Errores refractarios en estudiantes de medicina en un hospital docente / Refractory errors in medical students in a Teaching Hospital

Los errores de refracción contribuyen como un gran problema de salud pública. Las crecientes tasas de prevalencia de la miopía han alcanzado los niveles de epidemia en varias áreas. Este estudio tuvo como objetivo determinar las tasas de prevalencia de errores de refracción en los estudiantes de medicina. Se realizó un estudio prospectivo en el Departamento de Oftalmología, durante un período de un año desde enero de 2020 hasta diciembre de 2020. Los estudiantes de medicina fueron seleccionados al azar, como un total de 250 sujetos. Todos se sometieron a un examen oftálmico. De 250 estudiantes, se documentaron 148 (59.2%) casos de RE. La mayoría de los casos comunes eran mujeres (89, 60.1%), mientras que los hombres eran (59, 39.9%). De estos, 98 estudiantes tienen miopía (66.2%), 42 casos tienen astigmatismo (28.4%) y 8 casos tienen hipermetropía (5.4%). La etapa tardía de las clases (sexto) tiene los casos RE más frecuentes. La miopía fue la RE predominante entre los estudiantes de medicina. La clase anticipada y la mujer son factores predisponentes.

Refractive errors are contributing as a major public health problem. The increasing prevalence rates of myopia have reaching to epidemic levels in several areas. This study was aimed to determine the prevalence rates of refractive errors in medical students. A prospective study was conducted in the Department of Ophthalmology, over a period of one year from Jan 2020 to Dec 2020. Medical students were randomly selected, as a total of 250 subjects. All were undergoing an ophthalmic examination. Of 250 students, 148(59.2%) cases of RE were documented. Most common cases were female (89, 60.1%), whereas male was (59, 39.9%). Of these, 98 students have myopia (66.2%), 42 cases have astigmatism (28.4%) and 8 cases have hypermetropia (5.4%). The late stage of classes (6th) has the most frequent RE cases. Myopia was the predominant RE among the medical students. Advance class and female are predisposing factors

Síndrome de Moebius incompleto. Presentación de un caso clínico / Incomplete Moebius syndrome. Clinical case presentation

RESUMEN El síndrome de Moebius es un trastorno polimalformativo no progresivo que se caracteriza por parálisis facial congénita. Se define como una "parálisis congénita de los núcleos de los pares craneales VI y VII, cuyo espectro clínico es variable y se asocia a múltiples malformaciones óseas y musculares. Es poco frecuente y de etiología vascular, genética o multifactorial. El trabajo, basándose en los fundamentos teóricos más actualizados, pretendió describir las manifestaciones clínicas del síndrome de Moebius y su posible etiología, a propósito de un caso. Se trató de un paciente de 11 años de edad, que al nacimiento presentó asimetría facial, desviación de la comisura labial hacia la izquierda, boca semiabierta, lagrimeo constante y pabellón auricular derecho malformado. Por ser una entidad clínica poco conocida, se expuso el presente caso, portador de un síndrome de Moebius incompleto de causa vascular y multifactorial (AU).

ABSTRACT Moebius syndrome is a non-progressive poli-formative disorder characterized by facial congenital paralysis. It is defined as a congenital paralysis of the VI and VII cranial nerves nuclei, the clinical spectrum of which is variable and associated to several bone and muscular malformations. It is few frequent and has vascular, genetic or multifactorial etiology. This work, based on more updated theoretical fundaments, pretended to describe the clinical manifestations of the Moebius syndrome and its possible etiology on the purpose of a case. It is the case of a patient, aged 11 years, who presented facial asymmetry, lips commissure deviation to the left, semi-opened mouth, constant lagrimeo and deformed right auricular pavilion (pabellon auricular). Because it is a little known clinical entity, this case of a patient having an incomplete Moebius syndrome of vascular and multifactorial cause was presented (AU).

Manejo do astigmatismo residual após implante de lente intraocular / Management of residual astigmatism after intraocular lens implantation

RESUMO Relatamos um caso de astigmatismo residual, após cirurgia de catarata com implante de lente intra-ocular (LIO) tórica (Acrysof Toric, Alcon, Frot Worth TX). A refração residual (+1,25 -2,50 x 105º) e o posicionamento da LIO implantada neste olho, foram correlacionados com a aberrometria total obtida por ray tracing de pontos individuais integrada à da face anterior da córnea obtida por topografia de Plácido, para cálculo das aberrações internas (iTrace, Tracey, Technologies, Houston TX). O cálculo do eixo ideal da LIO, para minimizar a refração residual foi realizado de acordo com Berdahl & Hardten (astigmatismfix.com). A rotação da LIO foi realizada com sucesso 5 meses após a cirurgia inicial para o eixo indicado, reduzindo o erro residual para +0,25 -0,25 x 61º e promovendo reabilitação visual sem correção de 20/20.

