Article Text

Download PDFPDF

OP-1 Analysis and reporting of surgically induced keratometric effect (SIKE)
  1. Fadi Alfaqawi1,
  2. Luca Pagano1,
  3. Esmaeil M Arbabi1,
  4. Vito Romano1,
  5. Ahmed Al-Maskari1,
  6. Gabriela Czanner1,
  7. Stephen Kaye2
  1. 1Department of Eye and Vision Science, The University of Liverpool, Liverpool, UK
  2. 2Royal Liverpool and Broadgreen University Hospital, Liverpool, UK


*Correspondence, Fadi Alfaqawi:

Purpose To investigate the surgically induced keratometric effect (SIKE) associated with cataract surgery.

Methods Consecutive patients undergoing cataract operation by four surgeons were prospectively included. Two surgeons made an incision at 110 with one side port at 50 (location 1). Two surgeons made a temporal incision at 200 and 20 for right eyes and left eyes respectively, with two side ports (location 2). Biometry was acquired preoperatively and at 6-weeks postoperatively using an IOL Master 500 (Carl Zeiss Meditec, Jena, Germany) on the operated and unoperated fellow eye. Keratometric change was analysed after being transformed into Long’s formalism. Coupling was defined as a change between the mean pre to post K that was less than the change in the unoperated eye.

Results Two hundred patients were included, (132 in location 1 and 68 in location 2). There were significant differences in pre- to postoperative keratometry: location 1: preoperative and postoperative mean K were 43.65 (95%CI:40.27 to 47.04), 43.64 (95%CI:40.20 to 47.09) respectively, mean absolute difference 0.19 (SD0.19;p<0.01), location 2: preoperative and postoperative mean K were 43.29 (95%CI:39.89 to 46.70), 43.21 (95%CI:39.91 to 46.51) respectively, mean absolute difference 0.21 (SD0.21;p<0.01). For location 1, the mean SIKE was -0.23 @ 111/+0.21 @ 21 (95%CI:-1.43@122/+0.04 @ 32 to +1.04 @ 135/+0.30 @ 45). For location 2, the mean SIKE was -0.29 @ 104/+0.13 @ 14 (95%CI:-1.75@122/-0.19 @ 32 to +0.30 @ 47/+1.32 @ 137). Keratometric changes were not coupled in 69/132 (52%) for location 1 and in 42/68 (62%) for location 2, no significant difference between the coupling rate of location 1 and location 2 (p=0.51).

Conclusion The SIKE is relatively predictable for incision location and was surgeon independent. Coupling occurs in less than 50% of cases with a change in the mean keratometry.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: .

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.