The Arabidopsis UDP-glycosyltransferases UGT79B2 and UGT79B3, contribute to cold, salt and drought stress tolerance via modulating anthocyanin accumulation.

The plant family 1 UDP-glycosyltransferases (UGTs) are the biggest GT family in plants, which are responsible for transferring sugar moieties onto a variety of small molecules, and control many metabolic processes; however, their physiological significance in planta is largely unknown. Here, we revealed that two Arabidopsis glycosyltransferase genes, UGT79B2 and UGT79B3, could be strongly induced by various abiotic stresses, including cold, salt and drought stresses. Overexpression of UGT79B2/B3 significantly enhanced plant tolerance to low temperatures as well as drought and salt stresses, whereas the ugt79b2/b3 double mutants generated by RNAi (RNA interference) and CRISPR-Cas9 strategies were more susceptible to adverse conditions. Interestingly, the expression of UGT79B2 and UGT79B3 is directly controlled by CBF1 (CRT/DRE-binding factor 1, also named DREB1B) in response to low temperatures. Furthermore, we identified the enzyme activities of UGT79B2/B3 in adding UDP-rhamnose to cyanidin and cyanidin 3-O-glucoside. Ectopic expression of UGT79B2/B3 significantly increased the anthocyanin accumulation, and enhanced the antioxidant activity in coping with abiotic stresses, whereas the ugt79b2/b3 double mutants showed reduced anthocyanin levels. When overexpressing UGT79B2/B3 in tt18 (transparent testa 18), a mutant that cannot synthesize anthocyanins, both genes fail to improve plant adaptation to stress. Taken together, we demonstrate that UGT79B2 and UGT79B3, identified as anthocyanin rhamnosyltransferases, are regulated by CBF1 and confer abiotic stress tolerance via modulating anthocyanin accumulation.

The maize secondary metabolism glycosyltransferase UFGT2 modifies flavonols and contributes to plant acclimation to abiotic stresses.

Background and Aims: Nowadays, the plant family 1 glycosyltransferases (UGTs) are attracting more and more attention since members of this family can improve the properties of secondary metabolites and have significantly enriched the chemical species in plants. Over the past decade, most studies on UGTs have been conducted in Arabidopsis thaliana and they were proved to play diverse roles during the plant life cycle. The Zea mays (maize) GT1 family comprises a large number of UDP-glycosyltransferase (UGT) members. However, their enzyme activities and the biological functions are rarely revealed. In this study, a maize flavonol glycosyltransferase, UFGT2, is identified and its biological role is characterized in detail. Methods: The UFGT2 enzyme activity, the flavonol and glycoside levels in planta were examined by high- performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The functions of UFGT2 in modifying flavonols, mediating flavonol accumulation and improving stress tolerance were analysed using two ufgt2 mutants and transgenic arabidopsis plants. Key Results: By in vitro enzyme assay, the maize UFGT2 was found to show strong activity towards two flavonols: kaemferol and quercetin. Two ufgt2 knockout mutants, Mu689 and Mu943, exhibited obvious sensitivity to salt and drought stresses. The endogenous quercetin and kaempferol glycosides, as well as the total flavonol levels were found to be substantially decreased in the two ufgt2 mutants, with declined H2O2-scavenging capacity. In contrast, ectopic expression of UFGT2 in arabidopsis led to increased flavonol contents and enhanced oxidative tolerance. Moreover, expression of typical stress-related genes in arabidopsis and maize were affected in UFGT2 overexpression plants or knockout mutants in response to abiotic stresses. UFGT2 was also transferred into the arabidopsis ugt78d2 mutant and it was found to recover the deficient flavonol glycoside pattern in the ugt78d2 mutant, which confirmed its catalysing activity in planta. Conclusion: It is demonstrated in our study that a maize glycosyltransferase, UFGT2, involved in modifying flavonols, contributes to improving plant tolerance to abiotic stresses.

Effect of uncorrection versus full correction on myopia progression in 12-year-old children.

