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Radial Keratotomy Correction

MetadataDetails
Publication Date2021-07-31
JournalStatPearls
AuthorsLanxing Fu, Bhupendra C. Patel
InstitutionsUniversity of Utah, King’s College Hospital
Citations2

Refractive surgery is surgical or laser procedures to alter the eye’s refractive power and decrease the patient’s dependence on spectacles and contact lenses. Radial keratotomy (RK) was one of the first and most commonly performed refractive surgical procedures of the 20th century. Approximately 10% of practicing ophthalmologists in the United States have performed several hundred thousand RK procedures. Lans demonstrated that deep radial incisions in the anterior cornea caused central corneal flattening with peripheral steepening in the late 19th century, followed by Sato, who performed posterior RKs in a series of eight keratoconus patients in the 1930s. Enhanced flattening was achieved with longer and deeper incisions. Although initially successful, Sato’s technique ultimately resulted in bullous keratopathy in up to 70% of patients due to endothelial damage. Improvements to the technique so that incisions were placed solely on the anterior corneal surface were undertaken in the 1970s in Russia, where the use of multifactorial formulae and nomograms which incorporated patient and surgical variables led to improved predictability. Radial keratotomy correction was introduced to the USA in 1978 by Bores et al., Myers, and Cowden, with multiple surgeons performing and publishing anecdotal results. Early publications were optimistic, and there were few reported complications. This led the National Institutes of Health to fund the Prospective Evaluation of Radial Keratotomy (PERK) study to assess the safety, efficacy, stability, and predictability of RK. The PERK study involved 12 surgeons practicing in nine clinical centers who performed RKs on 793 eyes of 435 patients who had 2.00-8.00 D of myopia. Technique refinements and improvements continued after the PERK study. Younger patients have a greater rate and degree of wound healing, and therefore require more surgery for the same effect compared to older individuals. Better equipment e.g., diamond blades and calibration with ultrasonic pachymeters, further improved predictability.With the introduction of more accurate and stable laser refractive surgery i.e., photorefractive keratectomy (PRK), Laser In Situ Keratomileusis (LASIK), small incision lenticule extraction (SMILE), and intraocular lens surgery the popularity of radial keratotomy correction has decreased considerably. However, due to the number of patients who have undergone this procedure, knowledge of the procedure and its variations are required to manage this group of patients who may require visual rehabilitation in later life.