The comparison of corneal higher-order aberration and surgically induced astigmatism between the clear corneal incision and the limbus tunnel incision of posterior chamber implantable collamer lens implantation.

BACKGROUND: This study aimed to compare the corneal high-order aberrations and surgically induced astigmatism between the clear corneal incision and limbus tunnel incision for posterior chamber implantable collamer lens (ICL/TICL) implantation. METHODS: A total of 127 eyes from 73 myopic patients underwent ICL V4c implantation, with 70 eyes receiving clear corneal incisions and 57 eyes receiving limbus tunnel incisions. The anterior and back corneal surfaces were measured and the Root Mean Square of all activated aberrations (TRMS) was calculated, including higher-order aberration (HOA RMS), spherical aberration Z40, coma coefficients (Coma RMS) Z3-1 Z31, and surgically induced astigmatism (SIA). The measurements were taken preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months. In this study, the corneal higher-order aberration was estimated as the Zernike coefficient calculated up to 5th order. The measurements were taken at a maximum diameter of 6.5 mm using Pentacam. RESULTS: One week after the operation, the corneal back Z31 of the clear corneal incision group was 0.06 ± 0.06, while the limbus tunnel incision group showed a measurement of 0.05 ± 0.06 (p = 0.031). The corneal back Z40 of the clear corneal incision group was -0.02 ± 0.25, compared to -0.04 ± 0.21 in the limbus tunnel incision group (p = 0.01). One month after the operation, the corneal back SIA of the clear corneal incision group was 0.11 ± 0.11, compared to 0.08 ± 0.11of the limbus tunnel incision group (p = 0.013), the corneal total SIA of the clear corneal incision group was 0.33 ± 0.30, compared to 0.15 ± 0.16 in the limbus tunnel incision group (p = 0.004); the clear corneal incision group exhibited higher levels of back astigmatism and total SIA than the limbus tunnel incision in the post-operation one month period. During the 6- month post-operative follow-up period, no significant difference in Z31, Z40, and other HOA RMS data was observed between the two groups. The total SIA of the corneal incision group and the limbus tunnel incision group were 0.24 ± 0.14 and 0.33 ± 0.32, respectively (p = 0.393), showing no significant difference between the two groups 6 months after the operation. CONCLUSION: Our data showed no significant difference in the high-order aberration and SIA between clear corneal incision and limbus tunnel incision up to 6 months after ICL-V4c implantation.

Echocardiographic measurements of left ventricular dimensions and function in newborns with omphalocele and pulmonary.

PURPOSE: The purpose of this study was to explore echocardiographic parameters of the left ventricle (LV) in relation to the outcomes of omphalocele neonates with pulmonary hypertension (PH). METHODS: This retrospective study was conducted among omphalocele patients with PH born from 2019 to 2020. Patients in this study did not have additional severe malformations or chromosomal aberrations. Patients who died under palliative care were excluded. The echocardiographic parameters of LV were obtained within 24 h after birth. Clinical and outcomes data were recorded, echocardiograms evaluated for left ventricular internal dimension in end-diastole (LVIDd), end-diastolic volume (EDV), stroke volume (SV) and cardiac output index (CI), among others. RESULTS: There were 18 omphalocele newborns with PH, of whom 14 survived and 4 died. Both groups were comparable in the baseline characteristics. Non-survival was associated with a smaller LV [LVIDd (12.2 mm versus15.7 mm, p < 0.05), EDV (3.5 ml versus 6.8 ml, p < 0.05)] and with worse systolic function [SV (2.3 ml versus 4.2 ml, p < 0.05), and CI (1.7 L/min/m2 versus 2.9 L/min/m2, p < 0.01)]. CONCLUSION: In the cohort of omphalocele patients with PH, lower LVIDd, EDV, SV and CI were associated with mortality. LEVEL OF EVIDENCE: Level III.

[Risk factors and prognosis of hypotension within 72 hours after birth in extremely preterm infants]. / è¶ æ—©äº§å„¿ç”ŸåŽ72 hå† ä½Žè¡€åŽ‹å‘ç”Ÿçš„å±é™©å› ç´ åŠé¢„åŽåˆ†æž.

