title: Implantable collamer lens V4b and V4c for correction of high myopia.
abstract: OBJECTIVE
  To evaluate the visual outcome and intraocular pressure changes after Visian Implantable Collamer Lens (ICL) implantation V4b and V4c (with central hole) for correction of high myopia.
  
  
  METHODS
  A prospective, consecutive, interventional comparative case series of V4b and V4c ICL implantation was done in high myopic patients who were unsuitable for laser vision. The main outcome measures studied were uncorrected and corrected distant visual acuity (UDVA, CDVA), ICL vault, intraocular pressure (IOP), endothelial cell count (ECC), and development of subcapsular lens opacities. The patients were evaluated at postoperative 1,3,6, and 9 months.
  
  
  RESULTS
  A total of 62 eyes of 32 patients (24.56 ± 4.8 years) underwent V4b ICL implantation (21 non-toric, 41 toric ICL-TICL) with intraoperative peripheral iridectomy (PI), and 10 eyes of 5 patients (26.13 ± 3.8 years) had implantation of V4c ICL (4 non-toric, 6 TICL). The mean preoperative manifest spherical equivalent (MSE) was -9.98 ± 2.8 D and -9.14 ± 2.4 D in the V4b and V4c groups, respectively, which reduced to postoperative values of -0.24 ± 1.3 D and -0.2 ± 1.18 D, respectively. At the end of 9 months follow-up, mean ECC loss was 6.4% and 6.1%, mean vault was 573.13 ± 241.13 μ, and 612 ± 251.14 μ, respectively, in the V4b and V4c groups. Anterior subcapsular opacities were present in 6.9% and 3.14% of eyes with V4b and V4c groups, respectively. Four eyes from V4b (9.75%) and 1 eye from V4c (16.66%) had rotation of more than 30° and required realignment surgery, which was done successfully. Two eyes (3.22%) with V4b ICL implantation had high postoperative IOP (>35 mm Hg) due to blocked PI and required Nd:Yag laser iridotomy, which was done with successful control of IOP. The safety indices were 1.11 and 1.14, and efficacy indices were 1.4 and 1.5 in the V4b and V4c groups, respectively, at the end of 9 months.
  
  
  CONCLUSIONS
  ICL implantation is a safe and effective surgery for correction of high myopia. Implantation of ICL with a central hole showed negligible postoperative IOP fluctuations without a peripheral iridectomy.
authors.affiliation: Sankara Eye Center, Sivanadapuram, Sathy Road, Coimbatore, India.
authors.forename: Vipul
authors.initials: V
authors.lastname: Bhandari
authors.affiliation: Sankara Eye Center, Sivanadapuram, Sathy Road, Coimbatore, India.
authors.forename: Smitha
authors.initials: S
authors.lastname: Karandikar
authors.affiliation: Sankara Eye Center, Sivanadapuram, Sathy Road, Coimbatore, India.
authors.forename: Jagdeesh K
authors.initials: JK
authors.lastname: Reddy
authors.affiliation: Sankara Eye Center, Sivanadapuram, Sathy Road, Coimbatore, India.
authors.forename: Kirti
authors.initials: K
authors.lastname: Relekar
keywords: High myopia; Implantable collamer lens; Intraocular pressure