AimsTo evaluate the 1-year efficacy of two new myopia control spectacle lenses with lenslets of different asphericity.MethodsOne hundred seventy schoolchildren aged 8–13 years with myopia of −0.75 D to −4.75 D were randomised to receive spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL), or single-vision spectacle lenses (SVL). Cycloplegic autorefraction (spherical equivalent refraction (SER)), axial length (AL) and best-corrected visual acuity (BCVA) were measured at baseline and 6-month intervals. Adaptation and compliance questionnaires were administered during all visits.ResultsAfter 1 year, the mean changes in the SER (±SE) and AL (±SE) in the SVL group were −0.81±0.06 D and 0.36±0.02 mm. Compared with SVL, the myopia control efficacy measured using SER was 67% (difference of 0.53 D) for HAL and 41% (difference of 0.33 D) for SAL, and the efficacy measured using AL was 64% (difference of 0.23 mm) for HAL and 31% (difference of 0.11 mm) for SAL (all p<0.01). HAL resulted in significantly greater myopia control than SAL for SER (difference of 0.21 D, p<0.001) and AL (difference of 0.12 mm, p<0.001). The mean BCVA (−0.01±0.1 logMAR, p=0.22) and mean daily wearing time (13.2±2.6 hours, p=0.26) were similar among the three groups. All groups adapted to their lenses with no reported adverse events, complaints or discomfort.ConclusionsSpectacle lenses with aspherical lenslets effectively slow myopia progression and axial elongation compared with SVL. Myopia control efficacy increased with lenslet asphericity.Trial registration numberChiCTR1800017683.

In this report, we investigated the frequency and spectrum of mitochondrial 12S rRNA variants in a large cohort of 1642 Han Chinese pediatric subjects with aminoglycoside-induced and nonsyndromic hearing loss. Mutational analysis of 12S rRNA gene in these subjects identified 68 (54 known and 14 novel) variants. The frequencies of known 1555A>G and 1494C>T mutations were 3.96% and 0.18%, respectively, in this cohort with nonsyndromic and aminoglycoside-induced hearing loss. Prevalence of other putative deafness-associated mutation at positions 1095 and 961 were 0.61% and 1.7% in this cohort, respectively. Furthermore, the 745A>G, 792C>T, 801A>G, 839A>G, 856A>G, 1027A>G, 1192C>T, 1192C>A, 1310C>T, 1331A>G, 1374A>G and 1452T>C variants conferred increased sensitivity to ototoxic drugs or nonsyndromic deafness as they were absent in 449 Chinese controls and localized at highly conserved nucleotides of this rRNA. However, other variants appeared to be polymorphisms. Moreover, 65 Chinese subjects carrying the 1555A>G mutation exhibited bilateral and sensorineural hearing loss. A wide range of severity, age-of-onset and audiometric configuration was observed among these subjects. In particular, the sloping and flat shaped patterns were the common audiograms in individuals carrying the 1555A>G mutation. The phenotypic variability in subjects carrying these 12S rRNA mutations indicated the involvement of nuclear modifier genes, mitochondrial haplotypes, epigenetic and environmental factors in the Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptMitochondrion. Author manuscript; available in PMC 2011 June 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript phenotypic manifestation of these mutations. Therefore, our data demonstrated that mitochondrial 12S rRNA is the hot spot for mutations associated with aminoglycoside ototoxicity.

This randomized clinical trial aimed to evaluate whether spectacle lenses with aspherical lenslets slow myopia progression over 2 years and whether the level of lenslet asphericity affects myopia control efficacy in a dose-dependent manner.

Mitochondrial 12S rRNA 1555A>G mutation is one of the important causes of aminoglycosideinduced and nonsyndromic deafness. Our previous investigations showed that the A1555G mutation was a primary factor underlying the development of deafness but was insufficient to produce deafness phenotype. However, it has been proposed that mitochondrial haplotypes modulate the phenotypic manifestation of the 1555A>G mutation. Here, we performed systematic and extended mutational screening of 12S rRNA gene in a cohort of 1742 hearing-impaired Han Chinese pediatric subjects from Zhejiang Province, China. Among these, 69 subjects with aminoglycoside-induced and nonsyndromic deafness harbored the homoplasmic 1555A>G mutation. These translated to a frequency of ~3.96% for the 1555A>G mutation in this hearing impaired population. Clinical and genetic characterizations of 69 Chinese families carrying the 1555A>G mutation exhibited a wide range of penetrance and expressivity of hearing impairment. The average penetrances of deafness were 29.5% and 17.6%, respectively, when aminoglycoside-induced hearing loss was included or excluded. Furthermore, the average age-of-onset for deafness without aminoglycoside exposure ranged from 5 and 30 years old, with the average of 14.5 years. Their mitochondrial genomes exhibited distinct sets of polymorphisms belonging to ten Eastern Asian haplogroups A, B, C, D, F, G, M, N, R and Y, respectively. These indicated that the 1555A>G mutation occurred through