OBJECTIVES: To investigate the risk factors and prognosis of hypotension within 72 hours after birth in extremely preterm infants. METHODS: A retrospective analysis was conducted on clinical data of extremely preterm infants admitted to the Children's Hospital of Zhejiang University School of Medicine from January 2019 to April 2022. Based on the presence of hypotension within 72 hours after birth, the eligible infants were divided into a hypotension group (41 cases) and a normotension group (82 cases). The clinical characteristics, echocardiographic parameters within 72 hours after birth, and early complications were compared between the two groups. Multivariate logistic regression analysis was used to explore the risk factors for hypotension within 72 hours after birth, and receiver operating characteristic curve analysis was performed to evaluate the predictive value of relevant indicators for the occurrence of hypotension within 72 hours after birth in the preterm infants. RESULTS: The proportion of infants who required medication or surgical closure of patent ductus arteriosus (PDA), the proportions of infants with intraventricular hemorrhage ≥ grade III and severe pulmonary hemorrhage, and the mortality rate within 7 days in the hypotension group were significantly higher than those in the normotension group (P<0.05). Multivariate logistic regression analysis showed that lower birth weight, larger PDA diameter, and hemodynamically significant PDA were risk factors for the occurrence of hypotension within 72 hours after birth in extremely preterm infants (P<0.05). The receiver operating characteristic curve analysis showed that the combination of birth weight, PDA diameter, and hemodynamically significant PDA had an area under the curve of 0.873 (95%CI: 0.802-0.944, P<0.05) for predicting hypotension within 72 hours after birth, with a sensitivity of 73.2% and specificity of 91.5%. CONCLUSIONS: Hypotension within 72 hours after birth is closely related to birth weight and PDA, and increases the risk of early severe complications and mortality in extremely preterm infants.

An interpretable machine-learning model for predicting the efficacy of nonsteroidal anti-inflammatory drugs for closing hemodynamically significant patent ductus arteriosus in preterm infants.

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely used in the closure of ductus arteriosus in premature infants. We aimed to develop and validate an interpretable machine-learning model for predicting the efficacy of NSAIDs for closing hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. Methods: We assessed 182 preterm infants ≤ 30 weeks of gestational age first treated with NSAIDs to close hsPDA. According to the treatment outcome, patients were divided into a "success" group and "failure" group. Variables for analysis were demographic features, clinical features, as well as laboratory and echocardiographic parameters within 72 h before medication use. We developed the machine-learning model using random forests. Model performance was assessed by the area under the receiver operating characteristic curve (AUC). Variable-importance and marginal-effect plots were constructed to explain the predictive model. The model was validated using an external cohort of two preterm infants who received ibuprofen (p.o.) to treat hsPDA. Results: Eighty-three cases (45.6%) were in the success group and 99 (54.4%) in the failure group. Infants in the success group were associated with maternal chorioamnionitis (p = 0.002), multiple births (p = 0.007), gestational age at birth (p = 0.020), use of indometacin (p = 0.007), use of inotropic agents (p < 0.001), noninvasive ventilation (p = 0.001), plasma albumin level (p < 0.001), PDA size (p = 0.038) and Vmax (p = 0.013). Multivariable binary logistic regression analysis showed that maternal chorioamnionitis, multiple births, use of indomethacin, use of inotropic agents, plasma albumin level, and PDA size were independent risk factors influencing the efficacy of NSAIDs (p < 0.05). The AUC of the random forest model was 0.792. The top-three features contributing most to the model in the variable-importance plot were the plasma albumin level and platelet count 72 h before treatment and 24-h urine volume before treatment. In the external cohort, treatment succeeded in one case and failed in the other. The probabilities of success and failure predicted by the random forest model were 60.2% and 48.4%, respectively. Conclusion: Based on clinical, laboratory, and echocardiographic features before first-time NSAIDs treatment, we constructed an interpretable machine-learning model, which has a certain reference value for predicting the closure of hsPDA in premature infants under 30 weeks of gestational age.

