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Dive into the research topics where Guillermo Salcedo-Villanueva is active.

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Featured researches published by Guillermo Salcedo-Villanueva.


Journal of Aapos | 2014

Comparison of iridocorneal angle in infants with retinopathy of prematurity and healthy infants using spectral domain optical coherence tomography.

Linda A. Cernichiaro-Espinosa; Maria M. García-Huerta; Veronica Giordano; Samantha Salinas-Longoria; Rafael Romero-Vera; Gerardo Garcia-Aguirre; Guillermo Salcedo-Villanueva; Hugo Quiroz-Mercado; Maria Ana Martinez-Castellanos

PURPOSE To compare measurements and morphologic characteristics of the iridocorneal angle in preterm infants with retinopathy of prematurity (ROP) and healthy infants using spectral domain optical coherence tomography (SD-OCT). METHODS In this observational, case-control study, the eyes of children with ROP and healthy controls under 1 year old were imaged using SD-OCT without sedation to capture the iridocorneal angle. The ROP staging was made by a pediatric retinal specialist. The following measurements were analyzed with custom software: angle opening distance (AOD500) at 500 μm; angle opening in degrees (AOG); and angle recess area (ARA750). RESULTS A total of 27 eyes of 14 children with ROP and 21 of 13 children without ROP were included. The mean gestational age of children in the ROP group was 30 weeks; of the controls, 35 weeks. The mean birth weight in the ROP group was 1,545 g; in the non-ROP group 2,100 g. Mean age at the time of the study was 18.1 (ROP group) vs 25.7 weeks (non-ROP). In the ROP group AOD500 was 477 μm (95% CI, 358-597 μm), AOG was 37.3° (95% CI, 30.4°-44.3°), and ARA750 was 231 mm(2) (CI 95%, 171-291 mm(2)). The same parameters on the non-ROP group were 400 μm (CI 95% 333-468 μm), 34.7° (CI 95% 30.4°-39°), and 203 mm(2) (95% CI, 171-236 mm(2)). The iris showed a more convex pattern on eyes with ROP (56% vs 23%). CONCLUSIONS In this study cohort, children with ROP showed higher AOD500, AOG, and ARA750, perhaps because of different patterns of physiological development in children with ROP.


Retina-the Journal of Retinal and Vitreous Diseases | 2016

ANATOMICAL AND FUNCTIONAL OUTCOMES OF SYMPTOMATIC IDIOPATHIC VITREOMACULAR TRACTION: A Natural History Study From the Pan American Collaborative Retina Study Group

Lihteh Wu; Marcelo Zas; Maria H. Berrocal; J. Fernando Arevalo; Marta S. Figueroa; Francisco J. Rodriguez; Martin Serrano; Federico Graue; Arturo Alezzandrini; Roberto Gallego-Pinazo; José A. Roca; Matias Iglicki; José Dalma-Weishauz; Igor Kozak; Alberto Collado; Josep Badal; Mauricio Maia; Guillermo Salcedo-Villanueva; Hugo Quiroz-Mercado; Jans Fromow-Guerra; David Lozano-Rechy; Marcos Pereira de Ávila; Jay Chhablani

