Alejandro Navas

Prof. Alejandro Navas

Institute of Ophthalmology Conde de Valenciana
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orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 January 2016 in British Journal of Ophthalmology
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Journal Article
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JVJayesh Vazirani
Jayesh Vazirani
MAMohammed Hasnat Ali
Mohammed Hasnat Ali
NSNamrata Sharma
Namrata Sharma
NGNidhi Gupta
Nidhi Gupta
VMVikas Mittal
Vikas Mittal
JCJames Chodosh
James Chodosh
Purpose To report outcomes of autologous simple limbal epithelial transplantation (SLET) performed for unilateral limbal stem cell deficiency (LSCD) at multiple centres worldwide. Methods In this retrospective, multicentre, interventional case series, records of patients who had undergone autologous SLET for unilateral LSCD, with a minimum of 6 months of follow-up, were reviewed. The primary outcome measure was clinical success, defined as a completely epithelised, avascular corneal surface. Kaplan–Meier survival curves were constructed and survival probability was calculated. A Cox proportional hazards analysis was done to assess association of preoperative characteristics with risk of failure. Secondary outcome measures included the percentage of eyes achieving visual acuity of 20/200 or better, percentage of eyes gaining two or more Snellen lines and complications encountered. Results 68 eyes of 68 patients underwent autologous SLET, performed across eight centres in three countries. Clinical success was achieved in 57 cases (83.8%). With a median follow-up of 12 months, survival probability exceeded 80%. Presence of symblepharon (HR 5.8) and simultaneous keratoplasty (HR 10.8) were found to be significantly associated with a risk of failure. 44 eyes (64.7%) achieved a visual acuity of 20/200 or better, and 44 eyes (64.7%) gained two or more Snellen lines. Focal recurrences of pannus were noted in 21 eyes (36.8%) with clinical success. Conclusion Autologous SLET is an effective and safe modality for treatment of unilateral LSCD. Clinical success rates and visual acuity improvement are equal to or better than those reported with earlier techniques.

1 July 2015 in Cornea
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Journal Article
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JHJulio C. Hernandez-Camarena
Julio C. Hernandez-Camarena
EGEnrique O. Graue-Hernandez
Enrique O. Graue-Hernandez
MOMariana Ortiz-Casas
Mariana Ortiz-Casas
ARArturo Ramirez-Miranda
Arturo Ramirez-Miranda
ANAlejandro Navas
Alejandro Navas
VLVictor M. Bautista-De Lucio
Victor M. Bautista-De Lucio
To report the distribution and trends in microbiological and antibiotic sensitivity patterns of infectious keratitis in a 10-year period at a reference center in Mexico City. In this retrospective observational case series, samples were obtained from corneas with a diagnosis of infectious keratitis from January 2002 to December 2011 at the Institute of Ophthalmology "Conde de Valenciana" in Mexico City. Results of cultures, stains, and specific sensitivity/resistance antibiograms for each microorganism were analyzed. A total of 1638 consecutive corneal scrapings were analyzed. Pathogen was recovered in 616 samples (38%), with bacterial keratitis accounting for 544 of the positive cultures (88%). A nonsignificant increasing trend in gram-negative isolates (P = 0.11) was observed. The most commonly isolated pathogen was Staphylococcus epidermidis, and the most common gram-negative isolated species was Pseudomonas aeruginosa. Methicillin-resistant Staphylococcus aureus (MRSA) was present in 45% of the S. aureus isolates; meanwhile, 53.7% coagulase-negative Staphylococcus isolates were methicillin resistant (MRCNS). Pseudomonas aeruginosa resistance to ceftazidime increased from 15% in the first period to 74% for the last 5 years of the study (P = 0.01). The overall sensitivity for vancomycin of MRSA was 87.5%, whereas 99.6% of the MRCNS were sensitive. There was a nonsignificant increase in the recovered gram-positive and gram-negative microorganisms over time. We observed an increased resistance to methicillin in almost half of the MRSA and MRCNS isolates.