Giant omphalocele associated pulmonary hypertension: A retrospective study.

Background: Omphalocele is a common congenital defect of the abdominal wall, management of giant omphalocele (GO) is particularly for pediatric surgeons and neonatologists worldwide. The current study aimed to review and summarize the clinical features and prognosis in neonates with GO complicated with pulmonary hypertension (PH), which is associated with increased mortality, while in hospital. Materials and methods: Medical records of infants with GO between July 2015 and June 2020 were retrospectively analyzed. The patients enrolled were divided into PH and non-PH groups based on the presence or absence of PH, and patients with PH were divided into death and survival groups based on survival status. Clinical characteristics and outcomes were compared between groups, respectively. The risk factors for PH were analyzed by binary logistic regression. Results: In total, 67 neonates were identified as having GO and 24 (35.8%) were complicated with PH. Infants with PH were associated with intubation within 24 h after birth (p = 0.038), pulmonary dysplasia (p = 0.020), presence of patent ductus arteriosus (PDA; p = 0.028), a staged operation (p = 0.002), longer mechanical ventilation days (p < 0.001), oxygen requirement days (p < 0.001), parenteral nutrition (PN) days (p < 0.001), length of neonatal intensive care unit (NICU) or hospital stay (p = 0.001 and 0.002, respectively), and mortality (p = 0.001). The results of multivariable logistic regression analysis revealed that a staged operation was independently associated with PH. In addition, PH patients with lower birth weight, higher peak of pulmonary arterial systolic pressure, and refractory to pulmonary vasodilators (PVD) had increased mortality. Conclusion: Pulmonary hypertension is a serious complication and significantly increases the mortality and morbidities in infants with a GO. In addition, early and serial assessment of PH by echocardiography should be a routine screening scheme, especially in the neonatal omphalocele population who required a staged surgical repair. Clinicians should be aware that infants with PH who had low weight, severe and refractory PH have a higher risk of death.

Delayed diffuse lamellar keratitis after small-incision lenticule extraction related to immunoglobulin A nephropathy: A case report.

BACKGROUND: Diffuse lamellar keratitis (DLK) is a complication of laser-assisted in situ keratomileusis (LASIK). This condition can also develop after small-incision lenticule extraction (SMILE) with a distinctive appearance. We report the case involving a female patient with delayed onset DLK accompanied by immunoglobulin A (IgA) nephropathy. CASE SUMMARY: A 22-year-old woman was referred to our department for DLK and a decline in vision 1 mo after undergoing SMILE. The initial examination showed grade 2 DLK in the flap involving the central visual axis of the right eye. She was immediately administered with a large dose of a topical steroid for 30 d. However, the treatment was ineffective. Her vision deteriorated from 10/20 to 6/20, and DLK gradually worsened from grade 2 to 4. Eventually, interface washout was performed, after which her vision improved. DLK completely disappeared 2 mo after washout. Six months after SMILE, the patient was diagnosed with IgA nephropathy due to a 4-year history of interstitial hematuria. CONCLUSION: DLK is a typical complication of LASIK but can also develop after SMILE. Topical steroid therapy was ineffective in our patient, and interface washout was required. IgA nephropathy could be one of the factors contributing to the development of delayed DLK after SMILE.

[Timing of surgical ligation of patent ductus arteriosus in very low birth weight infants]. / æžä½Žå‡ºç”Ÿä½“é‡å„¿åŠ¨è„‰å¯¼ç®¡æœªé—­æ‰‹æœ¯ç»“æ‰Žæ—¶æœºçš„ç ”ç©¶.

