J Korean Ophthalmol Soc.  2011 Jan;52(1):67-73. 10.3341/jkos.2011.52.1.67.

Analysis of Effect of Inferior Oblique Myectomy in Patients With Inferior Oblique Overaction

• Park JH
• Kang SH
• Choi DG

• KMID: 2214140
• DOI: http://doi.org/10.3341/jkos.2011.52.1.67

Abstract

PURPOSE
To investigate the effect of inferior oblique (IO) myectomy by analyzing the correlation of the amount of inferior oblique overaction (IOOA), hypertropia and excyclotorsion before, between, and after IO myectomy in patients with various degrees of IOOA.
METHODS
A total of 86 eyes from 59 patients with IOOA who underwent IO myectomy were enrolled in the present study. The correlation analysis was performed for the amount of IOOA, hypertropia and excyclotorsion before and after surgery, according to the preoperative amount of IOOA, hypertropia, and excyclotorsion.
RESULTS
The IOOA decreased from +2.5 +/- 0.6 before surgery to -0.01 +/- 0.25 (p < 0.05) after surgery. The vertical deviation was 5.7 +/- 6.3 prism diopter (PD) and 2.3 +/- 5.2 PD (p < 0.05) postoperatively. The amount of cyclodeviation was 15.3 +/- 7.6degrees before surgery and 6.6 +/- 5.7degrees (p < 0.05) after surgery. The amount of surgical correction for IOOA and the hypertropia was significantly correlated with preoperative deviation (p < 0.05, p < 0.05). The amount of excyclotorsion before and after surgery was also positively correlated but was not statistically significant (p = 0.05).
CONCLUSIONS
IO myectomy can correct any degree of IOOA, hypertropia, and related excyclotorsion.

Keyword

Excyclotorsion; Hypertropia; Inferior oblique myectomy; Inferior oblique overaction

MeSH Terms

Eye
Humans
Strabismus

Figure

• 

  Figure 1. Measurement of cyclotorsion on fundus photograph. The angle (α) between horizontal line and imaginary line across the center of the macula and optic nerve head was measured.

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  Figure 2. The preexisting IOOA (inferior oblique muscle overaction) positively correlated with the amount of correction (Pearson's correlation coefficiency, r = 0.927, R2 = 0.86, p < 0.05) (A) and with the postoperative residual IOOA significantly (r = 0.318, R2 = 0.101, p < 0.05) (B).

• 

  Figure 3. The preexisting hypertropia in primary gaze positively correlates with the amount of correction (Pearson's correlation coefficiency, r = 0.837, R2 = 0.701, p < 0.05) (A) but not with the postoperative residual hypertropia (r = 0.202, R2 = 0.041, p = 0.092) (B).

• 

  Figure 4. The preexisting excyclotorsion dosen't correlate with the amount of correction significantly (Pearson's correlation coefficiency, r = 0.051, R2 = 0.003, p = 0.832) (A). But the preexisting excyclotorsion positively correlates with the postoperative residual excyclotorsion (r = 0.572, R2 = 0.328, p < 0.05) (B).

Reference

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