Purpose: To describe the natural history of eyes with symptomatic idiopathic vitreomacular traction (VMT). Methods: Retrospective multicenter study of 168 eyes with spectral-domain optical coherence tomography (SD-OCT) findings consistent with idiopathic VMT. All eyes were graded according to SD-OCT findings. Grade 1 was defined as incomplete cortical vitreous separation with foveal attachment. Grade 2 was defined as Grade 1 plus intraretinal cysts or clefts. Grade 3 was defined as Grade 2 plus a foveal detachment. All patients were followed for at least 6 months. Results: There were 168 patients (51 men) with a mean age of 68.8 ± 10.7 years. Patients were followed for a mean of 22.7 ± 20.1 months. The mean duration of symptoms before the initial presentation was 3.65 ± 5.42 months. At baseline, 72 eyes had Grade 1, 74 eyes had Grade 2, and 22 eyes had Grade 3 SD-OCT findings. Over the follow-up period, 36 eyes (21.4%) had spontaneous resolution of the VMT with normalization of the foveal anatomy. The mean time to resolution was 12.3 ± 12.6 months. An unfavorable anatomical outcome occurred in 7.7% (13 of 168) of the eyes, with 6 eyes developing a lamellar macular hole and 7 eyes developing a full-thickness macular hole. This occurred at a mean of 10.3 ± 10.7 months after the presentation. Subgroup analysis based on baseline SD-OCT grade showed that 4.1% (3 of 73) of Grade 1 eyes compared with 6.8% (5 of 74) of Grade 2 eyes, and 23.8% (5 of 21) of Grade 3 eyes developed a full-thickness macular hole or lamellar macular hole (P = 0.0109, chi-square test). In the remaining 119 eyes, at the last follow-up, 65 eyes had Grade 1, 42 eyes had Grade 2, and 12 eyes had Grade 3 VMT. On average, the best-corrected visual acuity improved from 0.40 ± 0.35 logarithm of the minimum angle of resolution (Snellen, 20/50) at baseline to 0.35 ± 0.36 logarithm of the minimum angle of resolution (Snellen, 20/45; P = 0.0372), and the mean central macular thickness improved from 350 ± 132 &mgr;m to 323 ± 121 &mgr;m. Conclusion: Spontaneous resolution of VMT occurred in 21.4% (36 of 168) of eyes after a mean follow-up of 11.4 ± 12.6 months. An unfavorable anatomical outcome occurred in 7.7% (13 of 168) of eyes. The baseline SD-OCT grade may predict the progression to full-thickness macular hole.


British Journal of Ophthalmology | 2016

Intravitreal bevacizumab for diabetic macular oedema: 5-year results of the Pan-American Collaborative Retina Study group

J. Fernando Arevalo; Andres F. Lasave; Lihteh Wu; Dhariana Acon; Michel Eid Farah; Roberto Gallego-Pinazo; Arturo Alezzandrini; Veronica Fortuna; Hugo Quiroz-Mercado; Guillermo Salcedo-Villanueva; Mauricio Maia; Martin Serrano; Sergio Rojas

Background/aims To report the long-term anatomical and functional outcomes of patients with centre-involved diabetic macular oedema (DME) treated with intravitreal bevacizumab (IVB). Methods Retrospective case series. Patients diagnosed with centre-involved DME that were treated with at least one injection of 1.25 mg IVB and had a minimum follow-up of 60 months. Patients underwent measurement of best-corrected visual acuity (BCVA), ophthalmoscopy, optical coherence tomography and fluorescein angiography at baseline, 6-month, 12-month, 24-month, 36-month, 48-month and 60-month visits. The paired samples t test was used to compare the central macular thickness (CMT) and BCVA with baseline values. Statistical significance was indicated by p<0.05. Results Two hundred and one consecutive patients (296 eyes) were included. The mean number of IVB injections per eye was 8.4±7.1 (range: 1–47 injections). At 5 years, the BCVA remained stable at 20/100 (logarithm of the minimum angle of resolution=0.7±0.4). Eighty-six (29%) eyes improved ≥2 lines of BCVA, 129 (43.6%) eyes remained stable and 81 (27.4%) eyes lost ≥2 lines of BCVA at 60 months. Mean CMT decreased from 403.5±142.2 μm at baseline to 313.7±117.7 μm over 5 years follow-up (p≤0.0001). Conclusions The early visual gains due to IVB were not maintained 5 years after treatment.


Seminars in Ophthalmology | 2015

Enhanced High-Density Line Spectral-Domain Optical Coherence Tomography Imaging of the Vitreoretinal Interface: Description of Selected Cases.

