Metabolic signatures of tear extracellular vesicles caused by herpes simplex keratitis.

PURPOSE: Herpes simplex keratitis (HSK), caused by type 1 herpes simplex virus (HSV) reactivation, is a severe infectious disease that leads to vision loss. HSV can trigger metabolic reprogramming in the host cell and change the extracellular vesicles (EV) cargos; however, little is known about the EV metabolic signatures during ocular HSV infection. Here, we aimed to depict the EV-associated metabolic landscape in HSK patients' tears. METHODS: We collected 82 samples from 41 participants with unilateral HSK (contralateral unaffected tears were set as negative control), including subtype cohorts of 13 epithelial, 20 stromal, and 8 endothelial HSK. We isolated tear EVs via our previously established platform and conducted metabolic analysis using LC-MS/MS. The metabolic signatures for recognizing HSK and subtypes were assessed through differential analysis and machine learning algorithms. RESULTS: Hypopsia and increased extracellular CD63 levels were observed in affected eyes. We identified 339 metabolites based on sEVs isolated from tears. Differential analysis revealed alterations in energy and amino acid metabolism, as well as the infectious microenvironment. Furthermore, we observed dysregulated metabolite such as methyldopa, which is associated with inappropriate neovascularization and corneal sensation loss, contributing to the HSK severity particularly in the stromal subtype. Moreover, machine learning classification also suggested a set of EV metabolic signatures that have potential for pan-keratitis detection. CONCLUSIONS: Our findings demonstrate that tear EV metabolites can serve as valuable indicators for comprehending the underlying pathological mechanisms. This knowledge is expected to facilitate the development of liquid biopsy means and therapeutic target discovery.

Highly Selective Purification of Plasma Extracellular Vesicles Using Titanium Dioxide Microparticles for Depicting the Metabolic Signatures of Diabetic Retinopathy.

Extracellular vesicle (EV) cargos with regular fluctuations hold the potential for providing chemical predictors toward clinical diagnosis and prognosis. A plasma sample is one of the most important sources of circulating EVs, yet the technical barrier and cost consumption in plasma-EV isolation still limit its application in disease diagnosis and biomarker discovery. Here, we introduced an easy-to-use strategy that allows selectively purifying small EVs (sEVs) from human plasma and detecting their metabolic alternations. Fe3O4@TiO2 microbeads with a rough island-shaped surface have proven the capability of performing efficient and reversible sEV capture owing to the phospholipid affinity, enhanced binding sites, and size-exclusion-like effect of the rough TiO2 shell. The proposed system can also shorten the separation procedure from hours to 20 min when compared with the ultracentrifugation method and yield approximately 108 sEV particles from 100 µL of plasma. Metabolome variations of sEVs among progressive diabetic retinopathy subjects were finally studied, observing a cluster of metabolites with elevated levels and suggesting potential roles of these sEV chemicals in diabetic retinopathy onset and progression. Such a scalable and flexible EV capture system can be seen as an effective analytical tool for facilitating plasma-based liquid biopsies.

Protection of Human Lens Epithelial Cells from Oxidative Stress Damage and Cell Apoptosis by KGF-2 through the Akt/Nrf2/HO-1 Pathway.

Oxidative stress exerts a significant influence on the pathogenesis of various cataracts by inducing degradation and aggregation of lens proteins and apoptosis of lens epithelial cells. Keratinocyte growth factor-2 (KGF-2) exerts a favorable cytoprotective effect against oxidative stress in vivo and in vitro. In this work, we investigated the molecular mechanisms of KGF-2 against hydrogen peroxide- (H2O2-) induced oxidative stress and apoptosis in human lens epithelial cells (HLECs) and rat lenses. KGF-2 pretreatment could reduce H2O2-induced cytotoxicity as well as reactive oxygen species (ROS) accumulation. KGF-2 also increases B-cell lymphoma-2 (Bcl-2), quinine oxidoreductase-1 (NQO-1), superoxide dismutase (SOD2), and catalase (CAT) levels while decreasing the expression level of Bcl2-associated X (Bax) and cleaved caspase-3 in H2O2-stimulated HLECs. LY294002, the phosphatidylinositol-3-kinase (PI3K)/Akt inhibitor, abolished KGF-2's effect to some extent, demonstrating that KGF-2 protected HLECs via the PI3K/Akt pathway. On the other hand, KGF-2 activated the Nrf2/HO-1 pathway by regulating the PI3K/Akt pathway. Silencing nuclear factor erythroid 2-related factor 2 (Nrf2) by targeted-siRNA and inhibiting heme oxygenase-1 (HO-1) through zinc protoporphyrin IX (ZnPP) significantly decreased cytoprotection of KGF-2. Furthermore, as revealed by lens organ culture assays, KGF-2 treatment decreased H2O2-induced lens opacity in a concentration-dependent manner. As demonstrated by these data, KGF-2 resisted H2O2-mediated apoptosis and oxidative stress in HLECs through Nrf2/HO-1 and PI3K/Akt pathways, suggesting a potential protective effect against the formation of cataracts.

