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J Retzlaff

Publications and source records attributed to J Retzlaff.

9 recordsLinked to original sources
PubMed1988

Comparison of the SRK II formula and other second generation formulas.

A simple modification of the SRK formula was developed for use with extreme axial length cases (short and long eyes) to maximize prediction accuracy in these groups. For "average" eyes (over 75% of all cases), SRK needed no modifications to maintain maximum predictive accuracy. The new, modified SRK formula (SRK II) was compared with current second generation formulas and the Binkhorst formula. The SRK II formula, while maintaining the simplicity and ease of the SRK, was comparable to and in some cases superior to the other formulas. Overall, 80.0% of 2,068 posterior chamber intraocular lenses from seven different manufacturers demonstrated less than one diopter of prediction error and only 0.5% had three or more diopters of error. In short eyes (less than 22 mm), 74.0% were corrected to within one diopter and less than 2.0% had three or more diopters of error. In long eyes (greater than or equal to 24.5 mm), 78.0% of cases demonstrated less than one diopter of error and less than 1.0% had three or more diopters of error. Although the SRK II formula is incorporated in most new A-scan units, the modifications are so simple that surgeons can take the standard SRK predictions and mentally calculate the modifications for extreme cases.

Humans↗
PubMed1984

Lens cortex irrigation/aspiration in extracapsular cataract extraction.

There are many good methods of removing lens cortex during extracapsular cataract extraction in use today. Features of some of these are presented. Flow volume of irrigation solution and depth of the anterior chamber are discussed, and it is recommended that adequate flow volume be used to maintain a comfortably deep anterior chamber during irrigation and aspiration.

Anterior Chamber↗
PubMed1983

Comparison of empirically derived and theoretical aphakic refraction formulas.

A formula for predicting aphakic refraction from axial length and keratometry measurements was derived from 120 cases, using linear regression analysis, as follows: Psp = 80.4 - 1.65L -0.7K, where P indicates aphakic spectacle power in diopters; L, axial length in millimeters; and K, result of keratometry in diopters. The prediction accuracy of this simple formula was compared with that of a complex theoretic formula based on geometric optics in 205 additional cases. The prediction accuracy of the theoretic and linear regression-derived formulas was virtually identical despite their differences in complexity and derivation. The differences and similarities between theoretic-derived and regression-derived aphakic and pseudophakic prediction formulas are discussed.

Aphakia↗
PubMed1981

Comparison of the accuracy of the Binkhorst, Colenbrander, and SRK implant power prediction formulas.

The prediction accuracy of the Binkhorst, Colenbrander, and SRK formulas were compared in five series from different sources totalling 654 cases. The SRK formula was superior to both the other formulas by having a smaller average error per case, a smaller range of error from highest minus to highest plus, and a smaller proportion of cases with greater than 2 diopters (D) of error in all five series studied. In four of the five series, the SRK formula also had the greatest proportion of cases with less than 1 D of error. The Colenbrander formula was superior to the Binkhorst formula in all five series with regard to average error, proportion of cases with less than 1 D of error, and proportion of cases with more than 2 D of error. The range of error from highest minus to highest plus was equivalent with the two formulas. All available published literature on the accuracy of implant power prediction formulas was reviewed and appears to support our findings.

Humans↗
PubMed1980

A new intraocular lens calculation formula.

Data from 166 eyes with iridocapsular implants were analyzed and different prediction methods were compared. A new formula was derived which predicted implant power better than any other method. The theoretic formulas and correction factors of Fyodorov, Colenbrander, and others were examined in detail and compared to the more accurate, simpler linear regression formula derived in this study.

Computers↗