Yu Cheol Kim; Mariana Harasawa; Guillermo Salcedo-Villanueva; Frank S Siringo; Miguel Paciuc-Beja; Jeffrey L. Olson; Naresh Mandava; Hugo Quiroz-Mercado

Abstract Purpose: We introduce a new method to observe the morphologic features of the vitreous with spectral-domain optical coherence tomography (SD-OCT) by evaluating and describing the posterior vitreous structure of various selected cases using enhanced high-density (HD) line mode. Methods: This is a descriptive case series of SD-OCT images with enhanced HD line at Denver Health Medical Center, University of Colorado School of Medicine, in 2014. The medical records with ocular images for these patients were analyzed. Results: Enhanced HD line in vitreoretinal mode with SD-OCT offered wide images with well-visible vitreoretinal interface. The posterior precortical vitreous pocket (PPVP), often mistaken as a posterior vitreous detachment on standard retina-based cross line mode, was easily identified. Vitreomacular adhesion and traction, absence or presence of connecting channels between PPVP and Cloquet’s canal, liquefied vitreous lacuna, and emulsified silicone oil droplet-layer could be observed. Conclusions: SD-OCT using enhanced HD line in vitreoretinal mode enables clear visualization of the posterior vitreous structure and often reclassifies patients previously thought to have a posterior vitreous detachment.


Clinical Ophthalmology | 2016

Long-term follow-up of patients with choroidal neovascularization due to angioid streaks

Maria Guadalupe Martinez-Serrano; Abelardo Rodríguez-Reyes; Jose Luis Guerrero-Naranjo; Guillermo Salcedo-Villanueva; Jans Fromow-Guerra; Gerardo Garcia-Aguirre; Virgilio Morales-Canton; Raul Velez-Montoya

Background The following case series describes the long-term anatomical and functional outcome of a group of seven patients with choroidal neovascularization (CNV), secondary to angioid streaks (AS), who were treated with antiangiogenic drugs in a pro re nata (PRN) regimen. After the 4-year mark, visual acuity tends to return to pretreatment level. Treatment delays and lack of awareness and self-referral by the patients are believed to be the cause of the PRN regimen failure. Purpose To assess the long-term outcomes (>4 years) of patients with CNV due to AS treated with a PRN regimen of antiangiogenic. Methods This was a retrospective, case series, single-center study. We reviewed the electronic medical records from patients with CNV due to AS. From each record, we noted general demographic data and relevant medical history; clinical presentation, changes in best-corrected visual acuity (BCVA) over time, optical coherent tomography parameters, treatment and retreatment details, and systemic associations. Changes in BCVA and central macular thickness were assessed with a Wilcoxon two-sample test, with an alpha value of ≤0.05 for statistical significance. Results The mean follow-up time was 53.8±26.8 months. BCVA at baseline was: 1.001±0.62 logMAR; at the end of follow-up: 0.996±0.56 logMAR (P=0.9). Central macular thickness at baseline was: 360.85±173.82 μm; at the end of follow-up: 323.85±100.34 μm (P=0.6). Mean number of intravitreal angiogenic drugs: 6±4.16 injections (range 4–15). Mean time between injections was 3.8±2.7 months (range 1.9–5.8 months). Conclusion Despite initial anatomical and functional improvement, patients at the end of the follow-up had no visual improvement after a pro re nata regimen of antiangiogenic drugs. The amount of retreatments, number of recurrences, and time between intravitreal injections were similar to previous reports with shorter follow-up.


BMC Ophthalmology | 2010

Comparison of the biometric values obtained by two different A-mode ultrasound devices (Eye Cubed vs. PalmScan): A Transversal, descriptive, and comparative study

Raul Velez-Montoya; Eugene M. Shusterman; Miriam J. Lopez-Miranda; Mariana Mayorquin-Ruiz; Guillermo Salcedo-Villanueva; Hugo Quiroz-Mercado; Virgilio Morales-Canton

