摘要
目的探讨高度近视合并白内障患者术前如何精确计算人工晶状体的屈光度。方法回顾性分析轴长大于27.0mm的高度近视合并白内障患者96例(118眼),所有病例均行透明角膜切口超声乳化白内障吸出联合后房型人工晶状体植入术,分别应用SRKⅡ、SRK/T、HofferQ和Holladay 1等公式计算所植入人工晶状体应产生的术后理论屈光状态,分析4个公式所得理论值与实际值的差别。结果各公式平均误差值分别为:SRKⅡ(-0.5±0.84)、SRK/T(-0.18±0.68)、Hoffer Q(0.33±0.72)、Holladay1(0.26±0.66),各误差值比较无统计学意义(P>0.05)。SRK Ⅱ和SRK/T公式存在高估IOL屈光度的趋势,使术后出现比预期更高的近视;而Hoffer Q和Holladay 1公式则相反,存在低估IOL屈光度的趋势,使术后残留近视度数比预期低甚至出现远视。不同眼轴长度时SRK/Ⅱ平均绝对误差值明显大于第三代公式;SRK/T、Hoffer Q、Holladay 1三者平均绝对误差值大致相等,但SRK/T及Holladay 1表现稍优于Hoffer Q;各公式平均绝对误差值与轴长无明显对应关系。部分误差值较大者合并较明显的巩膜后葡萄肿,提示眼轴长度测量准确性具有重要意义。结论在高度近视合并白内障眼计算IOL屈光度时,第三代计算公式较第二代计算公式准确,SRK/T与Holladay 1公式准确性最高,在临床中应尽量采用。
Objective To investigate how to accurately calculate the power of intraocular lens （IOL） preoperatively in cataract with extreme myopia. Methods Ninety-six cataract patients （ 118 eyes） with extreme myopia and axial lengths longer than 27.0 mm were retrospective studied and performed clear comeal incision phacoemulsification with posterior chamber IOL implantation. Four formulas SRK Ⅱ, SRK/T, Hoffer Q and Holladay 1 were used to predict the refraction and their performance were compared. Resuits （ 1 ） The mean errors are - 0.5 ± 0.84 to SRK Ⅱ , -0.18 ±0.68 to SRK/F,0.33 ±0.72 to Hoffer Qand 0.26 ±0.66 to Holladay 1 ,which showing no statistically significant （ p 〉 0.05 ）. （ 2 ） The SRK Ⅱ and SRK/F tended to overpower IOLs, leading a myopia a little higher than the predicted;but the Hoffer Q and Holladay 1 tended to underestimate the IOLs＇ power, leading a myopia a lithe lower than the predicted even a hyperopia. （ 3 ） The mean absolute error of SRK Ⅱ was higher than that of the third generation formulas in different axial length. The mean absolute errors of SRK/F,Hoffer Q and Holladay 1 were approximately equal,but SRK/F and Holladay 1 performed a little better than Hoffer Q The errors of all the four formulas were not in proportional to the axial lengths. （4） Some poorer predicting capacity came from those with severe posterior pole staphyloma, which suggested that the accurate measurment of axial lengths was important. Conclusion When calculateing the IOLs＇ power for cataract with high myopia, the third generation IOL power calculation formulas are more accurate than the second generation for mulas. SRK/F and Holladay 1 appear to perform better than others. The B- scan ultrasonography examination should be performed routinely preoperatively to locate the center of the fovca,which would help to improve the predictive capacity. ±
出处
《眼科新进展》
CAS
2007年第8期606-608,共3页
Recent Advances in Ophthalmology
关键词
高度近视
白内障
人工晶状体
屈光
数学计算
high myopia
cataract
intraocular lenses
refraction
mathematical computing
