Bifocal Soft Contact Lenses and Their Effect on Myopia Progression in Children and Adolescents.

Overview

The purpose of this study is to determine whether bifocal soft contact lenses are effective in controlling the progression of myopia in children and adolescents that exhibit a tendency to excessively cross their eyes while reading (esophoria or eso fixation disparity). Several studies have demonstrated that bifocal or progressive multifocal spectacles are effective in slowing the progression of myopia in children either with near point esophoria and/or with inadequate focusing at near. A prominent theory for one cause of myopia progression is that poorly focused images on the back of the eye (retina) cause the eye to lengthen, causing an increase in myopia. Bifocal contact lenses may reduce this retinal defocus, reducing the stimulus to eye elongation, and thus may reduce myopia progression.

Myopia has become the focus of growing attention and concern because the prevalence of myopia appears to increasing in some populations (reaching 90% for some university student populations in Asia). There are serious risks to higher levels of myopia, including cataracts, glaucoma, retinal detachment and myopic retinal degeneration. Several studies have shown mild to moderate control of myopia progressionwith bifocal or multifocal spectacles in children with esophoria at near and/or with accommodative deficiencies. Pilot studies by the P.I. have suggested that bifocal contact lenses may control myopia progression in children with near point eso fixation disparity. CONTROL is a controlled, randomized, prospective, double-blind, one year study of the changes in myopia in 80-90 subjects from age 8-18 with low to moderate levels of myopia, low levels of astigmatism, and eso fixation disparity at near, when fitted with either bifocal soft contact lenses or single vision soft contact lenses. The primary outcome measures will be cycloplegic refraction and axial length measures.