Alejandro Tello

• Centro Oftalmologico Virgilio Galvis

PURPOSE Identify the factors associated with endothelial cell density in donor corneas. METHODS A cross-sectional analytical study of the records of 269 corneas procured between December 2016 and September 2021 in an eye bank of an ophthalmological institute in Colombia. RESULTS The median age of the 269 donors was 47 years (range: 18–72 years)....

Aim: To determine risk factors associated with keratoconus in Bucaramanga, Colombia. Material and methods: A paired case-control study was conducted at Bucaramanga, Colombia, between November 2022 and December 2023. The controls were age- and sex-matched. Patients answered a questionnaire designed for this study regarding their family history of...

Aims: This scoping review was conducted to investigate whether nocturnal eye compression from inappropriate sleeping postures may contribute to the development or asymmetry of keratoconus (KC), by examining the association between sleeping positions and KC. Material and methods: A systematic search of CENTRAL, MEDLINE, EMBASE, LILACS, ClinicalTr...

The determination of sulcus-to-sulcus measurements has been challenging due to the limitations of current approaches. Ultrasound methods are highly operator-dependent and require extensive training, while traditional optical devices cannot visualize structures posterior to the iris. However, modern optical anterior segment coherence tomography (AS-...

Aims: To investigate the concordance between the corneal power determined by various approaches with two tomographers (MS-39® and Galilei G6®) and the clinical history method (CHM) in patients undergoing photorefractive surgery with excimer laser for myopic errors. Material and methods: Prospective cohort study. Patients undergoing keratorefract...

Definition of iris retraction syndrome (IRS) has been changing over the years. The purpose of this article is to document through multimodal imaging the clinical signs found in two individuals who presented with IRS. This is a case series. Multimodal imaging was performed in a 34-year-old and a 57-year-old male patient with IRS. A literature search...

Aims/Purpose: To develop a method for measuring the exact dimensions of the ciliary sulcus in order to improve the predictability of accommodative intraocular lens sizing. Methods: Patients scheduled for cataract surgery have been pre‐operatively examined with the anterior segment optical coherence tomographer (AS‐OCT) CASIA2 (Tomey, Nagoya, Japan)...

Background Ocular trauma is one of the most important causes of ocular morbidity and inadequate visual acuity in developed and developing countries. In some countries, eye trauma is the leading cause of monocular blindness. Studies conducted in developing countries like Colombia suggest that there is a lack of awareness of preventive measures. In C...

Computerized medical evaluation of the corneal endothelium is challenging because it requires costly equipment and specialized personnel, not to mention that conventional techniques require manual annotations that are difficult to acquire. This study aims to obtain reliable segmentations without requiring large data sets labeled by expert personnel...

Refractive surgery with excimer laser has been a very common surgical procedure worldwide during the last decades. Currently, patients who underwent refractive surgery years ago are older, with a growing number of them now needing cataract surgery. To establish the power of the intraocular lens to be implanted in these patients, it is essential to...

Background Intracameral antibiotics, such as moxifloxacin and cefuroxime, are safe to corneal endothelial cells and effective prophylaxis of endophthalmitis after cataract surgery. Corneal endothelial cells decrease in density after cataract surgery. Any substance used in the anterior chamber may affect corneal endothelial cells and lead to a great...

Purpose: To describe clinical visual outcomes, spectacle independence, and patient satisfaction after cataract surgery with blending implantation of ReSTOR (Alcon laboratories) multifocal intraocular lenses. Material and methods: A single-arm, non-randomized prospective study assessed patients undergoing cataract surgery with ReSTOR® +2.50 intra...

Refractive surgery with excimer laser has been a very common surgical procedure worldwide during the last decades. Currently, patients who underwent refractive surgery years ago are older, with a growing number of them now needing cataract surgery. To establish the power of the intraocular lens to be implanted in these patients, it is essential to...

Aim and background Precision of optical coherence tomography (OCT) measurements of the optic nerve head (ONH), retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) is essential for the diagnosis and monitoring of glaucoma. The purpose of this research was to evaluate the repeatability and reproducibility of retinal and ONH parame...

Specular microscopy assessment of the human corneal endothelium (CE) in Fuchs’ dystrophy is challenging due to the presence of dark image regions called guttae. This paper proposes a UNet-based segmentation approach that requires minimal post-processing and achieves reliable CE morphometric assessment and guttae identification across all degrees of...

Objective To evaluate the knowledge, attitudes, and practices of the physicians of a fourth-level institution in Colombia, regarding vaccination against Herpes-zoster. Methodology An email survey was applied to 141 general physicians and specialists in various areas. Results 85.3 % of those surveyed knew about the existence of the vaccine against...

