Comparabilidad del autorrefractómetro portátil Retinomax K-plus 3 en modo rápido versus autorrefractómetro de sobremesa en modo estándar / Comparability of the Retinomax K-plus 3 handheld autorefractometer in quick mode versus on-table autorefractometer in standard mode

I ntroducción Este estudio analiza la comparabilidad de las medidas tomadas por un autorefractómetro portátil Retinomax K-plus 3 en modo Quick (rápido) y un autorrefractómetro de sobremesa Topcon KR-800 en modo estándar sobre la población pediátrica, y establece su correlación. Método Es un estudio comparativo retrospectivo. Se midieron las variables potencia dióptrica esférica (SPH), potencia dióptrica cilíndrica (CYL), ángulo del eje cilíndrico (AX) y equivalente esférico (SE) con el Retinomax en modo Quick y con el Topcon en modo estándar. Cada paciente fue evaluado en condiciones ciclopléjicas y no ciclopléjicas por ambos autorefractómetros. Se realizó la prueba t de Student entre ambos instrumentos para SPH, CYL y SE. Se calculó el coeficiente de correlación de Pearson y se representó la dispersión mediante gráficas de Bland-Altman, evaluándose también el subgrupo de pacientes menores de 4 años. Se realizó un análisis descriptivo de los porcentajes de medidas que diferían. Resultados Incluyó 98 ojos de 49 sujetos (rango de edad: 3-16 años). Los datos de SPH sin cicloplejia son prácticamente idénticos, mientras que con cicloplejia hay un sesgo hipermetrópico de +0,5 dioptrías medidas con Retinomax. Los resultados de CYL son muy similares con y sin cicloplejia. Existe una gran correlación de Pearson para ambos instrumentos (>0,91) y un bajo grado de dispersión en los gráficos de Bland-Altman bajo cicloplejia. Conclusión Los datos del Retinomax fueron consistentes con los obtenidos por el Topcon. El Retinomax es un instrumento útil para detectar errores de refracción en niños de entre 3 y 16 años (AU)

Introduction This study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation. Methods It is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student's t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed. Results It included 98 eyes of 49 subjects (age range: 3-16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia. Conclusion The Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age (AU)

Comparability of the Retinomax K-plus 3 handheld autorefractometer in quick mode versus on-table autorefractometer in standard mode.

INTRODUCTION: This study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in Quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation. METHODS: It is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in Quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student's t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed. RESULTS: It included 98 eyes of 49 subjects (age range: 3-16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia. CONCLUSION: The Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age.

El efecto del uso prolongado y nocturno de las lentes de contacto en la córnea. A propósito de un caso de descompensación corneal y descenso del recuento endotelial / The effect of prolonged and nocturnal use of contact lenses on the cornea: About a case of corneal decompensation and decreased endothelial count

El edema corneal y la disminución del recuento de células endoteliales son complicaciones relacionadas con la hipoxia crónica de bajo grado, que experimentan los usuarios de lentes de contacto, principalmente debido al uso prolongado y nocturno. Este caso muestra el ejemplo de un paciente que presenta problemas de visión borrosa en ambos ojos, y a quien se le realizó un examen oftalmológico completo que incluyó fotografías, topografía corneal y conteo de células endoteliales. Posteriormente se revisa el metabolismo corneal, la etiopatogenia y las complicaciones derivadas del uso de lentes de contacto (AU)

Corneal edema and decreased endothelial cell count are complications related to chronic low-grade hypoxia experienced by contact lens wearers, primarily due to prolonged and overnight wear. This case shows the example of a patient who has blurred vision problems in both eyes and who underwent a complete ophthalmologic examination that included photographs, corneal topography and endothelial cell count. Subsequently, the corneal metabolism, the etiopathogenesis and the complications derived from the use of contact lenses are reviewed (AU)

The effect of prolonged and nocturnal use of contact lenses on the cornea: about a case of corneal decompensation and decreased endothelial count.

Corneal edema and decreased endothelial cell count are complications related to chronic low-grade hypoxia experienced by contact lens wearers, primarily due to prolonged and overnight wear. This case shows the example of a patient who has blurred vision problems in both eyes and who underwent a complete ophthalmologic examination that included photographs, corneal topography and endothelial cell count. Subsequently, the corneal metabolism, the etiopathogenesis and the complications derived from the use of contact lenses are reviewed.

Lesión permanente de las capas internas de la retina en una paciente con migraña: un caso diferente de maculopatía paracentral aguda media / Permanent damage of the inner retinal layers in a patient with migraine: A different case of paracentral acute middle maculopathy

Presentamos el caso de una paciente mujer de 20 años que consultó por un escotoma paracentral en su ojo izquierdo que no había desaparecido después de una crisis de migraña 2 días antes. La exploración realizada evidenció la presencia de 2 áreas de palidez retiniana sugestivas de isquemia aguda. Tras descartar varias causas de isquemia retiniana aguda, se llegó al diagnóstico de un síndrome vasoespástico retiniano. Un año después, la paciente presenta una atrofia de las capas internas de la retina afectada y sufre un escotoma paracentral crónico en su ojo izquierdo. Los vasoespasmos retinianos pueden provocar un daño irreversible y crónico debido a la destrucción tisular por la isquemia. Este inusual caso describe una lesión permanente secundaria a un vasoespasmo arterial tras una crisis de migraña. El hallazgo de lesiones retinianas características y la historia de migraña hacen el diagnóstico compatible con un episodio de maculopatía paracentral aguda media (AU)

We report the case of a 20-year-old patient who presented a paracentral scotoma in her left eye that had not disappeared after a migraine attack 2 days before. Ocular examination showed 2 pale paracentral areas suggesting an acute ischemia insult. Several causes of retinal ischemia were ruled out and the patient was diagnosed with secondary retinal vasospasm. One year later, the patient suffers an atrophy of the inner layers of the affected retina and has a paracentral chronic scotoma in her left eye. Retinal vasospasms can result in irreversible lesions and chronic symptoms due to ischemia and cell destruction. This unusual case reports a permanent damage due to retinal vasospasm secondary to migraine attack. The finding of typical lesions and the history of migraine could be compatible with the diagnosis of paracentral acute middle maculopathy (AU)

Permanent damage of the inner retinal layers in a patient with migraine: a different case of paracentral acute middle maculopathy.

