Dataset Information

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter.

ABSTRACT:

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 elongation (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 treatment and then every six 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) ([Formula: see text], 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 baseline parameters, RMS HOAs, RMS SA, RMS coma, and primary ([Formula: see text] and secondary ([Formula: see text] 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.

Trial registration

ClinicalTrial.gov, NCT03191942. Registered 19 June 2017, https://clinicaltrials.gov/ct2/show/NCT03191942 .

SUBMITTER: Guo B

PROVIDER: S-EPMC10314406 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter.

Guo Biyue B Cho Pauline P Cheung Sin Wan SW Kojima Randy R Vincent Stephen S

Eye and vision (London, England) 20230701 1

<h4>Purpose</h4>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 elongation (AE) over two years.<h4>Methods</h4>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 Zer ...[more]

PMID: 37391828

Similar Datasets

Project description:PurposeThe purpose of this study was to quantify the corneal power changes after wearing orthokeratology lenses of different back optic zone diameters (BOZDs) and to propose a novel 4-parameter model capable of revealing the associations between each parameter and axial length growth (ALG).MethodsA prospective self-controlled study was conducted between June 2022 and December 2023. One eye in each subject (N = 33) was randomly assigned to wear a lens with a BOZD of either 5 mm (5 oz) or 6 mm (6 oz). Axial lengths were measured at 6 and 12 months and ALG was calculated from those measurements. Corneal topography obtained at baseline, 6 months, and 12 months after lens-wearing was analyzed, and the central flatten region is considered as the treatment zone (TZ). The power change profile was fitted with a riverbank model with parameters describing the amplitude, location shift, slope, and base. A linear mixed model was used to evaluate the association between ALG and model parameters.ResultsALG was significantly slower in eyes wearing 5 oz lenses (0.19 ± 0.15 vs. 0.26 ± 0.15 mm, P < 0.01). TZ sizes were smaller in the 5 oz group (6.76 ± 2.21 vs. 8.07 ± 2.01 mm2, P < 0.01). For relative corneal refractive powers shift (RCRPS) profiles averaged across 360 degrees, greater amplitudes (4.70 ± 1.05 vs. 4.33 ± 0.99 diopter [D], P = 0.04) and smaller location shifts (1.97 ± 0.32 vs. 2.11 ± 0.27 mm, P < 0.01) were found in the 5 oz group. For RCRPS profiles calculated in eight different meridians, strong meridional modulations were found in the parameters in each group. Moreover, significant inter-group parameter differences (P < 0.01) were only found on the temporal side. Multiple regression showed that only location shift was significantly associated with ALG (P = 0.01).ConclusionsEyes wearing a 5 oz lens had significantly slower ALG, compared with the eyes wearing 6 oz lens. Such difference may be attributed to the smaller location shift on the temporal side.

Project description:ObjectiveTo study the one-year effect of wearing orthokeratology (OK) lenses on the visual quality of juvenile myopia.MethodsThe right eyes of 36 juvenile myopias were retrospectively studied in this work. Q-value, e-value, corneal curvature, strehl ratio (SR), modulation transfer function (MTF) and wavefront aberration (WA) were compared before and at 1, 3 and 12 months after wearing OK lenses. The SR, MTF and WA of cornea, internal optic and ocular were analyzed separately. The spherical and cylinder diopter, vision acuity, compensating factor (CF) and compensative rate (CF%) were compared before and at 12 months after wearing OK lenses.Results(1) The vision of LogMAR increased and the corneal curvature decreased significantly after wearing OK lenses. There was no significant difference for the e-value before and after wearing OK lenses. The Q-value increased at 1 month but decreased at 3 and 12 months remarkably. (2) The ocular and internal optic SR and MTF increased significantly at 1 month and then remained stable. The MTF in different spacial frequencies increased after wearing OK lenses. There was no significant difference for the corneal SR before and after wearing OK lenses, and the corneal MTF decreased significantly after wearing OK lenses. (3) For the ocular, the total higher order aberration (HOA), spherical, coma and trefoil aberrations increased, and the total aberration, total lower order aberration (LOA) and defocus aberration decreased obviously except astigmatism. The corneal aberrations increased significantly after wearing OK lenses except astigmatism. For the internal optic, the total aberration, total LOA and defocus aberration decreased, and the total HOA, coma and trefoil aberration increased significantly except the astigmatism and spherical aberrations. (4) The CF and CF% of total aberration, total LOA, total HOA and coma aberrations increased, and those of astigmatism and spherical decreased at 12 months.ConclusionsOrthokeratology is effective in correcting the refractive error and improving the vision quality of juvenile myopia over the one-year follow-up period.