KGF-2 Regulates STAP-2-Mediated Signal Transducer and Activator of Transcription 3 Signaling and Reduces Skin Scar Formation.

Hypertrophic scar is a common complication of burns, skin trauma, and postoperative trauma, which involves excessive proliferation of fibroblasts and accumulation of a large amount of disorganized collagen fibers and extracellular matrix. KGF-2 plays important roles in the regulation of cellular homeostasis and wound healing. In this study, we investigated the effect and underlying mechanism of KGF-2 on scar formation after wound healing both in vitro and in vivo. We show that KGF-2 attenuates mechanical stress-induced scar formation while promoting wound healing. Mechanistically, KGF-2 inhibits STAP-2 expression and signal transducer and activator of transcription 3 activation, leading to significantly reduced collagen I and collagen III levels. Our results provide an insight into the role of KGF-2 in wound healing and scar formation and the therapeutic potential for reducing scarring while promoting wound healing.

Toxicity Evaluation of Long-Term Topical Application of Recombinant Human Keratinocyte Growth Factor-2 Eye Drops on Macaca Fascicularis.

Recombinant human keratinocyte growth factor-2 (rhKGF-2), an effective agent for the regeneration of epithelial tissue, was found to have great potential for use in treatments of corneal diseases that involve corneal epithelial defects. Furthermore, the safety of long-term and high-dose external use of KGF-2 eye drops in rabbits has been well established previously. The aim of this study is to determine the safe dose range and target organs for toxicity of rhKGF-2 eye drops in Macaca fascicularis (M. fascicularis). The M. fascicularis animals were administered with different doses of rhKGF-2 eye drops (125, 500, and 2000 µg/ml) for four consecutive weeks, followed by a 2 week recovery period. No significant differences in weight, electrocardiogram characteristics, blood and urine indexes, pathology, and bone marrow cells were detected among the animals in different groups. The corneas of some animals in the middle- and high-dose groups showed fluorescence when stained with sodium fluorescein, and then the staining disappeared on days 28 and 42. Anti-rhKGF-2 antibodies were detected in a small number of animals in the high-dose group, and their level decreased after rhKGF-2 withdrawal. No neutralizing antibodies were detected. The result demonstrated that there was no obvious adverse reaction when topical application of rhKGF-2 eye drops at the dosage of 125 or 500 µg/ml on the M. fascicularis. This study is of great significance for the future clinical transformation of rhKGF-2 eye drops.

Comparative Change in Anterior Corneal Asphericity After FS-LASIK and SMILE.

PURPOSE: To evaluate changes in anterior corneal asphericity (ΔQ) by calculating tangential radius (rt) after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). METHODS: Sirius corneal topography (Costruzione Strumenti Oftalmici) was used to evaluate 120 right eyes from patients with moderate and high myopia who had previously undergone FS-LASIK and SMILE. The preoperative and postoperative tangential radii obtained in reference to various semi-meridional regions and radii zones were compared. Variation in ΔQ values in semi-meridional regions across 360 degrees of the anterior surface after FS-LASIK and SMILE were compared. RESULTS: The tangential radii in the 1.2- and 1.8-mm radii zones were lower in patients who underwent SMILE compared to those who underwent FS-LASIK. The tangential radii in the 2.4- and 3-mm zones were higher in patients who underwent SMILE compared to those who underwent FS-LASIK. In both the moderate and high myopia groups, postoperative Q-values and ΔQ-values were lower in patients who had undergone SMILE than in patients who had undergone FS-LASIK. Postoperative Q-values and ΔQ-values were lower in the moderate myopia group than in the high myopia group for FS-LASIK and SMILE. The magnitude of variation in ΔQ as a function of semi-meridional region was lower in patients who had undergone SMILE than in patients who had undergone FS-LASIK. CONCLUSIONS: FS-LASIK and SMILE alter anterior corneal tangential radius and anterior corneal asphericity in patients with moderate or high myopia. SMILE is more effective than FS-LASIK in preserving normal anterior corneal asphericity. [J Refract Surg. 2021;37(3):158-165.].

