Effect of visual acuity on biometry prediction error after cataract surgery

Claire Daniel, Stephen Tuft, Alex Ionides, Catey Bunce

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

PURPOSE: To determine the effect of visual acuity on biometry prediction error.

SETTING: Postgraduate teaching hospital.

METHODS: The study was an observational case series of the first operated eye of 2149 consecutive patients who had cataract surgery. Biometry prediction error was defined as the difference between the planned refraction determined by biometry and the spherical equivalent of the final refraction. The principal outcome measure was the percentage of eyes within +/-1.00 diopter (D) of the intended refraction. This outcome was calculated for patients with visual loss caused by cataract alone, defined as eyes with a postoperative acuity of 6/6 or better, and eyes with different levels of postoperative visual acuity.

RESULTS: Complete data were available for 1978 eyes (92%). Of these, 1438 (73%) were within +/-1.00 D of the intended refraction. When the final corrected visual acuity was 6/6 or better, the percentage of eyes within +/-1.00 D of the predicted refraction was at least 78%. When the preoperative acuity was worse than 6/60, 74% in the counting fingers group and 69% in the hand movements group with a final corrected acuity of 6/6 or better were within +/-1.00 D. This trend bordered on statistical significance (P =.05). There was a rapid reduction in the percentage of eyes within +/-1.00 D of the intended refraction as the postoperative acuity decreased because of ocular comorbidity, with a statistically significant difference between eyes with a postoperative acuity of 6/6 or better and each group with an acuity of 6/9 or worse (P<.01).

CONCLUSIONS: In eyes without visually significant ocular comorbidity, cataract must reduce vision to 6/60 or worse before there is an increase in biometry prediction error. In contrast, ocular comorbidity that reduces the postoperative acuity causes an early and marked increase in biometry prediction error.

Original languageEnglish
Pages (from-to)1365-9
Number of pages5
JournalJournal of Cataract and Refractive Surgery
Volume29
Issue number7
Publication statusPublished - Jul 2003

Keywords

  • Biometry
  • Cataract Extraction
  • Humans
  • Postoperative Period
  • Prognosis
  • Retrospective Studies
  • Visual Acuity
  • Journal Article

Fingerprint

Dive into the research topics of 'Effect of visual acuity on biometry prediction error after cataract surgery'. Together they form a unique fingerprint.

Cite this