Tao Ming Thomas Chia,1 Minh T Nguyen,2 Hoon C Jung3,4 1Roski Eye Institute, University of Southern California, Los Angeles, CA, USA; 2Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; 3Department of Ophthalmology, University of Washington, Seattle, WA, USA; 4Eye Clinic, VA Puget Sound Health Care System, Seattle, WA, USA Purpose: To ascertain if optical biometry determination of axial length (AL) and intraocular lens (IOL) power is significantly different compared to ultrasound (US) biometry in cases with borderline signal-to-noise ratio (SNR).Patients and methods: Sixty patients who had cataract and IOL Master biometry with borderline SNR (1.6–2.0) were included. A retrospective chart review was performed to compare data collected with optical biometry and US biometry in cataract cases with borderline SNR.Results: Results showed that optical biometry IOL and AL measurements were not significantly different from the US measurements. Analysis also demonstrated good agreement between the two methods.Conclusion: Our study suggests that, in cases of borderline quality data, IOL power and AL measurements with optical biometry are still useful in surgical planning and that additional US measurements may be used more as a corroborative tool. Keywords: cataract, intraocular lens, optical biometry, ultrasound biometry