Specular microscopy assessment of the human corneal endothelium (CE) in Fuchs' dystrophy is challenging due to the presence of dark image regions called guttae. This paper proposes a UNet-based segmentation approach that requires minimal post-processing and achieves reliable CE morphometric assessment and guttae identification across all degrees of...

A correction about phakic intraocular lens power calculation process, as it was stated by Li, Song & Song, is provided. It is explained that this calculation is based on the Van der Heijde formula and not on biometric formulas. A comment about the mechanisms of late endothelial cell loss following phakic intraocular lenses is done.

Aims: To describe the aetiology and microbial susceptibility profile of endophthalmitis cases treated at an ophthalmological referral centre in Colombia. Material and methods: A retrospective descriptive study was carried out with all endophthalmitis cases referred to the Fundación Oftalmológica de Santander FOSCAL (Floridablanca, Colombia) from...

Purpose: To determine the changes in endothelial cell density, refractive results, and risk factors associated with endothelial loss in patients with irisclaw phakic intraocular lenses for myopia/myopic astigmatism (Artisan). Methodology: Data collection was obtained from an existing database with information on patients with a phakic Artisan le...

Purpose: The main purpose of this study was to report a case of cystoid macular edema (CME) after gonioscopy-assisted transluminal trabeculotomy (GATT). Methods: We describe the case of a 73-year-old woman with ocular hypertension and history of cataract surgery combined with posterior vitrectomy and epiretinal membrane peeling 2 years before, w...

Donor to host transmission of infectious agents is a well-recognized entity, more commonly related to Endothelial Keratoplasty (EK) than to Penetrating Keratoplasty (PK), that involves complications ranging from interface keratitis to endophthalmitis. A systematic review of the literature was conducted to identify the published articles until Decem...

Purpose To assess visual results (including the Lapid-Kushlin defocus coefficient), and satisfaction, following the implantation of PanOptix® a trifocal intraocular lens. Methods Observational, retrospective cohort study. 130 eyes of 65 subjects with bilateral implantation were included. Binocular uncorrected visual acuities [distance (Binocular U...

Purpose: To report the rare case of a 29-year-old male with a history of keratoconus, who presented with a primary iris stromal cyst which eventually showed spontaneous regression. Methods: Description of the clinical findings in the case of a 29-year-old male with a prior history of keratoconus, but no eye surgery or trauma, who consulted for a...

Purpose To describe the results of topical atropine 1% weekly combined with a fixed combination of ocular hypotensives (dorzolamide + timolol), versus ocular hypotensives alone, in children and adolescents. Methods A retrospective review of medical records of myopic children and adolescents from September 2003 to June of 2019. The unit of analysis...

Myopia is a worldwide major public concern, aside from the visual disturbance needing optical correction, myopia may be associated with open angle glaucoma, retinal detachment and myopic maculopathy. The higher the myopia the higher the risk for retinal associated comorbidities, and the axial length is the more important measure to estimate risk of...

A man with a history of blind eye due to trauma 22 years earlier consulted at 53 years of age with a large conjunctival neoplastic lesion, compromising almost the entire temporal limbus, and reaching a size of approximately 16 mm on its larger diameter, in the conjunctiva. Management was started with topical and subconjunctival chemotherapy (interf...

Objective: To determine bacteria obtained from eye infections, both resistance and minimal inhibitory concentration (MIC) to gatifloxacin, moxifloxacin, tigecycline, linezolid and imipenem, in vitro. Methods: A cross-sectional descriptive study was undergone with 50 samples from 50 eyes of patients diagnosed with keratitis or endophthalmitis, who c...

Both genetic and environmental factors have been considered to play a role in the etiology keratoconus. Eye rubbing, and more recently eye compression due to sleeping position, have been identified to be highly related to the condition, and are present in a high percentage of patients. Today, the predominant model is that these factors can provide...

Eye burns due to the accidental application of pharmacological or nonpharmacological substances packaged in plastic dropper bottles have been described for more than three decades and continue to occur. These burns can cause potentially serious corneal injuries. We report the case of a patient who mistakenly applied salicylic acid to the right eye...

Automated cell counting in in-vivo specular microscopy images is challenging, especially in situations where single-cell segmentation methods fail due to pathological conditions. This work aims to obtain reliable cell segmentation from specular microscopy images of both healthy and pathological corneas. We cast the problem of cell segmentation as a...

Objective: To compare late mid-term results of two different surgical approaches of surface excimer laser ablation for myopic and astigmatic errors in contralateral eyes of the same patients. Methods: Prospective cohort study. A photorefractive keratectomy technique was performed on the right eye and single-step transepithelial photorefractive kera...

Accurate endothelial cell density with specular microscopy is essential for correct clinical assessment of the cornea. Commercial specular microscopes incorporate automated cell segmentation methods to estimate cell density. However, these methods are prone to false cell detections in pathological corneas. This project aims to obtain a reliable aut...

