The relationship between clinical measures of aniseikonia and stereoacuity before and after LASIK / Relación entre las mediciones clínicas de aniseiconía y estereoagudeza antes y después de la cirugía LASIK

PURPOSE: To determine the significance of changes and and inter-relationships between three markers of binocular function (aniseikonia, distance and near stereoacuity) following unremarkable LASIK at 3 and 6 months postoperatively. METHODS: All patients underwent LASIK using the Schwind Amaris 750S and the flaps were created using Intralase 150 kHz. Patients were I, monocular myopes II, binocular myopes III, binocular hyperopes IV, binocular astigmats V, anisometropes and VI, matched age and gender control (n = 20 in each group except III where n = 18). Aniseikonia (Awaya test), distance and near stereoacuity (Randot tests) were measured before surgery, and at 3 and 6 months after surgery. At all times data were collected under constant conditions and analyzed using appropriate non-parametric statistical tests. RESULTS: The following statistically significant changes were found after applying the Bonferroni correction (p ≤ 0.001); aniseikonia reduced (groups I, III, IV, V), stereoacuity improved at distance (groups I, III-V) and near (groups I, V). Inter-group differences in aniseikonia distance and near stereoacuity were significant preoperatively, but not postoperatively. In groups I, IV and V, the changes in aniseikonia and stereoacuity (near and distance) were significantly correlated with the preoperative value. Aniseikonia was significantly correlated with distance and near stereoacuity preoperatively but not postoperatively. CONCLUSION: Binocular function improved in all groups after LASIK except in binocular myopes. In general, binocular function was still low compared with the control group at six months postoperatively. It is unclear why binocular function improved in the binocular astigmats

OBJETIVO: Determinar la significancia de cualquier cambio, así como las interrelaciones entre tres marcadores de la función binocular (aniseiconía, estereoagudeza de lejos y de cerca) tras LASIK sin complicaciones a los 3 y 6 meses postoperatorios. MÉTODOS: A todos los pacientes se les realizó cirugía LASIK con el laser Schwind Amaris 750S, creándose los flaps con Intralase 150 kHz. Los grupos de pacientes fueron: I miopes monoculares, II miopes binoculares, III hipermétropes binoculares, IV astígmatas binoculares, V anisométropes y VI controles equivalentes en edad y género (n = 20 en cada grupo, exceptuando III donde n = 18). Se midió la aniseiconía (prueba de Awaya), la estereoagudeza de lejos y de cerca (pruebas Randot) durante el preoperatorio, y a los 3 y 6 meses posteriores a la cirugía. En todo momento se recabaron los datos en condiciones constantes, analizándose los mismos con pruebas estadísticas no paramétricas adecuadas. RESULTADOS: Se encontraron los siguientes cambios estadísticamente significativos tras aplicar la corrección de Bonferroni (p ≤ 0,001); se redujo la aniseiconía (grupos I, III, IV, V), y mejoró la estereoagudeza de lejos (grupos I, III-V) y de cerca (grupos I, V). Las diferencias inter-grupo en cuanto a aniseiconía de lejos y de cerca y la estereoagudeza de cerca fueron significativas en el preoperatorio, pero no en el postoperatorio. En los grupos I, IV y V, los cambios en cuanto a aniseiconía y estereoagudeza (de cerca y de lejos) guardaron una correlación significativa con el valor preoperatorio. La aniseiconía guardó una correlación significativa con la estereoagudeza de lejos y de cerca en el preoperatorio, pero no el postoperatorio. CONCLUSIÓN: La función binocular mejoró en todos los grupos tras la cirugía LASIK, excepto en la miopía binocular. En general, la función binocular fue aún baja al compararse con el grupo control a los seis meses postoperatorios. No queda claro por qué la función binocular mejoró en el astigmatismo binocular

The relationship between clinical measures of aniseikonia and stereoacuity before and after LASIK.

PURPOSE: To determine the significance of changes and and inter-relationships between three markers of binocular function (aniseikonia, distance and near stereoacuity) following unremarkable LASIK at 3 and 6 months postoperatively. METHODS: All patients underwent LASIK using the Schwind Amaris 750S and the flaps were created using Intralase 150 kHz. Patients were I, monocular myopes II, binocular myopes III, binocular hyperopes IV, binocular astigmats V, anisometropes and VI, matched age and gender control (n = 20 in each group except III where n = 18). Aniseikonia (Awaya test), distance and near stereoacuity (Randot tests) were measured before surgery, and at 3 and 6 months after surgery. At all times data were collected under constant conditions and analyzed using appropriate non-parametric statistical tests. RESULTS: The following statistically significant changes were found after applying the Bonferroni correction (p ≤ 0.001); aniseikonia reduced (groups I, III, IV, V), stereoacuity improved at distance (groups I, III-V) and near (groups I, V). Inter-group differences in aniseikonia distance and near stereoacuity were significant preoperatively, but not postoperatively. In groups I, IV and V, the changes in aniseikonia and stereoacuity (near and distance) were significantly correlated with the preoperative value. Aniseikonia was significantly correlated with distance and near stereoacuity preoperatively but not postoperatively. CONCLUSION: Binocular function improved in all groups after LASIK except in binocular myopes. In general, binocular function was still low compared with the control group at six months postoperatively. It is unclear why binocular function improved in the binocular astigmats.