OBJECTIVES: To study the effect of timing of surgical ligation of patent ductus arteriosus (PDA) on the prognosis of very low birth weight infants (VLBWI). METHODS: The medical data of VLBWI who underwent transthoracic ligation for PDA from June 2018 to May 2021 were reviewed retrospectively. The infants were divided into early ligation group (≤21 days of age) and late ligation group (>21 days of age) based on the age of ligation. The two groups were compared in terms of perioperative clinical features, complications, and mortality. The risk factors for early surgical ligation were analyzed. RESULTS: A total of 72 VLBWI were enrolled, with 19 infants (26%) in the early ligation group and 53 infants (74%) in the late ligation group. There were significant differences in birth weight, gestational age, weight at operation, days of age at operation, rates of preoperative invasive and noninvasive mechanical ventilation, incidence rate of pulmonary hemorrhage, incidence rate of hypotension, preoperative PDA internal diameter (mm/kg), intraoperative PDA external diameter (mm/kg), incidence rate of post-ligation cardiac syndrome, and duration of postoperative invasive mechanical ventilation between the two groups (P<0.05). A binary logistic regression analysis showed that pulmonary hemorrhage was an indication of early surgical ligation of PDA (P<0.05). There were no significant differences in the incidence rates of post-operative complications and the mortality rate between the early ligation and late ligation groups. CONCLUSIONS: Early surgical ligation may be performed for VLBWI who are experiencing pulmonary hemorrhage and hemodynamically significant PDA confirmed by cardiac ultrasound after birth. However, post-ligation cardiac syndrome should attract enough attention. In addition, early surgical ligation of PDA does not increase the risk of surgery-related and long-term complications or death, indicating that it is a safe and feasible treatment option.

Value of bedside echocardiography in predicting persistent patency of the ductus arteriosus during the early postnatal period in very low birth weight infants. / ç”ŸåŽæ—©æœŸåºŠæ—å¿ƒè„è¶ å£°é¢„æµ‹æžä½Žå‡ºç”Ÿä½“é‡å„¿åŠ¨è„‰å¯¼ç®¡æŒç»­å¼€æ”¾çš„ç ”ç©¶.

OBJECTIVES: To study the value of bedside echocardiography in predicting persistent patency of the ductus arteriosus during the early postnatal period in very low birth weight (VLBW) infants. METHODS: A retrospective analysis was performed for 51 VLBW infants who were admitted from March 2020 to June 2021, with an age of ≤3 days and a length of hospital stay of ≥14 days. According to the diameter of patent ductus arteriosus (PDA) on days 14 and 28 after birth, the infants were divided into three groups: large PDA group (PDA diameter ≥2 mm), small PDA group (PDA diameter <2 mm), and PDA closure group (PDA diameter =0 mm). The echocardiographic parameters measured at 72 hours after birth were compared among the three groups. The receiver operating characteristic (ROC) curve was used to evaluate the value of the echocardiographic parameters in predicting persistent patency of the ductus arteriosus (PDA≥2 mm) at the ages of 14 and 28 days. RESULTS: On day 14 after birth, there were 17 infants in the large PDA group, 11 in the small PDA group, and 23 in the PDA closure group. On day 28 after birth, there were 14 infants in the large PDA group, 9 in the small PDA group, and 26 in the PDA closure group. There were significant differences in gestational age, birth weight, rate of pulmonary surfactant use, and incidence rate of hypotension among the three groups (P<0.05). PDA diameter, end-diastolic velocity of the left pulmonary artery, left ventricular output, and left ventricular output/superior vena cava flow ratio measured at 72 hours after birth were associated with persistent patency of the ductus arteriosus at the ages of 14 and 28 days (P<0.05), and the ratio of the left atrium to aorta diameter was associated with persistent patency of the ductus arteriosus at the age of 28 days (P<0.05). The ROC curve analysis showed that the area under the curve that the PDA diameter measured at 72 hours after birth predicting the persistent patency of the ductus arteriosus at the ages of 14 and 28 days was the largest (0.841 and 0.927 respectively), followed by end-diastolic velocity of the left pulmonary artery, with the area under the curve of 0.793 and 0.833 respectively. CONCLUSIONS: The indicators obtained by beside echocardiography at 72 hours after birth, especially PDA diameter and end-diastolic velocity of the left pulmonary artery, can predict persistent patency of the ductus arteriosus at the ages of 14 and 28 days in VLBW infants, which provides a basis for the implementation of early targeted treatment strategy for PDA.

