Purpose To compare changes in ocular aberrations in children wearing orthokeratology(ortho-k)lenses with a back optic zone diameter(BOZD)of 6 mm(6-MM group)or 5 mm(5-MM group)and their associations with axial elonga-t...Purpose To compare changes in ocular aberrations in children wearing orthokeratology(ortho-k)lenses with a back optic zone diameter(BOZD)of 6 mm(6-MM group)or 5 mm(5-MM group)and their associations with axial elonga-tion(AE)over two years.Methods Seventy Chinese children,aged 6 to 11 years,with myopia between-4.00 to-0.75 D,were randomly allocated to 5-MM and 6-MM groups.Ocular aberrations were measured,rescaled to a 4-mm pupil,and fitted with a 6th order Zernike expansion.Measurements,including axial length,were taken prior to commencing ortho-k treat-ment and then every 6 months over two years.Results After two years,the 5-MM group displayed a smaller horizontal treatment zone(TZ)diameter(by 1.14±0.11 mm,P<0.001)and less AE(by 0.22±0.07 mm,P=0.002)compared with the 6-MM group.A greater increase in total root mean square(RMS)of higher-order aberrations(HOAs),primary spherical aberration(SA)(C_(4)^(0)),and coma were also observed in the 5-MM group at all follow-up visits.The horizontal TZ diameter was significantly associated with changes in RMS HOAs,SA(RMS,primary and secondary SA),and RMS coma.After controlling for base-line parameters,RMS HOAs,RMS SA,RMS coma,and primary(C_(4)^(0))and secondary(C_(6)^(0))SA were significantly associated With AE.Conclusions Ortho-k lenses with a smaller BOzD created a smaller horizontal TZ diameter and a significant increase in total HOAs,total SA,total coma,and primary SA and a decrease in secondary SA.Of these ocular aberrations,total HOAs,total SA,and primary SA were negatively correlated with AE over two years.展开更多
文摘Purpose To compare changes in ocular aberrations in children wearing orthokeratology(ortho-k)lenses with a back optic zone diameter(BOZD)of 6 mm(6-MM group)or 5 mm(5-MM group)and their associations with axial elonga-tion(AE)over two years.Methods Seventy Chinese children,aged 6 to 11 years,with myopia between-4.00 to-0.75 D,were randomly allocated to 5-MM and 6-MM groups.Ocular aberrations were measured,rescaled to a 4-mm pupil,and fitted with a 6th order Zernike expansion.Measurements,including axial length,were taken prior to commencing ortho-k treat-ment and then every 6 months over two years.Results After two years,the 5-MM group displayed a smaller horizontal treatment zone(TZ)diameter(by 1.14±0.11 mm,P<0.001)and less AE(by 0.22±0.07 mm,P=0.002)compared with the 6-MM group.A greater increase in total root mean square(RMS)of higher-order aberrations(HOAs),primary spherical aberration(SA)(C_(4)^(0)),and coma were also observed in the 5-MM group at all follow-up visits.The horizontal TZ diameter was significantly associated with changes in RMS HOAs,SA(RMS,primary and secondary SA),and RMS coma.After controlling for base-line parameters,RMS HOAs,RMS SA,RMS coma,and primary(C_(4)^(0))and secondary(C_(6)^(0))SA were significantly associated With AE.Conclusions Ortho-k lenses with a smaller BOzD created a smaller horizontal TZ diameter and a significant increase in total HOAs,total SA,total coma,and primary SA and a decrease in secondary SA.Of these ocular aberrations,total HOAs,total SA,and primary SA were negatively correlated with AE over two years.