PURPOSE: To investigate the effects of no correction versus full correction on myopia progression in Chinese children over a period of 2 years. METHODS: Myopia was defined as cycloplegic spherical equivalent (SE) of ≤ -0.50 D. Uncorrection was defined as no spectacles worn, and full correction was defined as when the value of SE subtracted from the dioptric power of the child's current spectacles was less than 0.5 D. Ocular examinations included visual acuity, cycloplegic autorefraction, axial length and vertometer measurements. Questionnaires were completed by parents on behalf of the children. RESULTS: A total of 121 myopic children, with a median age of 12.7 years, were screened from the Anyang Childhood Eye Study, with 65 in the uncorrected group and 56 in the full correction group. At 2-year follow-up, children with no correction had slower myopia progression (-0.75 ± 0.49 D vs. -1.04 ± 0.49 D, P < 0.01) and less axial elongation (0.45 ± 0.18 mm vs. 0.53 ± 0.17 mm, P = 0.02) than children with full correction. In multivariate modeling, adjusting for baseline SE or axial length, age, gender, height, number of myopic parents, age at myopia onset, and time spent in near work and outdoors, children with no correction still had slower myopia progression (-0.76 ± 0.07 vs. -1.03 ± 0.08 D, P < 0.01) and less axial elongation (0.47 ± 0.03 mm vs. 0.51 ± 0.03 mm, P < 0.01). Myopia progression decreased significantly with an increasing amount of undercorrection in all children (r = 0.22, b = 0.16, P = 0.01). CONCLUSION: Our findings suggest that myopic defocus slows the progression of myopia in already myopic children, supporting previous findings from animal studies.

[Characteristics and Source Analysis of Volatile Organic Compounds in Typical Ozone Pollution Processes During Summer in Jinan, China].

Based on a typical ozone （O3） pollution process in Jinan City from June 16 to 26, 2021, the variation characteristics of O3 and its precursor volatile organic compounds （VOCs） during different pollution periods （clean period （CP）, pollution rise period （PRP）, heavy pollution period （HPP）, and pollution decline period （PDP）） in the urban area were analyzed. Both positive matrix factorization （PMF） and an observation-based model （OBM） were used to identify the main sources of VOCs, O3 production mechanisms, and sensitive species. The results showed that the average value of ρ（O3-8h） during the HPP period in the urban area was （246.67±11.24） µg·m-3, and ρ（O3-1h） had a peak value of 300 µg·m-3. The volume fractions of VOCs and NO2 concentration were affected by the decrease in planetary boundary layer and wind speed, which were 76.99%-145.36% and 127.78%-141.18% higher than those in the other three periods, respectively, and were the main reasons for the aggravation of O3 pollution. Alkanes, oxygenated volatile organic compounds （OVOCs）, and halogenated hydrocarbons accounted for 43.81%, 20.98%, and 17.43% of VOCs in urban areas, respectively. All of them showed significant growth during the HPP period, with acetone, propane, and ethane being the top three species by volume in each stage and isopentane showing the highest growth during the HPP period. Alkene, alkanes, and aromatic hydrocarbons accounted for 40.19%, 28.06%, and 21.92% of the ozone generation potential （OFP）. 1-butene, toluene, isopentane, and isoprene were the species with higher OFP. Isoprene had the highest OFP during the PRP phase, and 1-butene had the highest OFP during the HPP phase. The volume fraction of isopentane significantly increased OFP. The correlation coefficient between VOCs and CO preliminarily indicated that motor vehicle exhaust and oil and gas volatilization were the main sources of VOCs during the HPP period. Further use of PMF revealed that solvent use sources, combustion sources, motor vehicle exhaust+oil and gas volatilization sources, industrial emission sources, and plant sources were important sources of VOCs in urban areas. The contribution of motor vehicle exhaust+oil and gas volatilization sources in the HPP period to VOCs was 3.09-14.72 times higher than that in other periods. The contribution of solvent use sources to VOCs was approximately 2.50 times higher than that in the CP and PRP periods. The main sources of VOCs volume fraction increase were motor vehicle exhaust, oil and gas volatilization sources, and solvent use sources. Potential sources and concentration weight analysis found that VOCs were also affected by the transmission of VOCs to Binzhou and Dongying in the northeast direction. The OBM results indicated that the main pathway of O3 formation in urban areas was the reaction of peroxide hydroxyl radicals （HO2·ï¼‰ and methyl peroxide radicals （CH3O2·ï¼‰ with NO, and the net ozone generation rate during the HPP phase [P（O3）net] was 24×10-9 h-1. Based on the sensitivity experiment results, the alkene components of 1-butene, propylene, cis-2-butene, and ethylene were the dominant species for O3 production.