ABSTRACT We report a case of residual astigmatism after cataract surgery with toric intraocular lens (IOL) implantation (Acrysof Toric, Alcon, Frot Worth TX). Residual refraction (+1,25 -2,50 x 105º) and IOL positioning were correlated with total ray-tracing wavefront aberrometry integrated with anterior corneal surface Placido-based topography to calculate internal aberrations (iTrace, Tracey Technologies, Houston TX). The ideal IOL axis to minimize residual refraction was calculated with Berdahl & Hardten (astigmatismfix.com). IOL rotation to the indicated axis was successfully performed 5 months after initial surgery, reducing residual error to +0,25 -0,25 x 61º, promoting visual reabilitation, with final uncorrected distance visual acuity 20/20.

Caracterización de los defectos refractivos en una población de niños de los 2 a los 14 años en Bogotá, Colombia / Characterization of Refractive Defects in a Population of Children Aged from 2 to14 years in Bogotá, Colombia

Introducción: Los defectos refractivos pueden repercutir de manera importante en el rendimiento de un individuo, sobre todo en la población pediátrica. Objetivo: Determinar la prevalencia de defectos refractivos en una muestra de 112 niños entre los 2 y los 14 años del Colegio La Candelaria, en la ciudad de Bogotá. Métodos: Estudio de corte transversal que valoró, por medio de la agudeza visual, motilidad ocular, oftalmoscopia, retinoscopia y examen subjetivo, la capacidad visual de los niños en cuestión. Resultados: Se encontró una prevalencia de defectos refractivos del 18,8 %, dentro de la cual el 13,4 % representaba astigmatismo; el 3,6%, hipermetropía, y el 1,8%, miopia. Discusión: Se compararon los resultados con aquellos de una tesis realizada en 1973, donde se estudiaron pacientes en condiciones similares. En esta, la prevalencia de defectos refractivos fue del 30,48 %, diferencia que se podría explicar por la variación de características poblacionales. Por último, se plantea la necesidad de tamizaje en otras comunidades.

Introduction: The refractive defects can have a great amount of repercussions in the performance of the individual, especially in the pediatric community. Objective: To determine the prevalence of refractive defects within a sample of 112 children between the ages of 2 and 14 from Colegio La Candelaria in the city of Bogotá. Methods: Cross-sectional study that valued through visual acuity, ocular motility, ophthalmoscopy, retinoscopy, and subjective exam, the visual capacity of the children in question. Results: We have found a prevalence of refractive defects of 18.8% were 13.4% represented astigmatism, 3.6% farsightedness and 1.8% shortsightedness. Discussion: These results were compared with those from a thesis performed in 1973 were patients with similar conditions were tested. In this one, the refractive defects were of 30.48%, a difference that can be explained by variations in population characteristics. Lastly, it arises the need of screening in other communities.

Síndrome de visión de la computadora en trabajadores de dos bancos metropolitanos de un área de salud / Computer vision syndrome observed in employees from two Metropolitan Banks in a health area

El ordenador, si no se utiliza adecuadamente, produce trastornos en la salud. La causa de estas alteraciones está relacionada con factores ergonómicos visuales del entorno de trabajo y la exacerbación de problemas visuales ya existentes. Objetivo: describir características clínicas del síndrome de visión de la computadora en trabajadores de dos bancos metropolitanos de un área de salud. Métodos: se realizó un estudio descriptivo transversal. La muestra la conformaron 40 trabajadores que refirieron sintomatología asociada al uso del ordenador y que cumplieron los criterios de inclusión. Se estudiaron las variables: edad, sexo, síntomas, signos biomicroscópicos, afecciones oculares asociadas y tipo de defecto refractivo. Resultados: el 82,5 por ciento de los pacientes tenían más de 30 años, con edad media de 41,7 años. Por cada 12,3 mujeres diagnosticadas con síndrome de visión de la computadora se diagnosticó un hombre. Ojo rojo intermitente y visión borrosa resultaron los síntomas más frecuente y la inyección conjuntival el signo. Las afecciones oculares más frecuentes fueron las ametropías con 87,5 por ciento y ojo seco con 57,5 por ciento. Dentro de las ametropías predominó el astigmatismo con 43 por ciento de casos. Conclusiones: el síndrome de visión de la computadora es un problema de salud real en la actualidad. Las personas que pasan muchas horas frente al ordenador generalmente presentan antecedentes de afecciones oculares como ametropías y ojo seco, por lo que deben asistir al oftalmólogo(AU)