Project description:AimTo explore the photopic pupil size behavior in myopic children undergoing overnight orthokeratology (ortho-k) over 1-year period and its effects on the axial elongation.MethodsA total of 202 Chinese myopic children were enrolled in this prospective clinical trial. Ninety-five subjects in ortho-k group and eighty-eight subjects in spectacle group completed the 1-year study. Axial length (AL) was measured before enrollment and every 6mo after the start of ortho-k. The photopic pupil diameter (PPD) was determined using the Pentacam AXL and measured in an examination room with lighting of 300-310 Lx. Stepwise multiple linear regression analysis was used to identify variables contribution to axial elongation.ResultsCompared with spectacle group, the average 1-year axial elongation was significantly slower in the ortho-k group (0.25±0.27 vs 0.44±0.23 mm, P<0.0001). In ortho-k group, PPDs significantly decreased from 4.21±0.62 mm to 3.94±0.53 mm after 1mo of lens wear (P=0.001, Bonferroni correction) and the change lasts for 3-month visit. No significantly change during the other follow-up visits was found (P>0.05, Bonferroni correction). The 4.81 mm PPD may be a possible cutoff point in the ortho-k group. Subjects with PPD below or equal to 4.81 mm tended to have smaller axial elongation compared to subjects with PPD above 4.81 mm after 1-year period (t=-3.09, P=0.003). In ortho-k group, univariate analyses indicated that those with older age, greater degree of myopia, longer AL, smaller baseline PPD (PPDbaseline) experienced a smaller change in AL. In multivariate analyses, older age, greater AL and smaller PPDbaseline were associated with smaller increases in AL. In spectacle group, PPD tended to be stable (P>0.05, Bonferroni correction) and did not affect axial growth.ConclusionPPDs experience significantly decreases at 1-month and 3-month ortho-k treatment. Children with smaller PPD tend to experience slower axial elongation and may benefit more from ortho-k.

Project description:PurposeTo determine the differences in myopia control efficiency and corneal reshaping between three different brands of orthokeratology (OK) lenses (Lucid, Euclid, and Alpha).MethodWe retrospectively reviewed subjects who started simultaneously using different brands of OK lenses. For each participant, every 6 months in the 19 months of following, the changes in axial length (AL), horizontal and vertical maximum distances of the treatment zone (HMDTZ and VMDTZ), width of the high convex zone (WHCZ), distance of decentration, and horizontal and vertical components of the decentration vector were measured. The average values of the above data, the average value of the decentration vector (ADV), and the average value of decentration calculated algebraically (ADA) were calculated.ResultsAll the three pairs (Lucid (n = 46) vs. Euclid (n = 46): groups Lucid-versus-Euclid-Lucid (LE-L) and LE-E), Lucid (n = 50) vs. Alpha (n = 50): groups LA-L and LA-A), and Euclid (n = 17) vs. Alpha (n = 17): groups EA-E and EA-A) showed good comparability. Regarding the change in AL during 19 months, none of the pairs showed significant differences (LE-L:0.27 ± 0.24 mm, LE-E:0.31 ± 0.24 mm (p = 0.68); LA-L:0.36 ± 0.26 mm, LA-A:0.36 ± 0.27 mm (p = 0.85); EA-E:0.34 ± 0.27 mm, EA-A:0.41 ± 0.28 mm (p = 0.63)). Regarding treatment zone, Lucid showed the largest HMDTZ and VMDTZ (both p < 0.05). Regarding the WHCZ, none of the pairs showed significant differences. For the ADV and ADA, Lucid had more ADV and ADA than Euclid (ADV: LE-L:0.73 ± 0.44 mm, LE-E:0.55 ± 0.45 mm, p < 0.05; ADA: LE-L:0.80 ± 0.41 mm, LE-E:0.63 ± 0.44 mm, p < 0.05), and the remaining pairs showed no significant difference. For the overall cohort with 113 eyes, the change in AL was weakly correlated with both ADV and ADA (both p < 0.05). Regarding the ADV/ADA, all pairs showed no significant differences, indicating equal lens position stability.ConclusionAfter OK, there were no significant differences between the different pairs of the three brands in AL growth, WHCZ, or lens position stability, although Lucid had a larger treatment zone than Euclid and Alpha, and Lucid had more decentration than Euclid. A larger lens decentration were weakly related to less AL growth.

Dataset Information

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter.

Purpose

Methods

Results

Conclusions

Trial registration

Publications

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets