Astigmatic Keratotomy Astigmatism Workup

  • Author: James Hays, MD; Chief Editor: Hampton Roy Sr, MD   more...
 
Updated: Feb 17, 2012
 

Imaging Studies

  • Corneal topography is vital in performing accurate AK. Fortunately, over the last 5 years, topographers have become commonplace in ophthalmic practices.
  • Combined elevation and thickness measurements can be obtained from the Orbscan machine. Since traditional AK is based upon ultrasonic pachymetry measurements, correlation between Orbscan pachymetry and standard ultrasonic pachymeter must be performed. Significant differences between thickness readings from ultrasonic pachymetry and the Orbscan machine have been reported.
Proceed to Treatment & Management
 
 
Contributor Information and Disclosures
Author

James Hays, MD  Consulting Staff, Department of Corneal Transplantation and Refractive Surgery, Atlanta Eye Surgery Center

Disclosure: Nothing to disclose.

Coauthor(s)

Spencer Thornton, MD  Medical Director, Thornton Eye Center

Spencer Thornton, MD is a member of the following medical societies: American Academy of Ophthalmology and American College of Surgeons

Disclosure: Nothing to disclose.

Antonio Pascotto, MD  Consulting Ophthalmologist, Pascotto, Istituto per la Salute degli Occhi, Clinica Mediterranea, Italy

Disclosure: Nothing to disclose.

Sergio Claudio Saccà, PhD  Professor of Ophthalmology, Department of Neurological and Visual Sciences, Ospedale San Martino, Italy

Disclosure: Nothing to disclose.

Mauro Fioretto, MD  Professor of Ophthalmology, University Eye Clinic of Genova; Head of Ophthalmology Department, Hospital of Casale Monferrato, Italy

Disclosure: Nothing to disclose.

Vincenzo Orfeo, MD  Head, Operating Unit, Clinica Mediterranea, Naples, Italy

Vincenzo Orfeo, MD is a member of the following medical societies: American Academy of Ophthalmology

Disclosure: Nothing to disclose.

Specialty Editor Board

Daniel S Durrie, MD  Director, Department of Ophthalmology, Division of Refractive Surgery, University of Kansas Medical Center

Daniel S Durrie, MD is a member of the following medical societies: American Academy of Ophthalmology and Association for Research in Vision and Ophthalmology

Disclosure: Alcon Labs Grant/research funds Independent contractor; Abbott Medical Optics Grant/research funds Independent contractor; Acufocus Ownership interest Consulting; WaveTec Ownership interest Consulting; Topcon Grant/research funds Independent contractor; Avedro Grant/research funds Independent contractor; ReVitalVision Independent contractor

Simon K Law, MD, PharmD  Associate Professor of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, David Geffen School of Medicine

Simon K Law, MD, PharmD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, and Association for Research in Vision and Ophthalmology

Disclosure: Nothing to disclose.

Louis E Probst  MD, Medical Director, TLC Laser Eye Centers

Louis E Probst is a member of the following medical societies: American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery, and International Society of Refractive Surgery

Disclosure: Nothing to disclose.

Lance L Brown, OD, MD  Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri

Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy Sr, MD  Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences

Hampton Roy Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, and Pan-American Association of Ophthalmology

Disclosure: Nothing to disclose.

References

  1. Thornton SP, Sanders DR. Graded nonintersecting transverse incisions for correction of idiopathic astigmatism. J Cataract Refract Surg. Jan 1987;13(1):27-31. [Medline].

  2. Buzard K, Haight D, Troutman R. Ruiz procedure for postkeratoplasty astigmatism. J Refractive Surgery. 1987;3:40-5.

  3. Price FW, Grene RB, Marks RG, Gonzales JS. Astigmatism reduction clinical trial: a multicenter prospective evaluation of the predictability of arcuate keratotomy. Evaluation of surgical nomogram predictability. ARC-T Study Group. Arch Ophthalmol. Mar 1995;113(3):277-82. [Medline].

