Comparison of the predictability of refractive cylinder correction by laser in situ keratomileusis in eyes with low or high ocular residual astigmatism.
OBJECTIVE
To compare the manifest refractive cylinder (MRC) predictability of myopic astigmatism laser in situ keratomileusis (LASIK) between eyes with low and high ocular residual astigmatism (ORA).


METHODS
London Vision Clinic, London, United Kingdom.


METHODS
Retrospective case study.


METHODS
The ORA was considered the vector difference between the MRC and the corneal astigmatism. The index of success (IoS), difference vector ÷ MRC, was analyzed for different groups as follows: stage 1, low ORA (ORA ÷ MRC <1), high ORA (ORA ÷ MRC ≥1); stage 2, low ORA group reduced to match the high ORA group for MRC; stage 3, grouped by ORA magnitude with low ORA (<0.50 diopters [D]), mid ORA (0.50 to 1.24 D), and high ORA (≥1.25 D); stage 4, high ORA group subdivided into low (<0.75 D) and high (≥0.75 D) corneal astigmatism.


RESULTS
For stage 1, the mean preoperative MRC and mean IoS were -1.32 D ± 0.65 (SD) (range -0.55 to -3.77 D) and 0.27, respectively, for low ORA and -0.79 ± 0.20 D (range -0.56 to -2.05 D) and 0.37, respectively, for high ORA. For stage 2, the mean IoS increased to 0.32 for low ORA. For stage 3, the mean IoS was 0.28, 0.29, and 0.31 for low ORA, mid ORA, and high ORA, respectively. For stage 4, the mean IoS was 0.20 for high ORA/low corneal astigmatism and 0.35 for high ORA/high corneal astigmatism.


CONCLUSIONS
The MRC predictability was slightly worse in eyes with high ORA when grouped by the ORA ÷ MRC. Matching for the MRC and grouping by ORA magnitude resulted in similar predictability; however, eyes with high ORA and high corneal astigmatism were less predictable.


BACKGROUND
Dr. Reinstein is a consultant to Carl Zeiss Meditec AG, has a proprietary interest in the Artemis technology (Arcscan, Inc.), and is an author of patents related to very-high-frequency digital ultrasound administered by the Center for Technology Licensing at Cornell University, Ithaca, New York, USA. No other author has a financial or proprietary interest in any material or method mentioned.
From the London Vision Clinic (Archer, Reinstein, Gobbe, Carp), London, United Kingdom; the Department of Ophthalmology (Reinstein), Columbia University Medical Center, New York, New York, USA; Centre Hospitalier National d'Ophtalmologie (Reinstein), Paris, France; School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom (Archer, Reinstein); Department of Optics, Pharmacology and Anatomy (Piñero), University of Alicante, Alicante, Spain.
Timothy J
TJ
Archer
From the London Vision Clinic (Archer, Reinstein, Gobbe, Carp), London, United Kingdom; the Department of Ophthalmology (Reinstein), Columbia University Medical Center, New York, New York, USA; Centre Hospitalier National d'Ophtalmologie (Reinstein), Paris, France; School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom (Archer, Reinstein); Department of Optics, Pharmacology and Anatomy (Piñero), University of Alicante, Alicante, Spain. Electronic address: dzr@londonvisionclinic.com.
Dan Z
DZ
Reinstein
From the London Vision Clinic (Archer, Reinstein, Gobbe, Carp), London, United Kingdom; the Department of Ophthalmology (Reinstein), Columbia University Medical Center, New York, New York, USA; Centre Hospitalier National d'Ophtalmologie (Reinstein), Paris, France; School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom (Archer, Reinstein); Department of Optics, Pharmacology and Anatomy (Piñero), University of Alicante, Alicante, Spain.
David P
DP
Piñero
From the London Vision Clinic (Archer, Reinstein, Gobbe, Carp), London, United Kingdom; the Department of Ophthalmology (Reinstein), Columbia University Medical Center, New York, New York, USA; Centre Hospitalier National d'Ophtalmologie (Reinstein), Paris, France; School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom (Archer, Reinstein); Department of Optics, Pharmacology and Anatomy (Piñero), University of Alicante, Alicante, Spain.
Marine
M
Gobbe
From the London Vision Clinic (Archer, Reinstein, Gobbe, Carp), London, United Kingdom; the Department of Ophthalmology (Reinstein), Columbia University Medical Center, New York, New York, USA; Centre Hospitalier National d'Ophtalmologie (Reinstein), Paris, France; School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom (Archer, Reinstein); Department of Optics, Pharmacology and Anatomy (Piñero), University of Alicante, Alicante, Spain.
Glenn I
GI
Carp
D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology