MacLaren Robert E, Sagoo Mandeep S, Restori Marie, Allan Bruce D S
Moorfields Eye Hospital, London, United Kingdom.
J Cataract Refract Surg. 2005 Feb;31(2):280-90. doi: 10.1016/j.jcrs.2004.04.054.
To audit the accuracy of biometry using the SRK/T formula when negative- or zero-powered intraocular lenses (IOLs) are predicted and to compare the results between A-scan, B-scan, and optical methods of biometry.
Moorfields Eye Hospital, London, United Kingdom.
This retrospective analysis comprised 78 eyes of 54 patients having cataract surgery with zero- or negative-powered IOLs. Axial lengths were measured with A-scan, B-scan, applanation, or optical methods. Differences between SRK/T-predicted and actual postoperative refraction were analyzed for 75 eyes having cataract surgery. Ocular comorbidity, visual acuity, and biometry readings were also compared.
Forty-one percent of 75 patients analyzed were within +/-1.00 diopter (D) of the predicted refraction, although there was a significant tendency toward a hyperopic overcorrection by 1.14 D (95% confidence interval, 0.89-1.39 D). This overcorrection error was consistent across all 3 biometry methods used to estimate axial length and increased with the use of stronger (more negative) IOLs.
Surgeons should be aware of the tendency for negative-powered lenses to overcorrect and lead to a hyperopic outcome when using the SRK/T biometry formula in highly myopic eyes. A weaker-powered negative IOL is recommended to aim for a more myopic postoperative outcome by about 1.00 to 2.00 D.
当预测使用负屈光度或零屈光度人工晶状体（IOL）时，评估使用SRK/T公式进行生物测量的准确性，并比较A超、B超和光学生物测量方法的结果。
英国伦敦摩尔菲尔德眼科医院。
这项回顾性分析包括54例接受白内障手术并植入零屈光度或负屈光度IOL的患者的78只眼。使用A超、B超、压平或光学方法测量眼轴长度。分析了75例接受白内障手术患者的SRK/T预测的术后屈光与实际术后屈光之间的差异。还比较了眼部合并症、视力和生物测量读数。
在分析的75例患者中，41%的患者术后屈光在预测屈光的±1.00屈光度（D）范围内，尽管有明显的远视过矫倾向，过矫1.14 D（95%置信区间，0.89-1.39 D）。这种过矫误差在用于估计眼轴长度的所有3种生物测量方法中都是一致的，并且随着使用更强（更负）的IOL而增加。
在高度近视眼中使用SRK/T生物测量公式时，外科医生应意识到负屈光度镜片有过矫并导致远视结果的倾向。建议使用屈光度较弱的负IOL，以使术后结果更接近近视约1.00至2.00 D。
