Cyclotorsion as a structural and functional biomarker of ocular and neuroophthalmic diseases
Agata Joanna Ordon, Piotr Jerzy Loba
Cyclotorsion is the rotational movement of the eye around its anteroposterior axis and represents an important component of ocular motility and binocular alignment. This review examines the physiological mechanisms underlying ocular torsion, the extraocular muscles involved, and the clinical relevance of cyclotorsional deviations in ocular and neuro-ophthalmic disorders. Particular attention is given to subjective and objective assessment methods, including fundus photography, optical coherence tomography, scanning laser ophthalmoscopy, and measurement of the disc-foveal angle. The review discusses the diagnostic and therapeutic implications of cyclotorsion in trochlear nerve palsy, skew deviation, pulley disorders, inferior oblique overaction, thyroid eye disease, heavy eye syndrome, and sagging eye syndrome. Quantitative assessment of ocular torsion may support differential diagnosis, improve surgical planning, and provide an objective measure for monitoring treatment outcomes. However, differences in imaging protocols, measurement techniques, and patient populations remain important limitations. Further prospective, multicenter research using standardized methods and externally validated automated tools is needed to establish cyclotorsion as a robust structural and functional biomarker in ophthalmology and neuro-ophthalmology.