El ángulo papila-fóvea y la torsión ocular compensatoria, clave en su interpretación / Disc-foveal angle and ocular counterrolling as a key in its interpretation

OBJETIVO: Describir una técnica rápida para medir el ángulo papila-fóvea (APF), determinar sus valores normales y su relevancia a la hora de analizar retinografías apareadas. MÉTODOS: En 20 sujetos se realizaron 440 retinografías (3 D OCT-2000, Topcon Corporation, Tokio, Japón) en 11 posiciones diferentes de la cabeza (cervical range of motion [CROM], Performance Attainment Associates). Se analizó el APF mediante el programa Keynote v.6.2.2 y se estudió la reproducibilidad y correlación entre los retinógrafos 3 D OCT-2000 y TRC-50EX (Topcon Corporation, Tokio, Japón). RESULTADOS: La media del APF en el ojo derecho (OD) y en el ojo izquierdo (OI) fue de 5,5 ± 3,4° y de 8,6 ± 2,9°, con una diferencia de 3,1° (p = 0,001 test del signo-rango de Wilcoxon). La media de la diferencia absoluta del APF entre ambos ojos fue de 3,5 ± 2,6°; aumentando con la inclinación cefálica en el plano frontal (p = 0,000 test del signo-rango de Wilcoxon). La media de la suma del APF de ambos ojos fue de 14,1 ± 5,4°. La media de la torsión ocular compensatoria (TOC) con la cabeza inclinada 20 y 40° a la derecha fue de 7,1 y 12,2° en el OD y de 7,7 y 12,1° en el OI. Con la cabeza inclinada 20 y 40° a la izquierda, la media fue de 4,4 y 8° en el OD y de 4,2 y 8,7° en el OI (p = 0,000 test del signo-rango de Wilcoxon). Los retinógrafos mostraron alta correlación y reproducibilidad. CONCLUSIÓN: Nuestra técnica es rápida y reproducible. El OI muestra mayor APF que el OD. La TOC solo ocurre en el plano frontal. Estos aspectos son relevantes al analizar retinografías apareadas

PURPOSE: Describe a time-sparing technique to measure disc-foveal angle (DFA), determine normal values and its role when analyzing paired fundus photographs. METHODS: DFA was analysed using the software program Keynote v.6.2.2 on 440 fundus photographs (3 D OCT 2000, Topcon Corporation, Tokio, Japan) of 20 individuals. The 11 different head positions were determined with the cervical range of motion device (CROM, Performance Attainment Associates). A reproducibility and correlation study between two fundus cameras (OCT 3 D-2000 and TRC-50EX, Topcon Corporation, Tokio, Japan) was performed. RESULTS: Mean DFA of the right and left eye was 5.5 ± 3.4° and 8.6 ± 2.9°, with a difference of 3.1° (P = 0.001 Wilcoxon signed-rank test) in the upright head position. Mean absolute difference in DFA between eyes was 3.5 ± 2.6°; an increase was seen with increasing head tilt (p = 0.000 Wilcoxon signed-rank test). Mean sum of DFA in both eyes was 14.1 ± 5.4°. On head-tilt of 20° and 40° to the right, mean ocular counterrolling (OCR) was 7.1° and 12.2° in the right eye and 7.7° and 12.1° in the left eye. On head-tilt of 20° and 40° to the left, OCR was 4.4° and 8° in the right eye and 4.2° and 8.7° in the left eye (P = 0.000 Wilcoxon signed-rank test). The two cameras showed strong correlation and high reproducibility. CONCLUSIONS: Our DFA measurement technique is time-sparing and reproducible. Left eye shows higher DFA than right eye. OCR occurs only in the roll plane. This information is of value when analyzing paired fundus photographs

Disc-foveal angle and ocular counterrolling as a key in its interpretation. / El ángulo papila-fóvea y la torsión ocular compensatoria, clave en su interpretación.

PURPOSE: Describe a time-sparing technique to measure disc-foveal angle (DFA), determine normal values and its role when analyzing paired fundus photographs. METHODS: DFA was analysed using the software program Keynote v.6.2.2 on 440 fundus photographs (3D OCT 2000, Topcon Corporation, Tokio, Japan) of 20 individuals. The 11 different head positions were determined with the cervical range of motion device (CROM, Performance Attainment Associates). A reproducibility and correlation study between two fundus cameras (OCT 3D-2000 and TRC-50EX, Topcon Corporation, Tokio, Japan) was performed. RESULTS: Mean DFA of the right and left eye was 5.5±3.4° and 8.6±2.9°, with a difference of 3.1° (P=0.001 Wilcoxon signed-rank test) in the upright head position. Mean absolute difference in DFA between eyes was 3.5±2.6°; an increase was seen with increasing head tilt (P=0.000 Wilcoxon signed-rank test). Mean sum of DFA in both eyes was 14.1±5.4°. On head-tilt of 20° and 40° to the right, mean ocular counterrolling (OCR) was 7.1° and 12.2° in the right eye and 7.7° and 12.1° in the left eye. On head-tilt of 20° and 40° to the left, OCR was 4.4° and 8° in the right eye and 4.2° and 8.7° in the left eye (P=0.000 Wilcoxon signed-rank test). The two cameras showed strong correlation and high reproducibility. CONCLUSIONS: Our DFA measurement technique is time-sparing and reproducible. Left eye shows higher DFA than right eye. OCR occurs only in the roll plane. This information is of value when analyzing paired fundus photographs.