The computer, if not properly used, may cause health disorders. The cause is already related with visual ergonomic factors of the work environment and the exacerbation of already existing visual problems. Objective: to describe the clinical characteristics of the computer vision syndrome in employees from two metropolitan banks in a health area. Method: a cross-sectional descriptive study was carried out. The sample made up of 40 workers who had symptoms associated to the use of computer and met the inclusion criteria. The study variables were age, sex, symptoms, biomicroscopy signs, other eye pathologies and type of refractive defect. Results: in the study group, 82,5 percent of the patients were older than 30 years old, being the mean age of 41,7 years. One man per 12,3 women was diagnosed with the computer vision syndrome. Intermittent red eye and blurred vision were the most frequent symptoms and the conjunctival injection was the sign. The most frequent ocular pathologies turned to be the ametropia with 87,5 percent and dry eye with 57,5 percent of cases. Astigmatism prevailed in 43 percent of the group. Conclusions: the computer vision syndrome is a real health problem at the present time people that spend many hours working with computer generally show eye alterations as ametropia and dry eye, and they should go to the ophthalmologist(AU)

Comparison of Astigmatism Induced by Combined Inferior Oblique Anterior Transposition Procedure and Lateral Rectus Recession Alone

PURPOSE: The purpose of this study is to compare the magnitude and axis of astigmatism induced by a combined inferior oblique (IO) anterior transposition procedure with lateral rectus (LR) recession versus LR recession alone. METHODS: Forty-six patients were retrospectively analyzed. The subjects were divided into two groups: those having concurrent inferior oblique muscle overaction (IOOA) and intermittent exotropia (group 1, 20 patients) and those having only intermittent exotropia as a control (group 2, 26 patients). Group 1 underwent combined anterior transposition of IO with LR recession and group 2 underwent LR recession alone. Induced astigmatism was defined as the difference between preoperative and postoperative astigmatism using double-angle vector analysis. Cylinder power, axis of induced astigmatism, and spherical equivalent were analyzed at 1 week, 1 month, and 3 months after surgery. RESULTS: Larger changes in the axis of induced astigmatism were observed in group 1, with 4.5° incyclotorsion, than in group 2 at 1 week after surgery (axis, 84.5° vs. 91°; p < 0.001). However, there was no statistically significant inter-group difference thereafter. Relaxation and rapid regression in the incyclotorsion of induced astigmatism were observed over-time. Spherical equivalent significantly decreased postoperatively at 1 month in both groups, indicating a myopic shift (p = 0.011 for group 1 and p = 0.019 for group 2) but did not show significant differences at 3 months after surgery (p = 0.107 for group 1 and p = 0.760 for group 2). CONCLUSIONS: Combined IO anterior transposition procedures caused an increased change in the axis of induced astigmatism, including temporary incyclotorsion, during the first week after surgery. However, this significant difference was not maintained thereafter. Thus, combined IO surgery with LR recession does not seem to produce a sustained astigmatic change, which can be a potential risk factor of postoperative amblyopia or diplopia compared with LR recession alone.

Diagnóstico y control del astigmatismo en la cirugía del cristalino / Diagnosis and control of astigmatism in the crystalline surgery

Se realizó una revisión bibliográfica con el objetivo de conocer las opciones quirúrgicas para la corrección del astigmatismo preoperatorio y posoperatorio en la cirugía de catarata. Fueron abordados tópicos como los estudios preoperatorios detallados que nos permiten realizar una planificación quirúrgica personalizada, así como las diferentes soluciones quirúrgicas actuales, tanto las incisiones anastigmáticas en la facoemulsificación, como las incisiones relajantes limbares combinadas o no con las lentes intraoculares tóricas y los procederes con excímer láser. Se consultaron investigaciones que abarcan varios años hasta el presente para conocer los diferentes resultados de la utilización de estos procederes quirúrgicos hasta llegar a técnicas más novedosas en estudio como el láser femtosecond y las lentes intraoculares ajustables con la luz. Todo esto puede maximizar la corrección refractiva total y lograr en el paciente una óptima calidad visual y una mejor calidad de vida. La corrección refractiva total no es fácil de lograr; no obstante, es posible y debe ser la meta de cada cirujano de catarata(AU)

