Korean J Ophthalmol.  2013 Aug;27(4):276-281. 10.3341/kjo.2013.27.4.276.

Measurement of Strabismic Angle Using the Distance Krimsky Test

• Joo KS
• Koo H
• Moon NJ

• KMID: 1705424
• DOI: http://doi.org/10.3341/kjo.2013.27.4.276

Abstract

PURPOSE
To evaluate the correlation of the distance Krimsky test and the alternate prism cover test (APCT) for the distance deviation in patients with horizontal strabismus.
METHODS
Forty patients with horizontal strabismus (20 esotropia and 20 exotropia) were included in this study. Patients with a variable angle of deviation, vertical angle over 5 prism diopters, impaired binocular vision, or poor cooperation were excluded. We instructed the patient to look a target 6 meters away, and applied a prism over the patient's dominant eye while flashing a light source 33 centimeters from the middle of both eyebrows. When the corneal light reflexes were located on the center of each cornea, we measured the angle of deviation. We defined this method as 'distance Krimsky test,' and the angle measured by this method was compared with the conventional Krimsky test and APCT at distance. We analyzed the accuracy and intra- and inter-observer reliability.
RESULTS
The angle of strabismus measured by the distance Krimsky test showed a significant agreement and correlation with the deviation angle measured by the APCT. We elicited the correlation gradient between the angle measured by the distance Krimsky test and the APCT. In addition, the distance Krimsky test showed significant intra- and inter-observer reliabilities.
CONCLUSIONS
The distance Krimsky test is expected to be more useful than the Krimsky test in measuring the distance angle of deviation for patients with strabismus in whom it is difficult to measure the angle of deviation using the APCT. The distance Krimsky test can be an accurate and useful test through the improvement of proficiency of examiners and the establishment of individualized normative data.

Keyword

Distance Krimsky test; Esotropia; Exotropia; Strabismus

MeSH Terms

Adolescent
Adult
Child
Esotropia/*diagnosis/physiopathology
Exotropia/*diagnosis/physiopathology
Female
Humans
Male
Observer Variation
Social Distance
Strabismus/diagnosis/physiopathology
Vision Tests/*methods/standards/statistics & numerical data
Vision, Binocular
Young Adult

Figure

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  Fig. 1 Inter-observer reproducibility of the distance Krimsky test in exotropia (A) and esotropia (B). The mean angle of deviation and the difference of the measurements of two observers are showed using the Bland and Altman method. The bias between the two measurements was assessed statistically as the mean of the differences compared to zero. The 95% limits of agreement between the two measurements were ±4.5 prism diopters (PD) for exotropia, and ±5.6 PD for esotropia. Differences between the two measurements were included in the standard deviation of ±1.96, and the mean differences are near zero for each exotropia and esotropia, illustrating good inter-observer agreement.

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  Fig. 2 Correlation between the corneal reflection test and the alternate prism cover test (APCT) at distance for the strabismic angle in exotropia. (A) The correlation between the conventional Krimsky test and the APCT was close to Y = 0.738X (X, prism diopter measured with the conventional Krimsky test; Y, prism diopter measured with the APCT). (B) The correlation of the distance Krimsky test and the APCT was found to be Y = 0.981X (X, prism diopter measured with the distance Krimsky test; Y, prism diopter measured with the APCT). The extent of the concordance between the distance Krimsky test and the APCT was higher than that of the conventional Krimsky test and the APCT in exotropia.

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  Fig. 3 The correlation between the corneal reflection test and the alternate prism cover test (APCT) at distance for the strabismic angle in esotropia. (A) The correlation between the conventional Krimsky test and the APCT was Y = 0.651X (X, prism diopter measured with the conventional Krimsky test; Y, prism diopter measured with the APCT). (B) The correlation of the distance Krimsky test and the APCT was found to be Y = 0.919X (X, prism diopter measured with the distance Krimsky test; Y, prism diopter measured with the APCT). This illustrates the extent of concordance between the distance Krimsky test and the APCT; it was higher than the concordance between the conventional Krimsky test and the APCT in esotropia.

Reference

1. Von Noorden GK, Campos EC. Examination of patient-II: motor signs in heterophoria and heterotropia. In : Von Noorden GK, Campos EC, editors. Binocular vision and ocular motility: theory and management of strabismus. 6th ed. St. Louis: Mosby;2002. p. 85–100. p. 168–210.

2. Lee JA, Lee HY. New method for measurement of strabismic angle using corneal reflex and photograph. J Korean Ophthalmol Soc. 2002; 43:1988–1992.

3. Choi RY, Kushner BJ. The accuracy of experienced strabismologists using the Hirschberg and Krimsky tests. Ophthalmology. 1998; 105:1301–1306.

4. Cho YA, Roh KH. Early surgery for infantile esotropia. J Korean Ophthalmol Soc. 1993; 34:1251–1256.

5. Parks MM. Symposium: infantile esotropia: summary and conclusions. Am Orthopt J. 1968; 18:19–22.

6. Ing MR. Early surgical alignment for congenital esotropia. Ophthalmology. 1983; 90:132–135.

7. Zak TA, Morin JD. Early surgery for infantile esotropia: results and influence of age upon results. Can J Ophthalmol. 1982; 17:213–218.

8. Thompson JT, Guyton DL. Ophthalmic prisms: measurement errors and how to minimize them. Ophthalmology. 1983; 90:204–210.

9. Wright KW. The ocular motor examination. In : Wright KW, Spiegel PH, editors. Pediatric ophthalmology and strabismus. 2nd ed. New York: Springer;2003. p. 189–203.

10. Yang HK, Han SB, Hwang JM, et al. Assessment of binocular alignment using the three-dimensional Strabismus Photo Analyzer. Br J Ophthalmol. 2012; 96:78–82.

11. Von Noorden GK, Helveston EM. Decentered corneal light reflex. In : Von Noorden GK, Helveston EM, editors. Strabismus: a decision making approach. St. Louis: Mosby;1994. p. 26–27.