ABSTRACT
Background Orthokeratology has been proved to temporarily alter the equivalent sphere,but its effects on visual quality deserve attention.Objective The present study was to investigate the visual quality after overnight orthokeratology in pre-adolescent myopes.Methods Written informed consent was obtained form each subject prior to entering into this series.A descriptive study design was used.One hundred and fifty eyes of 76 teenagers aged (14.90± 1.24)years with low and moderate myopia (-2.79 ± 0.82)D were included in the study.Fitted with Ortho-K contact lens,the lens was wore every night for over 8 hours.Subjective refraction,uncorrected visual acuity (UCVA),contrast sensitivity function,corneal-topography,and aberrometry were examined before,1 week and 3 months after the initiation of orthokeratology.Visual quality was generally evaluated by comparing before wearing,1 week and 3 months after wearing using the National Eye Institute refractive error quality of life instrument (NEI-RQL-42TM).All the procedures were performed by the same clinician.Results Spherical equivalent refractions were (-0.33± 1.02) D and (-0.26 ± 0.60) D 1 week and 3 months after orthokeratology,showing significant decline in comparison with (-2.79±0.82) D of before orthokeratology (P =0.001,0.001).However,no considerable difference was seen between 1 week and 3 months after orthokeratology (P=0.161).Contrast sensitivity function was significantly different in all spatial frequencies before wearing,1 week and 3 months after wearing,and those of 1 week and 3 months after wearing were significantly lower than those of before wearing (1 week:3 cpd P =0.001,6 cpd P=0.001,12 cpd P＜0.05,18 epd P＜0.05 ;3 months:3 cpd P=0.001,6 cpd P=0.001,12 cpd P＜0.05,18 cpd P＜0.05).There was no significant change in contrast sensitivity function between 1 week and 3 months of orthokeratology (P＞0.05).Flat K,steep K and corneal eccentricity (e) were significantly reduced (P =0.000),and surface asymmetry index (SAI) and surface regularity index (SRI) were significantly improved after orthokeratology in comparison with before orthokeratology (both P =0.001).Root mean square (RMS) of total higher-order,third-order and fourth-order aberrations were significantly increased (P＜0.05),but RMS of whole aberration and second-order aberrations significantly decreased after orthokeratology (P＜ 0.05).There were no significant changes in the fifth-order,sixth-order and seventh-order aberration among pre-wear,1 week and 3 months after orthokeratology.Scales of dark to bright,nocturnal driving,glare,visual fluctuate and halo were lower than those before orthokeratology (P＜0.05).The scales of visual fluctuate between 1 month and 3 months after orthokeratology had significant differences (P＜0.01),while the rest of the scales had no significant differences (P＞0.05).Conclusions Orthokeratology can reduce myopic diopter 1 week after orthokeratology.The overnight wearing of fitted orthokeratology can decrease contrast sensitivity and increase corneal surface irregularity and RMS of third-order and fourth-order.Compared with spectacles,orthokeratology reduces subjective visual quality,especially nocturnal quality.
ABSTRACT
Higher order aberrations (HOAs) were measured in 54 anisometropic amblyopic children using the ZY-WAVE II aberrometer. The results were compared in normal fellow and amblyoic eyes which were determined by the corrected visual acuity. Between the normal eyes and anisometropic amblyopic eyes, no statistically significant difference were found in mean root square of total HOAs, total coma (TC), total spherical aberration (TSA), and the 5th root mean square (RMS5). There was no correlation among best corrected visual acuity (BCVA), HOAs, TC, TSA, and RMS5. There was some positively correlation between the degree of anisometropia and TC. HOAs increase with the increasing of the degree of anisometropic amblyopia. Lower order aberrations are the main refractive factors leading to amblyopia, and HOAs is related to anisometropia amblyopia. The study helps us understand the mechanism of amblyopia and make the further study.
Subject(s)
Adolescent , Child , Female , Humans , Male , Aberrometry , Amblyopia , Diagnosis , Corneal Wavefront Aberration , Refraction, Ocular , Physiology , Visual Acuity , PhysiologyABSTRACT
The most common forms of treatment for amblyopia are occlusion therapy and pharmacologic penalization. But these methods can not recover all the visual deficits of amblyopes and there are some disadvantages of the treatment which need to be considered, including adverse effects, compliance and social stigma. Recently, some novel approaches are investigated for improving the effectiveness and compliance of treatment for amblyopia.