The present literature review was aimed at finding out the surgical options for the preoperative and postoperative correction of astigmatism in the cataract surgery. The addressed topics were detailed preoperative studies that allow customized surgical planning as well as several current solutions including anartigmatic incisions in phacoemulsification and relaxing limbal incisions either combined or not and Excimer laser procedures. Several research studies comprising various years up to the present were consulted to learn about different results from the use of these surgical methods as well as the most state-of-the-art techniques under study such as fentosecond laser and light-adjustable intraocular lenses. All this may maximize the total refractive correction and achieve optimal visual quality and better quality of life for the patient. It is not easy to reach complete refractive correction but it is possible and should be the goal to be accomplished by every cataract surgeon(AU)

Caracterización morfológica de la superficie corneal posterior en córneas normales / Morphological characterization of the posterior corneal surface in normal corneas

OBJETIVO: describir las características de la superficie corneal posterior en córneas normales y las modificaciones de esta en pacientes a quienes se les realizó queratomileusis con láser in situ. MÉTODOS: fue realizado un estudio descriptivo, longitudinal y prospectivo en 282 ojos de pacientes que asistieron a la consulta de cirugía refractiva. Las variables estudiadas fueron: queratometría media central posterior, equivalente esférico, paquimetría óptica en la posición más delgada, astigmatismo topográfico anterior y posterior, astigmatismo refractivo y variación morfológica del mapa topográfico de elevación posterior respecto a la esfera de mejor ajuste. Fueron escogidos 27 ojos, los cuales reunían los criterios para cirugía refractiva láser y se les realizó la técnica queratomileusis con láser in situ. Se analizaron también las variables cantidad de ablación, estroma residual y diferencia de elevación posterior corneal, esta última obtenida del mapa de diferencia del tomógrafo Pentacam HR. RESULTADOS: la queratometría media posterior fue de -6,37 ± 0,22 dioptrías; la correlación entre la queratometría media posterior con respecto a la paquimetría óptica fue muy significativa (p= 0,008). La media de la diferencia de elevación máxima con respecto a la esfera de mejor ajuste posterior fue 5,33 µm; el 93,3 % de la muestra se encontraba dentro de valores normales. La diferencia de elevación posterior a través del tiempo fue de 18,38 µm ± 7,47 al mes y 14,95 µm ± 10,02. Se observó relación con la paquimetría y el estroma residual. CONCLUSIONES: la queratomileusis con láser in situ determina modificaciones en la superficie corneal posterior. El estroma residual es el factor más relacionado con estas modificaciones.

OBJECTIVE: to describe the characteristics of the posterior corneal surface in normal corneas and its changes in patients who underwent laser in situ keratomileusis. METHODS: prospective, longitudinal and descriptive study of 282 eyes from patients who went to the refractive surgery service. The studied variables were posterior central mean keratomery, spheral equivalent, optical pakimetry at the thinnest position, anterior and posterior topographic astigmatism, refractive astigmatism and morphological variation of the posterior elevation topographic map in relation to the best fit sphere. In this group, 27 eyes were selected, which met the criteria for laser refractive surgery using the laser in situ keratomileusis. Other analyzed variables were ablation amount, residual stroma and posterior corneal elevation difference, being the latter taken from the difference map outlined with the Pentacam HR tomography. RESULTS: mean posterior keratometry was -6,37 ± 0,22 dioptries; the correlation between mean posterior keratometry and optical pakimetry was very significant (p= 0,008). The mean difference of maximum elevation with respect to the best posterior fit sphere was 5,33 µm; 93,3 % of the sample was within the normal values. The correlation between the posterior elevation and the spheral equivalent was also significant (p= 0,019). The difference of the posterior elevation throughout the period was 18,38 µm ± 7,47 after a month and 14,95 µm ± 10,02 at the end of the period. There was correlation with pakimetry and residual stroma. CONCLUSIONS: laser in situ keratomileusis causes changes in the posterior corneal surface. The residual stroma is the factor most related with these changes.

