Email updates

Keep up to date with the latest news and content from BMC Ophthalmology and BioMed Central.

Open Access Research article

Prospective study of toric IOL outcomes based on the Lenstar LS 900® dual zone automated keratometer

Kjell Gunnar Gundersen1* and Richard Potvin2

Author Affiliations

1 Privatsykehuset Haugesund, Haraldsgaten 139, Haugesund, 5527, Norway

2 Science in Vision, 13860 E. Riviera Dr., Burleson, Texas, 76028, USA

For all author emails, please log on.

BMC Ophthalmology 2012, 12:21  doi:10.1186/1471-2415-12-21

Published: 16 July 2012



To establish clinical expectations when using the Lenstar LS 900® dual-zone automated keratometer for surgery planning of toric intraocular lenses.


Fifty eyes were measured with the Lenstar LS 900® dual-zone automated keratometer . Surgical planning was performed with the data from this device and the known surgically induced astigmatism of the surgeon. Post-operative refractions and visual acuity were measured at 1 month and 3 months.


Clinical outcomes from 43 uncomplicated surgeries showed an average post-operative refractive astigmatism of 0.44D ±0.25D. Over 70% of eyes had 0.50D or less of refractive astigmatism and no eye had more than 1.0D of refractive astigmatism. Uncorrected visual acuity was 20/32 or better in all eyes at 3 months, with 70% of eyes 20/20 or better. A significantly higher number of eyes had 0.75D or more of post-operative refractive astigmatism when the standard deviation of the pre-operative calculated corneal astigmatism angle, reported by the keratometer, was > 5 degrees.


In this single-site study investigating the use of the keratometry from the Lenstar LS 900® for toric IOL surgical planning, clinical outcomes appear equivalent to those reported in the literature for manual keratometry and somewhat better than has been reported for some previous automated instruments. A high standard deviation in the pre-operative calculated astigmatism angle, as reported by the keratometer, appears to increase the likelihood of higher post-operative refractive astigmatism.

Toric IOL; Astigmatism; Cataract surgery; Cataract surgery planning; Keratometer; Lenstar LS 900®