Five-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 4 Report.

PURPOSE: To evaluate (1) the long-term efficacy of low-concentration atropine over 5 years, (2) the proportion of children requiring re-treatment and associated factors, and (3) the efficacy of pro re nata (PRN) re-treatment using 0.05% atropine from years 3 to 5. DESIGN: Randomized, double-masked extended trial. PARTICIPANTS: Children 4 to 12 years of age originally from the Low-Concentration Atropine for Myopia Progression (LAMP) study. METHODS: Children 4 to 12 years of age originally from the LAMP study were followed up for 5 years. During the third year, children in each group originally receiving 0.05%, 0.025%, and 0.01% atropine were randomized to continued treatment and treatment cessation. During years 4 and 5, all continued treatment subgroups were switched to 0.05% atropine for continued treatment, whereas all treatment cessation subgroups followed a PRN re-treatment protocol to resume 0.05% atropine for children with myopic progressions of 0.5 diopter (D) or more over 1 year. Generalized estimating equations were used to compare the changes in spherical equivalent (SE) progression and axial length (AL) elongation among groups. MAIN OUTCOMES MEASURES: (1) Changes in SE and AL in different groups over 5 years, (2) the proportion of children who needed re-treatment, and (3) changes in SE and AL in the continued treatment and PRN re-treatment groups from years 3 to 5. RESULTS: Two hundred seventy (82.8%) of 326 children (82.5%) from the third year completed 5 years of follow-up. Over 5 years, the cumulative mean SE progressions were -1.34 ± 1.40 D, -1.97 ± 1.03 D, and -2.34 ± 1.71 D for the continued treatment groups with initial 0.05%, 0.025%, and 0.01% atropine, respectively (P = 0.02). Similar trends were observed in AL elongation (P = 0.01). Among the PRN re-treatment group, 87.9% of children (94/107) needed re-treatment. The proportion of re-treatment across all studied concentrations was similar (P = 0.76). The SE progressions for continued treatment and PRN re-treatment groups from years 3 to 5 were -0.97 ± 0.82 D and -1.00 ± 0.74 D (P = 0.55) and the AL elongations were 0.51 ± 0.34 mm and 0.49 ± 0.32 mm (P = 0.84), respectively. CONCLUSIONS: Over 5 years, the continued 0.05% atropine treatment demonstrated good efficacy for myopia control. Most children needed to restart treatment after atropine cessation at year 3. Restarted treatment with 0.05% atropine achieved similar efficacy as continued treatment. Children should be considered for re-treatment if myopia progresses after treatment cessation. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effects of firsthand tobacco smoking on retinal vessel caliber: a systematic review and meta-analysis.

PURPOSE: To review the effects of firsthand tobacco smoking on central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) of firsthand tobacco smokers. METHODS: We performed a search on EMBASE and PubMed for studies up to 15th July 2022. Two independent reviewers selected studies with baseline data of CRAE and CRVE of current smokers, nonsmokers, and former smokers. Initial search identified 893 studies, of which 10 were included in the meta-analysis. Two independent reviewers extracted data from the included studies. The quality of studies was assessed by the Newcastle-Ottawa Scale. RESULTS: In this meta-analysis, 7431 nonsmokers, 2448 current smokers and 5786 former smokers, as well as 7404 nonsmokers, 2430 current smokers and 5763 former smokers were included in CRAE and CRVE analysis respectively. Nonsmokers had narrower CRVE (Weighted mean difference [WMD], -12.15; 95% CI, -17.33 - -6.96) and CRAE (WMD, -4.77; 95% CI, -7.96 - -1.57) than current smokers, and narrower CRVE (WMD, -3.08; 95% CI, -6.06 - -0.11) than former smokers. Current smokers had wider CRVE (WMD, 10.42; 95% CI, 7.80 - 13.04) and CRAE (WMD, 7.05; 95% CI, 6.65 - 7.46) than former smokers. Subgroup analysis and sensitivity analysis were performed. CONCLUSION: Firsthand tobacco smoking resulted in wider CRAE and CRVE in current and former smokers, particularly in CRVE, and such changes may not be reversible after smoking cessation. Therefore, retinal vessel caliber may reflect the effects of firsthand tobacco smoking and be used to estimate the risk of cardiovascular diseases.

Vitamin D and Ocular Diseases: A Systematic Review.

