Preoperative Biometry in Jos

Abstract

Purpose: To assess the accuracy of preoperative biometry in predicting emmetropia and evaluate the visual outcome following cataract surgery with intraocular lens (IOL) implantation in eyes that had biometry.
Methodology: This is a hospital based retrospective study of eyes that had preoperative biometry at the Jos University Teaching Hospital, Jos in Plateau State, north-central Nigeria from February 2005 to January 2007.  Children, patients with complicated and traumatic cataracts, patients with coexisting ocular morbidity, patients with difficult keratometry and patients with grade 3 intraoperative complications were excluded from the study. The SRK II formula was used in determining the IOL power necessary to achieve emmetropia. The visual outcomes at discharge and at 1 week as well as the refraction results at 6 weeks were all recorded. The accuracy of biometry was determined at 6 weeks.
Results: Five hundred and sixty eight eyes had cataract extraction during the study period but only 300 eyes (53%) of 286 patients met the study criteria and were analysed. One hundred and sixty five eyes (55%) had documented refractions at 6 weeks. Sixty one percent of eyes refracted were within ±1D of the intended refraction while 88% were within ± 2D. Proportion of eyes with a good outcome increased from 40% before correction to 83% with correction at 6weeks.
Conclusion: Preoperative biometry in Jos achieved a fairly good degree of accuracy. Retraining of residents who perform biometry as well as periodic monitoring of the accuracy of measurements is recommended for better results.