Distrofia corneal de Schnyder / Schnyder crystalline dystrophy

La principal entidad hereditaria con depósitos de lípidos en el estroma corneal es la distrofia cristalina central, conocida como distrofia de Schnyder, quien la describió en Suiza en 1927. Se caracteriza por depósitos blanco-amarillentos en el estroma corneal central y superficial. Se presenta un paciente de 28 años, del sexo masculino y piel negra, con antecedente de salud anterior. Acudió a consulta y refirió una disminución de la visión y cambio de coloración progresiva de ambos ojos, de años de evolución. En la exploración oftalmológica de ambos ojos se apreciaron lesiones blanquecinas anulares a nivel del estroma corneal, con ligera turbidez corneal central. Los estudios refractivos realizados constataron un astigmatismo hipermetrópico simple. El resto del examen oftalmológico fue negativo. Para el diagnóstico de certeza se empleó el microscopio confocal. Se concluye que el caso presenta una distrofia corneal estromal de tipo cristalina, de Schnyder.

Central crystalline dystrophy known as Schnyder´s dystrophy, called like this because he was the first one to describe it in 1927 in Switzerland, is the main inherited entity with liquid deposits in the corneal stroma. This disease is characterized by white-yellow deposits into the central and superficial corneal stroma. A 28 years old black male patient, with previous history of health problems, went to the doctor´s office and mentioned visual reduction and progressive coloring changes in both eyes that had lasted some years. Ophthalmologic examination of both eyes showed annular white lesions at the corneal stroma, with light central corneal haze. Simple hypermetropic astigmatism was detected in the refractive exams. The rest of ophthalmologic exams was negative. For more secure diagnosis, confocal microscope was used. It was concluded that the patient had stromal corneal dystrophy, or Schnyder´s crystalline dystrophy.

Biometric Risk Factors for Corneal Neovascularization Associated with Hydrogel Soft Contact Lens Wear in Korean Myopic Patients

PURPOSE: To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. METHODS: This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. RESULTS: Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (> or =2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. CONCLUSIONS: High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.

Comparison of Surgically-induced Astigmatism after Combined Phacoemulsification and 23-Gauge Vitrectomy: 2.2-mm vs. 2.75-mm Cataract Surgery

PURPOSE: The 2.2-mm microincision cataract surgery and small-gauge vitrectomy system is known to result in less surgically-induced astigmatism (SIA) in comparison to conventional surgical methods. We compared the amounts of SIA after combined phacoemulsification and 23-gauge transconjunctival sutureless vitrectomy (23G-TSV) using the 2.2-mm microincision and 2.75-mm standard incision methods. METHODS: We studied 59 patients (61 eyes) who underwent combined phacoemulsification and 23G-TSV from November 2008 to September 2012. Twenty-eight patients (28 eyes) underwent 2.2-mm microincision coaxial phacoemulsification, and 31 patients (33 eyes) underwent 2.75-mm standard incision phacoemulsification. SIA was evaluated using Naeser's polar method with the simulated keratometric values obtained from corneal topography. Preoperative and 1-week and 1-month postoperative KP (Naeser's polar value along the specific axis) and DeltaKP values were compared between the 2.2-mm microincision and 2.75-mm standard incision groups. RESULTS: One week after surgery, both groups exhibited similar amounts of SIA (-DeltaKP[120], 0.40 +/- 0.41 vs. 0.51 +/- 0.56 diopters [D]; p = 0.390). One month after surgery, however, the amount of SIA was significantly smaller in the 2.2-mm microincision group as compared to the 2.75-mm standard incision group (-DeltaKP[120], 0.31 +/- 0.54 vs. 0.56 +/- 0.42 D; p = 0.045). CONCLUSIONS: In combined phacoemulsification with 23G-TSV, 2.2-mm microincision coaxial phacoemulsification induces less SIA than does 2.75-mm standard coaxial phacoemulsification.

Corneal topographic changes after 20-gauge pars plana vitrectomy associated with scleral buckling for the treatment of rhegmatogenous retinal detachment

PURPOSE: To evaluate the changes in corneal topography after 20-gauge pars plana vitrectomy associated with scleral buckling for the repair of rhegmatogenous retinal detachment. METHODS: Twenty-five eyes of 25 patients with rhegmatogenous retinal detachment were included in this study. 20-gauge pars plana vitrectomy associated with scleral buckling was performed in all patients. The corneal topography of each was measured before surgery and one week, one month, and three months after surgery by computer-assisted videokeratoscopy. RESULTS: A statistically significant central corneal steepening (average, 0,9 D , p<0,001) was noted one week after surgery. The total corneal astigmatism had a significant increase in the first postoperative month (p=0,007). All these topographic changes persisted for the first month but returned to preoperative values three months after the surgery. CONCLUSION: Pars plana vitrectomy with scleral buckling was found to induce transient changes in corneal topography.