Diurnal fluctuations of macular vessel density in patients with primary open-angle glaucoma and healthy subjects.

PURPOSE: To investigate the diurnal fluctuations of macular vessel density (VD) in primary open-angle glaucoma (POAG) and healthy subjects using optical coherence tomography angiography. METHODS: A total of 22 POAG eyes and 15 healthy eyes were included in this study. Macular VD, intraocular pressure, and blood pressure were repeatedly measured from 8 AM to 8 PM at a 2-h interval on a single day. MAIN OUTCOME MEASURES: the macular VD measurements, their diurnal fluctuations, including the difference between their maximal and minimal value (max-min) and their coefficient of variation (CV) in superficial capillary plexus (SCP) and deep capillary plexus (DCP). The mixed-effects model was performed to compare the fluctuations between groups. RESULTS: After adjusted age, the diurnal fluctuations of macular VD in SCP and DCP were significantly higher in POAG eyes compared with healthy subjects (max-min: 6.65 ± 3.54%, 3.92 ± 3.63%, respectively; p = 0.037 and CV: 0.06 ± 0.03, 0.04 ± 0.03, respectively; p = 0.003). The fovea VD in DCP of POAG eyes was higher than in healthy subjects (31.52 ± 4.68% and 25.71 ± 3.70%, p = 0.009). However, there was no significant difference between the fovea VD in SCP in two groups (20.97 ± 4.75% and 19.29 ± 4.35%, p = 0.670). The diurnal macular superficial VD measured in most of the participants was lower in the morning. CONCLUSIONS: Whether it is a max-min or a CV assessment method, the POAG eyes had more significant diurnal fluctuations of macular VD than healthy controls, suggesting impaired vascular autoregulation in POAG eyes.

Seroreactive Profiling of Filoviruses in Chinese Bats Reveals Extensive Infection of Diverse Viruses.

Southern China is a hot spot of emerging infectious diseases, in which diverse species of bats dwell, a large group of flying mammals considered natural reservoirs for zoonotic viruses. Recently, divergent filoviruses (FiVs) have been identified in bats within this region, which pose a potential risk to public health, but the true infection situation in bats remains largely unclear. Here, 689 archived bat serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA), Western blotting, and neutralization assay to investigate the seroprevalence and cross-reactivity of four divergent FiVs and two other viruses (rabies virus and Tuhoko pararubulavirus 1) of different families within the order Mononegavirales Results showed no cross-antigenicity between FiVs and other mononegaviruses but different cross-reactivity among the FiVs themselves. The total FiV seroreactive rate was 36.3% (250/689), with infection by the indigenous Chinese FiV DH04 or an antigenically related one being the most widely and the most highly prevalent. Further viral metagenomic analysis of fruit bat tissues also identified the gene sequence of a novel FiV. These results indicate the likely prevalence of other so far unidentified FiVs within the Chinese bat population, with frugivorous Rousettus leschenaultii and Eonycteris spelaea bats and insectivorous Myotis horsfieldii and Miniopterus schreibersii bats being their major reservoirs.IMPORTANCE Bats are natural hosts of many FiVs, from which diverse FiVs were serologically or virologically detected in Africa, Europe, and East Asia. Recently, very divergent FiVs were identified in the Chinese bat population, but their antigenic relationship with other known FiVs remains unknown. Here, we conducted serological characterization and investigation of Chinese indigenous FiVs and prototypes of other viruses in bats. Results indicated that Chinese indigenous FiVs are antigenically distant to other FiVs, and infection of novel or multiple FiVs occurred in Chinese bats, with FiV DH04 or an antigenically related one being the most widely and the most highly prevalent. Additionally, besides Rousettus leschenaultii and Eonycteris spelaea bats, the insectivorous Myotis horsfieldii and M. schreibersii bats are highly preferential hosts of FiVs. Seroreactive and viral metagenomic results indicated that more as yet unknown bat-borne FiVs circulate in Southern China, and to uncover them further, investigation and timely surveillance is needed.