1 August 2014 in Journal of Refractive Surgery
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JHJulio C. Hernández-Camarena
Julio C. Hernández-Camarena
MSMagda Patricia Chirinos Saldaña
Magda Patricia Chirinos Saldaña
ANAlejandro Navas
Alejandro Navas
ARArturo Ramirez-Miranda
Arturo Ramirez-Miranda
AMAngie de la Mota
Angie de la Mota
EHEnrique Graue Hernández
Enrique Graue Hernández
PURPOSE: To assess the reliability of three different Scheimpflug systems and their agreement. METHODS: Eighty-four eyes of 42 patients were examined with three Scheimpflug devices: the Galilei G2 Dual Scheimpflug Analyzer (Ziemer Ophthalmic Systems AG, Port, Switzerland), Pentacam HR system (Oculus Optikgeräte GmbH, Wetzlar, Germany), and Sirius 3D imaging system (Costruzione Strumenti Oftalmici, Florence, Italy). The central corneal thickness, maximum anterior and posterior corneal elevation, anterior radius of curvature, total higher-order aberrations, and anterior chamber depth were evaluated. Repeatability and reproducibility were evaluated using coefficients of variation and intraclass correlation coefficients. Interdevice agreement was assessed by Bland–Altman comparison analysis. RESULTS: The three Scheimpflug systems had excellent repeatability for central corneal thickness, anterior radius of curvature, and anterior chamber depth (coefficients of variation being less than 1%). Repeatability for anterior and posterior corneal evaluation was good for the Pentacam HR and Galilei G2 (coefficients of variation < 10%) and excellent for the Sirius 3D (coefficients of variation = 0). Reproducibility was excellent in the three devices, (intraclass correlation coefficient of more than 0.9). Interdevice agreement was excellent ( P > .05) for anterior radius of curvature, central corneal thickness, and anterior chamber depth, but was poor ( P < .05) for corneal elevation and higher-order aberrations. CONCLUSIONS: Reliability was good to excellent in the three devices for all measured variables. Interdevice agreement analysis suggests that measurements for anterior radius of curvature, central corneal thickness, and anterior chamber depth, but not for maximum anterior and posterior corneal elevation and total higher-order aberrations, from the Sirius 3D and Galilei G2 can be interchangeable with the Pentacam HR. [ J Refract Surg. 2014;30(9):616–621.]

1 September 2011 in Journal of Refractive Surgery
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Journal Article
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MJMartha Jaimes
Martha Jaimes
FXFiona Xacur-García
Fiona Xacur-García
DADiana Alvarez-Melloni
Diana Alvarez-Melloni
EGEnrique O. Graue-Hernández
Enrique O. Graue-Hernández
TRTito Ramirez-Luquín
Tito Ramirez-Luquín
ANAlejandro Navas
Alejandro Navas
PURPOSE: To report the clinical characteristics and surgical outcomes of patients with nonprogressive keratoconus treated with in-the-bag toric intraocular lens (IOL) implantation. METHODS: A retrospective review was conducted of the medical records of patients diagnosed with keratoconus treated with refractive lens exchange (RLE) and in-the-bag toric IOL implantation (models T3 to T9, AcrySof SN60TT; Alcon Laboratories Inc). Age, pre- and postoperative uncorrected (UDVA) and corrected distance visual acuity (CDVA), objective and subjective refraction, spherical equivalent refraction, total keratometric power, total astigmatism, axis, and toric IOL model and power were analyzed. All cases had topographic and/or refractive stability for at least 1 year prior to undergoing IOL implantation. RESULTS: Nineteen eyes of 13 patients (mean age 48.15±6.6 years), including 12 patients with a topographic diagnosis of keratoconus and 1 with pellucid marginal degeneration, were evaluated. Mean follow-up after RLE was 7.89±6.61 months. Mean preoperative sphere was −5.25±6.40 diopters (D), and mean postoperative sphere was 0.22±1.01 D ( P <.001). Mean preoperative cylinder was 3.95±1.30 D, which decreased to 1.36±1.17 D postoperatively ( P <.001). Mean pre- and postoperative spherical equivalent refractions were −7.10±6.41 D and −0.46±1.12 D, respectively ( P <.001). Preoperative mean UDVA was 1.35±0.36 D (20/447 Snellen) and postoperative mean UDVA was 0.29±0.23 D (20/39 Snellen) ( P <.001). CONCLUSIONS: Toric IOL implantation may be an effective therapeutic option in the optical rehabilitation of patients with stable and nonprogressive keratoconus.

1 November 2009 in Journal of Cataract & Refractive Surgery
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Journal Article
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ANAlejandro Navas
Alejandro Navas
RSRaúl Suárez
Raúl Suárez
We present 2 cases of toric intraocular lens implantation for keratoconus: A 55-year-old man with forme fruste keratoconus with a preoperative uncorrected distance visual acuity (UDVA) of 20/800 and a refraction of -6.50-3.00x135 and a 46-year-old man with a claw-shaped topographic pattern, a family history of keratoconus, and a UDVA of 20/800 with a refraction of -5.00-3.00x85. The refraction had been stable for at least 5 years in both patients. Phacoemulsification and implantation of an acrylic toric IOL were uneventful. One year postoperatively, the UDVA was 20/25 in both cases, with a refraction of -0.25-0.50x140 and 0.25-0.50x60, respectively. No progression and no IOL rotation were observed. Toric IOLs may provide excellent outcomes in patients with stable and nonprogressive corneal ectasia.

1 July 2019 in Survey of Ophthalmology
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Journal Article
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EHErick Hernandez-Bogantes
Erick Hernandez-Bogantes
ANAlejandro Navas
Alejandro Navas
ANAndrea Naranjo
Andrea Naranjo
GAGuillermo Amescua
Guillermo Amescua
EGEnrique O. Graue-Hernandez
Enrique O. Graue-Hernandez
IAIke Ahmed
Ike Ahmed