OBJETIVO: Avaliar as alterações topográficas da córnea após a realização de vitrectomia via pars plana 20-gauge associada à introflexão escleral para o tratamento do descolamento de retina regmatogênico. MÉTODOS: Vinte e cinco pacientes com descolamento de retina regmatogênico foram incluídos neste estudo. Vitrectomia via pars plana 20-gauge associada à introflexão escleral foi realizada em todos os pacientes. O exame de topografia de córnea computadorizada de cada paciente foi realizado antes da cirurgia e ao sétimo dia, trigésimo dia e três meses após a cirurgia. RESULTADOS: Um aumento da curvatura corneana estatisticamente significativo foi encontrado no sétimo dia após a cirurgia (média 0,9 D, p<0,001). O astigmatismo corneano total teve um aumento significativo no primeiro mês pós-operatório (p=0,007).Todas as alterações topográficas persistiram no primeiro mês pós-operatório, mas retornaram aos valores pré-operatórios três meses após a cirurgia. CONCLUSÃO: A vitrectomia via pars plana associada à introflexão escleral pode induzir alterações transitórias na topografia corneana.

Is noncycloplegic photorefraction applicable for screening refractive amblyopia risk factors?

Purpose: To compare the accuracy of noncycloplegic photorefraction [NCP] with that of cycloplegic refraction [CR] for detecting refractive amblyopia risk factors [RARFs] and to determine cutoff points

Methods: In this diagnostic test study, right eyes of 185 children [aged 1 to 14 years] first underwent NCP using the Plusopti Chi SO4 photoscreener followed by CR. Based on CR results, hyperopia [>/=+3.5 D], myopia [>/=-3 D], astigmatism [>/=1.5 D], and anisometropia [>/=1.5 D] were set as diagnostic criteria based on AAPOS guidelines. The difference in the detection of RARFs by the two methods was the main outcome measure

Results: RARFs were present in 57 [30.8%] and 52 [28.1%] of cases by CR and NCP, respectively, with an 89.7% agreement. In contrast to myopia and astigmatism, mean spherical power in hyperopic eyes was significantly different based on the two methods [P<0.001], being higher with CR [+5.96 +/- 2.13 D] as compared to NCP [+2.37 +/- 1.36 D]. Considering CR as the gold standard, specificities for NCP exceeded 93% and sensitivities were also acceptable [>/=83%] for myopia and astigmatism. Nevertheless, sensitivity of NCP for detecting hyperopia was only 45.4%. Using a cutoff point of+1.87 D, instead of+3.5 D, for hyperopia, sensitivity of NCP was increased to 81.8% with specificity of 84%

Conclusion: NCP is a relatively accurate method for detecting RARFs in myopia and astigmatism. Using an alternative cutoff point in this study, NCP may be considered an acceptable device for detecting hyperopia as well

Resultados preliminares de um sistema de topografia de grande-ângulo usando videoceratógrafo com discos de Plácido / Preliminary results of a wide-angle corneal topography system for Placido-based videokeratographers

OBJETIVO: Desenvolver a instrumentação e o "software" para topografia de córnea de grande-ângulo usando o tradicional disco de Plácido. O objetivo é permitir o mapeamento de uma região maior da córnea para topógrafos de córnea que usem a técnica de Plácido, fazendo-se uma adaptação simples na mira. MÉTODOS: Utilizando o tradicional disco de Plácido de um topógrafo de córnea tradicional, 9 LEDs (Light Emitting Diodes) foram adaptados no anteparo cônico para que o paciente voluntário pudesse fixar o olhar em diferentes direções. Para cada direção imagens de Plácido foram digitalizadas e processadas para formar, por meio de algoritmo envolvendo elementos sofisticados de computação gráfica, um mapa tridimensional completo da córnea toda. RESULTADOS: Resultados apresentados neste trabalho mostram que uma região de até 100 por cento maior pode ser mapeada usando esta técnica, permitindo que o clínico mapeie até próximo ao limbo da córnea. São apresentados aqui os resultados para uma superfície esférica de calibração e também para uma córnea in vivo com alto grau de astigmatismo, mostrando a curvatura e elevação. CONCLUSÃO: Acredita-se que esta nova técnica pode propiciar a melhoria de alguns processos, como por exemplo: adaptação de lentes de contato, algoritmos para ablações costumizadas para hipermetropia, entre outros.

