Accuracy of Intraocular Lens Calculation by SRK/T Formula in Pediatric Cataracts

J Med Assoc Thai. 2015 Aug:98 Suppl 7:S198-203.

Abstract

Objective: To examine the accuracy of the intraocular lens calculation by SRK/T formula in pediatric cataract patients, by means of the prediction error after the cataract surgery.

Material and method: A retrospective review of pediatric patients requiring cataract extraction with intraocular lens implantation, between January 2006 and December 2013 was performed. Post-operative spherical equivalent was compared with the predicted calculation value from pre-operative SRK/T measurement, defined as prediction error (PE).

Results: 139 eyes from 106 patients were studied. The median age of patients at surgery was 4.56 years (IQR, 14). The two most common causes of cataract were idiopathic and traumatic; 85 eyes (61.2%) and 36 eyes (25.9%), respectively. Primary intraocular lens (IOL) implantation was performed in 87 (62.6%) eyes. The mean PE was -1.32±1.89 D (-7.78, 2.24). At one to three months after surgery, the mean PE of IOL in bag and sulcus were -0.87 D and -2.02 D, respectively. In non-traumatic group, the mean PE of IOL in bag and sulcus were -1.1 D and 2.28 D, respectively, whilst the traumatic group was -0.33 D and -1.16 D, respectively. Post-operative PE within ±1 diopter was found in 30 eyes (37.97%) at one to three months of follow-ups.

Conclusion: The majority of post-operative refraction was more myopic than the taigeted refractive error, which was calculated by SRK/T formula. Aiming for a more hyperopic target and IOL implantation in the bag would decrease the post-operative prediction error in the use of the SRK/T formnula in pediatric cataract patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cataract / physiopathology*
  • Cataract Extraction
  • Child, Preschool
  • Female
  • Humans
  • Lenses, Intraocular*
  • Male
  • Models, Theoretical*
  • Postoperative Period
  • Refraction, Ocular / physiology*
  • Reproducibility of Results
  • Retrospective Studies
  • Vision Tests / methods*
  • Visual Acuity