[Different Subtypes Caused by c.721C>T Substitution in the Exon 7 of ABO Gene].

OBJECTIVE: To analyze the different subtypes caused by c.721C>T substitution in the exon 7 of the ABO gene, and to investigate the related molecular mechanism of different antigens expression. METHODS: ABO subtypes in 7 samples were identified by standard serological methods. The exons 6, 7, and adjacent intron of ABO gene were amplified by Polymerase Chain Reaction (PCR), and the PCR products were analyzed by direct DNA sequencing and cloning sequencing. RESULTS: ABO subtypes phenotypes were AW (1 case), BW (3 cases), ABW (2 cases), A2 or Aint (1 case). The result showed that the 7th exon of ABO gene was c.721C>T variety based on A1.02, B1.01, and O.01.02; the alleles were AW.43（1 case）, BW.03（5 cases） and O.01.07（1 case）, ABO genotypes were ABO*AW.43/O.01.02 (1 case) , ABO*BW.03/O.01.02 (3 cases), ABO*A1.02/BW.03 (2 cases), and ABO*A2.05/O.01.07 (1 case). CONCLUSION: c.721C>T substitution in the ABO gene causes p.Arg241Trp exchange resulting in the decreasing of GTA or GTB activities and weaker antigen expression. O.01.07 is a null allele which cannot form a functional catalytic enzyme has no effect on A2 subtype antigen expression.

Exogenous endophthalmitis caused by Enterococcus casseliflavus: A case report.

BACKGROUND: Endophthalmitis caused by Enterococci is rare, and cases involving vancomycin-resistant enterococci are even rarer. We report the first case of Enterococcus casseliflavus endophthalmitis associated with injury caused by a pig. We also review reported cases of exogenous endophthalmitis caused by Enterococcus casseliflavus and discuss the clinical management and prognosis of this disease. CASE SUMMARY: A 43-year-old man with no previous visual problems complained of endophthalmitis in his left eye following injury caused by a pig. Visual acuity was light perception and B-ultrasonography revealed vitreous opacities with retinal detachment. He was treated with intravitreal vancomycin and ceftazidime after refusing vitrectomy. However, the vitreous opacities and retinal detachment deteriorated and he underwent vitrectomy 5 d post-injury. Intraoperatively, advanced rhegmatogenous and tractional retinal detachment with proliferative vitreoretinopathy were observed. On postoperative day 5, vitreous cultures grew Gram-positive cocci identified as Enterococcus casseliflavus. A 2-wk course of intravenous ampicillin and dexamethasone was commenced. On postoperative day 14, visual acuity improved to hand movement. At 6 mo post-injury, visual acuity improved to 20/667, but optic atrophy was present. CONCLUSION: Systemic administration of linezolid in the treatment of Enterococcus casseliflavus endophthalmitis can improve visual acuity. However, intravitreal amikacin should be considered despite concerns of toxicity when oral linezolid fails to prompt improvement.

[Size Estimation of HLA -â class Typed Platelet Apheresis Donor Bank].

OBJECTIVE: To estimate the size of HLA -Ⅰ class typed platelet apheresis donor bank. METHODS: A total of 16062 blood samples from Chinese Han voluntary unrelated marrow donors in Jiangsu were included in this study. Luminex-SSO was used to detect the HLA -Ⅰ class(A,B locus) antigens. The probability of finding at least one HLA matched unrelated donor was calculated based on the HLA -I class phenotype frequency. RESULTS: The population genetic data of HLA -Ⅰ class in Jiangsu were obtained, the optinal bans size in HLA typed apheresis plateler donor registry databane hrad been estimated by evaluating the population genetic data of HLA-1 class same donor. CONCLUSION: The establishment of HLA-1 class typed apheresis platelet donor bank with a total size of 1500 persons is acceptable, which can satisty the patients with phenotype freguency>0.002 to find at least 1 phenotype same donor in 95% probavility.

