Espesor coroideo en población pediátrica y su relación con el defecto refractivo y la presencia de ambliopía
- Autores: Cristina Del Prado Sánchez
- Directores de la Tesis: Alfonso Arias Puente (dir. tes.), Olga Seijas Leal (codir. tes.)
- Lectura: En la Universidad de Alcalá ( España ) en 2022
- Idioma: español
- Tribunal Calificador de la Tesis: José Manuel Ramírez Sebastián (presid.), Miguel Ángel Teus Guezala (secret.), Laura Cabrejas Martínez (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencias de la Visión por la Universidad Complutense de Madrid; la Universidad de Alcalá; la Universidad de Murcia; la Universidad de Santiago de Compostela y la Universidad de Valladolid
- Materias:
- Enlaces
- Resumen
- español
Introducción: La coroides es la capa vascular del ojo. Estudios han demostrado que el desenfoque miópico o hipermetrópico es compensado con cambios en la longitud axial y en el espesor coroideo. En 2008, Spaide et Al describieron la técnica de obtención de imágenes con profundidad mejorada, que permite el análisis no invasivo in vivo de la coroides.
Justificación, hipótesis, objetivos: estudios en población pediátrica han concluido que el espesor coroideo está asociado positivamente con el equivalente esférico, siendo menor en miopes. Además, algunos autores concluyen que el espesor es mayor en ojos ambliopes. La hipótesis de este trabajo es que el espesor coroideo en menores de 16 años se ve influido por el defecto refractivo, pero no por la presencia de ambliopía. Los objetivos principales de este trabajo son determinar el espesor coroideo medio en pacientes pediátricos con hipermetropía baja, moderada-alta y miopes, así como en pacientes ambliopes, y valorar su relación con el defecto refractivo y la ambliopía.
Material y métodos: este trabajo consta de dos partes, la primera se realizó como un estudio observacional prospectivo y la segunda como un estudio observacional transversal. Ambos estudios están constituidos por tres grupos de pacientes sanos menores de 16 años: el grupo 1 incluye ojos con equivalente esférico negativo, el grupo 2 ojos con equivalente esférico entre 0 y +2 dioptrías y el grupo 3 ojos con equivalente esférico mayor de +2 dioptrías. A todos los pacientes se les realizó una tomografía de coherencia óptica, empleando cortes horizontales de alta resolución para estudio de coroides. A los pacientes del estudio prospectivo, además, se les realizó la medida de la longitud axial. Se analizaron las medias de espesor coroideo, macular central y de la capa de células ganglionares por grupo refractivo y en función de la presencia o no de ambliopía y se estudió la correlación en función del grupo, el sexo, la edad y la longitud axial.
Resultados: Se incluyeron un total de 266 ojos de 135 pacientes. Como parte del estudio prospectivo se encontró un espesor coroideo medio basal de 338,44 +/- 82,76 µm y 325,49 +/- 73,90 µm a los 12 meses. El espesor medio de la capa de células ganglionares al inicio fue 84,26 +/- 8,07 µm y 83,35 +/- 7,81 µm al final del seguimiento. El espesor macular central medio basal fue 248,67 +/- 21,46 µm y 253,52 +/- 20,77 µm a al año. La longitud axial media basal fue 22,89 +/- 1,10 mm y 23,10 +/- 1,01 mm a los 12 meses de seguimiento. Durante el estudio transversal el espesor coroideo subfoveolar medio fue 348 +/- 85,03µm, siendo 313,28 +/- 81,79µm en el grupo 1, 366,80 +/- 80,37µm en el grupo 2 y 378,22 +/- 77,23µm en el grupo 3. Por otro lado, el espesor coroideo subfoveolar medio en ojos no ambliopes fue de 346,69 +/- 85,29 µm y de 363,33 +/- 82,33 µm en ojos ambliopes. El espesor de la capa de células ganglionares fue 83,69 +/- 8,98 µm, siendo 81,85 +/- 8,40µm en el grupo 1, 84,19 +/- 9,79µm en el grupo 2 y 85,86 +/- 8,41µm en el grupo 3. Respecto a la presencia de ambliopía, el espesor medio en ojos no ambliopes fue de 84,19 +/- 8,12 µm y de 77,90 +/- 15,08 µm en los ambliopes. El espesor macular central medio fue 251,63 +/- 20,39µm, siendo 252,29 +/- 19,67µmen el grupo 1, 253,02 +/- 22,09µmen el grupo 2 y 249,03 +/- 19,43µm en el grupo 3. Por otro lado, en ojos no ambliopes fue de 250,83 +/- 19,84 µm y de 260,90 +/- 24,66 µm en ojos ambliopes.