ABSTRACT.Purpose: To determine the distribution of choroidal thickness (CT) and ocular factors associated with CT in high myopic eyes in comparison with emmetropic eyes of young healthy adults. Methods: A case-control study of 648 young, male subjects, including 520 high myopes and 128 emmetropes. Choroidal imaging was performed using enhanced depth imaging spectral domain optical coherence tomography. Images were postprocessed using adaptive compensation for quality enhancement. CT was measured at nine locations, including subfovea and 1.5 and 3 mm nasal, temporal, superior and inferior to fovea. Results: The CT at the subfovea was significantly thinner (mean AE standard error: 225.87 AE 5.51 lm) for high myopes compared to emmetropes (375.15 AE 6.58 lm, p < 0.001). Likewise, CT in high myopic group was significantly thinner than emmetropic control group at all locations (p for trend <0.001 for all locations). Distribution of CT showed a markedly different pattern in high myopic eyes (thickest superiorly at 3 mm, 265.97 AE 5.97 lm) and emmetropic eyes (thickest subfoveally, 375.15 AE 6.58 lm). Choroid was thinnest at nasal 3 mm location in both the myopic (108.85 AE 3.97 lm) and emmetropic (238.25 AE 6.72 lm) groups. Among the ocular factors studied, axial length, posterior staphyloma and chorioretinal atrophy were the significant predictors of CT. Conclusions: Highly myopic eyes have significantly thinner choroid and showed different distribution pattern, compared to emmetropes. Axial length, posterior staphyloma and chorio-retinal atrophy are the strongest determinants of CT.

Our results show that the prevalence of myopia and high myopia remained high and the prevalence of astigmatism increased in young male adults in Singapore over a 13-year period after controlling for age, education and ethnicity.

Purpose: This study aimed to evaluate short-term visual performance and optical quality of three different lenslet configurations on myopia control spectacle lenses.Materials and Methods: This study utilized a cross-over design. Distance visual acuity (VA) was measured in 50 myopic children; contrast sensitivity (CS) was measured in 36 myopic children. For each test, four spectacle lenses were evaluated in a random order: single-vision lens (SVL), lens with concentric rings of highly aspherical lenslets (HAL), lens with concentric rings of slightly aspherical lenslets (SAL), and lens with honeycomb configuration of spherical lenslets (HC). The modulation transfer function (MTF) and MTF area (MTFa) were used to determine optical quality. All tests were performed monocularly on the right eye with full correction.Results: HAL and SAL had larger MTFa than HC. VA in lenses with lenslets was significantly reduced compared to SVL (all p &lt; 0.01). The reduction in VA was worse with HC than with SAL (p = 0.02) and HAL (p = 0.03); no effect of lenslet asphericity was found (p &gt; 0.05). VA changes induced by lenslets showed no correlation with spherical equivalent refraction (all p &gt; 0.05) and were weakly positively associated with age for SAL (r = 0.36, p = 0.01) and HC (r = 0.31, p = 0.03), but not for HAL (p = 0.30). The area under the log contrast sensitivity function (AULCSF) decreased with HAL and HC (all p &lt; 0.001) in all illumination levels, and AULCSF with HAL was higher than that with HC in a photopic condition (1.17 ± 0.10 vs. 1.10 ± 0.13, p = 0.0004). The presence of lenslets did not affect CS at 3 cycles per degree (cpd) (p = 0.80). At 6 to 18 cpd, CS was significantly reduced by HAL and HC (all p &lt; 0.05), but not SAL (p &gt; 0.05) compared to SVL. At high spatial frequencies (&gt;12 cpd) both SAL and HAL reduced CS significantly less than HC (all p &lt; 0.01).Conclusion: Short-term visual performance was minimally impaired by looking through the lenslet structure of myopia control spectacle lenses. Concentric rings with aspherical lenslets had a significantly lower impact on both VA and CS than honeycomb configuration with spherical lenslets.

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