Riboflavin/ultraviolet A-induced collagen cross-linking in rabbit corneal scar.

AIM: To evaluate the biomechanical stability of the corneal scar treating with riboflavin and ultraviolet A (UVA). METHODS: Totally 86 New Zeal rabbits were divided into control group (group A, n=8) and trauma groups [group B (n=27), group C (n=24) and group D (n=27)]. Then groups B, C and D were divided into three sub-groups according to the time points of sacrifice, i.e. groups Ba, Ca and Da (4wk, n=8); Bb, Cb and Db (6wk, n=8); Bc (n=11), Cc (n=8) and Dc (8wk, n=11). The right corneas of these 78 rabbits in the trauma groups were penetrated. Group B were only sutured. Group C were treated with corneal cross-linking (CXL) immediately after suturing. Group D were treated with CXL seven days after suturing. The corneal scar strips of 4.0×10.0 mm2 were cut and the stress and Young's modulus at 10% strain were evaluated. Samples from the three rabbits of group Bc and three of group Dc were used to measure the expression of alpha smooth muscle action (α-SMA). RESULTS: The mechanical strength of the corneal scar increased with time, and was strongest at 8wk after the injury. The ultimate stress of corneal scar (group D) were 2.17±0.52 MPa, 2.92±0.63 MPa, and 4.21±0.68 Mpa at 4wk, 6wk and 8wk, respectively; Young's modulus were 10.94±1.57 MPa, 11.16±2.50 MPa, and 13.36±2.10 Mpa, which were higher than that of other groups except for normal control. The expression of α-SMA in group B and group D were 0.28±0.11 and 0.65±0.20, respectively, and the difference was statistically significant (P=0.048). CONCLUSION: CXL with riboflavin/UVA at seven days after suturing improved the biomechanical properties of corneal scars most effectively in the present study.

Biomechanics of sclera crosslinked using genipin in rabbit.

AIM: To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS: Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon's capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements (n=5). The remaining five treated eyes were prepared for histological examination. RESULTS: Compared to the untreated scleral strips, the genipin-crosslinked scleral strips showed that the ultimate stress and Young's modulus at 10% strain were increased by the amplitude of 130% and 303% respectively, ultimate strain was decreased by 24%. There had no α-smooth muscle actin (α-SMA) positive cells in control and treated sclera. Histologically, there was no sign of apoptosis in the sclera, choroid, and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area. CONCLUSION: Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera, with no α-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral, choroidal, and retinal cells, genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.

Four-year follow-up of corneal aberrations and visual functions of myopic patients after laser in situ keratomileusis.

OBJECTIVE: To report on 4-year follow-up of corneal higher-order aberrations and daily visual functions of myopic patients after laser in situ keratomileusis (LASIK). METHODS: One hundred thirty four eyes of 67 patients who underwent LASIK guided by aspherical ablation were included in this study. The vision, corneal spherical aberration (SphA) and Coma were recorded before LASIK and at 6 month and 4 year after LASIK. The evaluation of the questionnaire about daily visual functions was performed by the same physician after LASIK. RESULTS: No eye decreased the BCVA during 4 year follow-up. The effect index and safety index were 1.08±0.16, 1.11±0.17 and 1.12±0.16, 1.13±0.14 respectively at 6 month and 4 year post-LASIK. After LASIK the corneal SphA and Coma were significantly increased, however the difference between 6 month and 4 year post-LASIK was no statistical significance. Most patients (94.3%-92.4%) felt satisfaction or high satisfaction about the ability to perform each daily visual function after LASIK. Meanwhile there was still about 7.4%-9.2% patients who complained that they could not drive at night. Further analysis showed that the score of driving at night was negative correlation with corneal SphA (r=-0.645, p=0.040; r=-0.688, p=0.040 at 6 month and 4 year post-LASIK respectively). CONCLUSIONS: Our four-year follow-up outcomes indicated that the myopic patients after LASIK had the long-term stable corneal aberration and satisfaction of daily visual functions.

