title: Using continuous intraoperative optical coherence tomography measurements of the aphakic eye for intraocular lens power calculation.
abstract: OBJECTIVE
  To include intraoperative measurements of the anterior lens capsule of the aphakic eye into the intraocular lens power calculation (IPC) process and to compare the refractive outcome with conventional IPC formulae.
  
  
  METHODS
  In this prospective study, a prototype operating microscope with an integrated continuous optical coherence tomography (OCT) device (Visante attached to OPMI VISU 200, Carl Zeiss Meditec AG, Germany) was used to measure the anterior lens capsule position after implanting a capsular tension ring (CTR). Optical biometry (intraocular lens (IOL) Master 500) and ACMaster measurements (Carl Zeiss Meditec AG, Germany) were performed before surgery. Autorefraction and subjective refraction were performed 3 months after surgery. Conventional IPC formulae were compared with a new intraoperatively measured anterior chamber depth (ACD) (ACDIntraOP) partial least squares regression (PLSR) model for prediction of the postoperative refractive outcome.
  
  
  RESULTS
  In total, 70 eyes of 70 patients were included. Mean axial eye length (AL) was 23.3 mm (range: 20.6-29.5 mm). Predictive power of the intraoperative measurements was found to be slightly better compared to conventional IOL power calculations. Refractive error dependency on AL for Holladay I, HofferQ, SRK/T, Haigis and ACDintraOP PLSR was r(2)=-0.42 (p<0.0001), r(2)=-0.5 (p<0.0001), r(2)=-0.34 (p=0.010), r(2)=-0.28 (p=0.049) and r(2)<0.001 (p=0.866), respectively,
  
  
  CONCLUSIONS
  ACDIntraOP measurements help to better predict the refractive outcome and could be useful, if implemented in fourth-generation IPC formulae.
authors: VIROS-Vienna Institute for Research in Ocular Surgery, A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria.
authors: Nino
authors: N
authors: Hirnschall
authors: Landauerlaan 17, Leek, The Netherlands.
authors: Sverker
authors: S
authors: Norrby
authors: VIROS-Vienna Institute for Research in Ocular Surgery, A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria.
authors: Maria
authors: M
authors: Weber
authors: VIROS-Vienna Institute for Research in Ocular Surgery, A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria.
authors: Sophie
authors: S
authors: Maedel
authors: VIROS-Vienna Institute for Research in Ocular Surgery, A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria.
authors: Sahand
authors: S
authors: Amir-Asgari
authors: VIROS-Vienna Institute for Research in Ocular Surgery, A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria Department of Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors: Oliver
authors: O
authors: Findl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology*; D001036:Aphakia, Postcataract / Q000534:rehabilitation*; D058452:Axial Length, Eye; D001699:Biometry; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D055095:Optics and Photonics; D018918:Phacoemulsification; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Intraocular pressure; Lens and zonules; Optics and Refraction; Treatment Surgery