공지사항
2008-10-06
SEE삼성안과
라식이나 라섹등의 굴절이상의 교정수술후, 수술과 상관 없이 나이들어 노화현상으로 백내장이 생긴 경우
지금까지는 수술 전 데이타(각막곡률반경, 굴절력 등)를 알고 있어야 정확한 인공수정체 값의 계산이 가능했다.
최근 인공수정체 돗수를 정확하게 측정하는 Haigis formula 로 각광받는 독일의 Dr Haigis는 수술전 측정치가 없이
수술 후 각막곡률반경이나 안축장길이만 가지고도 인공수정체 돗수를 정확하게 측정할수 있는 Haigis-L fomula를
개발하였다. 이 수식으로 계산하여 수술한 결과 비교적 정확한 백내장 수술후 결과를 얻었다.
이에따라 앞으로는 굴절수술 환자가 나중에 노화로 백내장이 생긴경우, 수술전 데이타를 다 알지 못해도
현재 눈의 상태만으로도 손쉽게 정확한 인공수정체 돗수를 측정하여 원활한 수술이 가능해졌다고 생각된다.
이러한 계속적인 의학의 발전은 라식이나 라섹 수술을 앞두고 계신 분들에게는 또하나의 희소식이 아닐수 없다.
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Intraocular lens calculation after refractive surgery for myopia: Haigis-L formula
Accepted 20 June 2008.
Purpose
To describe the Haigis-L formula for the calculation of intraocular lenses (IOLs) after refractive laser surgery for myopia based on current biometry and keratometry and present clinical results.
Setting
University Eye Hospital, Wuerzburg, Germany, and various clinics and private practices.
Methods
The basic concepts of the new algorithm were described and summarized. The Haigis formula was analyzed with respect to its usability for eyes after laser surgery for myopia and modified accordingly. Correction curves for IOLMaster keratometry were derived from previous studies. The new formula was checked using the postoperative results of 187 cataract procedures in which 32 IOL types were implanted by 57 surgeons. Input data were current IOLMaster biometry as follows: axial length (AL), anterior chamber depth (ACD), and keratometry (corneal radii) measurements.
Results
Before IOL surgery, the mean spherical equivalent was −7.60 diopters (D) ± 3.90 (SD) (range −20.00 to −1.25 D); the mean AL, 27.02 ± 2.01 mm (range 23.09 to 35.32 mm); the mean ACD, 3.52 ± 0.36 mm (range 2.43 to 4.39 mm); and the mean of the measured corneal radii, 8.70 ± 0.60 mm (range 7.28 to 10.96 mm). The mean arithmetic refractive prediction error was −0.04 ± 0.70 D (range −2.30 to +2.40 D) and the median absolute error, 0.37 D (range +0.01 to +2.40 D). The percentages of correct refraction predictions within ±2.00, ±1.00, and ±0.50 D were 98.4%, 84.0%, and 61.0%, respectively.
Conclusions
The new formula would produce promising results in eyes without refractive history. Its refractive predictability fulfills the current criteria for normal eye.