Correlation of discoloration and biomechanical properties in porcine sclera induced by genipin.

AIM: To study the feasibility of using the discoloration to evaluate the biomechanical properties after treating with genipin. METHODS: Porcine cadaver eyes were treated for 30min with 1.0% (by w/v) genipin. Untreated samples were used as controls. After treatment, scleral strips of 4.0×10.0-mm(2) were cut. The denaturation temperature (Td) measurement and stress-strain test were performed after taking photograph to analyze the color. RESULTS: Within 24h after treating with genipin, the sclera exhibited a bluish color which became deeper with time. And the denaturation temperature also was increased gradually. Compared with untreated groups, at 1, 6, 12, 24 and 36h after treatment, the ultimate stress were increased by 56%, 153%, 173%, 225% and 211% respectively. The Young's modulus at 10% strain also increased by 170%, 246%, 264%, 389% and 288% respectively. There were strong correlation between the discoloration and the biomechanical properties (ΔE-Ultimate stress: R(2)=0.892, P=0.00; ΔE-Young's modulus: R(2)=0.602, P=0.00). CONCLUSION: Genipin could be used to strengthen collagen gradually in a relatively short time span. And the biomechanical properties could be reliably evaluated via simple visible discoloration.

Collagen crosslinking of porcine sclera using genipin.

PURPOSE: To evaluate the effect of collagen cross-linking induced by genipin in porcine sclera. METHODS: Porcine cadaver eyes were treated with genipin at concentrations (by w/v) of 0.01%, 0.03%, 0.1%, 0.3%, 1.0% for 15 and 30 min. Riboflavin/ultraviolet A(UVA)-treated and untreated samples were used as controls. After treatment, scleral strips of 4.0 × 10.0 mm were cut. Twenty-four hours later, the stress-strain parameters of the strips were measured using a biomaterial microtester. The stress and Young's modulus at 8% strain were evaluated. RESULTS: Compared with untreated groups, after treatment with genipin for 15 min, the stress was increased by 66-246%, depending on the concentration of genipin. As for the 30-min groups, the stress was 171-444% higher than that of the control. The difference of the Young's modulus between genipin 15-min groups, except the 0.01% groups (p = 0.095), also had statistical significance (p < 0.05). The Young's modulus had significant difference between the untreated group and the genipin 30-min groups (all p < 0.05). Of 0.3% genipin for 15 min or 0.01% genipin for 30 min had a similar stress-strain curve with those of eyes treated with the riboflavin/UVA group. The sclera exhibited a bluish colour which became deeper with increase concentration and cross-linking time. CONCLUSIONS: Collagen cross-linking induced by genipin could increase the biomechanical strength in porcine sclera. The effect depends on the concentration and treatment time of genipin.

Stability of axis and patient satisfaction after toric implantable collamer lens implantation for myopic astigmatism.

OBJECTIVES: To assess the stability of axis and patient satisfaction after toric visian implantable collamer lens (TICL) implantation for moderate to high myopic astigmatism. METHODS: Total 33 eyes of 21 consecutive patients who underwent implantation of TICL for the correction of moderate to high myopic astigmatism were recorded and a minimum follow-up of six months was performed. The deviation of axis of TICL was detected from one week to six months postoperatively. The evaluation of the visual functions was done by the same clinician at six months after surgery. RESULTS: The mean refractive cylinder decreased from -2.48±0.91 diopters (D) preoperatively to -0.54±0.25D and -0.50±0.19D at one week and six months after surgery respectively. Mean changes in astigmatism from one week to six months after surgery was 0.03±0.17D. The mean deviation of axis of TICL from one week to six months postoperatively was 2.48±1.25°(range,1°~ 6°) and no TICL required secondary repositioning. 14.3% patients felt difficult about the middle distant visual function (Reading Computer Screen). Evaluations of other visual functions were positive or very positive. Conclusions : Six months after implantation of the TICL, it showed slightly axis rotation and high satisfaction about the visual functions.