Aim. To analyze clinical features, treatment, and results of patients with non-penetrating traumatic hyphema in an ophthalmological center in Colombia. Methods. A retrospective cohort study in which medical records of patients with traumatic hyphema were analyzed between 2013 and 2018. Results. 38 eyes of 37 patients (34 men, 3 women) were included...

Excimer laser refractive surgery is a procedure performed worldwide to solve refractive errors and reduce dependence on glasses or contact lenses. There has been an increase in the number of procedures performed around the world. Myopia is the most common indication for corneal photorefractive surgery. Myopic patients have a higher risk of developi...

Excimer laser refractive surgery is a procedure performed worldwide to solve refractive errors and reduce dependence on glasses or contact lenses. There has been an increase in the number of procedures performed around the world. Myopia is the most common indication for corneal photorefractive surgery. Myopic patients have a higher risk of developi...

Excimer laser refractive surgery is a procedure performed worldwide to solve refractive errors and reduce dependence on glasses or contact lenses. There has been an increase in the number of procedures performed around the world. Myopia is the most common indication for corneal photorefractive surgery. Myopic patients have a higher risk of developi...

Purpose To evaluate the endothelial cell loss in patients with iris-claw phakic lenses (Artisan®) in a long-term follow-up. Methods We analyzed the medical records of patients who had undergone iris-claw phakic lens implantation and who had at least 5 years of follow-up. Results We included 67 eyes with myopic errors (follow-up 9.6 ± 3.0 years) a...

A 71-year-old woman presented with spontaneous microhyphema in her left eye, causing blurry vision. Bleeding stopped spontaneously shortly after several cycles of digital compression on the upper eyelid, (which were documented in video), and therefore, did not require laser photocoagulation, a possible approach previously explained to the patient....

Introducción. Diversas condiciones oftalmológicas son causas de consultas a los servicios de urgencias. El objetivo de este trabajo fue determinar las causas más comunes de consulta al servicio de urgencias oftalmológicas de una institución terciaria en Colombia y, así, poder explorar en el futuro la posibilidad de identificar algunas medidas preve...

Purpose: To describe the indications and techniques of corneal grafting in a tertiary institution in a middle-sized city in Colombia. Methods: A retrospective review of surgical reports and medical records of patients undergoing keratoplasty from January 2012 to December of 2016. Results: A total of 346 eyes from 316 patients were included. Th...

Purpose To evaluate the results of optical biometry using the IOLMaster 500, Lenstar LS 900 and Aladdin in eyes with cataract. Methods In 231 eyes of 152 patients with cataract, the measurements of 3 different biometers were retrospectively compared. Paired comparisons were performed for axial length (AL), mean keratometry (mean K) and anterior ch...

Figura A. OI: fotografía en lámpara de hendidura con filtro de azul de cobalto. La tinción con fluoresceína permiteapreciar dos úlceras separadas de aspecto dendrítico (flechas blancas) que comprometen la media periferia, tantosuperonasal (meridiano de las 9 y 10:30 horas), como superior (meridiano de las 12 y las 2 horas). Adicionalmente,lesión ul...

76-year-old female patient, with past medical history of relapsing-remitting multiple sclerosis manifested by retrobulbar optic neuritis in both eyes with an interval of one year between the first episode in the left eye and the one in the right eye and after three decades of remission, who consulted due to bilateral blurred and foggy vision. Subse...

Massive hyphaema presentation after a laser iridotomy is very rare. We report a 63-year-old man with ischaemic heart disease on dual antiplatelet therapy (aspirin plus ticagrelor) who was diagnosed as a primary angle-closure suspect and was to undergo a neodymium-doped yttrium aluminium garnet laser iridotomy at Centro Oftalmológico Virgilio Galvis...

Purpose: To describe a simple finding, consisting of a double-line reflection from the graft inside the anterior chamber, that can be used to determine the correct donor tissue orientation in Descemet membrane endothelial keratoplasty: which we would like to call Berrospi's sign. Methods: Evaluation of the presence of linear reflection from the...

Abstract Postoperative flap displacements after Laser In Situ Keratomileusis (LASIK) are uncommon complications, and flap losses are even less frequent, occurring most commonly within 24 hours after the procedure. Although cases of late subluxation have been reported up to 14 years after the surgery, the longest reported time after surgery for late...

Introducción. La determinación del poder corneal, después de la cirugía refractiva con láser excimer, es difícil. Diferentes alternativas con el uso de tomógrafos corneales se han utilizado para esta medición. Objetivo. Evaluar diversos métodos de determinación del poder corneal en pacientes operados de cirugía fotorrefractiva, incluyendo pruebas d...

Background and objective In view of the increasing bacterial resistance to antibiotics, it is necessary to determine it locally in order to serve as a guide in clinical management. The purpose of this study was to characterize the pattern of antibiotic sensitivity in cases of eye infections in a third level ophthalmological institution in Floridabl...