Vessel Density and Structural Measurements in Primary Angle-Closure Suspect Glaucoma Using Optical Coherence Tomography Angiography.

PURPOSE: To measure the macular retinal vessel density (VD) and peripapillary retinal nerve fiber layer (RNFL) in primary angle-closure suspects (PACS) by Angio-OCT to be compared with normal subjects. METHODS: Primary angle-closure suspect patients and normal subjects were enrolled in this study. The demographic and clinical characteristics of all subjects, such as RNFL thickness, retinal vessel density, and ocular perfusion pressure, were compared. RESULTS: No significant difference was found in both groups on age, sex distribution, intraocular pressure (IOP), and retinal vessel density. The PACS group exhibited significantly thicker RNFL thickness compared with the control group. The deep vessel density was negatively associated with age (P = -0.034), while IOP had negative association with ACD (P = -0.019). OPP was independently associated with RNFL (B = 0.334, P = 0.038) in the PACS group. CONCLUSIONS: OCTA showed significant thicker change on RNFL in the PACS group. Only OPP was independently associated with RNFL in the PACS group.

Evaluation of choroidal thickness in amblyopia using optical coherence tomography.

OBJECTIVE: To investigate the choroidal thickness in children with amblyopia through spectral-domain optical coherence tomography. METHODS: A total of 31 children with unilateral amblyopia and 31 right eyes of controls with normal vision were enrolled in the study. The choroidal thickness was measured directly below the fovea and at 12 other locations: 1, 2 and 3 mm superior, temporal, inferior, and nasal to the fovea. All the parameters were compared between amblyopic eyes, fellow eyes, and control eyes. RESULTS: The mean subfoveal choroidal thickness was 398.03 ± 74.60, 354.13 ± 81.78, and 328.12 ± 65.93 µm in amblyopic eyes, fellow eyes, and control eyes, respectively. Significant difference was found in choroidal thickness among three groups at subfoveal choroidal thickness, N1, and S1 using multivariate analysis of covariance after adjusting for axial length. Significant negative correlation was found only between subfoveal choroidal thickness and axial length in amblyopic eyes (r = -0.463, p = 0.01). CONCLUSION: The subfoveal choroid is significantly thicker in amblyopic eyes than control eyes only at subfoveal choroidal thickness, N1, and S1. The choroidal thickness was thickest in the subfoveal region and thinnest in the nasal region. There are other changes in choroidal structure associated with amblyopia.

Comparative Analysis of KGF-2 and bFGF in Prevention of Excessive Wound Healing and Scar Formation in a Corneal Alkali Burn Model.

PURPOSE: Basic fibroblast growth factor (bFGF) is an effective drug for corneal injury. However, the explicit role of bFGF in corneal scar formation still remains unclear. Keratinocyte growth factor-2 (KGF-2) is associated with the treatment of wound healing. We aimed to compare the efficacy of bFGF and KGF-2 in prevention of excessive wound healing and consequent scar formation in a rat alkali burn model, which provides important clues on the significance of KGF-2 to be developed as a new drug for such injuries. METHODS: The epithelial defect area was evaluated using fluorescein sodium at a concentration of 0.5%. The therapeutic effect of KGF-2 and bFGF on proliferation of rabbit corneal fibroblasts (RCFs) was evaluated by methylthiazoletetrazolium. RCF migration assays were performed with a modified scratch method. Activation of mitogen-activated protein kinase (MAPK) was evaluated by Western blot with specific antibodies. RESULTS: All corneal wounds treated with KGF-2 were found closed within 7 days; however, the wounds treated with bFGF or phosphate buffer saline (PBS) required 14 days to close. RCFs treated with KGF-2 or bFGF showed similar dose-dependent proliferation. The KGF-2 group significantly promoted cell migration compared with the bFGF group. The KGF-2 group showed less expression of α-smooth muscle actin (SMA) and numbers of myofibroblasts compared with the bFGF group. Our findings suggested identification of cascade reaction of extracellular regulated protein kinases (ERK)1/2 and p38 signals in KGF-2- and bFGF-induced proliferation and migration of RCFs. In addition, KGF-2 showed stronger effects during ERK1/2 and p38 phosphorylation in methylthiazoletetrazolium proliferation assay and scratch migration assay. CONCLUSIONS: KGF-2 exhibited better effects than bFGF in reepithelialization, acceleration of migration, and reduction of scar formation, which has potential to become a new drug to cure corneal injury.