BackgroundTo assess the reliability of the measurements obtained with the PalmScan™, when compared with another standardized A-mode ultrasound device, and assess the consistency and correlation between the two methods.MethodsTransversal, descriptive, and comparative study. We recorded the axial length (AL), anterior chamber depth (ACD) and lens thickness (LT) obtained with two A-mode ultrasounds (PalmScan™ A2000 and Eye Cubed™) using an immersion technique. We compared the measurements with a two-sample t-test. Agreement between the two devices was assessed with Bland-Altman plots and 95% limits of agreement.Results70 eyes of 70 patients were enrolled in this study. The measurements with the Eye Cubed™ of AL and ACD were shorter than the measurements taken by the PalmScan™. The differences were not statistically significant regarding AL (p < 0.4) but significant regarding ACD (p < 0.001). The highest agreement between the two devices was obtained during LT measurement. The PalmScan™ measurements were shorter, but not statistically significantly (p < 0.2).ConclusionsThe values of AL and LT, obtained with both devices are not identical, but within the limits of agreement. The agreement is not affected by the magnitude of the ocular dimensions (but only between range of 20 mm to 27 mm of AL and 3.5 mm to 5.7 mm of LT). A correction of about 0.5 D could be considered if an intraocular lens is being calculated. However due to the large variability of the results, the authors recommend discretion in using this conversion factor, and to adjust the power of the intraocular lenses based upon the personal experience of the surgeon.


Journal of Ophthalmology | 2017

Changes in Retinal and Choroidal Vascular Blood Flow after Oral Sildenafil: An Optical Coherence Tomography Angiography Study

David Berrones; Guillermo Salcedo-Villanueva; Virgilio Morales-Canton; Raul Velez-Montoya

Purpose To describe changes in the retina and choroidal flow by optical coherence tomography angiography (OCT-A) after a single dose of oral sildenafil. Method A case-control study. Patients in the study group received 50 mg of oral sildenafil. Patients in the control group received a sham pill. Retinal and choroidal images were obtained at baseline (before pill ingestion) and 1 hour after ingestion. Central macular and choroidal thickness, choroidal and outer retina flow, and the retinal and choroidal vascular density were compared using a Mann-Whitney U test. Results Twenty eyes were enrolled into the study group and 10 eyes in the control group. There was a significant difference in central choroidal thickness and outer retina blood flow between groups after 1 hour of sildenafil ingestion (p < 0.01). There were no differences in central macular thickness, choroidal flow, and retinal vascular density among groups. Conclusions A single dose of oral sildenafil increases choroidal thickness, probably due to sildenafil-induced vasodilation.


Journal of Clinical & Experimental Ophthalmology | 2016

Effect of Caffeine Intake on Retinal Microsurgical Performance

Andrea Elizabeth Arriola-Lopez; Virgilio Morales-Canton; Gerardo Garcia-Aguirre; Guillermo Salcedo-Villanueva; Jose Dalma-Weiszhausz; Raul Velez-Montoya

Objective: To assess the effects of prior caffeine intake on tremor control and internal limiting membrane peeling proficiency of experienced retinal surgeons using a microsurgical simulator. Methods: Experienced vitreoretinal surgeons were included. On two separate days, each subject underwent a test on a level 4 anti-tremor test and internal limiting membrane peeling test on a microsurgical simulator (Eye-Si/ Series 199, VRMagic, Sofware 2.9, Mannheim, Germany) first with no caffeine intake and after 40 minutes of taking an oral dose of caffeine (200 mg and 400 mg). Each subject underwent blood pressure and heart rate measurements before and 40 min after caffeine intake. The same technician measured both surgical performances. Results: Mean age was 46.4 ± 10.1 years. All subjects were male. The mean anti-tremor results were: baseline scores 61.2 ± 19.15, 200 mg 61.6 ± 12.63 and 400 mg 75.4 ± 15.09. The mean internal limiting membrane peeling results were: baseline score 55.9 ± 5.46, 200 mg 54.8 ± 10.05 and 400 mg 62.6 ± 9.63. Blood pressure and heart rate remained stable. After consumption of higher doses of caffeine some adverse effects were reported such as headache and a transient episode of anxiety. Conclusion: Caffeine consumption prior to surgery is discouraged by microsurgeons due to potential adverse effects. Our results showed no significant change on the surgical ability after 200 and 400 mg of oral caffeine. There was a non-significant improvement on the overall score after 400 mg.


