Journal List > J Korean Ophthalmol Soc > v.54(3) > 1009624

Lee, Lee, and Lee: Comparison of Postoperative Outcomes According to Deviation Angle in Moderate-Angle Intermittent Exotropia of Basic Type

Abstract

Purpose

This study was conducted to compare the surgical outcomes and stereoacuities after medial rectus (MR) muscle and lateral rectus (LR) muscle recessions, as deviation angle in 20-30 PD basic intermittent exotropia.

Methods

A total of 72 patients were classified into three groups, according to the deviation angle and measured stereoacuities. Twenty-five patients in Group 1, with a deviation angle of 20 prism diopter (PD), underwent MR resection of 4.0 mm and LR recession of 5.0 mm. Group 2, which consisted of 26 patients with 25 PD, underwent 5.0 mm and 6.0 mm. And 21 patients in Group 3 with 30 PD underwent 5.5 mm and 7.0 mm. The success of surgery was determined by the range of a deviation angle within ±8 PD for both near and distance.

Results

The average age was 7.8 years, 7.2 years, and 8.6 years in Group 1, Group 2, and Group 3, respectively. On the final observation, the success rate of the surgery was 84%, 88%, and 90.4% in Group 1, Group 2, and Group 3, respectively. There was no case of overcorrection. Near stereoacuities was found without significant difference at preoperative with postoperative in Group 1, Group 2, and Group 3, respectively (p = 0.26). Postoperative distance stereoacuities showed significant improvements in Group 1, Group 2, and Group 3 (p = 0.04).

Conclusions

Basic intermittent exotropia, which has deviation angle of 20, 25, 30 PD showed no difference in surgical outcomes, according to the deviation angle. There were improvements in the distance stereoacuities after MR resection and LR recession procedure.

References

1. Min EJ, Lee MK, Park BI. A clinical study on strabismus in children. J Korean Ophthalmol Soc. 1991; 32:379–88.
2. Wolff SM, Loupe DN. Binocularity after surgery for intermittent exotropia. In : Campos EC, editor. Strabismus and Ocular Motility Disorders : Proceedings of the Sixth Meeting of the International Strabismological Association, Surfers Paradise, Australia, 1990. Hampshire: Macmillian Press;1991. p. 375.
3. R Jenkins. Demographics: geographic variations in the prevalence and management of exotropia. Am Orthopt J. 1992; 42:82–7.
4. Von Noorden GK. Divergence excess and simulated divergence; Diagnosis and surgical management. Doc Ophthalmol. 1969; 26:719–28.
5. Burian HM, Spivey BE. The surgical management of exodeviations. Trans Am Ophthalmol Soc. 1964; 62:276–306.
6. Jeong TS, You IC, Park SW, Park YG. Factors of surgical success with unilateral recession and resection in intermittent exotropia. J Korean Ophthalmol Soc. 2006; 47:1987–92.
7. Lee BH, Lee JW, Lee JH. The accuracy of estimating postoperative deviation in exotropia with over 40 prism diopters. J Korean Ophthalmol Soc. 2010; 51:1614–9.
crossref
8. Wright KW, Ryan SJ. Color atlas of ophthalmic surgery: Strabismus. 1st ed.Philadelphia: Lippincott & Wilkins;1991. p. 241–3.
9. Kim SJ, Lee WS. Clinical analysis of surgical results in exodeviation. J Korean Ophthalmol Soc. 1992; 33:724–32.
10. von Noorden GK. Binocular vision & ocular motility. 5th ed.St. Louis: Mosby-Tear Book;1996. p. 341–59.
11. Wright KW. Pediatric ophthalmology and strabismus. 1st ed. St. Louis: Mosby-Tear Book;1995. p. 195–209.
12. Prieto-Diaz J, Souza-Dias C. Strabismus, 4th ed. Boston: Butterworth- Heinemann;2000. p. 223–32.
13. Roh YB, Kim CM, Oum BS, Lee JS. Distance stereoacuity in children with intermittent exotropia using B-VAT II video acuity tester. J Korean Ophthalmol Soc. 1998; 39:578–82.
14. Suh WJ, Lee UK, Kim MM. Change of postoperative distance stereoacuity in intermittent exotropic patients. J Korean Ophthalmol Soc. 2000; 41:758–63.
15. Baker JD, Davies GT. Monofixational intermittent exotropia. Arch Ophthalmol. 1979; 97:93–5.
crossref
16. Simons K. Stereoacuity norms in young children. Arch Ophthalmol. 1981; 99:439–45.
crossref
17. Yildirim C, Altinsoy HI, Yakut E. Distance stereoacuity norms for the mentor B-VAT II-SG video acuity tester in young children and young adults. J AAPOS. 1998; 2:26–32.
crossref

