BackgroundObtaining accurate axial length (AL) is very important for the establishment of animal models of myopia. The purpose of this study is to compare the accuracy of Quantel A-B scan, OD-1 A scan, and vernier caliper in measuring AL in Sprague Dawley (SD) rats.MethodsIn total, 60 5-week-old SD rats were divided into female rat group (n = 30) and male rat group (n = 30). Quantel A-B scan and OD-1 A scan were, respectively, used to measure the AL of both eyes of each living rat, and vernier caliper was used to measure the anterior-posterior diameter of each rat’s eyeball. Besides, the correlation between refractive error (RE) and AL measured by different instruments was evaluated, and the accuracy of the three measurement methods was compared according to gender and left/right eyes.ResultsThere were significant differences in AL and diopter of SD rats at the same age (p < 0.05). the AL of male rats was greater than that of female rats, while diopter (D) was the opposite; There was no significant difference in AL and D between left and right eyes in the same SD rats (p > 0.05); There were statistical differences among the three measurement methods (p < 0.05), AL measured by vernier caliper was the largest, followed by Quantel A-B scan, OD-1 A scan; Difference in AL between male and female was not statistically significant between the results obtained by Quantel A-B scan and vernier caliper (p > 0.05), but there were statistically significant differences between the other two measurement methods (p < 0.05).ConclusionSex is the influencing factor of AL and RE. Imaging measurement can accurately measure the AL in living small rodents. Compared with OD-1 A scan, Quantel A-B scan may be more accurate.

Purpose: In order to evaluate the e cacy of intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs, photodynamic therapy (PDT), and laser treatment (LT) for anatomical and functional improvement in myopic choroidal neovascularization (mCNV) patients were evaluated in a mesh meta-analysis. Methods: Two researchers independently searched PubMed, Cochrane Library, Web of Science, CNKI, WanFang Data, Embase, and other databases to screen RCTs and retrospective studies comparing best-corrected visual acuity (BCVA) and foveal center thickness (FCT) changes after mCNV treatment. The retrieval time limit is from the database construction to November 30, 2021. ADDIS1.16.8 and R 3.5.3 software were used to conduct mesh meta-analyses of RCTs and retrospective studies, respectively.Results: A total of 601 eyes in 8 RCTs involving 6 treatment options: intravitreal bevacizumab (IVB), intravitreal ranibizumab (IVR), intravitreal conbercept (IVC), intravitreal a ibercept (IVA), LT, PDT, sham rst followed by IVA (Sham /IVA). The results of the mesh meta-analysis showed that: in the RCTs, IVB and IVR were superior to PDT [MD=0.18, 95%CI (0.01, 0.42)] in improving BCVA of mCNV patients, and all the therapeutic effects from high to low might be intravitreal IVA, IVB, IVR, LT, Sham/IVA, and PDT; the order of FCT thickness reduction from high to low is IVA, IVR, IVB, PDT. In addition, the results of BCVA after long-term treatment in retrospective studies showed that all the therapeutic effects from high to low might be IVA, IVC, IVB /IVR, IVB, IVR, PDT, PDT with IVB /IVR; as for the order of FCT thickness reduction from high to low is IVA, IVC, IVR, IVB, PDT.Conclusions: Anti-VEGF treatment in patients with long-term improvement in mCNV vision effect is best, using IVB or IVR alone to treat mCNV may be better than IVB or IVR combined with PDT; There was no signi cant difference in the improvement of visual acuity and macular edema in mCNV patients with different anti-VEGF drugs. Due to the limited number and quality of included literature, the above conclusions need to be con rmed by more large-sample and high-quality articles.

Aim: Myopia is a common chronic eye disease, this study is to investigate the effects of exogenous retinoic acid (RA) on intraocular parameters, especially choroidal thickness (CT) and retinal thickness (RT), in guinea pigs with form deprivation myopia (FDM).Methods: A total of 80 male guinea pigs were divided randomly into 4 groups: Control, FDM, FDM + RA, and FDM + Citral groups. The FDM + RA group was given 24 mg/kg RA dissolved in 0.4 mL peanut oil; the FDM + Citral group was given citral 445 mg/kg dissolved in 0.4 mL peanut oil; The other two groups were given 0.4 mL peanut oil. After 4 weeks, the refractive error (RE), axial length (AL), and intraocular pressure (IOP) of all guinea pigs were measured, and the parameters of RT and CT were obtained using enhanced depth imaging optical coherence tomography (EDI-OCT).Results: After 4 weeks, both the RE and AL in the FDM and FDM + RA groups were increased, and the RT and CT in both groups were smaller than those in the Control group (p < 0.05). Only the IOP of the right eye in the FDM + RA group increased significantly (p < 0.05). The RT of the right eye of the 4 groups was compared: Control group > FDM + Citral group > FDM group > FDM + RA group. Compared with the RT of the left eye and the right eye among the 4 groups, the RT of the right eye in the FDM and FDM + RA groups was significantly less than that in the left eye (p < 0.05). Moreover, the CT of the right eye in the Control group was greater than that in the other three groups (p < 0.0001). There was no significant difference in the CT among the FDM, FDM + RA, and FDM + Citral groups (p > 0.05). In contrast to the RT results, the CT results of the left and right eyes in the FDM + Citral group showed statistically significant differences (p < 0.05).Conclusion: RA participates in the progression of FDM as a regulatory factor. Exogenous RA can increase the RE, AL, and IOP of FDM guinea pigs, and might aggravate the retinal thinning of FDM guinea pigs. Citral can inhibit these changes, but RA might not affect the thickness of the choroid.