Declines in PDE4B activity promote myopia progression through downregulation of scleral collagen expression

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

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AP2M1 Supports TGF-β Signals to Promote Collagen Expression by Inhibiting Caveolin Expression

International Journal of Molecular Sciences ◽

10.3390/ijms22041639 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1639

Author(s):

Saerom Lee ◽

Ga-Eun Lim ◽

Yong-Nyun Kim ◽

Hyeon-Sook Koo ◽

Jaegal Shim

Keyword(s):

Rna Seq ◽

Gene Encoding ◽

Caveolin 1 ◽

Collagen Expression ◽

Disease States ◽

Tumor Growth Factor ◽

Complex Process ◽

Collagen Protein ◽

Complex Regulation ◽

Collagen Genes

The extracellular matrix (ECM) is important for normal development and disease states, including inflammation and fibrosis. To understand the complex regulation of ECM, we performed a suppressor screening using Caenorhabditis elegans expressing the mutant ROL-6 collagen protein. One cuticle mutant has a mutation in dpy-23 that encodes the μ2 adaptin (AP2M1) of clathrin-associated protein complex II (AP-2). The subsequent suppressor screening for dpy-23 revealed the lon-2 mutation. LON-2 functions to regulate body size through negative regulation of the tumor growth factor-beta (TGF-β) signaling pathway responsible for ECM production. RNA-seq analysis showed a dominant change in the expression of collagen genes and cuticle components. We noted an increase in the cav-1 gene encoding caveolin-1, which functions in clathrin-independent endocytosis. By knockdown of cav-1, the reduced TGF-β signal was significantly restored in the dpy-23 mutant. In conclusion, the dpy-23 mutation upregulated cav-1 expression in the hypodermis, and increased CAV-1 resulted in a decrease of TβRI. Finally, the reduction of collagen expression including rol-6 by the reduced TGF-β signal influenced the cuticle formation of the dpy-23 mutant. These findings could help us to understand the complex process of ECM regulation in organism development and disease conditions.

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The Effect of Long-Term Low-Dose Atropine on Refractive Progression in Myopic Australian School Children

Journal of Clinical Medicine ◽

10.3390/jcm10071444 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1444

Author(s):

William Myles ◽

Catherine Dunlop ◽

Sally A. McFadden

Keyword(s):

Low Dose ◽

High Dose ◽

Eye Drops ◽

Myopia Progression ◽

At Risk Children ◽

Slow Group ◽

Blue Eyes ◽

Global Population ◽

Axial Growth

Myopia will affect half the global population by 2050 and is a leading cause of vision impairment. High-dose atropine slows myopia progression but with undesirable side-effects. Low-dose atropine is an alternative. We report the effects of 0.01% or 0.005% atropine eye drops on myopia progression in 13 Australian children aged between 2 and 18 years and observed for 2 years without and up to 5 years (mean 2.8 years) with treatment. Prior to treatment, myopia progression was either ‘slow’ (more positive than −0.5D/year; mean −0.19D/year) or ‘fast’ (more negative than −0.5D/year; mean −1.01D/year). Atropine reduced myopic progression rates (slow: −0.07D/year, fast: −0.25D/year, combined: before: −0.74, during: −0.18D/year, p = 0.03). Rebound occurred in 3/4 eyes that ceased atropine. Atropine halved axial growth in the ‘Slow’ group relative to an age-matched model of untreated myopes (0.098 vs. 0.196mm/year, p < 0.001) but was double that in emmetropes (0.051mm/year, p < 0.01). Atropine did not slow axial growth in ‘fast’ progressors compared to the age-matched untreated myope model (0.265 vs. 0.245mm/year, p = 0.754, Power = 0.8). Adverse effects (69% of patients) included dilated pupils (6/13) more common in children with blue eyes (5/7, p = 0.04). Low-dose atropine could not remove initial myopia offsets suggesting treatment should commence in at-risk children as young as possible.

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Myopia control effect of defocus incorporated multiple segments (DIMS) spectacle lens in Chinese children: results of a 3-year follow-up study

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-317664 ◽

2021 ◽

pp. bjophthalmol-2020-317664

Author(s):

Carly SY Lam ◽

Wing Chun Tang ◽

Paul H Lee ◽

Han Yu Zhang ◽

Hua Qi ◽

...