The contributory roles of vitamin D in ocular and visual health have long been discussed, with numerous studies pointing to the adverse effects of vitamin D deficiency. In this paper, we provide a systematic review of recent findings on the association between vitamin D and different ocular diseases, including myopia, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), dry eye syndrome (DES), thyroid eye disease (TED), uveitis, retinoblastoma (RB), cataract, and others, from epidemiological, clinical and basic studies, and briefly discuss vitamin D metabolism in the eye. We searched two research databases for articles examining the association between vitamin D deficiency and different ocular diseases. One hundred and sixty-two studies were found. There is evidence on the association between vitamin D and myopia, AMD, DR, and DES. Overall, 17 out of 27 studies reported an association between vitamin D and AMD, while 48 out of 54 studies reported that vitamin D was associated with DR, and 25 out of 27 studies reported an association between vitamin D and DES. However, the available evidence for the association with other ocular diseases, such as glaucoma, TED, and RB, remains limited.

Lateral rectus muscle differentiation potential in paralytic esotropia patients.

PURPOSE AND BACKGROUND: Recently, we found that maximal medial rectus recession and lateral rectus resection in patients with complete lateral rectus paralysis resulted in a partial restoration of abduction. In an attempt to understand some of the mechanisms involved with this effect we examined gene expression profiles of lateral recti from these patients, with our focus being directed to genes related to myogenesis. MATERIALS AND METHODS: Lateral recti resected from patients with complete lateral rectus paralysis and those from concomitant esotropia (controls) were collected. Differences in gene expression profiles between these two groups were examined using microarray analysis and quantitative Reverse-transcription PCR (qRT-PCR). RESULTS: A total of 3056 differentially expressed genes (DEGs) were identified between these two groups. Within the paralytic esotropia group, 2081 genes were up-regulated and 975 down-regulated. The results of RT-PCR revealed that PAX7, MYOG, PITX1, SIX1 and SIX4 showed higher levels of expression, while that of MYOD a lower level of expression within the paralytic esotropia group as compared with that in the control group (p < 0.05). CONCLUSION: The decreased expression of MYOD in the paralytic esotropia group suggested that extraocular muscle satellite cell (EOMSCs) differentiation processes were inhibited. Whereas the high expression levels of PAX7, SIX1/4 and MYOG, suggested that the EOMSCs were showing an effective potential for differentiation. The stimulation resulting from muscle surgery may induce EOMSCs to differentiate and thus restore abduction function.

Lidocaine Inhibits Myoblast Cell Migration and Myogenic Differentiation Through Activation of the Notch Pathway.

PURPOSE: To assess the cellular and molecular effects of lidocaine on muscles/myoblasts. METHODS: Cultured myogenic precursor (C2C12) cells were treated with varying concentrations of lidocaine. RESULTS: Cell viability of C2C12 cells was inhibited by lidocaine in a concentration-dependent manner, with concentrations ≥0.08%, producing a dramatic reduction in cell viability. These ≥0.08% concentrations of lidocaine arrested cell cycles of C2C12 cells in the G0/G1 phase. Moreover, lidocaine inhibited cell migration and myogenic processes in C2C12 cells at low concentrations. Results from QRT-PCR assays revealed that following treatment with lidocaine, Notch1, Notch2, Hes1, Csl and Dll4 all showed higher levels of expression, while no changes were observed in Mmal1, Hey1, Dll1 and Jag1. CONCLUSION: This work provides the first description of the effects of lidocaine upon the regeneration of muscles and maintenance of satellite cells at the cellular and molecular levels. In specific, we found that the Dll4-Notch-Csl-Hes1 axis was up-regulated suggesting that the Notch signaling pathway was involved in producing these effects of lidocaine. These findings provide a new and important foundation for future investigations into the effects of drug therapies in muscle diseases.

2,3,5,6-Tetramethylpyrazine protects retinal photoreceptors against endoplasmic reticulum stress by modulating ATF4-mediated inhibition of PRP aggregation.

