Stepped Strabismus Surgery

Figures & data

Table 1 Criteria for Intraoperative Second Step

Type of Strabismus	Intraop Assessment After First Step	Second Step
Esotropia	XT=10 to ET=8	No second step
	ET 9 to 15	Contralateral MR recession 4
	ET >15	Contralateral MR recession 5
Exotropia	ET=15 to XT=6	No second step
	XT 7 to 15	Contralateral LR recession 5
	XT>15	Contralateral LR recession 6
Superior oblique palsy	HT ± 4	No second step
	HT 5–10	Contralateral IR recession 3 or Ipsilateral SR recession 5*
	HT >10	Contralateral IR recession 4 Or Ipsilateral SR recession 6*

Note: *Ipsilateral SR recession was done in cases with ipsilateral limited depression in adduction (giving the appearance of pseudo overcorrection of the contralateral superior oblique).

Table 2 Demographic Data

		Esotropia	Exotropia	Superior Oblique Palsy
Gender
	Male	8/18 (44%)	6/11 (55%)	10/22 (45%)
	Test of significance	χ^2(df=2)=0.320
	p-value	p(MC)=0.874 NS
Age
	Range	17–42	19–49	18–45
	Mean and SD	27.33±8.27	30.36±9.22	29.95±8.53
	KS test of normality	D=0.146	D=0.195	D=0.111
		p=0.200 NS	p=0.200 NS	p=0.200 NS
	Test of significance	Z(KW)=1.317
	p-value	p=0.518 NS

Abbreviations: n, number of patients; χ², Chi square test; df, degree of freedom; KS, Kolmogorov–Smirnov; KW, Kruskal–Wallis test; MC, Monte Carlo correction for Pearson Chi-square; NS, statistically not significant (p≥0.05).

Table 3 Preoperative Angle and Postoperative Results

		Esotropia	Exotropia	Superior Oblique Palsy
Preoperative angle (PD)
	Mean & SD	15.9±3.4	18.0±2.7	19.4±4.2
	Range	10 to 20	12 to 20	14 to 30
Final postoperative angle (PD)*
	Mean & SD	2.9±5.3	2.4±6.8	1.6±3.3
	Range	−10 to 15	−12 to 14	−4 to 8
Intraoperative second step needed		6/18 (33.3%)	5/11 (45.5%)	5/22 (22.7%)
Re-operation**		2/18 (11.1%)	1/11 (9.1%)	2/22 (9.1%)
Re-operation due to undercorrection		2/2	1/1	1/2
Success***		15/18 (83.3%)	8/11 (72.7%)	18/22 (81.9%)
Final success at last follow up not met for patients not needing a second stage		2/12 (11.7%)	1/6 (16.7)	2/17 (11.7%)
Final success at last follow up not met for patients needing a second stage		0/6 (0%)	2/5 (40%)	2/5 (40%)

Notes: Reported angles are primary position deviations. *Negative values indicate overcorrection angles. **A second surgery was done within a year for unsatisfactory results. ***Defined as primary position deviation within 8 PD in horizontal cases and less than 4 PD in vertical cases after the primary procedure not including further re-operations.