Comparison of subjective cyclofusion ranges and objective ocular torsion in normal participants according to age

• Published in: Graefe's archive for clinical and experimental ophthalmology Vol. 260; no. 11; pp. 3675 - 3681
• Main Authors: Kawai, Manami, Goseki, Toshiaki, Okano, Takashi, Ishikawa, Hitoshi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2022; Springer Nature B.V
• Subjects: Age; Eye; Medicine; Medicine & Public Health; Neurophthalmology; Ophthalmology; Optic nerve; Retina; Strabismus; Disc fovea angle; Torsional strabismus; Ocular torsion; Age; Cyclofusion range
• ISSN: 0721-832X; 1435-702X
• DOI: 10.1007/s00417-022-05734-2

Purpose To investigate the relationship between subjective cyclofusion ranges and objective ocular torsion in normal participants according to age. Methods This cross-sectional study included 120 participants aged ≥ 20 years with no ocular diseases. The subjective cyclofusion ranges were measured centrifugally and centripetally in the direction of excyclotorsion and incyclotorsion, respectively, concurrently with rotational diplopia production by rotation using synoptophore. Disc fovea angle (DFA) was defined as the angle formed by two lines: a line passing through the center of the optic nerve papilla and fovea and a horizontal line passing through the center of gravity of the optic papilla using fundus photographs. Results The participants were aged 49.1 ± 17.7 years. The total cyclofusion centrifugal (sum of extorsion and intorsion) and centripetal ranges were 10.9 ± 2.2° and 7.2 ± 1.8°, respectively, both of which decreased in participants in their 60 s and 70 s ( p  < 0.01). The DFA was − 7.0 ± 3.4° in the right eye (− : excyclo, + : incyclo) and − 8.0 ± 3.2° in the left, which was associated with age ( p  < 0.001). The correlation between the DFA and centrifugal ( r  =  − 0.13, p  = 0.16) and centripetal ( r  =  − 0.002, p  = 0.99) cyclofusion ranges of extorsion was not significantly different. The centrifugal ( r  = 0.37, p  < 0.001) and centripetal ( r  = 0.40, p  < 0.001) cyclofusion ranges of intorsion were positively correlated. Conclusion Subjective cyclofusion ranges decreased in both extorsion and intorsion in the elderly. Objective ocular torsion showed excyclotorsion with age. When strabismus surgery is performed in elderly patients with torsional strabismus, the decrease in subjective cyclofusion ranges should be considered.