Refractive Corneal Surgery

Aka: Refractive Corneal Surgery, Refractive Surgery, Laser Thermal Keratoplasty, Intrastromal corneal ring, Intacs, Phakic Intraocular Lens

advertisement

II. Epidemiology

  1. Incidence: 600,000 procedures per year in U.S. (peaked at 1.4 Million in 2006)
  2. Age: 30-40 years old most typical

III. Indications

  1. Refractive Error Correction

IV. Contraindications

  1. See Laser In-Situ Keratomileusis (LASIK)

V. Background: Refractive Surgery reshapes Cornea

  1. Myopia (Near-sightedness)
    1. Eye globe is too long, and light rays focus in front of Retina
    2. Surgery flattens Cornea to focus light further back
  2. Hyperopia (Far-sightedness)
    1. Eye globe is too short, and light rays focus behind Retina
    2. Surgery steepens Cornea to focus light closer
  3. Astigmatism
    1. Cornea is non-spherical with uneven surface
    2. Surgery evens out Cornea, directs light at Retina

VI. Background

  1. See Cornea for anatomy
  2. Cornea undergoes computer-aided reshaping with multiple different techniques
    1. For Myopia, Corneal curvature decreased by removing central Corneal tissue
    2. For Hyperopia, Corneal curvature increased by removing peripheral Corneal tissue (less predictable)
    3. For Astigmatism, Corneal surface is smoothed
  3. Refractive Surgery mechanism
    1. Pulsatile laser (excimer laser) is used to a pre-programmed section of Corneal Stroma

VII. Techniques

  1. Laser In-Situ Keratomileusis (LASIK)
    1. Contact Lens sized flap is made into the Corneal Epithelium (via femtosecond/cutting laser or microtome)
    2. Cornea epithelial flap is folded over, allowing laser access to the underlying Corneal Stroma
    3. Corneal Stroma is removed via pulsatile (excimer) laser
    4. Corneal flap is folded back into place and spontaneously re-adheres
    5. Variant methods use Lenticule (lens-shaped) extraction: FLEx, SMILE
  2. Photorefractive Keratectomy (PRK)
    1. Epithelial surface is scraped away allowing access to Corneal Stroma (but causing a large Corneal Abrasion)
    2. As with LASIK, Corneal Stroma is removed via pulsatile (excimer) laser
    3. Replaced by LASIK for most patients
  3. LASEK
    1. Variant of PRK, in which the epithelial layer is removed with Alcohol
  4. Radial Keratotomy (RK)
    1. Replaced by LASIK
  5. Laser Thermal Keratoplasty (LTK)
    1. YAG laser mediated radial spot placement
    2. Heats Cornea and shrinks stromal Collagen
    3. Modifies anterior Corneal curvature
    4. Corrects presbyopic patient with <4 D Refraction
  6. Intrastromal corneal ring (ICR or Intacs)
    1. Polymethylmethacrylate (PMMA) ring implanted
    2. Flattens central Cornea
    3. Corrects low Myopia (<3 D)
    4. Surgery easily adjustable
    5. No risk of central Corneal scarring
  7. Phakic Intraocular Lens
    1. Plastic intraocular lens
    2. Placed anterior to natural crystalline lens
    3. Corrects high Myopia and Hyperopia

VIII. References

  1. Bower (2001) Am Fam Physician 64(7):1183-90 [PubMed]
  2. Sanders (1998) J Cataract Refract Surg 24:607 [PubMed]
  3. Schanzlin (1997) Ophthalmology 104:1067 [PubMed]
  4. Wilkinson (2017) Am Fam Physician 95(10): 637-44 [PubMed]
  5. (1999) Med Lett Drugs Ther 41(1068):121-3 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Refractive Corneal Surgery." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Ontology: Surgical ocular refractive procedure (C1274010)

Definition (MSH) Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.
Concepts Therapeutic or Preventive Procedure (T061)
MSH D054140
SnomedCT 373391005
Spanish procedimiento de refracción ocular quirúrgica (procedimiento), Procedimientos Quirúrgicos Refractivos, procedimiento de refracción ocular quirúrgica, cirugía refractaria, cirugía refractiva (procedimiento), cirugía refractiva
English Surgical Procedures, Refractive, Procedures, Refractive Surgical, Refractive Surgical Procedure, Surgical Procedure, Refractive, Surgeries, Refractive, Refractive Surgeries, Refractive Surgical Procedures, Procedure, Refractive Surgical, Surgery, Refractive, Refractive Surgery, Surgical ocular refraction procedure, Refractive surgery (procedure), Refractive surgery, Surgical ocular refraction procedure (procedure), Surgical ocular refractive procedure
Portuguese Procedimentos Cirúrgicos Refrativos
Finnish Refraktiivinen silmäkirurgia
French Chirurgie réfractive, Interventions de chirurgie réfractive, Procédures de chirurgie réfractive, Procédures chirurgicales réfractives, Corrections chirurgicales de troubles réfractifs
German Refraktive Chirurgie, Refraktive chirurgische Verfahren
Italian Chirurgia refrattiva
Russian КЕРАТОРЕФРАКТИВНЫЕ ХИРУРГИЧЕСКИЕ ОПЕРАЦИИ, KERATOREFRAKTIVNYE KHIRURGICHESKIE OPERATSII, РЕФРАКТИВНЫЕ ХИРУРГИЧЕСКИЕ ОПЕРАЦИИ, REFRAKTIVNYE KHIRURGICHESKIE OPERATSII
Czech refrakční chirurgické postupy, refrakční chirurgie, refrakční chirurgické výkony
Croatian Not Translated[Refractive Surgical Procedures]
Swedish Refraktiv kirurgi
Polish Procedury chirurgii refrakcyjnej, Metody chirurgii refrakcyjnej, Zabiegi chirurgiczne refrakcyjne
Japanese 屈折矯正手術, 角膜屈折矯正手術
Norwegian Refraksjonskirurgi
Derived from the NIH UMLS (Unified Medical Language System)

Related Topics in Surgery

advertisement

2025 Family Practice Notebook, LLC. Terms | Privacy | About | Site Map | Newsletter | Blog

Footer Site Logo