Background and objective: In view of the increasing bacterial resistance to antibiotics, it is necessary to determine it locally in order to serve as a guide in clinical management. The purpose of this study was to characterise the pattern of antibiotic sensitivity in cases of eye infections in a third level ophthalmological institution in Florida...

Purpose To evaluate the results of optical biometry using the IOLMaster 500, Lenstar LS 900 and Aladdin in eyes with cataract. Methods In 231 eyes of 152 patients with cataract, the measurements of 3 different biometers were retrospectively compared. Paired comparisons were performed for axial length (AL), mean keratometry (mean K) and anterior cha...

A 15-year-old male patient with corneal hydrops and a giant intrastromal cleft (pseudocyst) successfully received medical treatment with topical prednisolone, hypertonic saline solution and ocular hypotensive eyedrops. Anterior segment optical coherence tomography (OCT) was used as an auxiliary tool for assessing the response to treatment during fo...

Postoperative flap displacements after Laser In Situ Keratomileusis (LASIK) are uncommon complications, and flap losses are even less frequent, occurring most commonly within 24 hours after the procedure. Although cases of late subluxation have been reported up to 14 years after the surgery, the longest reported time after surgery for late flap los...

Case report A patient with a history of surgical resection of an acoustic neuroma presented with involvement of both the left facial nerve and the left trigeminal nerve. She initially consulted for exposure keratitis, but two weeks later presented with an infectious keratitis. After taking the corneal sample, she presented with persistent epithelia...

Clinical case A 51 year-old immunocompetent male was referred due to presenting with a large corneal ulcer with hypopyon in the right eye. Topical amphotericin B, fluconazole and moxifloxacin, as well as oral itraconazole were initially indicated. Following the report of mycotic structures on staining, topical natamycin was started. The result of t...

Objective/methods The aim of this study is to describe the use of botulinum toxin to increase tear retention in patients with dry eye through the description of 2 cases. Results Patients with moderate to severe dry eye who received an injection of type A botulinum toxin in the Horner's muscle. The results at one month and 3 months are reported. An...

El síndrome de retracción iridiana (SRI) fue descrito por primera vez en 1876 por Schnabel como un “peculiar desenlace” del desprendimiento de retina. Sin embargo, hasta 1916 Leber planteó las bases conceptuales del síndrome conocido como la hipotonía aguda de Leber el cual consistía en desprendimiento de retina, cámara anterior profunda, inflamaci...

We describe the case of a 52-year-old female with past history of LASIK, 21 years earlier, without Fuchs’ endothelial dystrophy, who underwent phacoemulsification and intraocular lens (IOL) implantation. During the early postoperative period severe corneal edema, anterior chamber cellularity and iris inflammation presented, accompanied by a clear s...

Objective/methods: The aim of this study is to describe the use of botulinum toxin to increase tear retention in patients with dry eye, using the description of 2 cases. Results: Patients with moderate to severe dry eye that were given an injection of type A botulinum toxin in the Horner's muscle. The results at one month and 3 months are report...

Clinical case: A 51 year-old immunocompetent male was referred due to presenting with a large corneal ulcer with hypopyon in the right eye. Topical amphotericin B, fluconazole and moxifloxacin, as well as oral itraconazole were initially indicated. Following the report of mycotic structures on staining, topical natamycin was started. The result of...

Case report: A patient with a history of surgical resection of an acoustic neuroma presented with involvement of both the left facial nerve and the left trigeminal nerve. She initially consulted for exposure keratitis, but two weeks later presented with an infectious keratitis. After taking the corneal sample, she presented with persistent epithel...

Purpose To determine the prevalence of refractive errors in Colombia and its relations with demographic and socioeconomic variables. Methods A cross-sectional study performed in 10 Colombian administrative districts (MIOPUR study), including children and adolescents from 8 to 17 years old and adults from 35 to 55 years old. Results 3608 individua...

A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. Ther...

A 68-year-old female underwent Descemet membrane endothelial keratoplasty (DMEK) in her right eye using a 3D visualization system with the surgeon looking directly to a digital screen instead of through the eyepieces of the surgical microscope. The procedure was uneventful. Five weeks after the surgery the DMEK graft was in good position and totall...

Purpose: The aim of this study was to establish the frequency of refractive errors in children and adolescents aged between 8 and 17 years old, living in the metropolitan area of Bucaramanga (Colombia). Methods: This study was a secondary analysis of two descriptive cross-sectional studies that applied sociodemographic surveys and assessed visua...

Hermann von Helmholtz (1821–1894) was one of the most important scientists of the nineteenth century in optics and ophthalmology. One of his significant contributions in the field of vision sciences was the invention of the ophthalmometer in 1850, which was the precursor of the keratometers still used in clinical practice today. However, this devel...