 ± 9.4 years, resp.; P = 0.15). Rim area, average cup-to-disc (C/D) ratio, vertical C/D ratio, and cup volume were different between both instruments (P < 0.001). All equivalent ONH parameters, except disc area, were different between both groups (P < 0.001). The best areas under the ROC curve were observed for vertical C/D ratio (0.980 for OCT and 0.942 for HRT3; P = 0.11). Sensitivities at 95% fixed-specificities of OCT parameters were higher than those of HRT3. Conclusions. Equivalent ONH parameters of Cirrus OCT and HRT3 are different and cannot be used interchangeably. ONH parameters measured with OCT yielded a slightly better diagnostic performance.
    BioMed Research International 01/2014; 2014:275654. · 2.88 Impact Factor
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    ABSTRACT: Background: To represent and interpret the three-dimensional (3D) geometry and the distribution of the axonal damage to the retinal nerve fiber layer (RNFL) in patients with multiple sclerosis (MS) compared with healthy subjects. To analyze alterations in RNFL morphology in eyes of MS patients with or without previous episodes of optic neuritis (ON). Methods: MS patients (n = 122) and age-matched healthy subjects (n = 108) were enrolled. The Spectralis optical coherence tomography system was used to determine the circumpapillary RNFL thickness. The 768 RNFL thickness measurements were used to evaluate thickness measurements in patients with or without antecedent ON and to design a 3D reconstruction of the RNFL thickness representing the mechanobiologic tissue response to neurodegeneration caused by MS and ON episodes. Results: RNFL thickness was decreased in MS patients, and was higher in the MS group with previous ON. Statistical analysis and 3D RNFL reconstruction revealed greater damage to the ganglionar cells in the superonasal RNFL area (101.77 µm in MS vs. 125.47 µm in healthy subjects) and in the inferotemporal RNFL (119.05 µm in MS eyes and 149.26 µm in healthy eyes). Conclusions: The 3D representation of RNFL thickness based on measurements allows physicians to better observe damage in the temporal areas, especially in patients with previous ON.
    Ophthalmic Research 06/2013; 50(1):72-81. · 1.56 Impact Factor
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    ABSTRACT: OBJECTIVE: To study the correlation between the sensitivity threshold values of the different points assessed by the Humphrey visual field analyzer (24-2 Swedish interactive threshold algorithm [SITA] standard strategy) in glaucoma patients. SUBJETS, MATERIAL AND METHODS: Prospective cross-sectorial study. One-hundred and four eyes of 104 glaucoma patients, defined by the appearance of the optic nerve head, were evaluated. Retinal threshold sensitivity points of standard automated perimetry (SA) with SITA standard 24-2 program were obtained. The upper and the lower hemifields were studied separately. Pearson correlation coefficients were calculated between the mean threshold sensitivity value at each point of the visual hemifield and the rest of the threshold points in the same hemifield. RESULTS: Perimetric correlation maps between retinal threshold sensitivity values in the same hemifield were obtained. Most of the points showed moderate to high correlations (r≥0.65. P<0.001) with neighboring points and distant points in the same hemifield. CONCLUSIONS: There is a functional relationship between neighboring and distant points in Humphrey Visual Field Analyzer (SITA Standard 24-2) in glaucoma patients. This correlation is related to the anatomical arrangement of ganglion cell axons. This fact enables perimetric patterns of glaucoma defects to be obtained.
    Archivos de la Sociedad Espanola de Oftalmologia 06/2013; 88(6):223-230.
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    ABSTRACT: To present the neuro-ophthalmology examination in 5 spastic ataxia of Charlevoix-Saguenay (ARSACS) patients showing significant increases in retinal nerve fiber layer (RNFL) thickness. All patients showed abnormal visual fields, normal optic discs with increased visibility of RNFL in color stereo-photographs, normal examination with Heidelberg Retina Tomography instrument, and moderate to markedly increased RNFL thickness in Cirrus Optical Coherence Tomography evaluation (average thickness: 119 to 220 microns). We found evidence that RNFL hypertrophy may be an alternative funduscopic finding to the hypermyelinated retinal fibers in previous reports. A revision of ARSACS diagnostic criteria, particularly with regard to retinal alterations, is necessary.