[Advanced research in the safety of UVA-riboflavin cross-linking for strengthening corneal and scleral tissue].

UVA-riboflavin cross-linking is an effective approach to increase the mechanical and biochemical rigidity of the collagen fiber, which has been used in treating some corneal diseases such as keratoconus, and might become a new treatment modality for strengthening scleral tissue to prevent progressive myopia, so the safety of the new therapy has be paid attention widely. This article focus on the diffusion process and saturation judgment of riboflavin and describes the effect of riboflavin, direct UV damage, photochemical damage and the prevention of side effects in cross-linking therapy.

[The progression of applying transgenic mice as an animal model of high myopia].

Gene engineering technology provides new methods for medical research. The application of transgenic animals and knock out animals makes it possible to study the biological characteristics of genes associated with some human diseases in vivo. Transgenic mice were first achieved in the early 1980s, while they were used extensively in the field of ophthalmology doing some research a few years later after that. Therefore, it can possibly be a new path to investigate the pathogenesis by establishing transgenic mouse model of candidate gene of high myopia.

[The clinical efficacy of 0.1% bromfenac sodium hydrate ophthalmic solution after excimer laser in situ keratomileusis].

OBJECTIVE: To investigate the clinical efficacy and safety of 0.1% bromfenac sodium hydrate ophthalmic solution in myopia and astigmatism eyes after sub-Bowman keratomileusis (SBK) METHODS: A case control study. Number of patients with low to moderate myopia (-6.00 D ≤ spherical equivalent < -2.00 D) in the test and control groups was 17 cases (32 eyes) and 20 cases (40 eyes), respectively. Number of patients with high myopia (-11.00 D ≤ spherical equivalent < -6.00 D) in the test and control groups was 22 cases (42 eyes) and 15 cases (26 eyes) respectively. The first day after SBK, 0.1% bromfenac sodium hydrate eye drops was administrated 2 times/day in patients in the test group and continued for 10 and 14 days in low and high myopia, respectively. In the control group, 0.1% fluorometholone eye drops was used 4 times/day, then reduced gradually and continuously for 16 days. Visual acuity, computer refraction, intraocular pressure (IOP) and corneal topography examination were conducted at different postoperative period. Symptoms and related complications were recorded. Ranked data were statistically analyzed using the Wilcoxon rank sum test and quantitative data were analyzed using independent samples t-test. RESULTS: For low to moderate myopic patients, average postoperative IOP and corneal curvature K2 after one and three months in the test group were (7.84 ± 1.35) and (8.13 ± 1.75) mm Hg(1 mm Hg = 0.133 kPa), and (38.66 ± 1.68) and (38.75 ± 1.45) D, respectively; in the control group, these parameters were (9.37 ± 1.28) and (9.47 ± 1.58) mm Hg and (39.56 ± 1.58), and (39.51 ± 1.50) D, respectively. All of these data in the test group were lower than those in the control group, the differences were statistically significant (t = -2.299, -2.112, P < 0.05). There were no significant differences (P < 0.05) in postoperative uncorrected visual acuity, spherical equivalent, corneal curvature K1, astigmatism CY, IOP (after 6 months) and corneal curvature K2 (after 6 months) between the test and control group. For the high myopic patients, mean postoperative uncorrected visual acuity in the test group and control group after 3 months were 5.14 ± 0.06 and 5.09 ± 0.07, respectively. The difference was statistically significant (t = 2.517, P = 0.015). There were no significant differences in symptoms between these two groups (two-sided test P > 0.1). High IOP and obvious myopia regression were not found in all patients. CONCLUSIONS: Bromfenac sodium hydrate eye drops (0.1%) can achieve the same therapeutic effect as fluorometholone eye drops after SBK and the former is better than the later in postoperative IOP control.

[Detection of differentially expressed lumican gene mRNA level in scleral tissue in human eye].