Conclusiones: Se concluyó que el espesor coroideo subfoveolar en pacientes pediátricos se ve influido por el defecto refractivo, pero no por la presencia de ambliopía. Adicionalmente, se halló una correlación negativa y estadísticamente significativa con la longitud axial. También se encontró que el espesor era mayor en niñas. No se encontró correlación estadísticamente significativa con la edad.
- English
Introduction: The choroid is the posterior uvea or vascular layer of the eye. It has multiple functions, the main one being the metabolic support of the external retina. The influence of this layer on the emmetropization and refraction process has been studied mainly in animal models. These studies have shown that myopic or hyperopic blurred vision is compensated for by changes in axial length and choroidal thickness. In 2008, Spaide et al. described the “Enhanced Depth Imaging” (EDI) technique, which allows a non-invasive in vivo analysis of the choroid and, therefore, a better understanding of its structural characteristics.
Justification, hypothesis and objectives: The speed and simplicity of the analysis of the choroid which allows the latest technology developed facilitates the study of this vascular layer and its relationship with other variables. In recent years, multiple studies have been carried out in adults that conclude that choroidal thickness decreases with age, myopia, and greater axial length. Likewise, some studies have been carried out in the pediatric population, the majority in the Asian population, which conclude that the choroidal thickness is positively associated with the spherical equivalent, the thickness being less in myopic patients. Furthermore, some authors have hypothesized that the choroidal thickness would be influenced by the presence of amblyopia, concluding that the thickness is greater in amblyopic eyes. The hypothesis of this work is that choroidal thickness in children under 16 years of age is influenced by the refractive defect, but not by the presence of amblyopia. The main objectives of this work are to determine the mean choroidal thickness in pediatric patients with low, moderate, and high hyperopia, and myopic patients, as well as in amblyopic patients, and to evaluate its relationship with refractive error and amblyopia. The secondary objectives of the work are to study the correlation of choroidal thickness with sex, age, and axial length, to determine the relationship between the axial length and the refractive defect, to determine the central macular and the ganglion cell layer thickness in pediatric patients with low, moderate-high hyperopia, and myopic, both healthy and amblyopic patients, as well as their correlation with sex, age, and axial length.
Material and methods: This work consists of two consecutive parts, the first of which was conducted as a nonrandomized prospective comparative observational study and the second as a nonrandomized cross-sectional observational study. Both studies are made up of three groups of patients: group 1 includes eyes with a negative spherical equivalent (myopic eyes), eyes of group 2 with a spherical equivalent between 0 and +2 diopters (eyes with low hyperopia), and eyes of group 3 with a spherical equivalent greater than +2 diopters (eyes with moderate-high hyperopia). Healthy patients under 16 years of age with adequate collaborative capacity were recruited to perform an optical coherence tomography and biometry. Patients with a history of ocular or systemic pathology with ocular involvement and those who had received prior ophthalmological medical or surgical treatment were excluded. All patients underwent a complete ophthalmological examination. Subsequently, an optical coherence tomography was performed with Cirrus 5000 HD-OCT (Carl Zeiss Meditec), using high-resolution horizontal slices for the study of the choroid (EDI). In addition, patients in the prospective study had axial length measured using IOL Master (Carl Zeiss Meditec). During the prospective study, examinations and tests were performed at the time of inclusion, at 6 and 12 months. Choroidal thickness measurement was performed manually between the outer edge of the retinal pigment epithelium and the inner scleral edge, following a vertical path between these limits, at the subfoveal level. Choroidal, central macular, and ganglion cell thicknesses were analyzed by refractive group and according to the presence or absence of amblyopia, and the correlation according to the group, sex, age, and axial length was studied.
