RESUMO
Background Sclera remodeling process in axial elongation is one of the main pathological mechanisms of axial myopia progression.Studies confirmed that transforming growth factor-β1(TGF-β1) participates in the sclera remodeling process,and Smad3 is one of TGF-β1 downstream signal gene transcriptive factors,so to explore its role in sclera remodeling process of myopic eyes is of great significance for pathogenesis and prevention research of myopia.Objective This study was to investigate the expressions of type Ⅰ collagen and Smad3,a TGF-31 downstream target,in sclera of form deprivation myopic (FDM) eyes and explore the impact of TGF-β1-Smad3-type Ⅰ collagen signaling pathway on collagen remodeling in myopic sclera.Methods Seventy-five 1-week-old guinea pigs were randomly divided into normal control group (25 guinea pigs) and FDM group (50 guinea pigs).Monocular FDM was induced by occluding the left eyes of guinea pigs in FDM group with translucent latex balloons for 2,4,6 weeks,respectively,and consecutive occluding for 4 weeks followed by uncovering for 1 week (4/-1 weeks).The refractive power was detected by retinoscopy and axial length was measured with A-type ultrasound.Immunohistochemistry and reverse transcription-PCR were employed to detect the dynamic expressions of type Ⅰ collagen and Smad3 protein ad mRNA in the sclera of guinea pigs with emmetropia and experimental myopia,ard the relationship between collagen Ⅰ and Smad3 levels was analyzed.Results The refraction was hypermetropic in both normal control group and FDM group before occluding of eyes (P＞0.05),and the hypermetropic power was gradually reduced over time in the normal control group.In the FDM group,the refractive power was gradually changed from (+2.09 ± 0.31)D before occluding to (-1.23±0.69),(-4.17±0.59),(-7.07±0.56) and (-4.30±0.58)D,and the axial length was increased from (5.93-±0.39)mm to (6.62±0.36),(7.30±0.34),(7.99--0.32),and (7.21 ±0.36) mm at weeks 2,4,6,and 4/-1 after occluding,respectively,indicating significant differences in refractive power and axial length over time in the FDM group from normal control group and self-control group (all at P＜0.05).The expressions of Smad3 and type Ⅰ collagen protein and mRNA in the sclera of the FDM group was significantly lower than those of the control group and self-control group in various time points (all at P＜0.05).The positive correlation were found in the expression of Smad3 on the myopic sclera with that of type Ⅰ collagen in both protein and mRNA levels (protein:r=0.993,P＜0.05;mRNA:r=0.954,P＜0.05).Conclusions The myopic power and ocular axis increase dependent upon occluding time,and the expressions of Smad3 and type Ⅰ collagen in the sclera are correspondingly weakened in FDM eyes.A consistent expression trend is found between Smad3 and type Ⅰ collage,suggesting Smad3 and type Ⅰ collagen participate in the regulation of sclera remodeling in myopia by TGF-β1-Smad3-Collagen Ⅰ signaling pathway.
RESUMO
To evaluate the visual performance of aspheric multifocal intraocular lens (SN6AD1+3. 0D) implanta-tion in age-related cataract surgery. Forty-eight patients (60 eyes) with age-related cataract were divided into two groups, 28 patients(30 eyes)in the multifocal group (implanted with SN6AD1+3. 0D multifocal intraocular lens), and 20 patients(30 eyes)in the monofocal group (implanted with SN60WF monofocal intraocular lens). The uncor-rected and the best corrected distance,intermediate and near visual acuity and the amplitude of pseudoaccommoda-tion were measured after surgery,and the subjective visual performance was evaluated by the questionnaire. The un-corrected intermediate and near visual acuity were statistically better in the multifocal group than the monofocal group. The amplitude of pseudoaccommodation of multifocal and monofocal group was (2. 65 ± 0. 48) D and (0. 38 ± 0. 15)D. The spectacle independent rates of multifocal and monofocal group were 86% and 13% respectively.
RESUMO
Background JAK/ signal transducer and activator of transcription 3 (STAT3) signal pathway plays a critical role during the sclera remodeling of experimental myopia.As a tyrosine kinase inhibitor,AG490 can inhibit the activation of this pathway.But whether AG490 plays a role in delaying the development of myopia is not completely clear.Objective This study was to investigate the inhibition of AG490 to activation of STAT3 signaling pathway and the sequential arresting effect on the sclera remodeling in form-deprived myopia (FDM) models.Methods Forty guinea pigs were randomly divided into the normal control group,model control group,PBS control group and AG490 treatment group.FDM models were established by the occlusion of the right eyes of guinea pigs for consecutive 4 weeks using translucent goggles in the model control group,PBS control group and AG490 treated group,and 25 μl PBS or AG490 were respectively injected into vitreous since the first day of modeling in two-day interval till the fourth week in the PBS control group and AG490 treated group.Refractive state and axial length were examined with retinoscopy and A-scan ultrasonography before and 4 weeks after experiment.The experimental eyes were extracted in the fourth week,and the expressions of scleral STAT3,p-STAT3,metal matrix proteinase-2 (MMP-2) proteins and STAT3 mRNA,MMP-2 mRNA were detected by immunocytochemstry and semi-quantitative reverse transcription PCR (RT-PCR) respectively.The use and care of experimental animals followed ARVO.Results Compared to the normal control group,the negative refraction power and axial length were significantly increased in the model control group,PBS control group and AG490 treated group,and the axial length in the AG490 treated group was smaller than those in the model control group and PBS control group,showing significant differences among the 4 groups (refraction:F =89.063,P =0.000;axial length:F =96.145,P =0.000).The expressions of STAT3,MMP-2 and p-STAT3 in scleral tissue were weaker in the normal control group.The expressional values (A values) of STAT3,p-STAT3 and M MP-2 were 0.064 ± 0.016,0.019 ± 0.002 and 0.155 ± 0.052 in the AG490 treated group,which were lower than 0.129±0.008,0.071 ±0.021,0.425 ±0.004 of the model control group and 0.130±0.004,0.069±0.002,0.421 ±0.042 of the PBS control group (STAT3:t =4.641,9.364,both at P＜0.01;p-STAT3:t =4.638,4.488,both at P＜ 0.05;MMP-2:t =9.123,9.029,both at P ＜ 0.05),however,these expressions were still higher than those of the normal control group (t =2.674,2.251,2.682,all at P ＜0.05).The expressional levels (A values) of STAT3 mRNA and MMP-2 mRNA in the AG490 treated group were 0.295±0.032 and 0.569±0.019,which were significantly lower than 0.547±0.015 and 0.782±0.051 in the model group as well as 0.544±0.015 and 0.779±0.048 in the PBS control group (STAT3 mRNA:t =10.115,11.703,both at P＜0.01;MMP-2 mRNA:t =9.218,9.494,both at P＜0.01).The expressional levels (A values) of STAT3 mRNA and MMP-2 mRNA in the AG490 treated group were still higher than those in the normal control group (t=2.576,3.565,both at P＜0.05).Conclusions AG490 can ultimately inhibit the development of axial myopia by arresting the activation of STAT3 signaling pathway in the FDM eyes and further regulating the expression of MMP-2 in sclera and delaying the remodeling of sclera.