Keyword(s):

Repeated Measures ◽

Mean Difference ◽

Historical Control ◽

Control Group ◽

Control Effect ◽

Myopia Progression ◽

The Third ◽

Spherical Equivalent Refraction ◽

Mean Differences ◽

Myopia Control

AimsTo determine myopia progression in children who continued to wear the defocus incorporated multiple segments (DIMS) lenses or switched from single vision (SV) to DIMS lenses for a 1-year period following a 2-year myopia control trial.Methods128 children participated in this study. The children who had worn DIMS lenses continued to wear DIMS lenses (DIMS group), and children who had worn SV lenses switched to wear DIMS lenses (Control-to-DIMS group). Cycloplegic spherical equivalent refraction (SER) and axial length (AL) were measured at 6-month interval. Historical controls were age matched to the DIMS group at 24 months and used for comparing the third-year changes.ResultsOver 3 years, SER and AL changes in the DIMS group (n=65) were −0.52±0.69D and 0.31±0.26 mm; these changes were not statistically significant over time (repeated measures analysis of variance, p>0.05).SER (−0.04±0. 38D) and AL (0.08±0.12 mm) changes in the Control-to-DIMS group (n=55) in the third year were less compared with the first (mean difference=0.45 ± 0.30D, 0.21±0.11 mm, p<0.001) and second (0.34±0.30D, 0.12±0.10 mm, p<0.001) years.Changes in SER and AL in both groups over that period were significantly less than in the historical control group (DIMS vs historical control: mean difference=−0.18±0.42D, p=0.012; 0.08±0.15 mm, p=0.001; Control-to-DIMS versus historical control: adjusted mean differences=−0.30±0.42D, p<0.001; 0.12±0.16 mm, p<0.001).ConclusionsMyopia control effect was sustained in the third year in children who had used the DIMS spectacles in the previous 2 years and was also shown in the children switching from SV to DIMS lenses.

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Intravitreal brimonidine inhibits form-deprivation myopia in guinea pigs

Eye and Vision ◽

10.1186/s40662-021-00248-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yifang Yang ◽

Junshu Wu ◽

Defu Wu ◽

Qi Wei ◽

Tan Zhong ◽

...

Keyword(s):

Guinea Pig ◽

Intravitreal Injection ◽

Guinea Pigs ◽

Intravitreal Injections ◽

Eye Drops ◽

Rna Seq ◽

Myopia Progression ◽

Expression Levels ◽

Guinea Pig Model ◽

Administration Methods

Abstract Background The use of ocular hypotensive drugs has been reported to attenuate myopia progression. This study explores whether brimonidine can slow myopia progression in the guinea pig form-deprivation (FD) model. Methods Three-week-old pigmented male guinea pigs (Cavia porcellus) underwent monocular FD and were treated with 3 different methods of brimonidine administration (eye drops, subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for intravitreal injection (2 μg/μL, 4 μg/μL, 20 μg/μL, 40 μg/μL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure (IOP), refractive error and axial length (AL), respectively. On day 21, guinea pigs were sacrificed for RNA sequencing (RNA-seq) to screen for associated transcriptomic changes. Results The myopia model was successfully established in FD animals (control eye vs. FD eye, respectively: refraction at day 20, 0.97 ± 0.18 D vs. − 0.13 ± 0.38 D, F = 6.921, P = 0.02; AL difference between day 0 and day 21, 0.29 ± 0.04 mm vs. 0.45 ± 0.03 mm, F = 11.655, P = 0.004). Among the 3 different brimonidine administration methods, intravitreal injection was the most effective in slowing myopia progression, and 4 μg/μL was the most effective among the four different concentrations of brimonidine intravitreal injection tested. The AL and the refraction of the brimonidine intravitreal injection group was significantly shorter or more hyperopic than those of other 2 groups. Four μg/μL produced the smallest difference in AL and spherical equivalent difference values. FD treatment significantly increased the IOP. IOP was significantly lower at 1 day after intravitreal injections which was the lowest in FD eye of intravitreal injection of brimonidine. At day 21, gene expression analyses using RNA-seq showed upregulation of Col1a1 and Mmp2 expression levels by intravitreal brimonidine. Conclusions Among the 3 different administration methods, intravitreal injection of brimonidine was the most effective in slowing myopia progression in the FD guinea pig model. Intravitreal brimonidine at 4 μg/μL significantly reduced the development of FD myopia in guinea pigs. Expression levels of the Col1a1 and Mmp2 genes were significantly increased in the retinal tissues of the FD-Inj-Br group.

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