Posters

Preoperative ocular biometry before cataract surgery in a large clinical population

Poster Details

First Author: A.Hartwig GERMANY

Co Author(s):    H. Radhakrishnan   R. Morris   J. Dermott   C. O'Donnell     

Abstract Details

Purpose:

To achieve emmetropia after implantation of an intraocular lens (IOL) accurate ocular biometry is essential for the calculation of IOL power. The present study aimed to evaluate biometric parameters of a typical population of patients who present for cataract or lens replacement surgery, and to assess the effect of factors such as age on these biometric parameters using a regression model.

Setting:

Optegra Eye Hospitals, England, UK

Methods:

This is a retrospective study where biometry data from 5,785 right eyes and 5,682 left eyes are summarised. Patients aged between 21 and 100 years (mean SD 69 ± 11 years) were seen between January 2005 and May 2013. SE ranged between -25.25 and +11.88 D (mean SD -0.73 ± 4.21 D). Ocular biometry was measured using the IOL Master (Zeiss Meditec, Jena, Germany). Parameters including the following were acquired prior to intraocular lens implantation: keratometry (K1 and K2), axial length (AL), anterior chamber depth (ACD) and white-to-white (WTW) corneal-diameter. For the summary of biometric data, right and left eye data are reported separately. For the regression analysis right eye data are reported only, to avoid intraocular correlations confounding the results.

Results:

Ocular biometry data was as follows: K1 [D] OD: minimum 32.27; maximum 67.64; mean 43.19; SD 1.84; OS: minimum 33.65; maximum 67.64; mean 43.24; SD 1.82 K2 [D] OD: minimum 33.35; maximum 68.74; mean 44.22; SD 1.92; OS: minimum 34.13; maximum 69.16; mean 44.28; SD 1.90 AL [mm] OD: minimum 20.02; maximum 33.63; mean 23.86; SD 1.73; OS: minimum 20.01; maximum 33.50; mean 23.84; SD 1.73 ACD [mm] OD: minimum 2.00; maximum 5.85; mean 3.10; SD 0.409; OS: minimum 1.92; maximum 5.96; mean 3.12; SD 0.411 WTW corneal-diameter [mm] OD: minimum 9.90; maximum 13.50; mean 12.03; SD 0.411; OS: minimum 8.20; maximum 13.20; mean 12.03; SD 0.412 The regression model showed that 82% of the variation in AL was explained by spherical equivalent, keratometry, ACD, WTW corneal-diameter and age at the time of surgery. The model is described by the following regression formula: AL=27.21-0.31SE+1.03ACD+0.26WTW-0.24K+0.01A where AL is axial length, SE spherical equivalent refractive error, ACD anterior chamber depth, WTW corneal-diameter, K mean keratometry and A age at surgery, respectively.

Conclusions:

The present study provides a summary of ocular biometric data in a large population undergoing IOL implantation, these data may have applications for the design of IOLs. Our data show that from a biometric point of view, age has little effect on axial length. FINANCIAL INTEREST: NONE