PURPOSE: To develop the instrumentation and software for wide-angle corneal topography using a Placido-based videokeratographer. The objective is to allow the measurement of a greater area of the cornea using a simple adaptation to the Placido mire. METHODS: Using the traditional Placido disc of a commercial corneal topographer, 9 LEDs (Light Emitting Diodes) were installed on the conic mire so that the voluntary patient could gaze in different directions. For each direction Placido images were acquired and processed to form, using a sophisticated computer graphics algorithm, a tridimensional map of the whole cornea. RESULTS: It was shown that up to 100 percent more area of the cornea may be mapped using the here described technique. We present results for a spherical surface calibration and also for a highly astigmatic cornea and analyze quantitatively the additional area that is recovered in terms of curvature and true elevation. CONCLUSIONS: We believe that this new technique opens opportunities for the improvement of other applications which might benefit from this additional information, such as: contact lens adaptation and design improvement, algorithms for customized refractive surgery, among others.

Análise comparativa entre a refração clínica subjetiva e a automatizada obtida por sensor de frentes de onda / Comparative analyses between clinical refraction and automatic refraction obtained through a wave front sensor

OBJETIVO: Avaliar e comparar os resultados obtidos da refração estática clínica com a obtida por sensor de frentes de onda. MÉTODOS: Estudo prospectivo, não seqüencial, de 279 olhos de 147 pacientes. Todos os pacientes foram examinados sob cicloplegia. Primeiro realizamos a refração clínica e a seguir a automatizada por sensor de frentes de onda. Os dados refracionais obtidos foram decompostos para análise vetorial. Foram analisados separadamente os dados de um olho por paciente e dos dois olhos. RESULTADOS: A diferença entre a refração clínica e a automatizada foi de -0,19 DE combinada com -0,06 DC no eixo de 15° para os dados de um olho por paciente e -0,17 DE combinada com -0,05 DC no eixo de 3° para todos os olhos da amostra. CONCLUSÃO: Os dados da refração clínica são comparáveis com os da refração obtida por um sensor de frentes de onda.

PURPOSE: To evaluate and compare refractive errors obtained through clinical subjective and automatized wavefront refraction analyses in eyes under cycloplegia. METHODS: Prospective study of 147 patients, 279 eyes, undergoing preoperative examination for refractive surgery. Clinical subjective refraction was performed first followed by wavefront refraction. Results on astigmatism obtained from refraction were decomposed in power vectors for statistical analyses. Data were first analyzed in one eye and then in both eyes. RESULTS: The mean difference between clinical subjective refraction and automatized wavefront refraction on cycloplegic eyes was of -0.19 SD combined with -0.06 CD in the 15° axis for data in one eye, and -0.17 SD combined with -0.05 CD in the 3° axis for data in both eyes of the same patient. CONCLUSION: In the present study clinical subjective refraction and automatized wavefront refraction under cycloplegia had similar numerical values.

Clinical evaluation of corneal astigmatism in non diabetic and diabetic patients.

This study aimed to measurement of corneal astigmatism in non diabetic and diabetic patient with Keratometry. This perspective study was conducted at Nepal Medical College Teaching Hospital from March to June 2004 to find out clinical evaluation of corneal astigmatism in non diabetic and diabetic patients. A total 224 patients were include. Corneal astigmatism readings with the Takagi KM-1 Sutcliff type Keratometry was obtained by single examiners on 130 non diabetic patients (where as 112 right eye and 109 left eye) and 94 diabetic patients (both eyes) corneas. Corneal dioptric and magnitude of astigmatism were assessed. Average corneal diopters were 43.88 and 43.81 in non diabetic and diabetic cases. Average corneal astigmatism was 0.30 D and 0.07D in non diabetic and diabetic cases. Less astigmatism present on diabetic patient to compare non diabetic patients in total and both sex. Chances of diabetes mellitus are more visible in non astigmatism patient compare to astigmatism patients in both sexes (Table-1 and 2). No difference in astigmatic rule i.e. with the rule astigmatism in both diabetic and non diabetic patients but less astigmatism present in diabetic one.

