Purpose: To obtain the angle of objective cyclotorsion [the angle between the horizontal line and the line connecting the fovea and center of the optic disc, called as the disc-fovea angle (DFA)] in elderly individuals and to analyze the effects of aging and dominant eye on this angle.
Methods: Fundus photographs of good quality were collected from patients aged ≥76 years. Those with visual acuity <0.6, strabismus, or ocular diseases that could affect binocular fusion were excluded. DFA of the elderly patients was compared with previously reported data of 67 normal 65-year-old adults. The dominant eye was determined using the hole-in-the-card method.
Results: We analyzed 90 photographs of 45 elderly patients (age, 81.5±4.0 years). DFA of the left eye was greater than that of the right eye (10.0±4.1° and 7.3±4.3°, respectively; p<0.01). DFA of left eye in the elderly group was larger than that in the 65-year-old group (7.8±3.2°; p<0.01). The dominant eye was identified in 31 patients (right eye dominance: 18 cases, left eye dominance: 9 cases, non-laterality: 4 cases). DFA of the dominant eye was significantly smaller than that of the nondominant eye (6.9±3.6° and 10.6±4.7°, respectively; p<0.01).
Conclusions: DFA of the left eye increased in elderly individuals aged ≥76 years compared with those aged ≤65 years. DFA of the dominant eye was smaller than that of the nondominant eye. The difference in DFAs of the right and left eyes may be attributed to prevailing right-eye dominance.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 122: 499-502, 2018.