OBJECTIVE: To identify differentially expressed lumican in scleral tissue of eyes with primary open-angle glaucoma (POAG) and high myopia (HM). METHODS: Total RNA was isolated from scleral tissue of cadaveric eyes derived from normal donors, patient's eyes with diagnosed glaucoma and high myopia who accepted trabeculectomy. RNA was amplified, RT-PCR was used to measure the levels of mRNA. The ratio of the electrophoresis strips'gray scale values of the ß-actin over the lumican gene was obtained for ANOVA analysis. RESULTS: ß-actin/LUM of normal eye was significantly higher than that of POAG and POAG + HM eyes (P < 0.01), but there was no significant difference between POAG and POAG + HM eyes (P > 0.05). CONCLUSIONS: Differentially expressed lumican between POAG and control groups identified in this study have not been previously investigated for their role in the pathogenesis of POAG and thus are novel factors for further study of the mechanism of the disease and for their possible use as diagnostic markers.

[Caution to perform excimer laser corneal ablation on the ametropia with corneal guttata].

It is very important to avoid inadequate patients to perform excimer laser keratectomy in order to prevent from surgical complications. The ametropic eyes with corneal guttata is considered very carefully whether to perform excimer laser corneal ablation or not, especially for the patient with corneal guttata companied by Fuchs endothelial dystrophy family history is contraindicated to perform laser corneal refractive surgery.

Ocular Perfusion Pressure in 7- and 12-Year-Old Chinese Children: The Anyang Childhood Eye Study.

Purpose: The purpose of this study was to report the distribution of mean ocular perfusion pressure (MOPP) and its associated factors in Chinese children. Methods: We enrolled 3048 grade 1 students and 2258 grade 7 students of the Anyang Childhood Eye Study in central China. Systolic and diastolic blood pressure (SBP and DBP) were recorded with a digital automatic sphygmomanometer. Intraocular pressure (IOP) was assessed by a non-contact tonometer. MOPP was calculated as 2/3 × (DBP + 1/3[SBP - DBP]) - IOP. Risk factors for myopia were obtained through a questionnaire survey. Results: The MOPP was 33.83 ± 6.37 mm Hg (mean ± SD) in grade 1, which was lower than 36.99 ± 6.80 mm Hg in grade 7 (P < 0.001). Compared with myopic eyes, non-myopic eyes had higher MOPP in grade 7 (37.72 ± 6.72 mm Hg versus 36.58 ± 6.57 mm Hg, P < 0.001) and in grade 1 (33.88 ± 6.29 mm Hg versus 33.12 ± 7.03 mm Hg, P = 0.12). Multivariable analysis showed that higher MOPP was associated with less myopia (P < 0.001), higher body mass index (BMI; P < 0.001), thinner central corneal thickness (P < 0.001), less time on near work (P < 0.001), and more time on sleeping (P = 0.04). Conclusions: MOPP was higher in children of older age, with higher BMI, less time on near work, and more time on sleeping, and was higher in eyes with less myopia. Translational Relevance: We found that MOPP might be an indicator for the detection of myopia development.

The association of a single nucleotide polymorphism in the promoter region of the LAMA1 gene with susceptibility to Chinese high myopia.

PURPOSE: High myopia is a severe hereditary ocular disease leading to blindness. LAMA1 (alpha subunit of laminin) is a promising candidate gene for high myopia present in the MYP2 (myopia 2) region. The purpose of this study was to determine if high myopia is associated with single nucleotide polymorphism (SNP) variants in LAMA1 in Chinese subjects. METHODS: Ninety-seven Chinese subjects with high myopia and ethnically and sexually matched 103 normal controls were enrolled. Genomic DNA was prepared from peripheral blood. The 5 SNPs of LAMA1 were analyzed using PCR and SNaPshot. Allele frequencies were tested for Hardy-Weinberg disequilibrium. The genotype and allele frequencies were evaluated using the χ(2) tests or the Fisher exact tests. RESULTS: One of the 5 SNPs showed a significant difference between patients and control subjects (rs2089760: p(genotype)=0.005, p(allel)=0.003). There were no statistically significant differences between patients and control subjects for the other four SNPs: rs566655, rs11664063, rs607230, and rs3810046. CONCLUSIONS: Our results indicate that the polymorphism of rs2089760, located in the promoter region of LAMA1, may be associated with high myopia in the Chinese population and should be investigated further.

[Whether does the granular corneal dystrophy indicate for the excimer laser ablation surgery or not].

