Pseudolentogenic astigmatic effect of multifocal intraocular lenses: non-corneal ocular residual astigmatism (N-CORA) as a new parameter in astigmatic change analysis.
OBJECTIVE
This study was initiated to introduce the term non-corneal ocular residual astigmatism (N-CORA) as a new parameter in astigmatic change analysis after implantation of two different types of non-toric, multifocal intraocular lenses (MIOL).


METHODS
Seventy-two eyes from 72 consecutive patients after MIOL surgery were studied in terms of a retrospective, cross-sectional data analysis. Two types of spherical MIOL were used. Surgical technique in all patients was a 2.4-mm incision phacoemulsification, performed by one surgeon. To investigate the magnitude and axis of astigmatic changes, the true corneal astigmatism and Alpins vector method were applied.


RESULTS
There were no statistically significant between-group differences related to the preoperative refraction or ocular residual astigmatism (ORA). After surgery, the mean refractive surgically induced astigmatism (RSIA) and the topographic SIA (TSIA) did not differ significantly between the lenses. The magnitude and orientation of ORA and N-CORA changed after surgery.


CONCLUSIONS
There are no statistically significant differences in postoperative ORA in magnitude or axis when implanting different types of MIOL. The similarity of N-CORA between both MIOL types shows that both diffractive and refractive asymmetric MIOLs with plate haptics have the same pseudolentogenic astigmatic effect which could be presented in terms of the newly introduced parameter N-CORA.
Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany. andi.frings@gmail.com.
Andreas
A
Frings
Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.|Care Vision Refractive Centers, Hamburg, Germany.|zentrumsehstärke, Augenarztpraxis am UKE, Hamburg, Germany.
Johannes
J
Steinberg
Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
Vasyl
V
Druchkiv
Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.|Care Vision Refractive Centers, Hamburg, Germany.|zentrumsehstärke, Augenarztpraxis am UKE, Hamburg, Germany.
Stephan J
SJ
Linke
Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.|Care Vision Refractive Centers, Hamburg, Germany.
Toam
T
Katz
D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000009:adverse effects*; D057972:Posterior Eye Segment / Q000601:surgery*; D011183:Postoperative Complications; D011474:Prosthesis Design; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D016896:Treatment Outcome
Alpins vector method; Multifocal intraocular lens; Ocular residual astigmatism; Topographic astigmatism
J Cataract Refract Surg. 2010 Oct;36(10):1745-52
20870122
J Cataract Refract Surg. 1993 Jul;19(4):524-33
8355160
J Cataract Refract Surg. 1997 Jan-Feb;23(1):65-75
9100110
J Cataract Refract Surg. 2001 Jan;27(1):31-49
11165856
Cornea. 2013 Jun;32(6):783-90
23132451
J Cataract Refract Surg. 1990 Jul;16(4):413-22
2380922
Br J Ophthalmol. 2012 Feb;96(2):267-70
21515563
J Cataract Refract Surg. 2012 Oct;38(10):1764-70
22999600
J Cataract Refract Surg. 2012 Nov;38(11):1978-88
23010252
J Cataract Refract Surg. 2011 May;37(5):859-65
21397457
J Cataract Refract Surg. 2005 Mar;31(3):574-85
15811748
J Cataract Refract Surg. 2007 Feb;33(2):203-9
17276259