Cyclotorsion in the seated and supine patient

Abstract

We used Maddox double-rod measurements to determine if positionally induced ocular cyclotorsion occurs when a patient moves from the seated to supine position. Maddox double-rod measurements were determined twice while patients (N = 30) viewed a fixation light at a distance of 7 feet in both the seated and supine positions. The difference between axis measurements made in seated and supine positions was not statistically significant. There was also no significant difference between the two measurements made in the seated and in the supine positions. These data show that the eyes do not undergo positionally induced ocular cyclotorsion when a patient moves from a seated to a supine position.

Treatment Strategies and Clinical Outcomes of Aspheric Surgery for Astigmatism Using the SCHWIND Amaris Platform

“…Besides pre-existing risk factors, low residual stromal bed thickness is the single most important modifiable factor that increases the risk of iatrogenic post-LASIK ectasia. 38 Thin and ultrathin flap LASIK achieves a thicker residual stromal bed and therefore is believed to decrease the risk of post-LASIK ectasia. Current study indicates that thin and ultrathin LASIK is safe, efficacious, and predictable after short term follow up of 6 months.…”

Surgically induced astigmatism after phacoemulsification with and without correction for posture-related ocular cyclotorsion

“…Postural changes, such as moving from an upright to a supine position, can induce a mean ocular cyclotorsional effect of 0.4 to 4.2 degrees (range 0 to 16 degrees), [8][9][10][11][12] and this effect can be cyclotorsional or excylcotorsional. 8 However, keratometry is typically recorded with the patient upright, whereas ocular surgery is performed with the patient supine.…”

Comparison of Manual and Automated Methods to Measure Position-Induced Ocular Cyclotorsion

“…A 15-degree angle of error results in a 50% reduction in the magnitude of astigmatism corrected [4]. Therefore, manufacturers are making efforts to develop postoperatively stable toric IOLs, and surgeons are trying to place the axes of toric IOLs exactly on the astigmatism axis, because misalignment is the main problem with these lenses.One of the reasons of errors regarding axis marking is positioninduced cyclotorsion, which can occur when patients change from an upright position to a supine position [5][6][7][8]. These postural changes can induce a mean ocular cyclotorsional effect of 0.4 to 4.2 degrees (range 0 to 16 degrees) [5][6][7], depending on various methods for measuring ocular cyclotorsion.…”

“…These postural changes can induce a mean ocular cyclotorsional effect of 0.4 to 4.2 degrees (range 0 to 16 degrees) [5][6][7], depending on various methods for measuring ocular cyclotorsion. The degree of cyclotorsion has been measured indirectly using differences in Maddox double rod measurements [6], trial frame refraction [5], and video-keratography [9]. Swami et al [7] measured the rotational position of 240 eyes of 169 patients who underwent treatment for myopic or hyperopic astigmatism with excimer laser.…”

“…One of the reasons of errors regarding axis marking is positioninduced cyclotorsion, which can occur when patients change from an upright position to a supine position [5][6][7][8]. These postural changes can induce a mean ocular cyclotorsional effect of 0.4 to 4.2 degrees (range 0 to 16 degrees) [5][6][7], depending on various methods for measuring ocular cyclotorsion.…”