Biomaterial Database

Photorefractive keratectomy after radial keratotomy. 1996

A A al-Rajhi, and J M Risco, and I A Badr, and K D Teichmann

King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.

BACKGROUND Twenty-three eyes of 22 patients remained undercorrected 5 to 49 months after radial keratotomy, either alone or in combination with transverse keratotomy. METHODS We attempted to correct the residual myopia ranging from -1.25 to -5.75 diopters (D) (with astigmatism of 0 to 1.25 D) with photorefractive keratectomy. The mean age of patients was 26 years (range 22 to 40 years). RESULTS After photorefractive keratectomy (follow-up 6 to 17 months) uncorrected visual acuity was equal to or better than 20/20 in 39% (9 eyes), better than 20/25 in 65% (15 eyes), and better than 20/40 in 74% (17 eyes). Spectacle-corrected visual acuity was equal or better than 20/40 in all eyes; one eye (4%) lost two lines of spectacle-corrected visual acuity. Refractive error was within +/- 0.50 D in 48% (11 eyes) and within +/- 1.00 D in 65% (15 eyes). Undercorrections of more than 1.00 D occurred in 22% (5 eyes) and overcorrections of more than 1.00 D occurred in 13% (3 eyes). No or minimal haze was present in 57% (13 eyes), mild haze in 39% (9 eyes) and moderate haze in 4% (1 eye). Final uncorrected visual acuity was better (p = 0.0002) and haze was less (p = 0.003) in the group with less than -3.00 D than in the group with greater than or equal to -3.00 D. CONCLUSIONS Photorefractive keratectomy after radial keratotomy is safe but less effective and less predictable in eyes with greater than or equal to -3.00 D compared to those with less than -3.00 D.

UI	MeSH Term	Description	Entries
D007646	Keratotomy, Radial	A procedure to surgically correct REFRACTIVE ERRORS by cutting radial slits into the CORNEA to change its refractive properties.	Radial Keratotomy,Keratotomies, Radial,Radial Keratotomies
D009216	Myopia	A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.	Nearsightedness,Myopias,Nearsightednesses
D012086	Reoperation	A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.	Revision, Joint,Revision, Surgical,Surgery, Repeat,Surgical Revision,Repeat Surgery,Revision Surgery,Joint Revision,Revision Surgeries,Surgery, Revision
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D005500	Follow-Up Studies	Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.	Followup Studies,Follow Up Studies,Follow-Up Study,Followup Study,Studies, Follow-Up,Studies, Followup,Study, Follow-Up,Study, Followup
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D014792	Visual Acuity	Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.	Acuities, Visual,Acuity, Visual,Visual Acuities
D016896	Treatment Outcome	Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.	Rehabilitation Outcome,Treatment Effectiveness,Clinical Effectiveness,Clinical Efficacy,Patient-Relevant Outcome,Treatment Efficacy,Effectiveness, Clinical,Effectiveness, Treatment,Efficacy, Clinical,Efficacy, Treatment,Outcome, Patient-Relevant,Outcome, Rehabilitation,Outcome, Treatment,Outcomes, Patient-Relevant,Patient Relevant Outcome,Patient-Relevant Outcomes
D054018	Lasers, Excimer	Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)	Argon Fluoride Excimer Lasers,Excimer Lasers,Krypton Chloride Excimer Lasers,Xenon Chloride Excimer Lasers,ArF Excimer Lasers,ArF Lasers,Argon Fluoride Lasers,Excimer Laser,Excimer Lasers, ArF,Excimer Lasers, Argon Fluoride,Excimer Lasers, KrCl,Excimer Lasers, Krypton Chloride,Excimer Lasers, XeCl,Excimer Lasers, Xenon Chloride,KrCl Excimer Lasers,Krypton Chloride Lasers,Lasers, ArF Excimer,Lasers, Argon Fluoride Excimer,Lasers, KrCl,Lasers, Krypton Chloride,Lasers, Krypton Chloride Excimer,Lasers, XeCl Excimer,Lasers, Xenon Chloride,Lasers, Xenon Chloride Excimer,XeCl Lasers,Xenon Chloride Lasers,ArF Excimer Laser,ArF Laser,Argon Fluoride Laser,Chloride Laser, Krypton,Chloride Laser, Xenon,Chloride Lasers, Krypton,Chloride Lasers, Xenon,Excimer Laser, ArF,Excimer Laser, KrCl,Excimer Laser, XeCl,Fluoride Laser, Argon,Fluoride Lasers, Argon,KrCl Excimer Laser,KrCl Laser,KrCl Lasers,Krypton Chloride Laser,Laser, ArF,Laser, ArF Excimer,Laser, Argon Fluoride,Laser, Excimer,Laser, KrCl,Laser, KrCl Excimer,Laser, Krypton Chloride,Laser, XeCl,Laser, XeCl Excimer,Laser, Xenon Chloride,Lasers, ArF,Lasers, Argon Fluoride,Lasers, KrCl Excimer,Lasers, XeCl,XeCl Excimer Laser,XeCl Excimer Lasers,XeCl Laser,Xenon Chloride Laser