    Archivos de la Sociedad Espanola de Oftalmologia 04/2013;
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    ABSTRACT: Purpose. To evaluate the ability of frequency-doubling technology (FDT) perimetry in detecting visual field defects in young adults with type I diabetes prior to retinopathy or with minor retinovascular changes. Methods. This comparative cross-sectional study included 30 healthy subjects and 73 age-matched patients with type I diabetes mellitus. All subjects underwent a full ocular examination including an FDT with the threshold C-20-5 strategy. Only one eye per subject was randomly included in the statistical analysis. FDT results and time to perform the test were compared between the groups. Results. The mean age was 27.1 years in the control group and 26.6 years in the diabetic group (P = 0.875). The mean period from the onset of diabetes was 12.6 ± 6.7 years, while minimal retinovascular changes were observed in 18 eyes. Mean deviation of FDT did not differ between the groups. Although global indices of FDT were within normal limits, pattern standard deviation of FDT was higher in the diabetic group (P = 0.035). The area under the receiver operating characteristic curve was 0.647 for pattern standard deviation of FDT (standard error = 0.052; P = 0.017). Conclusion. FDT can detect retinal dysfunctions in diabetic patients prior to the onset of significant vascular complications.
    BioMed research international. 01/2013; 2013:341269.
  • Investigative ophthalmology & visual science 01/2013; 54(3):2011-2. · 3.43 Impact Factor
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    ABSTRACT: PURPOSE: To evaluate and compare the ability of a new method for measuring hemoglobin (Hb) levels at the optic nerve head (ONH) to that of visual field evaluation, scanning laser ophthalmoscopy (HRT), scanning laser polarimetry (GDx), and optical coherence tomography (OCT) for diagnosing glaucoma. Methods: Healthy eyes (n=102) and glaucoma eyes (n=101) underwent reliable Oculus Spark perimetry, and imaging with the HRT, GDx, and Cirrus OCT. In addition, ONH color images were acquired with a non-mydriatic fundus camera. The Laguna ONhE program was then used to calculate the Hb amount in each of 24 sectors of the ONH. Sensitivities at 95% fixed specificity, diagnostic agreement, and linear correlations between parameters with the best diagnostic ability were calculated RESULTS: The Glaucoma Discriminant Function (GDF) of the Laguna program, evaluating Hb in the vertical intermediate sectors and center/periphery Hb amount slope, yielded an 89.1% sensitivity and 95.1% specificity, which was superior or similar to the other tests. The best GDF diagnostic agreement was for the OCT-vertical cup-to-disc (C/D) ratio (kappa = 0.772) and the final phase Spark pattern standard deviation (kappa =0.672). Hb levels strongly correlated with the Spark mean sensitivity (first phase,0.70; final phase, 0.71). Hb also correlated well with the Reinhard OW Burk discriminant function of the HRT (0.56), Nerve Fiber Indicator of GDx (-0.64), and vertical CD ratio of OCT (0.71). Conclusion: Hb levels evaluated by color analysis of ONH photographs had high reproducibility, a high sensitivity-specificity balance, and moderate to strong agreement with other structural and functional tests.
    Investigative ophthalmology & visual science 12/2012; · 3.43 Impact Factor
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    The British journal of ophthalmology 10/2012; · 2.92 Impact Factor
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    ABSTRACT: Purpose To determine the variability of retinal nerve fiber layer (RNFL) parameters measured with scanning laser polarimetry (SLP) with enhanced corneal compensator (GDx ECC) in healthy eyes. Methods Eighty-two healthy individuals were prospectively selected. Only one eye per subject was randomly included in the study. All participants had intraocular pressure less than 21 mmHg and normal standard automated perimetry (Humphrey 24-2 SITA Standard). Peripapillary RNFL parameters were measured using the GDxPRO (Carl Zeiss Meditec, Dublin, CA) 3 consecutive times on the same session. Left eye data were converted to a right eye format. The same operator performed all acquisitions with the same device. Intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability were calculated for all SLP parameters: TSNIT average, superior average, inferior average, TSNIT standard deviation and the nerve fiber indicator (NFI). Results Mean age was 56.08 ± 9.4 years. The ICC was higher than 0.928 for all SLP parameters. The TSNIT average had the highest ICC (0.967), while the TSNIT standard deviation showed the lowest ICC (0.928). The COVs ranged from 2.4% (TSNIT average) to 21.8% (NFI). Test-retest variability was 6.55 for the NFI and 2.51 for the TSNIT average. Conclusion The reproducibility of RNFL measurements acquired with the GDxPRO was excellent. Variability was higher for NFI than for other SLP parameters.