Toxicology study of long-term administration of rhKGF-2 eye drops on rabbit corneas.

Keratinocyte growth factor -2 promotes corneal repair. Its mechanism of action involves regulating regeneration and migration of corneal cells, as well as activating corneal limbal stem cells. However, KGF-2 being a carcinogenic growth factor and its potential adverse effect in over dosage long-term treatment had not yet been reported. In this study, we used New Zealand white rabbits to study possible toxic effects of ocular administration of recombinant human keratinocyte growth factor-2 eye drops. Animals in the medium- and high-dose groups had some ocular irritant reactions during the course of drug administration; however this reaction was harmless to the cornea and it ended up when administration was stopped. Serum biochemistries were largely unaffected by treatment. Pathological examinations were unremarkable. We found that over-dosed administration of these eye drops caused some ocular irritation, but this irritant reaction was harmless to the eye, and it reversed after the drug was stopped. There were no apparent systemic effects of the drug.

Posterior pole asymmetry analysis and retinal nerve fibre layer thickness measurements in primary angle-closure suspect patients.

PURPOSE: To measure peripapillary retinal nerve fiber layer (RNFL) thickness and posterior pole retinal thickness in primary angle-closure suspects (PACS) by Spectral domain optical coherence tomography (SD-OCT) and to be compared with normal subjects. METHODS: Thirty five primary angle-closure suspect patients and thirty normal subjects were enrolled in this study. Peripapillary RNFL and posterior pole retinal thickness by posterior pole asymmetry analysis (PPAA) in SD-OCT were measured. RESULTS: No significant difference was found in both groups on age, sex distribution, refractive error, intraocular pressure (IOP) and axial length. The PACS group exhibited significantly thinner macular retinal thickness and larger asymmetry on posterior pole region compared with the control group. Yet no significant difference of peripapillary RNFL parameters was found between PACS group and normal control group. A negative correlation was observed between the total retinal thickness on posterior pole region and age when all the PACS participants were analyzed. CONCLUSIONS: Posterior pole retinal thickness measurements obtained by Heidelberg Spectralis SD-OCT using PPAA showed significant thinner change in PACS group than healthy controls. Only age seemed to be an indicator in the occurrence of glaucomatous damage in PACS patients.

Seroprevalence, cross antigenicity and circulation sphere of bat-borne hantaviruses revealed by serological and antigenic analyses.

Bats are newly identified reservoirs of hantaviruses (HVs) among which very divergent HVs have been discovered in recent years. However, their significance for public health remains unclear since their seroprevalence as well as antigenic relationship with human-infecting HVs have not been investigated. In the present study archived tissues of 1,419 bats of 22 species from 6 families collected in 5 south and southwest provinces in China were screened by pan-HV RT-PCR following viral metagenomic analysis. As a result nine HVs have been identified in two bat species in two provinces and phylogenetically classified into two species, Laibin virus (LAIV, ICTV approved species, 1 strain) and Xuan son virus (XSV, proposed species, 8 strains). Additionally, 709 serum samples of these bats were also analyzed by ELISA to investigate the seroprevalence and cross-reactivity between different HVs using expressed recombinant nucleocapsid proteins (rNPs) of LAIV, XSV and Seoul virus (SEOV). The cross-reactivity of some bat sera were further confirmed by western blot (WB) using three rNPs followed by fluorescent antibody virus neutralization test (FAVNT) against live SEOV. Results showed that the total HV seropositive rate of bat sera was 18.5% (131/709) with many cross reacting with two or all three rNPs and several able to neutralize SEOV. WB analysis using the three rNPs and their specific hyperimmune sera demonstrated cross-reactivity between XSV/SEOV and LAIV/XSV, but not LAIV/SEOV, indicating that XSV is antigenically closer to human-infecting HVs. In addition a study of the distribution of the viruses identified an area covering the region between Chinese Guangxi and North Vietnam, in which XSV and LAIV circulate within different bat colonies with a high seroprevalence. A circulation sphere of bat-borne HVs has therefore been proposed.

