PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 15499256

Study design issues in a corneal reshaping contact lens myopia progression study.

Jeffrey J Walline
View original source ↗Export metadata ↓

Abstract

Advances in contact lens design have led to corneal reshaping contact lenses that can be worn at night to temporarily reduce myopia so that patients can see clearly without glasses or contact lenses. Children are able to wear corneal reshaping contact lenses, but we do not know how they may affect the progression of myopia. A myopia control study with corneal reshaping contact lenses poses study design problems that other studies do not encounter because they temporarily reduce the refractive error. A discussion of the choice of primary outcome and control group will highlight some of these unique study design issues.

Explore related subjects

Contact LensesCorneaHumansMyopiaProsthesis DesignJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jeffrey J Walline. 2004. Study design issues in a corneal reshaping contact lens myopia progression study.. https://doi.org/10.1097/01.icl.0000140229.53294.52

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Modern scleral lenses part II: patient satisfaction.

PURPOSE: To evaluate the subjective performance of modern scleral lenses in patients of the clinics of Visser Contact Lens Practice. METHODS: In this cross-sectional survey, all the necessary data were collected at the first follow-up visit during the 5-month study period. In accordance with the preformed fitting technique developed at Visser Contact Lens Practice, four types of scleral lenses were used: spherical, front-surface toric, back-surface toric, and bitoric. Subjective performance was investigated during an interview that included the use of a five-point Likert scale and by means of a questionnaire supplemented by a 100-mm visual analog scale (VAS). RESULTS: The interview and questionnaire showed high scores for patient satisfaction with the current scleral lens in the 178 patients (284 eyes) (median score, 4; range Likert scale, 1-5; median score, >or=75; range VAS, 1-100). Significant increases in scores were seen with the current scleral lens compared to the former correction: 78.9% for comfort, 78.2% for visual quality, and 87.7% for overall satisfaction (n=284 eyes) (P<0.001). In the 99 eyes that switched from back-surface spherical to back-surface toric designs, the following significant increases were seen: 61.6%, 37.4%, and 65.7%, respectively (P<0.001). CONCLUSIONS.: High patient satisfaction was seen with all the modern scleral lens designs in the management of several forms of corneal abnormality. The interview showed differences in comfort, visual quality, and overall satisfaction in favor of the back-surface toric designs compared to the back-surface spherical designs.

Contact Lenses↗
PubMed2006

Karl Otto Himmler, manufacturer of the first contact lens.

In 1889 August Müller (1864-1949) reported the correction of his own high myopia with a ground scleral contact lens that had been manufactured in Berlin two years earlier. This paper provides the first conclusive identification, based upon primary sources, of the manufacturer of these lenses. They were made by an optical engineer, Karl Otto Himmler (1841-1903), whose firm enjoyed, until the outbreak of World War II, an international reputation for the manufacture of microscopes and their accessories.

Contact Lenses↗
PubMed2006

Calculated tear oxygen tension under contact lenses offering resistance in series: piggyback and scleral lenses.

BACKGROUND: Models of oxygen delivery to the cornea with contact lens wear have considered the customary situation of one lens being worn on the cornea. However, two lenses, such as a rigid lens piggybacked on a soft lens, may be worn by patients with special ocular and visual needs. This paper extends existing single lens models to circumstances where two lenses offer resistance to oxygen in series. METHODS: Theoretical oxygen tensions are calculated for tear layers trapped beneath piggyback contact lens systems (and scleral lenses) and the anterior corneal surface with a simple single chamber corneal model using a personal computer software spreadsheet. RESULTS: Acceptable values are anticipated for contact lens materials of modern oxygen permeability values of approximately 60-100 Fatt Dk units under open eye conditions. CONCLUSIONS: The results of this spreadsheet model of oxygen supply to the anterior corneal surface offer a useful guide to clinicians concerned about providing their patients with physiologically acceptable piggyback lens systems.

Contact Lenses↗