The Importance of Biometry to Cataract Outcomes in a Surgical Unit in Africa

Abstract

Purpose: To determine how much difference biometry makes to refractive outcomes in a population in Sub-Saharan Africa compared to using standard-power intraocular lenses (IOLs).

Methods: In a secondary eye-clinic in Kenya, IOL-powers in half diopters (D) were implanted according to biometry prediction in patients undergoing routine cataract surgery with small-incision techniques. A model was generated to predict refractive outcomes if standard-IOLs had been used.

Results: Three-hundred-twenty-five eyes of 290 patients were operated on; 232 (71%) using phacoemulsification, the remainder using manual small-incision cataract surgery. Two-hundred-sixty-seven eyes (82.2%) achieved corrected visual acuity (VA) ≥6/18 and 202 eyes (62%) uncorrected VA ≥6/18. Pre-existing comorbidity was the single most common reason for a worse postoperative VA. Restricting analysis to one eye per patient, with biometry 71.1% had a good refractive outcome (defined as +1 to -1.5 D spherical equivalent), 27.6% became more than −1.5 D myopic and 1.3% more than +1.00 D hyperopic. With standard-power-IOLs 57.3% would have had a good refractive outcome and 16% would have become >1 D hyperopic. Using the post-op refractive data for A-constant optimization could potentially further increase good refractive outcomes to over 80%.

Conclusion: Biometry in combination with small-incision techniques improves refractive outcomes and decreases undesired postoperative hyperopia. Assuming good surgical skills, better outcomes with biometry justify cataract operation at an earlier stage, thereby reducing intra- and postoperative complications and avoiding years of visual disability.

KEYWORDS::

• Africa
• Biometry
• Cataract
• Refraction
• Outcome

ACKNOWLEDGMENTS

We are thankful to Jael Opiyo, Lilian Nyaboga and Miranda Buckle for data collection. We are thankful for the patience and cooperation of all participants.

The Corresponding Author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive licence on a worldwide basis to permit this article to be published in Ophthalmic Epidemiology.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.