The Influence Of Head Tilt On Fovea-Disc Angle

Objective To explore the influence of head tilt on fovea-disc angle(FDA).Methods Data of 30 patients(60 eyes) who have received treatment in XX Hospital from July 2014 to December 2014 were included. These 30 patients,15 male and 15 female aged from 6 to 52 years old, all demonstrated fine cooperation. All the subjects met the following criteria: BCVA?0.8,astigmatism?1.50 D,myopic degree?-3.0D,had normal eye position, no eye movement limitation and no history of eye surgery. 3D OCT-1000 was used to take fundus photos for 30 subjects at entopic position, head to the right at 30° and head to the left at 30° respectively. Corel DRAW X4 drawing software was used to measure the FDA values in these photos. The data were imported to SPSS17.0 software for t test, analysis of variance and linear regression.Results FDA values: the differences between right eye and head to the same side 13.50°±3.20°, entopic position 6.56°±2.55°and head to the contralateral side-0.46°±3.64°have statistical significance(F value is 146.430, P < 0.05). The FDA value of head to the same side group is significantly higher than that of the entopic position group(P< 0.05), while the FDA value of the entopic position group is significantly higher than head to the contralateral side group(P<0.05). The differences between left eye and head to the contralateral side 1.08°±3.09°, entopic position 7.31°±2.62°and head to the same side 13.50°±3.25°have statistical significance(F value is 128.248, P <0.05). The FDA value of head to the contralateral side group is significantly lower than that of the entopic position group(P< 0.05), while the FDA value of the entopic position group is significantly lower than head to the same side group(P<0.05). There are no significant differences between the FDA values of different genders(t=0.906,P>0.05). The different FDA values between different age groups are not statistically significant(r=0.001,t=0.006,P>0.05).Conclusion Head tilt has a significant influence on fovea-disc angle. In clinical practice, when fundus photography is used to evaluate the fundus rotation of patients, attention should be paid to the placement of head.