Accuracy of intraocular lens power calculation formulae for the Yamane technique of secondary fixation: a systematic review and meta-analysis

Objective This systematic review and meta-analysis aims to assess the refractive outcomes of the Yamane technique for intrascleral fixation of intraocular lenses (SF-IOL) and compare the predictive ability of the various intraocular lens power calculation formulae commonly used in conjunction with the technique. Methods A literature search was conducted in the Medline, Scopus, and Cochrane Library databases for articles published from January 2014 to May 2023. Studies that met the predetermined inclusion criteria were included and subjected to analysis. The primary outcome evaluated was the refractive predictive error, defined as the difference between predicted refraction and post-operative manifest refraction. Result Eleven studies met the inclusion criteria, with a cumulative sample size of 615 patients (mean age: 66.6 years). Various IOL formulae were used, with SRK/T being the most frequently adopted formula. The overall mean refractive predictive error for all formulae combined was -0.02 D, which was not statistically significant (p = 0.99). Subgroup analysis for individual formulae also showed no significant difference from predicted error for any formula (p > 0.05). Conclusion The Yamane technique for SF-IOL shows promising refractive outcomes, and the choice of IOL power calculation formula should be tailored based on patient characteristics and surgeon preference. No formula demonstrated superior predictive ability over others. Further research is needed to develop formulae specifically for eyes with secondary aphakia and poor capsular support.