Evaluation of peripapillary choroidal distribution in children by enhanced depth imaging optical coherence tomography.

BACKGROUND: To evaluate the peripapillary choroidal thickness (PPCT) in Chinese children aged 6 to 12 years old and to analyze correlative factors. METHODS: PPCT was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) in 154 children (76 myopes and 78 emmetropia) aged 6 to 12 years, with spherical equivalent refractive errors between + 0.50 and - 5.50 diopters(D). Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc. PPCT and the corresponding peripapillary retinal thickness (PPRT) were measured by EDI-OCT at nine positions: I, inferior; IN, inferonasal; IT, inferotemporal; N, nasal; T, temporal; S, superior; SN, superonasal; ST, superotemporal, and the Fovea Centralis. RESULTS: The mean global PPCT was 165.80 ± 39.86 µm.The mean global PPRT was 101.47 ± 10.74 µm. The Inferior had the thinnest PPCT but the thickest PPRT (p < 0.001), while the Nasal had thickest PPCT but the thinnest PPRT (p < 0.001). Significant differences in RT between the myopic group and the emmetropic group were found at all positions except T, TS, S and the fovea. Myopic group had thinner choroidal thickness (CT) than that of emmetropic group at all measured positions. Choroidal thickness had negative relation with the corresponding retinal thickness, age and axial length. CONCLUSION: The peripapillary choroid was thicker nasally and thinner inferiorly, while the peripapillary retina was thickest inferiorly and thinnest nasally. Myopic group had thinner PPCT. The axial length was found to be negatively correlated to PPCT.

Descemet stripping automated endothelial keratoplasty versus descemet membrane endothelial keratoplasty: a meta-analysis.

PURPOSE: To evaluate the efficacy and safety of descemet stripping automated endothelial keratoplasty (DSAEK) compared with descemet membrane endothelial keratoplasty (DMEK). METHODS: Databases including PubMed, EMBASE, and Cochrane Library were searched to find studies that compared DSAEK and DMEK outcomes. Efficacy parameters were the postoperative best-corrected visual acuity (BCVA) and spherical equivalent (SE). Safety parameters were postoperative endothelial cell loss (ECL), air injection (rebubbling), graft failure, graft rejection, and high intraocular pressure (IOP). Results from last visit were pooled for the analyses because the follow-up ranged from 3 to 24 months. RESULTS: A total of 7 trials including 433 eyes were selected for this meta-analysis. BCVA was reported in all 7 studies, ECL% and rebubbling rate were reported in 6, and the remaining outcomes were reported in only 3 or 2 studies. Postoperative logMAR BCVA was significantly better for DMEK than that for DSAEK (P < 0.00001). More patients achieved the postoperative BCVA ≥ 20/25 and 20/20 in DMEK group than that in DSAEK (P > 0.001), whereas the proportion of patients whose postoperative BCVA ≥ 20/40 and the amount of SE did not differ statistically (P = 0.32 and P = 0.50, respectively). The DSAEK group has a significantly lower frequency of rebubbling than the DMEK group (P < 0.0001). The postoperative ECL%, graft failure, graft rejection, and high IOP were comparable between the 2 groups (all P values >0.05). CONCLUSIONS: Our meta-analysis suggests that DMEK provided better visual outcomes with similar safety when compared to DSAEK. Given the limited sample size, further investigations are needed to validate these findings.

Axial Length and Ocular Development of Premature Infants without ROP.

