J Korean Ophthalmol Soc.  2015 Jul;56(7):1111-1116. 10.3341/jkos.2015.56.7.1111.

Learning Curve for Strabismus Surgery

• Lee JH
• Han SB
• Lee SJ
• Kim MS

• KMID: 2148813
• DOI: http://doi.org/10.3341/jkos.2015.56.7.1111

Abstract

PURPOSE
In the present study, we evaluated the learning curve of strabismus surgery performed by a single surgeon.
METHODS
We reviewed the data of 62 patients with exodeviation who underwent strabismus surgery and were followed up for at least 3 months between March 2011 and November 2014. Patients were divided into 3 groups classified chronologically and the success rate in each group was investigated. Additionally, the results of exotropia surgery were analyzed using cumulative sum (CUSUM) analysis. We compared 5 m distal angle deviation preoperatively and 3 months after strabismus surgery.
RESULTS
The overall surgical success rate of 62 patients was 72.6% (45/62). Success rates were 70% (14/20) in the first group, 71.4% (15/21) in the second group and 76.2% (16/21) in the third group. CUSUM analysis indicated that a surgeon's performance begins to improve at attempt number 11 and cumulative failure chart suggested the surgeon had achieved acceptable level of performance after 44 surgeries.
CONCLUSIONS
A novice strabismus surgeon showed performance improvement after 11 cases and achieved acceptable level of performance after 44 strabismus surgeries. Although additional statistical data using more cases is needed, we suggest surgeons should perform at least 50 strabismus surgeries to ensure a high success rate.

Keyword

Learning curve; Strabismus

MeSH Terms

Exotropia
Humans
Learning Curve*
Strabismus*

Figure

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  Figure 3. Cumulative sum (CUSUM) chart for strabismus surgery. Blue line represent learning curve of surgeon. Upper and lower limits are represented by the lines h0 (-1.855) and h1(1.855). Line crossing h0 from above indicate failure rates not significantly different from the acceptable failure rate.

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  Figure 1. Success rates of strabismus surgery classified * p-values were calculated using chi-square chronologically. test.

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  Figure 2. Cumulative failure (CF) graph of a series of 62 stra-bismus surgery by single surgeon from March 2011 to November 2014. CF acceptable rate set at 0.20, CF unacceptable failure rate set at 0.45. Type Ⅰ and Ⅱ error rates set at 0.10.

Reference

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