    Acta ophthalmologica 09/2012; 90(s249). · 2.44 Impact Factor
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    ABSTRACT: Purpose To report our case report with sustained-release dexamethasone 0.7 mg intravitreal implant (Ozurdex®; Allergan, Inc., Irvine, CA) in retinal vein occlusion with macular edema Methods A 81-years old male patient with recent retinal vein occlusion with macular edema treated with sustained-release dexamethasone 0.7 mg intravitreal implant and cataract surgery was performed. On initial examination, the right best-corrected visual acuity (BCVA) was 0,1. Right fundoscopy revealed retinal hemorrhage in the superior quadrant of the retina. The fluorescein retinal angiography showed a delay of filling time and spectral domain optical coherence tomography (Spectralis SD-OCT; Heidelberg Engineering, Heidelberg, Germany) showed macular edema 485 μm Results The patient was treated with two dexamethasone 0.7 mg intravitreal implant and cataract surgery in one year. During the first six months after implant the right BCVA was 0,4 and OCT: 294 μm. At six months the macular edema increased 335 μm and we treated with the second implant, the macular edema improved 280μm but not the BCVA and we realized cataract surgery and BCVA was improved to 0.5. Conclusion The dexamethasone drug delivery system is one of the most recent additions to the armamentarium against macular edema, and is intriguing for its potency, dose consistency, potential for extended duration of action, and favorable safety profile but can accelerate cataract surgery.In patients with macular edema in retinal vein occlusion, sustained-release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option to control macular edema
    Acta ophthalmologica 09/2012; 90(s249). · 2.44 Impact Factor
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    ABSTRACT: Purpose To assess the ability of optic nerve head (ONH) parameters measured with 2 different imaging technologies to discriminate between normal and glaucoma patients with visual field losses. Methods Sixty-seven normal eyes and 43 glaucoma patients were consecutive and prospectively selected. Participants were classified depending on the results of standard automated perimetry (SAP) and intraocular pressure. All of them underwent a comprehensive ophthalmic examination, at least 2 reliable SAP tests, and imaging of the ONH with the Heidelberg Retina Tomograph 3 (HRT; Heidelberg Engineering, Heidelberg, Germany) and with Cirrus OCT (Carl Zeiss Meditec, Dublin, Ca). Only one eye per subject was randomly included in the statistical analysis. The areas under the receiver operating characteristic curve (AUCs) were plotted and sensitivity-specificity pairs compared. Results The mean age was 55.713.6 years for the normal group and 59.16.2 years for the glaucoma group (p=0.133). The mean deviation of SAP was -0.71.2 dB and -5.96.1 dB (p
    Acta ophthalmologica 09/2012; 90(s249). · 2.44 Impact Factor
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    ABSTRACT: Comparison of Keeler Pulsair EasyEye tonometer and Ocular Response Analyzer for measuring intraocular pressure in healthy eyes Carmen Lopez-De La Fuentea,, Ana Sanchez-Canoa, Antonio Ferrerasbc, Isabel Fuertes-Lazarobc a Applied Physics Department, University of Zaragoza, Zaragoza, Spain b Department of Ophthalmology, Miguel Servet University Hospital, Aragon Health Sciences Institute, Zaragoza, Spain c Department of Surgery, Ginecology and Obstetrics, University of Zaragoza, Zaragoza, Spain Keywords Intraocular pressure. Noncontact tonometry. Glaucoma. Corneal biomechanics. Abstract Purpose To evaluate the relationship between intraocular pressure (IOP) measurements obtained with Pulsair EasyEye (PEE) and Ocular Response Analyser (ORA) in healthy patients. Methods Sixty-five eyes from 65 patients underwent a full optometric examination, including central corneal thickness (CCT), and IOP measured with PEE and ORA. Differences between IOP measurements between both tonometers were analyzed. Pearson correlation coefficients between IOP values and ORA corneal biomechanics parameters were also obtained. Results Statistically significant differences were found between IOP of PEE (IOPk) and Goldmann-corrected IOP of ORA (IOPg; p=0.001). IOPk and corneal resistance-corrected IOP of ORA (IOPcc) were also found to differ significantly (p=0.025). Mean differences between IOPg-IOPk, IOPcc-IOPk and IOPg-IOPcc were 0.71±1.66, 0.70±2.46 and 0.01±1.54mmHg (mean±standard deviation), respectively. Pearson correlation coefficients indicated that IOPk, IOPg, and IOPcc were significantly correlated among them (p<0.001): r=0.816 for IOPk-IOPg, r=0.826 for IOPcc-IOPg and r=0.587 IOPcc-IOPk. IOPk and IOPg were linearly associated with corneal resistance factor (CRF; r=0.626 and r=0.619, respectively) and with CCT (r=0.531 and r=0.579, respectively). IOPcc had a linear relationship with corneal hysteresis (CH) (r=−0.482) and similar results were found between CRF and CH (r=0.841), CRF and CCT (r=0.681) or between CH and CCT (r=0.466). Conclusions Differences between mean values of IOP measured with PEE and ORA are statistically significant, with ORA tonometer taking higher IOP values than PEE in most of the cases. IOPk, IOPcc and IOPg have, al least, moderate positive linear correlations and ORA biomechanics parameters CRF, CH and CCT have a linear positive relation between them.