With the development of excimer laser technologies, the corneal refractive surgical procedures are improved constantly and the indication of excimer laser keratectomy is expanded. In clinic, PRK or LASEK or PTK or LASIK were performed on the eyes of granular corneal dystrophy with refractive error and the early results were satisfied, but the reoccurrence and server opacity of cornea are worried. Is this corneal disease the indication of excimer laser keratectomy? Nowadays, the exact indication for the disease should be declared in clinic. In this article, the customized treatment nomogram for three types of granular corneal dystrophy is explicated according to the clear classification and exact diagnosis on this disease, in order to apply the excimer laser keratectomy reasonably and correctly for the patient approaching the safe, effective and long term satisfactory result.

[Advanced research in Sclera collagen cross-linking treating progressive myopia].

Collagen can link between or within collagen molecules through the covalent bond, which leads to increasing the tension and stability of collagen fiber. Collagen cross-linking had been widely used in other industries, the recent research showed that cross-linking of scleral collagen increased the scleral biomechanical rigidity efficiently, which might become a new treatment modality for strengthening scleral tissue to prevent progressive myopia. This review describes the sclera collagen characteristics of progressive myopia, traditional treatment and sclera collagen cross-linking therapy.

[Evaluation of intraocular lens power after keratorefractive surgery by IOLMaster].

OBJECTIVE: To study the accuracy of different formulas predicting intraocular lens (IOL) power after excimer laser keratorefractive surgery in order to calculate the diopter of IOL accurately in the clinical practice. METHODS: One hundred and eleven cases (222 eyes) were collected in this study and were divided into two groups (A and B) according to their axial length. Fifty-nine cases (118 eyes) with axial lengths of 24-26 mm were taken as group A, and 52 cases (104 eyes) with axial length of more than 26 mm were taken as group B. All of the subjects enrolled in this study were examined by the IOL-Master before and after LASIK, including the axial length, corneal curvature, anterior chamber depth (ACD), and the IOL power which was predicted by the SRK-II, SRK/T, Hoffer Q, Holladay, Haigis-L formulas and the Clinical History method offered by IOL-Master. The significance of the differences was analysed by using student's t-test. RESULTS: The corneal curvature after LASIK decreased significantly (t = 12.10, P < 0.01); the length of axis and ACD also decreased but had no significant differences as compared with pre-operation. The IOL powers of the two groups offered by the Haigis-L formula were significantly more than that offered by other formulas (t = 0.54, 1.21, P < 0.01). The difference between the Haigis and Haigis-L formulas was the smallest, and the difference between the SRK-II and Haigis-L formula was the greatest. The IOL powers offered by the clinical history method were higher than that offered by these formulas; the differences were significant in both group A and group B, except the group A in SRK-II (t = 0.00, -1.73, 0.00, P < 0.01). The IOL powers offered by Haigis-L were greater than that from the clinical history method or other formulas and showed significant differences except that between Haigis-L and CH-Haigis or CH-Haigis-L formula (P < 0.01). CONCLUSIONS: Taking into consideration the difference of IOL power offered by Haigis-L formula as compared with other current formulas, evaluation by IOL-Master will be helpful for improving the accuracy of IOL power prediction for the cataract eyes receiving corneal refractive surgery. However, the accuracy of the Haigis-L formula for eyes after corneal refractive surgery still requires to be confirmed by a further series of clinic data.

Stability of the Barrett True-K formula for intraocular lens power calculation after SMILE in Chinese myopic eyes.

