PMID: 8594507Feb 1, 1996Paper

Morning-to-evening change in refraction, corneal curvature, and visual acuity 11 years after radial keratotomy in the prospective evaluation of radial keratotomy study. The PERK Study Group

Ophthalmology
P J McDonnellG O Waring

Abstract

Previous reports demonstrate morning-to-evening changes in ophthalmic measurements at 3 months, 1 year, and 4 years after radial keratotomy. The authors determine whether diurnal change in refractive error persists 11 years after radial keratotomy surgery in the Prospective Evaluation of Radial Keratotomy (PERK) study. Seventy-one patients were examined in the morning and evening a mean of 11.1 +/- 0.6 years (range, 10-12.7 years) after undergoing radial keratotomy under a standardized protocol using a diamond blade. Between the morning and evening examinations, the mean change in the spherical equivalent of refraction was a 0.31 +/- 0.58-diopter (D) increase in minus power in first eyes. Thirty-six (51%) eyes had an increase in minus power of the manifest refraction of 0.50 to 1.62 D; 22 (31%) had a change in refractive cylinder power of 0.50 to 1.25 D; 9 (13%) had a decrease in uncorrected visual acuity of two to seven Snellen lines; and 25 (35%) showed central corneal steepening measured by keratometry of 0.50 to 1.94 D. Two (3%) eyes lost two lines of spectacle-corrected visual acuity, whereas one (1%) eye gained two lines. In patients whose both eyes underwent surgery, a high degree of symmetry was observed in morning-to-e...Continue Reading

Associated Clinical Trials

Citations

Jul 20, 2006·Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft·K A BeckerF G Holz
Apr 20, 2000·Journal of Cataract and Refractive Surgery·M D TwaD J Schanzlin
Nov 24, 2005·Contact Lens & Anterior Eye : the Journal of the British Contact Lens Association·J P Bergmanson, E J Farmer
Jul 15, 2004·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Richard J DennisWilliam T Thompson
Oct 1, 1992·The British Journal of Ophthalmology·A K BatesA D Steele
Oct 3, 1992·BMJ : British Medical Journal·S J BecharaG O Waring
Jun 15, 2011·Indian Journal of Ophthalmology·Rajesh SinhaRasik B Vajpayee
Nov 13, 2007·Eye & Contact Lens·Julie F Y ForisterBarry A Weissman
Sep 29, 2000·Journal of Cataract and Refractive Surgery·S B ShahN T Peters
Nov 21, 2000·Journal of Cataract and Refractive Surgery·T InoueY Tano
Apr 18, 2015·Journal of Refractive Surgery·J Bradley Randleman
Dec 7, 2007·Journal of Cataract and Refractive Surgery·Carina KoppenMarie-José Tassignon
Jul 6, 2004·Ophthalmology·Marcelo V Netto, Steven E Wilson
Feb 28, 1998·Ophthalmology·C G StephensonJ Marshall
Nov 18, 2014·PloS One·Kazutaka KamiyaHidenaga Kobashi
Jan 26, 2000·Journal of Cataract and Refractive Surgery·J L FebbraroM H Friedlander
Nov 14, 2008·Journal of Cataract and Refractive Surgery·Ruth Lapid-GortzakCarla P Nieuwendaal
Jul 26, 2005·Journal of Cataract and Refractive Surgery·Sanj S WickremasingheJulian D Stevens
Oct 1, 1996·Journal of Cataract and Refractive Surgery·K A BuzardB R Fundingsland
Aug 8, 2002·Current Opinion in Ophthalmology·David M ChoiFrancis W Price
Sep 8, 2000·Current Opinion in Ophthalmology·S K Rao, P Padmanabhan
Apr 13, 2019·International Ophthalmology·José F AlfonsoLuis Fernández-Vega
Jun 4, 2020·Current Opinion in Ophthalmology·Kyeong Hwan Kim, Shahzad I Mian

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.