Prevalência de astigmatismo refracional e sua relação com a acuidade visual de resolução em crianças de 2 a 36 meses / Refractional astigmatism prevalence and its relationship with grating acuity in children 2 to 36 months of age

OBJETIVO: A prevalência do astigmatismo refracional e sua relação com a acuidade visual de resolução foram avaliados em amostra de crianças pré-verbais. MÉTODOS: Foram submetidas a exame oftalmológico 482 crianças normais com idades variando entre 2 e 36 meses. Após exclusão da amostra de 14 crianças com evidências de doenças oculares que pudessem alterar a acuidade visual, permaneceram 468 crianças (936 olhos), sendo 230 (49 por cento) do sexo masculino e 238 (51 por cento) do feminino. Todas foram submetidas a exame de acuidade visual binocular e monocular pelo procedimento do olhar preferencial através do método dos cartões de acuidade de Teller. Foi realizado em todas as crianças exame de refração sob cicloplegia e fundoscopia com oftalmoscópio indireto. RESULTADOS: O astigmatismo foi encontrado em 222 (47,43 por cento), crianças da amostra, com predomínio do tipo hipermetrópico composto e da forma a favor da regra em todas as faixas etárias. Em relação à magnitude, esta ametropia foi maior ou igual a 1,00 dioptria cilíndrica em 24,35 por cento dos sujeitos, maior ou igual a 1,00 dioptria cilíndrica em 24,35 por cento dos sujeitos, maior ou igual a 2,00 dioptrias cilíndricas em 5,55 por cento, menor que 1,00 dioptria cilíndrica em 26,92 por cento e maior ou igual a 1,00 dioptria cilíndrica e menor que 2,00 dioptrias cilíndricas em 18,73 por cento. A acuidade visual esteve dentro da faixa de normalidade em 219 crianças da amostra, independentemente da magnitude, tipo e orientação do astigmatismo. CONCLUSÃO: A acuidade visual de resolução medida pelo método dos cartões de acuidade de Teller não foi influenciada pelo astigmatismo.

Irregular astigmatism after corneal refractive surgery an overview of the state of the Art

Irregular astigmatism is a challenging problem for the refractive surgeon. The aim of this paper is to describe the authors' experience and a present a literature review of the latest advances in the diagnosis and management of this difficult complication. We present a compilation of the different alternatives to treat irregular astigmatism secondary to corneal refractive surgery, as well as an innovative method to quantify the degree of irregular astigmatism, taking into account the clinical symptoms and the corneal aberrometric data. The outcome of the different choices to treat irregular astigmatism are presented, from contact lens fitting to the most recent ablative techniques based on corneal wavefront. Although irregular astigmatism is still one of the worst complications of refractive surgery, the better knowledge of the causes, the enhanced diagnostic devices and the improvement of the refractive surgical techniques have given the refractive surgeon a wide set of alternatives to improve the patients visual performance, and to avoid unwanted litigations.

Apresentação atípica de degeneração marginal pelúcida: relato de caso / Atypical presentation of pellucid marginal degeneration: case report

Os autores relatam o caso de paciente jovem do sexo masculino que desenvolveu quadro de degeneração marginal pelúcida bilateral atípica, com afinamento corneal periférico de 360°, abordando ainda os aspectos dos mapas topográficos e os resultados obtidos com a paquimetria ultra-sônica, além do tratamento adotado.

Guidelines for prescribing optical correction in children.

As the eye grows, the axial length increases while the cornea and lens flatten. High refractive errors which are common in the neonatal period, reduce rapidly during the first year of life through the process called emmetropization. The possibility that long-term full- time glasses wear may impede emmetropization must be considered. Hyperopia greater than 5.00 diopters (D) in young children is associated with an increased risk of amblyopia and strabismus, therefore optical correction should be prescribed. When hyperopia is associated with esotropia, full correction of the cycloplegic refractive error should be prescribed. Myopia greater than 8.00 D and astigmatism greater than 2.50 D are common causes of isometropic amblyopia. Patients with hyperopic anisometropia with as little as l D difference between the eyes may develop amblyopia while the difference should reach 3-4 D for myopic anisometropia to develop amblyopia. Full cycloplegic refractive difference between two eyes should be given to the anisometropic child in spite of age, strabismus and degree of anisometropia. Myopia control is the attempt to slow the rate of progression of myopia such as cycloplegic agents, plus lenses at near, and rigid contact lenses.