AIM: To compare the Barrett True-K formula with other formulas integrated in Lenstar 900 to predict intraocular lens (IOL) power after small-incision lenticule extraction (SMILE). METHODS: A theoretical prospective study was performed to predict the ratio of equivalent IOL power before and after SMILE using the SRK/T (Sanders, Retzlaff, Kraff/theoretical), Holladay 1, Haigis, and Barrett True-K formulas and compare the stability of their predictions. The study included 54 eyes (54 cases) with a manifest refraction spherical equivalent (MRSE) of -4.99±1.45 D. They were divided into two groups: 27 eyes with axial length of 24-26 mm in Group A, and 27 eyes with axial length >26 mm in Group B. All subjects enrolled in this study were examined with the Lenstar 900 before and 6mo after SMILE including measurements of axial length, corneal curvature, and anterior chamber depth (ACD). RESULTS: The prediction of equivalent IOL power of the two groups was more stable for the Barrett True-K formula, especially in long axial length eyes (Group B). The respective percentages for the SRK/T, Holladay 1, Haigis, and Barrett True-K formulas were 7.4%, 7.4%, 85.19%, and 88.89% for a margin of error within 0.5 D; 25.92%, 51.84%, 100%, and 100% for a margin of error within 1.0 D in Group A; 33.33%, 40.74%, 44.44%, and 81.48% for a margin of error within 0.5 D; and 44.44%, 59.26%, 66.66%, and 92.59% for a margin of error within 1.0 D in Group B. The respective percentages for Barrett True-K formulas were 100% for a margin of error within 2.0 D in Group B. CONCLUSION: Theoretically, the Barrett True-K formula provides more stable predictions than other formulas for cataract eyes after SMILE.

[Clinical evaluation on the cornea flap with different thickness after LASIK].

OBJECTIVE: To investigate morphologically the different changes of cornea tissue between thick and thin cornea flap with confocal microscope, and to compare visual function between thick and thin cornea flap after LASIK. METHODS: 70 cases (70 eyes) who had received LASIK were divided into the thin cornea flap group (36 eyes, group A) and the thick cornea flap group (34 eyes, group B). The age was (23 +/- 5) years old, spherical equivalent diopter (SE) were ( - 4.76 +/- 2.30) D and (- 3.03 +/- 2.20) D. Inspection items included visual acuity (VA), refraction, wave-front analysis, contrast sensitivity analysis (KONTRASTOMETER BA4, Germany) during pre-and post-LASIK, at the same time, all eyes were examined by confocal microcopy (HRT III, Germany). Using Moria 90 microm and 130 microm keratome with Allegretto Excimer laser machine. RESULTS: Refraction: there was no difference between the two groups. Post-LASIK 3 to 6 months: group A (0.35 +/- 0.21) D; group B (0.45 +/- 0.69) D (P > 0.05). Comparison results by confocal microscope. The thickness of cornea flap: group A (107.37 +/- 20.5) microm, group B (149 +/- 25.2) microm (P < 0.05). The thickness of wrinkle: group A (63.71 +/- 15.8) microm; group B (48.16 +/- 20.7) microm (P < 0.05). The thickness of acellular area: group A (69.93 +/- 15.8) microm; group B (55.63 +/- 23.7) microm (P < 0.05). The thickness of activation cornea cells: group A (60.15 +/- 30.9) microm; group B (51.86 +/- 27.9) microm (P < 0.05). The density of anterior stromal: group A (825.14 +/- 156.9) mm2; group B (853.54 +/- 126.8) mm2 (P < 0.05). There were significant differences on the thickness of cornea flap, the thickness of wrinkle, the thickness of acellular area, the thickness of activation cornea cells, the density of anterior stromal, but there was no difference on posterior stromal (P > 0.05). Wavefront analysis:there was no difference between two groups in Z3(-3), Z3(-1), Z3(1), Z3(3), Z4(0), RMS3, RMS4, RMS5, RMS6, RMSh (P > 0.05) pre-and post-operation. Contrast sensitivity analysis: there was also no difference between two groups (P > 0.05) pre-and post-LASIK 1-6 month. CONCLUSIONS: From the point of confocal microscope view, morphologic changes of cornea was significant with different thick flap. It is not cicatricial healing between the cornea flap and stromal. The cell injury of cornea tissue in the thin cornea flap was severe than that of in the thick cornea flap even though there was no significant difference between thin and thick cornea flap group in clinical refraction correction, wavefront and contrast sensitivity.

Early Changes of Ocular Biological Parameters in Rhesus Monkeys After Scleral Cross-linking With Riboflavin/Ultraviolet-A.