    Journal of Optometry 07/2012; 2012(5):139-46.
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    ABSTRACT: To determine whether retrobulbar blood flow (RBF) velocities are predictive of conversion to glaucoma. A total of 262 glaucoma suspects were prospectively selected. Participants had normal visual field, increased intraocular pressure, and glaucomatous optic disc appearance at baseline. Topographic analysis of the optic nerve head was performed using a confocal laser scanning ophthalmoscope and the blood flow velocity of retrobulbar vessels was measured by color Doppler imaging. Conversion to glaucoma was assessed according to the changes in the color-coded Moorfields Regression Analysis (MRA) classification of the confocal laser scanning system during a 48-month follow-up period. Survival curves and hazard ratios (HRs) for the association between RBF parameters and conversion to glaucoma were calculated. End-diastolic velocity and mean velocity in the ophthalmic artery were reduced in subjects that converted to glaucoma based on MRA (36 individuals, 13.7%), while resistivity (RI) and pulsatility indices were increased in the same vessel. Patients with RI values lower than 0.75 in the ophthalmic artery had a survival rate (MRA-converters versus nonconverters) of 93.9%, whereas individuals with RI values greater than 0.75 had a survival rate of 81.7% (HR = 3.306; P = 0.002). Abnormal RBF velocities measured by color Doppler ultrasound may be a risk factor for conversion to glaucoma. An RI value higher than 0.75 in the ophthalmic artery was associated with the development of glaucoma.
    Investigative ophthalmology & visual science 05/2012; 53(7):3875-84. · 3.43 Impact Factor
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    ABSTRACT: To perform a longitudinal multivariate analysis of the ability of Moorfields Regression Analysis (MRA) to predict the onset of glaucoma in a population of patients with suspected glaucoma due to appearance of the optic nerve head. Prospective longitudinal evaluation of a diagnostic test. Single, randomly selected eye of prospectively recruited patients with suspected glaucoma based on the optic nerve head appearance on stereophotographs and normal baseline visual field results. The MRA was evaluated at baseline (Heidelberg Retina Tomograph; Heidelberg Engineering, Dossenheim, Germany), and visual field tests were repeated every 6 months. A longitudinal multivariate proportional hazard ratio (HR) analysis was performed, and likelihood ratios and positive and negative predictive values were compared. Onset of visual field losses. The study included 230 eyes that were followed up during a mean period of 62±14 months, ranging from 4 to 7 years. The predicted HR (for onset of visual field losses) of the MRA temporal-inferior sector outside normal limits was 3.65 (95% confidence interval [CI], 2.32-5.75; P < 0.0001). An MRA temporal-superior sector outside normal limits had an HR of 3.43 (95% CI, 2.21-5.32; P < 0.0001). The temporal-inferior and temporal-superior positions of the MRA are highly predictive for the onset of visual field loss in glaucoma suspects.
    Ophthalmology 05/2012; 119(8):1558-62. · 5.56 Impact Factor
  • Archivos de la Sociedad Espanola de Oftalmologia 01/2012; 87(1):1-2.
  • Archivos de la Sociedad Espanola de Oftalmologia 01/2012; 87(1):1–2.

Publication Stats

309 Citations
173.07 Total Impact Points

Institutions

  • 2008–2014
    • University of Zaragoza
      • Department of Applied Physics
      Caesaraugusta, Aragon, Spain
    • Istituto di Cura e Cura a Carattere Scientifico Basilicata
      Rionero in Vulture, Basilicate, Italy
  • 2002–2014
    • Hospital Universitario Miguel Servet
      • Servicio de Neurología
      Caesaraugusta, Aragon, Spain
  • 2012–2013
    • Universidad de La Laguna
      San Cristóbal de La Laguna, Canary Islands, Spain
  • 2008–2012
    • Aragon Health Sciences Institute
      Caesaraugusta, Aragon, Spain
  • 2011
    • Azienda Ospedaliera San Paolo - Polo Universitario
      Milano, Lombardy, Italy