  4. Nordan LT. Quantifiable astigmatism correction: concepts and suggestions, 1986. J Cataract Refract Surg. Sep 1986;12(5):507-18. [Medline].

  5. Lindstrom RL. The surgical correction of astigmatism: a clinician's perspective. Refract Corneal Surg. Nov-Dec 1990;6(6):441-54. [Medline].

  6. Troutman RC, Swinger C. Relaxing incision for control of postoperative astigmatism following keratoplasty. Ophthalmic Surg. Feb 1980;11(2):117-20. [Medline].

  7. Krumeich JH, Kezirian GM. Circular keratotomy to reduce astigmatism and improve vision in stage I and II keratoconus. J Refract Surg. Apr 2009;25(4):357-65. [Medline].

  8. Hoffart L, Proust H, Matonti F, Conrath J, Ridings B. Correction of postkeratoplasty astigmatism by femtosecond laser compared with mechanized astigmatic keratotomy. Am J Ophthalmol. May 2009;147(5):779-87, 787.e1. [Medline].

  9. Navarro R, Palos F, Lanchares E, Calvo B, Cristobal JA. Lower- and higher-order aberrations predicted by an optomechanical model of arcuate keratotomy for astigmatism. J Cataract Refract Surg. Jan 2009;35(1):158-65. [Medline].

  10. Kymionis GD, Yoo SH, Ide T, Culbertson WW. Femtosecond-assisted astigmatic keratotomy for post-keratoplasty irregular astigmatism. J Cataract Refract Surg. Jan 2009;35(1):11-3. [Medline].

  11. Bahar I, Levinger E, Kaiserman I, Sansanayudh W, Rootman DS. IntraLase-enabled astigmatic keratotomy for postkeratoplasty astigmatism. Am J Ophthalmol. Dec 2008;146(6):897-904.e1. [Medline].

  12. Kumar NL, Kaiserman I, Shehadeh-Mashor R, Sansanayudh W, Ritenour R, Rootman DS. IntraLase-enabled astigmatic keratotomy for post-keratoplasty astigmatism: on-axis vector analysis. Ophthalmology. Jun 2010;117(6):1228-1235.e1. [Medline].

 
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Thornton astigmatic keratotomy ruler.
Close-up view of Thornton astigmatic keratotomy ruler.
Example 1. Routine astigmatic keratotomy. In this image, a nasal astigmatic keratotomy is shown. This image was taken minutes after performing the incision. Note that the area around the cut stains lightly with fluorescein.
Example 2. Routine astigmatic keratotomy following corneal transplant. This 30-year-old woman underwent corneal transplantation for keratoconus 6 years ago. She presented with a clear graft but with excessive astigmatism. Based on topography, an incision was placed just inside the donor-recipient interface from 250° to 300°. A second incision was placed between 30° and 70°. Refraction improved from +0.75 + 3.00 X 58° to +0.50 + 1.50 X 130°. Best-corrected vision remained 20/20. Note the precise flattening in the topographical map exactly at the axis of the incisions. Incisions were not paired at 180° apart, but they were localized precisely on the basis of topography. This photo is the preastigmatic keratotomy topography.
Postoperative topography following astigmatic keratotomy for case described in Media file 4 of a 30-year-old woman with penetrating keratoplasty for keratoconus.
Example 3. Astigmatic keratotomy with corneal transplant. This patient underwent corneal transplantation for Fuchs dystrophy. After all sutures were removed, she had approximately 6.5 diopters of keratometric astigmatism. The sutures seemed to be tighter temporally than nasally. She underwent astigmatic keratotomy with a 50° incision temporally and a 30° incision nasally. Residual astigmatism was slightly less than a diopter. This much astigmatism alteration, 5.5 diopters, from a total of 80° of relaxing incision in normal corneas is not expected. Posttransplant corneas are variable, and individual results can vary widely. Monitor the results as best as possible intraoperatively and be willing to go back and suture an overcorrection if it should appear. Topography shows preoperative and postoperative readings with differential.
 
 
 
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