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@#AIM: To investigate the prevalence of poor vision and ametropia and main influencing factors of myopia of primary and secondary school students in Xiangtan, providing scientific basis for prevention and control of myopia among primary and secondary school students.<p>METHODS:Cluster random sampling was performed. 6 164 samples were randomly chosen to be tested for uncorrected visual acuity, corrected visual acuity and eye position, and among those whose uncorrected far visual acuity of either eyes below 5.0, refractive power of both eyes were further tested. Self-questionnaire was designed to understand the influencing factors of myopia. <p>RESULTS: Among 6 164 samples, the rate of presenting visual acuity below 5.0 is 40.3%(1 249/3 099)for male and 43.8%(1 343/3 065)for female respectively(<i>P</i><0.01). The prevalence of myopia is 59.1% for male and 68.7% for female respectively(<i>P</i><0.01). The prevalence of myopia is 44.1% for primary school students and 71.3% for secondary school students; the prevalence of hyperopia is 3% for primary school students and 1.7% for secondary school students. Multivariate regression analysis showed that, homework time(>2h), average sleeping time(≤8h)and myopic parents are independent risk factors(<i>OR</i>=1.48, 1.55, 1.26, 1.58, 2.13,all <i>P</i><0.05)for myopia of primary and secondary school students.<p>CONCLUSION: The prevalence of visual impairment and myopia for primary and secondary school students in Xiangtan are high, which is influenced by many factors, by which should be intervened comprehensively.
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@#AIM: To evaluate the agreement and interchangeability of a Scheimpflug camera(Pentacam)and a partial coherence interferometry keratometer(IOL Master)in eyes having preoperative assessment for routine cataract surgery. <p>METHODS: In this prospective clinical study, 41 patients(64 eyes)with normal cornea from January 2017 to June 2017 in our hospital were enrolled. Simulated K, true net power and Holladay equivalent K(EKR)measured at 1.0 to 7.0 mm corneal diameters were measured by the Pentacam system and mean keratometer(Km)was measured by the IOL Master. Paired samples <i>t</i> test, Pearson correlation analysis and Bland-Altman method were used for statistical analysis. <p>RESULTS: Among patients with cataract of normal cornea, the mean Scheimpflug K for true net power and EKR at 1.0mm, 2.0mm, 3.0mm corneal diameters were statistically significantly less than the mean Km(IOL Master). The EKR at 4.5mm, 5.0mm, 6.0mm, 7.0mm of corneal diameters were significantly greater than the mean Km(IOL Master)(<i>P</i><0.01 for all). The difference between Sim K and EKR at 4.0mm measured by Pentacam and Km measured by IOL Master was the smallest(-0.03D±0.252D and 0.04D±0.244D, respectively; <i>t</i>=-1.018, <i>P</i>=0.313; <i>t</i>=1.461, <i>P</i>=0.149), and it had the best uniformity with 95% credible interval of -0.53D to 0.46D(sim K)and -0.43D to 0.52D(equivalent K at 4.0mm). A Pearson correlation revealed a high correlation for corneal power measurements between the two devices(<i>r</i>>0.9 for all, <i>P</i><0.01 for all).<p>CONCLUSION: The sim K and EKR at 4.0mm had the closest match with the Km(IOL Master)for Chinese patients with cataract of normal cornea. However, the application of these devices should be combined with clinical features.
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Background Diabetic complication is associated with lipid peroxidation.Aldehyde dehydrogenases (ALDH) catalyze the irreversible oxidation of a variety of biological aldehydes,including lipid-derived aldehydes (LDAs),and thus protect organs and tissues from toxic LDAs.Understanding the activity of ALDH in different ocular tissues in diabetic subjects is very important for prevention and treatment of diabetic ocular complications.Objective This research aimed to investigate the activity and expression of ALDH in different ocular tissues in diabetic rats and to explore the mechanism of ALDH in diabetes-induced eye disease.Methods Twenty-eight healthy SPF male Sprague-Dawley(SD) rats weighted 170-180 g were randomly divided into the normal control group and diabetic group.The diabetic animal model was established by intraperitonial injection of 4％ streptozotocin at 65 mg/kg.Isometric citric acid buffer was injected in the rats of the normal control group.The rats were sacrificed in each group 2 and 4 months after the establishment of the diabetic models,and eyeballs were obtained for the preparation of corneal,lens and retinal homogenates.ALDH activity was detected using a multifunctional microplate reader SpectraMax M5,and ALDH content was measured by ELISA at the wavelength of 450 nm with the SpectraMax M5 ELISA reader.Results The blood glucose level in diabetic rats was significantly elevated at various time points compared with the normal control group(P=0.000),and body weights were evidently lower in the diabetic group than in the normal group (P =0.000).The activities of ALDH (A340) in corneal,lens and retinal tissues in the diabetic group were increased in comparison with the normal control group (F =396.601,P=0.000),and showed an enhancement with the lapsing of time (F =53.139,P =0.000).In addition,the highest level of ALDH was found in the cornea and the lowest level in the lens(F =6973.000,P=0.000).The expression level of ALDH in the corneal,lens and retinal homogenates was significantly higher in the diabetic group compared with the normal control group (F=312.985,P =0.000) and showed a considerable increase over the course (F =19.203,P=0.000).The highest expression level was seen in the cornea and the lowest was in the lens,with a significant difference among these three kinds of tissues (F =3243.000,P =0.000).Conclusions ALDH can protect ocular tissue from the damage of lipid peroxidation.Thess results suggest that ALDH plays a role in preventing diabetes-related ocular complications.