Estimation of effective lens position using a method independent of preoperative keratometry readings.
AffiliationDepartment of Ophthalmology, Waterford Regional Hospital, Institute of Eye Surgery, Dublin, Ireland. email@example.com
Aged, 80 and over
Diagnostic Techniques, Ophthalmological
Lens Implantation, Intraocular
MetadataShow full item record
CitationEstimation of effective lens position using a method independent of preoperative keratometry readings. 2011, 37 (3):506-12 J Cataract Refract Surg
JournalJournal of cataract and refractive surgery
AbstractTo evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery.
Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland.
Evaluation of diagnostic test or technology.
The anterior chamber diameter and corneal height in eyes scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Corneal height and anterior chamber diameter were used to estimate the ELP in a K-independent method (using the SRK/T [ELP(rs)] and Holladay 1 [ELP(rh)] formulas).
The mean ELP was calculated using the traditional (mean ELP(s) 5.59 mm ± 0.52 mm [SD]; mean ELP(h) 5.63 ± 0.42 mm) and K-independent (mean ELP(rs) 5.55 ± 0.42 mm; mean ELP(rh) ± SD 5.60 ± 0.36 mm) methods. Agreement between ELP(s) and ELP(rs) and between ELP(h) and ELP(rh) were represented by Bland-Altman plots, with mean differences (± 1.96 SD) of 0.06 ± 0.65 mm (range -0.59 to +0.71 mm; P=.08) in association with ELP(rs) and -0.04 ± 0.39 mm (range -0.43 to +0.35 mm; P=.08) in association with ELP(rh). The mean absolute error for ELP(s) versus ELP(rs) estimation and for ELP(h) versus ELP(rh) estimation was 0.242 ± 0.222 mm (range 0.001 to 1.272 mm) and 0.152 ± 0.137 mm (range 0.001 to 0.814 mm), respectively.
This study confirms that the K-independent ELP estimation method is comparable to traditional K-dependent methods and may be useful in post-refractive surgery patients.