PURPOSE: To investigate the ocular parameters of premature infants without ROP at gestational age (GA) more than 28 weeks and their relationship with growth parameters. METHODS: 76 preterm infants without ROP and 65 term infants were involved to undergo portable slit lamp, RetCam3, ultrasonic A-scan biometry, and cycloplegic streak examination at their 40 weeks' postconceptional ages (PCA). Ocular parameters of infants' right eye and growth parameters were used for analysis. RESULTS: All the infants were examined at 40 weeks' PCA. No significant difference was found between male and female in axial length of preterm infants (p = 0.993) and term infants (p = 0.591). Significant differences were found in axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous depth (VD) between preterm and term infants. No significant correlation was found between AL and spherical equivalent in preterm infants' group. In preterm group, AL was significantly correlated with gestational age (GA), birth weight (BW), and head circumference (HC). CONCLUSIONS: Preterm infants had shorter AL, shallow ACD, thicker LT, and thinner VD compared to term infants. Refractive error in preterm infants at GA between 28 to 37 weeks was not related to axial length. Among all the growth parameters of preterm infants, GA, BW, and HC had effect on axial length.

Evaluation of myopia on retinal nerve fiber layer thickness measured by Spectralis optical coherence tomography.

The aim of the present study was to evaluate the retinal nerve fiber layer (RNFL) thickness of myopic subjects using Spectralis optical coherence tomography (OCT) and to determine variations with age and sex. A total of 271 Chinese participants with a spherical equivalent <+0.50 diopters were enrolled in the research. All subjects underwent a full ophthalmic examination. RNFL thickness was measured and compared according to sex, age and spherical equivalent. No significant difference was demonstrated between RNFL thickness in males and females. No significant difference was observed between RNFL thickness of the two age groups (≤12 years old and >12 years old). Significant differences were observed in all subfields of RNFL thickness among different spherical equivalent groups (P<0.05). In conclusion, myopia did have special influence on RNFL thickness, which was not related to sex or age.

Comprehensive Evaluation of Anterior Corneal Change in Asphericity Calculated by the Tangential Radius of Curvature after LASIK.

To evaluate the change in the anterior corneal asphericity (ΔQ) comprehensively calculated using the tangential radius (rt ) after LASIK. Forty-two right eyes were evaluated using the Orbscan II corneal topographer. The pre- and postoperative Q-values of the flat principal semimeridians calculated by the sagittal radius were compared to those by the tangential radius. The Q-value of each semimeridian in the horizontal region was calculated by rt . Fourier fitting was used to model the 360-semimeridional variation of Q-values and to fit the Q-values in the vertical region before and after surgery. There were significant differences in Q-values between the two methods before (P < 0.001) and after surgery (P = 0.003). A significant increase in postoperative Q-value was detected compared to preoperative Q-value (P < 0.001) calculated by rt . The 360-semimeridional variation of the Q-values was well fitted with a third- and fourth-degree Fourier function before and after surgery. The ΔQ-value distribution presented double valley variation, with the amount of ΔQ being lowest in the near-vertical regions and highest in the near-horizontal regions. Calculating the Q-value with rt combined with Fourier fitting, we evaluated 360 ΔQ-values' variation of semimeridians of the entire anterior corneal surface and then displayed true and complete anterior corneal shape after LASIK.

TGFBI Gene Mutation Analysis in Chinese Families with Corneal Dystrophies.

AIMS: To identify transforming growth factor beta-induced (TGFBI) gene mutations in four Chinese families affected by corneal dystrophies. METHODS: In this study, three families (21 patients and 18 normal relatives), respectively, with Reis-Bücklers corneal dystrophy (RBCD), classic lattice corneal dystrophy (LCDI), and variant LCD (LCDI/IIIA) were assessed. All subjects underwent a complete ophthalmological evaluation, including biomicroscopic inspection and dilated fundus examination. As a control, 100 individuals without corneal disease were selected from the general population. Polymerase chain reaction (PCR) and direct sequencing were used to screen for mutations in TGFBI. RESULTS: For the three families, a single heterozygous c.371G>T (R124L) point mutation was found in exon 4 of TGFBI in 14 affected members with RBCD, a single heterozygous c.370C>T (R124C) point mutation was found in exon 4 of TGFBI in four affected members with LCDI, and a single heterozygous c.1877A>G (H626R) point mutation was found in exon 14 of TGFBI in four affected members with LCDI/IIIA. TGFBI gene mutation had not been detected in the unaffected members and 100 normal controls. CONCLUSIONS: TGFBI gene mutations were present in all three Chinese families with corneal dystrophy, and our study further verified the relationship between phenotype and genotype of corneal dystrophy.