Endoplasmic reticulum (ER) stress is a common threat to photoreceptors during the pathogenesis of chronic retinopathies and often results in irreversible visual impairment. 2,3,5,6-Tetramethylpyrazine (TMP), which possesses many beneficial pharmacological activities, is a potential drug that could be used to protect photoreceptors. In the present study, we found that the cellular growth rate of 661 W cells cultured under low glucose conditions was lower than that of control cells, while the G2/M phase of the cell cycle was longer. We further found that the mitochondrial membrane potential (ΔΨm) was lower and that ER stress factor expression was increased in 661 W cells cultured under low glucose conditions. TMP reversed these trends. Visual function and cell counts in the outer nuclear layer (ONL) were low and the TUNEL-positive rate in the ONL was high in a C3H mouse model of spontaneous retinal degeneration. Similarly, visual function was decreased, and the TUNEL-positive rate in the ONL was increased in fasted C57/BL6j mice compared with control mice. On the other hand, ER stress factor expression was found to be increased in the retinas of both mouse models, as shown by reverse transcription real-time PCR (RT-qPCR) and western blotting. TMP reversed the physiological and molecular biological variations observed in both mouse models, and ATF4 expression was enhanced again. Further investigation by using western blotting illustrated that the proportion of insoluble prion protein (PRP) versus soluble PRP was reduced both in vitro and in vivo. Taken together, these results suggest that TMP increased the functions of photoreceptors by alleviating ER stress in vitro and in vivo, and the intrinsic mechanism was the ATF4-mediated inhibition of PRP aggregation. TMP may potentially be used clinically as a therapeutic agent to attenuate the functional loss of photoreceptors during the pathogenesis of chronic retinopathies. KEY MESSAGES: • Already known: TMP is a beneficial drug mainly used in clinic to enhance organ functions, and the intrinsic mechanism is still worthy of exploring. • New in the study: We discovered that TMP ameliorated retinal photoreceptors function via ER stress alleviation, which was promoted by ATF4-mediated inhibition of PRP aggregation. • Application prospect: In prospective clinical practices, TMP may potentially be used in the clinic as a therapeutic agent to attenuate the photoreceptors functional reduction in chronic retinopathies.

Flavonoids Sophoranone Promotes Differentiation of C2C12 and Extraocular Muscle Satellite Cells.

INTRODUCTION: Paralytic strabismus involves a functional loss of extraocular muscles resulting from muscular or neuronal disorders. Currently, only a limited number of drugs are available for functional repair of extraocular muscles. Here, we investigated the effects of a novel drug, flavonoids sophoranone, on the differentiation of extraocular muscles as assessed in bothin vivo and in vitro models. MATERIALS AND METHODS: The effect of flavonoids sophoranone on C2C12 cells was examinedin vitro as evaluated with use of apoptosis, reactive oxygen species (ROS), and cell viability assays. Then, both in vivo and in vitro effects of this drug were examined on the differentiation of C2C12 and satellite cells within extraocular muscles in rabbits. For these latter experiments, RT-PCR and Western blot assays were used to determine expression levels of markers for myogenic differentiation. RESULTS: With use of flavonoids sophoranone concentrations ranging from 0 to 10 µM, no effects were observed upon cell apoptosis, ROS, and cell cycle in C2C12 cells. Based on MTT assay results, flavonoids sophoranone was shown to increase C2C12 cell proliferation. Moreover, flavonoids sophoranone promoted the differentiation of C2C12 and satellite cells within extraocular muscles in rabbits, which were verified as based on cell morphology and expression levels of mRNA and protein markers of myogenic differentiation. Finally, flavonoids sophoranone treatment also increased gene expressions of Myh3, Myog, and MCK. CONCLUSION: The capacity for flavonoids sophoranone to upgrade the differentiation of both C2C12 and satellite cells within extraocular muscles in rabbits at concentrations producing no adverse effects suggest that this drug may provide a safe and effective means to promote repair of damaged extraocular muscles.

m6A methyltransferase METTL3 promotes retinoblastoma progression via PI3K/AKT/mTOR pathway.

Retinoblastoma (RB) is a common intraocular malignancy in children. Due to the poor prognosis of RB, it is crucial to search for efficient diagnostic and therapeutic strategies. Studies have shown that methyltransferase-like 3 (METTL3), a major RNA N (6)-adenosine methyltransferase, is closely related to the initiation and development of cancers. Nevertheless, whether METTL3 is associated with RB remains unexplored. Therefore, we investigated the function and mechanisms of METTL3 in the regulation of RB progression. We manipulated METTL3 expression in RB cells. Then, cell proliferation, apoptosis, migration and invasion were analysed. We also analysed the expression of PI3K/AKT/mTOR pathway members. Finally, we incorporated subcutaneous xenograft mouse models into our studies. The results showed that METTL3 is highly expressed in RB patients and RB cells. We found that METTL3 knockdown decreases cell proliferation, migration and invasion of RB cells, while METTL3 overexpression promotes RB progression in vitro and in vivo. Moreover, two downstream members of the PI3K/AKT/mTOR pathway, P70S6K and 4EBP1, were affected by METTL3. Our study revealed that METTL3 promotes the progression of RB through PI3K/AKT/mTOR pathways in vitro and in vivo. Targeting the METTL3/PI3K/AKT/mTOR signalling axis could be a promising therapeutic strategy for the treatment of RB.