title: Per-operative retinoscopy as a predictor of final post-operative refraction.
abstract: OBJECTIVE
  To assess the accuracy of streak retinoscopy performed at the end of cataract surgery as a predictor of final post-operative error.
  
  
  METHODS
  Retinoscopy was performed on 68 patients as they lay on the operating table after routine cataract extraction and intraocular lens implantation. In each case the predicted post-operative refraction by biometry and the retinoscopy at the end of the operation were compared with the 6 week post-operative subjective refraction.
  
  
  RESULTS
  The retinoscopy had a mean difference of 0.6 D (standard deviation of 0.5 D). The post-operative refraction predicted by biometric measurements had a mean difference of 1.6 D (standard deviation 0.6 D). When corrected for systematic error, 8% of patients were found to have an error of greater than 2 D as predicted by pre-operative biometry. Prediction by retinoscopy made no error greater than 2 D. The accuracy in the retinoscopic prediction of post-operative refraction was significantly better than the biometry using the F-test (p = 0.001).
  
  
  CONCLUSIONS
  Retinoscopy at the end of cataract surgery may be a valuable tool to alert the surgeon to an unexpected refractive error. This would enable immediate intraocular lens exchange, if required.
authors.affiliation: Charing Cross Hospital, London, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Tappin
authors.forename: V M
authors.initials: VM
authors.lastname: Ferguson
mesh_terms: D001699:Biometry / Q000379:methods; D002387:Cataract Extraction; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D007910:Lenses, Intraocular; D011184:Postoperative Period; D011446:Prospective Studies; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis* / Q000517:prevention & control