Results: A total of 266 eyes of 135 patients were included. In the first place, as part of the non-randomized prospective study, 97 non-amblyopic eyes belonging to 51 patients were analyzed, with a mean age of 9.13 +/- 2.83 years (range 5 to 15). 58.8% of the eyes were from female patients. Group 1 included 41 eyes with a negative spherical equivalent (myopia); Group 2 included 34 eyes with a spherical equivalent between 0 and +2 diopters (low hyperopia); Group 3 included 22 eyes with a 13 spherical equivalent greater than +2 diopters (moderate-high hyperopia). The mean refractive error at the time of inclusion was + 0.39D +/- 2.37 (range -6.00 to +6.75) and +0.15D +/- 2.46 (range -6.00 to +6.75) at the end of the follow-up. The mean baseline choroidal thickness was 338.44 +/- 82.76 µm and 325.49 +/- 73.90 µm at 12 months. The mean thickness of the ganglion cell layer at baseline was 84.26 +/- 8.07 µm and 83.35 +/- 7.81 µm at the end of follow-up. Baselines mean central macular thickness was 248.67 +/- 21.46 µm and 253.52 +/- 20.77 µm a year. The mean baseline axial length was 22.89 +/- 1.10 mm and 23.10 +/- 1.01 mm at the 12-month follow-up. Statistically significant differences (p <0.001) were found in axial length between the three groups, being greater in myopic eyes. A negative and statistically significant correlation was found between axial length and subfoveolar choroidal thicknesses (P <0.001, Pearson = -0.278) and ganglion cell layer (P <0.001, Pearson = -0.305), but no such correlation was found with central macular thickness. No statistically significant differences were found in subfoveolar choroidal or ganglion cell thicknesses throughout the study time, but an increase in central macular thickness and axial length was detected. However, a positive and statistically significant correlation was found between axial length and age. On the other hand, as part of the non-randomized cross-sectional study, 266 eyes belonging to 135 patients were analyzed, with a mean age of 9.18 +/- 2.83 years (range 3 to 15). 58.3% of the eyes were girls. Group 1 included 109 eyes with negative spherical equivalent (myopia); Group 2 included 84 eyes with a spherical equivalent between 0 and +2 diopters (low hyperopia); Group 3 included 73 eyes with a spherical equivalent greater than +2 diopters (moderate-high hyperopia). 245 eyes analyzed were non-amblyopes and 21 were amblyopes secondary to anisometropia. The mean subfoveolar choroid thickness was 348 +/- 85.03µm, being 313.28 +/- 81.79µm in group 1, 366.80 +/- 80.37µm in group 2 and 378.22 +/- 77, 23µm in group 3. The subfoveolar choroidal thickness was significantly lower (p <0.001) in group 1 (myopic eyes). On the other hand, the mean subfoveolar choroid thickness in non-amblyopic eyes was 346.69 +/- 85.29 µm and 363.33 +/- 82.33 µm in amblyopic eyes. The thickness of the ganglion cell layer was 83.69 +/- 8.98 µm, being 81.85 +/- 8.40 µm in group 1, 84.19 +/- 9.79 µm in group 2 and 85, 86 +/- 8.41 µm in group 3. The thickness of the ganglion cell layer was significantly lower (p <0.001) in myopic eyes, compared to eyes with moderate-high hyperopia. Regarding the presence of amblyopia, the mean thickness in non-amblyopic eyes was 84.19 +/- 8.12 µm and 77.90 +/- 15.08 µm in amblyopes. The mean central macular thickness was 251.63 +/- 20.39µm, with 252.29 +/- 19.67µm in group 1, 253.02 +/- 22.09µm in group 2 and 249.03 +/- 19 43µm in group 3. No statistically significant differences were found (P = 0.430). On the other hand, in nonamblyopic eyes it was 250.83 +/- 19.84 µm and 260.90 +/- 24.66 µm in amblyopic eyes. In none of the three variables were statistically significant differences found between the groups of healthy eyes and amblyopes. Regarding sex, it was found that the subfoveolar choroid thickness was greater in girls (P = 0.014), being 358.52 +/- 89.706 µm in these and 333.32 +/- 76.004 µm in boys. In contrast, the central macular thickness was higher in boys (P <0.001), with values of 258.81 +/- 19.83 µm in these and 246.48 +/- 19.25 µm in girls. However, no statistically significant differences were found in the thickness of the ganglion cell layer. Regarding age, a statistically significant positive correlation was found with the central macular thickness (P = 0.002 *, Pearson = 0.192), but no correlation was found with subfoveolar choroidal thickness or ganglion cell layer.
Conclusion: First, it was concluded that an optical coherence tomography is a valuable tool in the study of the choroid in pediatric patients. Regarding the subfoveolar choroidal thickness, it was concluded that in pediatric patients it is influenced by the refractive error, but not by the presence of amblyopia. Furthermore, a negative and statistically significant correlation was found with axial length. The thickness was also found to be greater in girls and this difference was statistically significant. However, no statistically significant correlation was found with age. Regarding macular thickness, no statistically significant differences were found between the different refractive groups, nor were they found when comparing amblyopic and nonamblyopic eyes. On the contrary, differences were found in the analysis by sex and age, being higher in girls and having a positive correlation with age. There was also no correlation with axial length. Regarding the thickness of the ganglion cell layer, it was found significantly less in myopic eyes, while no differences were found in the analysis by sex or age. Furthermore, a negative and statistically significant correlation with axial length was demonstrated. Finally, a positive and statistically significant correlation was found between central and subfoveolar choroidal macular thickness, as well as that of the ganglion cell layer.
- español
