Skip to main content

Empirical fitting of rigid gas permeable lenses (comfort relationship between correct and incorrect dioptric power rigid gas permeable lenses)

1 May 2005


Background: Rigid Gas Permeable lenses have proven to offer an increase in quality of vision, improved ocular health, long term comfort, durability, increased oxygen levels, and greater resistance to deposits. However, more practitioners are fitting soft contact lenses rather than RGP lenses due to the large selection of readily available trial lenses and initial comfort during the fitting and adaptation processes. The purpose of this study was to determine if empirically fit RGP lenses of correct refractive power would improve initial impressions and thereby increase patient motivation for long-term RGP wear.

Methods: Twenty subjects, all non-contact lens wearers, were chosen for this study. Each subject had two sets of lenses empirically designed: one set contained their habitual correction, while the second set was three diopters stronger. All other parameters of these lenses were identical. The subjects were divided into two groups: Group 1 was fit with their habitual correction first; Group 2 received the lenses which were three diopters stronger than habitual correction. While wearing the lenses, the subjects were asked a series of questions. After 7 to 14 days, the subjects returned to try the other pair of lenses and to repeat the questionnaire.

Results: With this subject population, there was no significant increase in initial comfort when comparing a habitual corrected lens to that of a lens three diopters stronger than the habitual prescription.

Conclusions: Results are inconclusive due to subject population which has no need for contact lens correction. Further studies should be conducted with subjects who need correction to determine if correct power contact lenses affect initial comfort in the fitting process.


Files are restricted to Pacific University. Sign in to view.