May 7, 2014
ORLANDO, Fla. – Researchers reported that they found the severity of high myopia and the presence of retinal pathology to be the two factors that are primarily associated with vision impairment in their study of 1,686 eyes with high myopia.
Brien A. Holden, PhD, DSc, LOSc, and colleagues reported in a poster here at the Association for Research in Vision and Ophthalmology meeting that increased ocular lens thickness and shallower anterior chamber depth were also associated, but to a lesser extent. Axial elongation was found to be an even weaker influence.
Participants from the Zhongshan Ophthalmic Centre clinics were between 7 and 70 years old with myopia of at least -6 D in both eyes.
According to study co-author Monica Jong, PhD, BOptom, the patients underwent cycloplegic refractions and were measured for best-corrected visual acuity, axial length, corneal curvature, anterior chamber depth and IOPs. They were also examined for retinopathy, she said.
“When we performed multiple regression, we found that vision impairment wasn’t as strongly linked to axial elongation; it was more linked to the level of refractive error,” Jong told Primary Care Optometry News. “When we compared those with good vision to those with low vision, we found significant differences in refractive error, age, axial length, lens thickness, anterior chamber depth and prevalence of retinal pathology.
“So it shows high myopia is affecting all aspects of the eye, it’s not just axial elongation,” she continued. “We found the most important factors associated with vision impairment were refractive error and lens thickness. What was interesting was that age and axial length were not the most significant factors associated with retinal pathology.”
Jong summarized the study results, saying that no vision impairment was found in 9% of eyes despite the presence of retinal pathology, and 59% had moderate or severe vision loss despite the absence of any retinal pathology.
She shared the study’s take-home message: “High myopia causes permanent visual impairment, and we as optometrists can do something about it. When these myopes come to our practice, when they are not yet high myopes, we should implement some kind of myopia control in terms of bifocal spectacles or multifocal contact lenses, advising them to reduce their near work or spend more time outdoors as protective factors. – by Nancy Hemphill
Disclosures: Holden, Jong and colleagues have no financial disclosures.