We report the case of a 20-year-old patient who presented a paracentral scotoma in her left eye that had not disappeared after a migraine attack two days before. Ocular examination showed two pale paracentral areas suggesting an acute ischemia insult. Several causes of retinal ischemia were ruled out and the patient was diagnosed with secondary retinal vasospasm. One year later, the patient suffers an atrophy of the inner layers of the affected retina and has a paracentral chronic scotoma in her left eye. Retinal vasospasms can result in irreversible lesions and chronic symptoms due to ischemia and cell destruction. This unusual case reports a permanent damage due to retinal vasospasm secondary to migraine attack. The finding of typical lesions and the history of migraine could be compatible with the diagnosis of paracentral acute middle maculopathy (PAMM).

Límites de la precisión en el resultado refractivo tras la cirugía de cataratas / Limits of the precision in refractive results after cataract surgery

Antecedentes y objetivo Para mejorar los resultados refractivos en cirugía de cataratas con implante de lente intraocular es importante conocer las fuentes de error, así como el límite de mejora de dicho proceso. Por tanto, el objetivo del presente trabajo es aproximar el límite teórico en la precisión en el resultado refractivo tras cirugía de cataratas con los medios disponibles en la actualidad y valorar el impacto de distintas fuentes de error en dicho proceso. Materiales y métodos Realizamos una búsqueda de la bibliografía para determinar la variabilidad aportada por cada componente del proceso. Tomando como base la fórmula de Barrett Universal-II realizamos un análisis de propagación de errores. El límite teórico fue definido como la situación en la que el resultado refractivo únicamente está afectado por la variabilidad en los parámetros introducidos en la fórmula, la tolerancia de la lente intraocular y la refracción subjetiva. Resultados Los principales contribuidores al error fueron: 1. La variabilidad intraoperatoria y postoperatoria, variables no consideradas por las fórmulas (49,33%). 2. La refracción subjetiva postoperatoria (38,29%). 3. La queratometría media (5,98%), y 4. la variabilidad en el etiquetado de la potencia de la lente intraocular (5,09%). El límite teórico obtenido para el cálculo de lente intraocular con los medios disponibles actualmente fue del 91,9% de los ojos entre + -0,50D. Conclusiones El límite teórico de la precisión es de 91,92% de los ojos entre + - 0,5D. Para aproximarnos al límite de precisión descrito en el estudio requiere de la utilización de biometría óptica y fórmulas de última generación, una técnica quirúrgica reproducible y la compensación de los errores sistemáticos mediante el ajuste de constantes (AU)

Background and objective In order to improve refractive results in cataract surgery with an intraocular lens implant, it is important to know the sources of error as well as the limit of this process. Therefore, the objective of the present work is to approximate the theoretical limit in the precision in the refractive result after cataract surgery with the currently available means and to assess the impact of different sources of error in this process. Materials and methods We conducted a search of the literature to determine the variability provided by each component of the process. Based on the Barrett Universal-II formula, we performed an error propagation analysis. The theoretical limit was defined as the situation in which the refractive result is only affected by the variability in the parameters introduced in the formula, the tolerance of the intraocular lens and the subjective refraction Results The main contributors to the error were: 1. Intraoperative and postoperative variability variables not considered by the formulas (49.33%). 2. Postoperative subjective refraction (38.29%). 3. Mean keratometry (5.98%), and 4. the variability in the labelling of the power of the intraocular lens (5.09%). The theoretical limit obtained for the intraocular lens calculation with the means available today was 91.9% of the eyes between + -0.50D. Conclusions We found a theoretical limit for the intraocular lens calculation of 91.9% of the eyes between + -0.50D. Approaching the precision limit described in the study requires the use of optical biometrics and state-of-the-art formulas, a reproducible surgical technique, and the compensation of systematic errors by adjusting constants (AU)

Limits of the precision in refractive results after cataract surgery.

BACKGROUND AND OBJECTIVE: In order to improve refractive results in cataract surgery with an intraocular lens implant, it is important to know the sources of error as well as the limit of this process. Therefore, the objective of the present work is to approximate the theoretical limit in the precision in the refractive result after cataract surgery with the currently available means and to assess the impact of different sources of error in this process. MATERIALS AND METHODS: We conducted a search of the literature to determine the variability provided by each component of the process. Based on the Barrett Universal-II formula, we performed an error propagation analysis. The theoretical limit was defined as the situation in which the refractive result is only affected by the variability in the parameters introduced in the formula, the tolerance of the intraocular lens and the subjective refraction. RESULTS: The main contributors to the error were (1) intraoperative and postoperative variability variables not considered by the formulas (49.33%), (2) postoperative subjective refraction (38.29%), (3) mean keratometry (5.98%) and (4) the variability in the labelling of the power of the intraocular lens (5.09%). The theoretical limit obtained for the intraocular lens calculation with the means available today was 91.9% of the eyes between ±0.50D. CONCLUSIONS: We found a theoretical limit for the intraocular lens calculation of 91.9% of the eyes between ±0.50D. Approaching the precision limit described in the study requires the use of optical biometrics and state-of-the-art formulas, a reproducible surgical technique, and the compensation of systematic errors by adjusting constants.