Table 1.
Surgical amount according to exodeviation angle at distance
Group Exodeviation angle (PD) Amount (mm) Number of patients
MR Resection LR Recession
1 20 4.0 5.0 25
2 25 5.0 6.0 26
3 30 5.5 7.0 21

PD = prism diopter; MR = medial rectus muscle; LR = lateral rectus muscle.

Table 2.
Comparison of mean age, gender and follow-up period
Group Age (mean ± SD, years) Gender (M/F) F/U period (mean ± SD, months)
1* 7.8 ± 1.3 15/10 16.5 ± 4.2
2 7.28 ± 1.8 13/13 15.0 ± 3.1
3 8.68 ± 2.1 11/10 17.7 ± 3.5
Mean 8.0 39/33 16.4

F/U = follow-up.

* Patients with intermittent exotropia of 20 PD who underwent MR resection of 4.0 mm and LR recession of 5.0 mm

Patients with intermittent exotropia of 25 PD who underwent MR resection of 5.0 mm and LR recession of 6.0 mm

Patients with intermittent exotropia of 30 PD who underwent MR resection of 5.5 mm and LR recession of 7.0 mm.

Table 3.
Comparison of exodeviation angle at preoperative and last follow-up
Group Mean exodeviation angle (PD)
Preoperative Last F/U
1* 20.0 6.1 ± 3.9
2
25.0 2.1 ± 4.1
3
30.0 4.2 ± 3.9

PD = prism diopter; F/U = follow-up; Preop. = preoperative.

* Patients with intermittent exotropia of 20 PD who underwent MR resection of 4.0 mm and LR recession of 5.0 mm

Patients with intermittent exotropia of 25 PD who underwent MR resection of 5.0 mm and LR recession of 6.0 mm

Patients with intermittent exotropia of 30 PD who underwent MR resection of 5.5 mm and LR recession of 7.0 mm.

Table 4.
Comparison of mean stereoacuity at preoperative and last follow-up
Group Mean steroacuity (Sec)
Preop. (near/far) Last F/U (near*/far)
1 108.3 / 125.0 100.4 / 105.7
2§ 88.0 / 117.0 81.5 / 96.5
3 63.3 / 137.7 60.6 / 109.9

Sec = seconds of arc; F/U = follow-up; Preop. = preoperative.

* Titmus test

Mentor B-VAT II-SG videoacuity tester

Patients with intermittent exotropia of 20 PD who underwent MR resection of 4.0 mm and LR recession of 5.0 mm

§ Patients with intermittent exotropia of 25 PD who underwent MR resection of 5.0 mm and LR recession of 6.0 mm

Patients with intermittent exotropia of 30 PD who underwent MR resection of 5.5 mm and LR recession of 7.0 mm.

Table 5.
Comparison of undercorrection and success rate
Group Undercorrection rate (%) Success rate (%)
1* 16.0 (4/25) 84.0 (21/25)
2 12.0 (3/26) 88.0 (23/26)
3 9.6 (2/21) 90.4 (19/21)

* Patients with intermittent exotropia of 20 PD who underwent MR resection of 4.0 mm and LR recession of 5.0 mm

Patients with intermittent exotropia of 25 PD who underwent MR resection of 5.0 mm and LR recession of 6.0 mm

Patients with intermittent exotropia of 30 PD who underwent MR resection of 5.5 mm and LR recession of 7.0 mm.

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