Blind spot heterotopia by automated static perimetry to assess static ocular torsion: centro-cecal axis rotation in normals

Ocular torsion and vertical misalignment

“…The central-cecal axis rotation is drawn by hand (using a magnifying lens and protractor), down to the nearest 0.5 o . Reproduced with permission from [24 ].…”

“…This method [24 ] should prove useful in documenting torsion, which may reach 28 8 in skew deviation, but will be limited to patients with steady visual fixation and without nystagmus in forward gaze. 22 Neuro-ophthalmology and neuro-otology Reproduced with permission from [23].…”

“…Use of the tangent screen visual field to record the static rotated position of the blindspot relative to the fixation position was reported by John Locke in 1957 to measure cylotorsion in vertical muscle palsies. Now a study [24 ] details the use of static automated perimetry with the Humphrey 24-2 threshold strategy. Average centro-cecal axis rotation -the angle between the centro-cecal axis connecting the point of visual fixation to the blindspot center -in 1000 normal eyes was 7.35 8 (SD 0.7, range 5.7-11 8 ) of excylotortion (Fig.…”

The bedside examination of the vestibulo-ocular reflex (VOR): An update

“…1). The direction of torsion can be determined by examining the fundus with the ophthalmoscope, by the bucket test for SVV examining each eye separately, or using visual field perimetry to detect the location of the blind spot relative to the fovea (Versino and Newman-Toker, 2010; Zwergal et al, 2009). …”

A new device to assess static ocular torsion

“…An alternative method for the objective measurement of ocular torsion based on the gray‐tone chart obtained by automated perimetry (Fig. 1) was recently proposed 3 …”