International Ophthalmology | 2016

Progression of gyrate atrophy measured with ultra-wide-field imaging

Guillermo Salcedo-Villanueva; Miguel Paciuc-Beja; Cristina Villanueva-Mendoza; Mariana Harasawa; Jesse M. Smith; Raul Velez-Montoya; Jeffrey L. Olson; Scott C. N. Oliver; Naresh Mandava; Hugo Quiroz-Mercado

Abstract The study aims to determine the progression of gyrate atrophy by measuring the area growth of chorioretinal atrophic lesions using ultra-wide-field images (UWFI). A retrospective, observational, and comparative study was conducted and UWFI (200°) were obtained from two patients with gyrate atrophy at baseline and follow-up. Measurements of atrophy were obtained for three types of lesions: Solitary atrophic lesions (SAL), De novo solitary lesions (DNSL), and peripapillary atrophy (PPA). Comparison of baseline and follow-up was done using t tests. Two patients with gyrate atrophy were included. Patient 1 presented 16 SAL, 5 DNSL, and PPA measured for both eyes (BE). Overall area growth (OAG) for SAL (expressed in decimals) presented a mean of 3.41, σ 3.07. DNSL area for BE presented a mean of 1586.08 P2, σ 1069.55. OAG for PPA presented a mean of 1.21, σ 0.17. Patient 2 presented 5 SAL, no DNSL, and PPA was measured for BE. OAG for SAL presented a mean of 1.58, σ 1.05 (range 1.02–3.47). OAG for PPA presented a mean of 1.05, σ 0.001. Gyrate atrophy progression can be determined by measuring the changes in area using UWFI.


Retina-the Journal of Retinal and Vitreous Diseases | 2015

Spectral Domain Optical Coherence Tomographic Analysis Of Healthy Retina In Branch Retinal Vein Occlusion And Its Response To Antiangiogenic Therapy

Guillermo Salcedo-Villanueva; Mariana Harasawa; Raul Velez-Montoya; Marc Mathias; Frank S Siringo; Jeffrey L. Olson; Scott C. N. Oliver; Naresh Mandava; Hugo Quiroz-Mercado

Purpose: To propose a model that measures the effect of intravitreal bevacizumab (IVB) on relatively healthy retina. The purpose is to analyze the remote effect of a branch retinal vein occlusion in the healthy retina, to determine the response it may have to IVB, and to determine if IVB has an atrophic effect on the healthy retina. Methods: Retrospective, longitudinal comparative analysis of patients with branch retinal vein occlusion treated with IVB. Eyes were divided into experimental (branch retinal vein occlusion eye) and control (contralateral eye) groups. Each eye was analyzed for thickness and area. Thickness measurements were performed for total retinal thickness, inner retina thickness, and outer retina thickness. Area was measured for photoreceptors, choroid, and total retina. Results: Eighteen eyes of 9 patients. For thickness analysis, 1,050 scans were studied, and 126 measurements were performed on 42 scans for area analysis. No difference was observed for thickness, except for inner retina thickness. No difference was observed for area. No difference was observed when analyzing a cumulative exposure to IVB. Conclusion: There is no evidence to suggest an atrophic effect caused by IVB when analyzing thickness or area in this experiment. This model could be used to analyze the long-term safety of IVB in larger studies.

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Hugo Quiroz-Mercado

University of Colorado Denver

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Gerardo Garcia-Aguirre

National Autonomous University of Mexico

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Raul Velez-Montoya

University of Colorado Denver

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Veronica Giordano

University of Buenos Aires

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Mariana Harasawa

University of Colorado Denver

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Jeffrey L. Olson

University of Colorado Denver

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Miguel Paciuc-Beja

University of Colorado Denver

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Naresh Mandava

University of Colorado Denver

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Scott C. N. Oliver

University of Colorado Denver

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Frank S Siringo

University of Colorado Denver

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