PURPOSE: To evaluate the ocular biological parameter difference between scleral corneal cross-linking (CXL) and control eyes in rhesus monkeys by using a rebound tonometer, A-scan ultrasonography, retinoscopy, optical coherence tomography, and electroretinography (ERG). METHODS: Six rhesus monkeys were used in this study, with ages ranging from 3 to 3.5 years. One eye of each rhesus monkey was randomly selected to receive riboflavin/ultraviolet-A CXL in the temporal quadrant of the equatorial sclera and the contralateral eye served as an intra-individual control. The ocular biological parameters were repeatedly measured in both eyes of the monkeys before scleral CXL and 1 week, 1 month, and 3 months postoperatively. RESULTS: The intraocular pressure, refractive state, total axial length, and axial dimensions of the anterior chamber, crystalline lens, vitreous chamber, and central corneal thickness were not statistically significantly different between the control and cross-linked specimens at the different time periods (each P > .05). No obvious changes in the waveform of the standard full-field ERGs were observed in the control and cross-linked specimens. There were no statistically significant differences between the control and cross-linked specimens in the dark-adapted 0.01 ERG, the dark-adapted 3.0 ERG, the light-adapted 3.0 ERG, and the amplitudes of the a-wave and b-wave for the different time periods (each P >.05). CONCLUSIONS: The scleral CXL laboratory technique might not significantly affect the ocular biological parameters of the rhesus monkey in the early postoperative period, but long-term effects and histological changes still need to be investigated further. [J Refract Surg. 2019;35(5):333-339.].

[Comparison of retaining or removing negative vertical coma in wavefront guided LASIK for myopia and astigmatism].

OBJECTIVE: To investigate the efficacy and safety of wavefront guided (WG) LASIK for the myopia and astigmatism. METHODS: This study is a randomized control trial. 42 cases (78 eyes) were collected in the study through the routine examinations and wavefront analysis, which were divided into two groups (A and B). The value of Z (3, -1) being less than -0.15 microm was evaluated as Group A (24 cases, 45 eyes); The value of Z (3, -1) being more than +0.15 microm was as Group B (18 cases, 33 eyes). Both A and B were also divided into two subgroups (test and control). WG-LASIK was performed in tested groups, and classic LASIK was performed in control group. Visual quality, wavefront examination, and CSF were analyzed after surgery 3-6 months compared with that of preoperation. RESULTS: In the earlier period of post-operation time, diopters of the two groups were both slightly overcorrected, and then began to decrease slightly later and the diopters of both tested and control groups were corrected perfectly. RMSh of tested group increased higher than that of control group when Z (3, -1) was negative and the CSF in control group was better than that in test group after WG-LASIK in Group A. RMSh of tested group increased lower than that of control group when Z (3, -1) was positive and the CSF in tested group was better than that in control group after WG-LASIK in Group B. CONCLUSIONS: These results suggest that retaining negative vertical coma and removing positive vertical coma were beneficial to the visual function after the WG-LASIK, which could save the corneal tissue reasonably in order to improve visual quality effectively.

Consistent comparison of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided LASIK for myopia by EX500 excimer laser.

AIM: To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis (LASIK) by EX500 excimer laser for myopia. METHODS: Totally 145 cases (290 consecutive eyes )with myopia received LASIK with a target of emmetropia. The ablation for 86 cases (172 eyes) was guided manually based on Oculyzer topography (study group), while the ablation for 59 cases (118 eyes) was guided automatically by Topolyzer Vario topography (control group). Measurement of adjustment values included data respectively in horizontal and vertical direction of cornea. RESULTS: Horizontally, synclastic adjustment between manually actual values (dxmanu) and Oculyzer topography guided data (dxocu) accounts 35.5% in study group, with mean dxmanu/dxocu of 0.78±0.48; while in control group, synclastic adjustment between automatically actual values (dxauto) and Oculyzer topography data (dxocu) accounts 54.2%, with mean dxauto/dxocu of 0.79±0.66. Vertically, synclastic adjustment between dymanu and dyocu accounts 55.2% in study group, with mean dymanu/dyocu of 0.61±0.42; while in control group, synclastic adjustment between dyauto and dyocu accounts 66.1%, with mean dyauto/dyocu of 0.66±0.65. There was no statistically significant difference in ratio of actual values/Oculyzer topography guided data in horizontal and vertical direction between two groups (P=0.951, 0.621). CONCLUSION: There is high consistency in angle Kappa adjustment guided manually by Oculyzer and guided automatically by Topolyzer Vario topography during corneal refractive surgery by WaveLight EX500 excimer laser.