IOL Power Calculation Using Dual Schiempflug Analyzer

Precision of Optical Biometry and Intraocular Lens Power Calculation Using Dual Schiempflug Analyzer

This study evaluates the various ocular parameters which are necessary for ocular biometry and the calculated IOL powers using both dual Schiempflug analyzer and optical low-coherence refelctometry.

The measured keratometry, axial length, anterior chamber depth, lens thickness, white-to-white corneal diameter, and calculated IOL powers using various formulas including Hoffer Q, Holladay I, SRK II and SRK T measured by dual Schiempflug analyzer and optical low-coherence refelctometry will be compared.

Inclusion Criteria:

• axial length between 21.0 and 27.0 mm
• older than 20 years old

Exclusion Criteria:

• other ophthalmic diseases such as severe dry eye, glaucoma, and age-related macular degeneration
• previous ophthalmic surgery including cataract surgery, and refractive surgery
• very dense media which cannot be measured by the optical biometries
• severe zonulysis