Title: The effects of overnight orthokeratology lenses on children's contrast visual acuity
Abstract: Objective To evaluate the effect of overnight orthokeratology (ortho-k) lenses on the children's contrast visual acuity and analyze relevant factors.Methods A prospective study was conducted on 28 children (15 males and 13 females with mean age ±SD of 10.25±1.60 years) wearing overnight ortho-k lenses.Mean spherical equivalent ±SD was-3.1786±1.07337D and best-corrected visual acuity (VA) reached at least 20/20.Contrast visual acuity (100%,25%,10%,5%)was determined by MFVA-100 before,one week and one month after commencement of the procedure.Results Either before or after wearing orthokeratology lenses,LogMAR values of VA gradually increased with the decrease of contrast.At contrast levels of 25%,10% and 5%,there was a statistically significant increase in the LogMAR value of VA after wearing orthokeratology lenses for one week (25%∶ P =0.042,t =-2.137; 10%∶ P =0.004,t =-3.157; 5%∶ P =0.006,t =-2.99) and one month (25%∶ P =0.028,t =-2.322; 10%∶ P =0.006,t =-2.958; 5%∶ P =0.006,t =-2.989).The difference was more obvious in lower contrast levels.There was no statistical difference between the LogMAR value of VA after wearing orthokeratology lenses for one week and one month.At contrast level of 5%,the changes of LogMAR value of VA induced by orthokeratology were significantly correlated with the amount of initial myopic diopter.Conclusions The ovemight ortho-k lenses improve naked visual acuity of children as well as reduce their contrast visual acuity,specifically at the low contrast levels.
Key words:
Orthokeratology lens; Contrast visual acuity; Children
Publication Year: 2013
Publication Date: 2013-06-10
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot