Comparison of biometry in phakic and dense modes.

Abstract

PURPOSE: To compare biometry readings in phakic and dense modes.

DESIGN: Comparative cross-sectional, analytical study.

METHOD: Biometry was done in phakic and dense modes separately, on ultrasound-based A-Scan Quantel Medical^®, of 68 normal eyes of 34 normal individuals.

RESULT: Readings were taken in both phakic and dense modes. Mean value of axial length in phakic mode was 23.7832 ± 0.14317 mm and that in dense mode was 23.7888 ± 0.14492 mm. Mean values of anterior chamber depth in phakic mode was 3.6806 ± 0.4398 mm and in dense mode, it was 3.6944 ± 0.4317 mm. Mean values of lens thickness in phakic and dense modes are 4.1485 ± 0.4934 mm and 4.2162 ± 0.5209 mm respectively. Mean values of vitreous length in phakic and dense modes came out to be 15.8490 ± 0.8281 mm and 15.7894 ± 0.7928 mm respectively. In the same way, mean values of calculated intraocular lens (IOL) by phakic mode was 19.4853 ± 0.18295 mm and that in dense mode was 19.5074 ± 0.18548 mm. Wilcoxon Signed Ranked Test was applied as all data was non-parametric. The results showed no significant difference (p>0.05) in readings taken in phakic and dense modes.

CONCLUSION: There is no significant difference between the measurements of anterior chamber, lens thickness, vitreous length, axial length and IOL power values taken either by phakic or by dense mode on ultrasound biometry. As dense mode is more sensitive and quick to perform, it is recommended that dense mode may be used for biometry even in normal conditions.