Distance stereotesting using vision test charts for intermittent exotropia

Figures & data

Table 1 The revised Newcastle Control Score

	Score
Home control
XT or monocular eye closure seen
Never	0
<50% of time fixing in distance	1
>50% of time fixing in distance	2
>50% of time fixing in distance + seen at near	3
Clinic control
Near
Immediate realignment after dissociation	0
Realignment with aid of blink or re-fixation	1
Remains manifest after dissociation/prolonged fixation	2
Manifest spontaneously	3
Distance
Immediate realignment after dissociation	0
Realignment with aid of blink or re-fixation	1
Remains manifest after dissociation/prolonged fixation	2
Manifest spontaneously	3
Total NCS: (Home + near + distance)

Abbreviations: NCS, Newcastle Control Score; XT, exotropia.

Table 2 Classification of the results of the stereotests into four categories

Category	Score	System Chart SC-1600 Pola (arcsec)	Distance Randot Stereotest (arcsec)	Titmus stereotest (arcsec)
Nil	4	Nil	Nil	Nil
Coarse	3	630	400	800, 400
Moderate	2	240, 120	200, 100	200–80
Fine	1	40, 60	60	60–40

Abbreviation: arcsec, seconds of arc.

Table 3 Median and ranges for each stereotests for cases and controls

Group	System Chart SC-1600 Pola (arcsec)	Distance Randot Stereotest (arcsec)	Titmus stereotest (arcsec)
Patients with IXT	90 (40–nil)	400 (60–nil)	40 (40–400)
Controls	60 (40–630)	100 (60–nil)	40 (40–80)
P-value	<0.01	<0.01	0.99

Abbreviations: IXT, intermittent exotropia; arcsec, seconds of arc.

Table 4 Categorical agreement between the System Chart SC-1600 Pola and the Distance Randot Stereotest in patients with intermittent exotropia

DR		SC
		Nil	Coarse	Moderate	Fine
	Score	4	3	2	1
Nil	4	1	3	1	7
Coarse	3		1	3	2
Moderate	2		1	1	5
Fine	1			3

Abbreviations: DR, Distance Randot Stereotest; SC, System Chart SC-1600 Pola.

Table 5 Categorical agreement between the System Chart SC-1600 Pola and the Distance Randot Stereotest in controls

DR		SC
		Nil	Coarse	Moderate	Fine
	Score	4	3	2	1
Nil	4				2
Coarse	3		1	2	1
Moderate	2			3	10
Fine	1				6

Abbreviations: DR, Distance Randot Stereotest; SC, System Chart SC-1600 Pola.

Figure 1 Relationship between NCS and distance stereoacuity using the SC test.

Notes: Stereoacuity scores were correlated (A) with the distance NCS (r_s=0.48, P=0.01) and (B) total NCS (r_s=0.60, P=0.0008).
Abbreviations: NCS, Newcastle Control Score; SC, System Chart SC-1600 Pola.

Figure 2 Relationship between NCS and distance stereoacuity using the DR test.

Notes: No significant correlation was found between DR test scores and the (A) distance NCS (r_s=0.03, P=0.90) and (B) total NCS (r_s=−0.07, P=0.73).
Abbreviations: DR, Distance Randot Stereotest; NCS, Newcastle Control Score.

Figure 3 Relationship between NCS and near stereoacuity using the TST.

Notes: No significant correlation was found between TST scores and the (A) near NCS (r_s=0.32, P=0.10) and (B) total NCS (r_s=0.33, P=0.08).
Abbreviations: NCS, Newcastle Control Score; TST, Titmus stereotest.