title: Femtosecond laser-assisted implantation of complete versus incomplete rings for keratoconus treatment.
abstract: OBJECTIVE
  To compare complete versus incomplete ring implantation for keratoconus correction.
  
  
  METHODS
  We investigated 25 eyes of keratoconic patients, of which 15 had femtosecond-assisted MyoRing corneal implantation (Group 1) and 10 had femtosecond-assisted Keraring segments (Group 2). Uncorrected distance visual acuity (UCVA), best corrected distance visual acuity (BCVA), mean K (K m), sphere, topographic cylinder, and corneal asphericity value (Q-value) were measured in all eyes preoperatively and at 4 weeks postoperatively (1 month).
  
  
  RESULTS
  In Group 1, the K m change was -6.15±2.16 D, with a mean change in sphere of 4.45±2.18 D and a mean change in refractive cylinder of 2.32±3 D. UCVA change was -0.57±0.273 logarithm of the minimum angle of resolution (LogMAR), BCVA change was -0.2±0.27 (LogMAR), and the Q-value change was 0.43±2.6. In Group 2, the K m change was -3.15±1.68 D, UCVA change was -0.48±0.37 (LogMAR), BCVA change was -0.09±0.15 (LogMAR), and the Q-value change was 0.5±0.21. Changes in the means did not significantly differ between groups, except for the K m change, which was significantly greater in Group 1 than in Group 2 (P=0.05).
  
  
  CONCLUSIONS
  Both complete ring and ring segment implantation are effective for improving corneal and visual parameters in keratoconus. Complete ring implantation may have a greater flattening effect on the anterior corneal surface.
authors: Department of Ophthalmology, Cairo University, Giza, Egypt.
authors: Mohamed
authors: M
authors: Hosny
authors: Department of Ophthalmology, Cairo University, Giza, Egypt.
authors: Esraa
authors: E
authors: El-Mayah
authors: Department of Ophthalmology, Cairo University, Giza, Egypt.
authors: Mohamed Karim
authors: MK
authors: Sidky
authors: Department of Ophthalmology, Cairo University, Giza, Egypt.
authors: Mohamed
authors: M
authors: Anis
keywords: KeraRing; MyoRing; femtosecond; keratoconus
references: Ophthalmology. 2011 Jul;118(7):1282-90
references: 21440940
references: J Cataract Refract Surg. 2010 Aug;36(8):1296-302
references: 20656151
references: Cont Lens Anterior Eye. 2010 Aug;33(4):157-66; quiz 205
references: 20537579
references: J Cataract Refract Surg. 2006 Jun;32(6):986-92
references: 16814057
references: J Cataract Refract Surg. 2007 Jun;33(6):966-70
references: 17531688
references: J Refract Surg. 2008 Sep;24(7):690-5
references: 18811111
references: J Cataract Refract Surg. 2006 Jun;32(6):978-85
references: 16814056
references: Am J Ophthalmol. 2007 Sep;144(3):387-389
references: 17640609
references: J Cataract Refract Surg. 2008 Feb;34(2):194-8
references: 18242439
references: Curr Opin Ophthalmol. 1998 Aug;9(4):9-14
references: 10387473
references: Surv Ophthalmol. 1998 Jan-Feb;42(4):297-319
references: 9493273
references: J Refract Surg. 2010 Mar;26(3):217-21
references: 20229955
references: J Refract Surg. 1995 Jul-Aug;11(4):248-52
references: 7496980
references: J Refract Surg. 1998 Sep-Oct;14(5):517-25
references: 9791818
references: J Refract Surg. 2011 Jan;27(1):63-8
references: 20166619
references: Clin Exp Ophthalmol. 2010 Mar;38(2):154-67
references: 20398105
references: Ophthalmology. 2009 Sep;116(9):1675-87
references: 19643498