A Rabbit Dry Eye Model Induced by Subcutaneous Scopolamine.

PURPOSE: To establish and characterize a dry eye model in New Zealand rabbits by subcutaneous injections of scopolamine hydrobromide (SCOP). METHODS: Twenty New Zealand male rabbits were injected subcutaneously SCOP for 14 consecutive days; subcutaneous saline was used as a negative control. The correlated clinical parameters of ocular surface dryness were detected in vivo using tear secretion and corneal fluorescein staining. The expression of IL-1ß and TNF-α on the ocular surface and in lacrimal glands were analyzed by real-time PCR and western blot on the 14th day. The expression of Mucin-5 subtype AC (MUC5AC) was detected by Immunofluorescence staining in conjunctival tissue. RESULTS: The SCOP-treated rabbits exhibited significantly decreased aqueous tear secretion and increased corneal fluorescein staining scores over time. Both the mRNA expression levels and the protein expression levels of IL-1ß and TNF-α were significantly increased after SCOP treatment compared with those after saline treatment. The loss of conjunctival MUC5AC was found in the SCOP-injected rabbits. Some infiltrated inflammatory cells and atrophic acinar cells were observed in the lacrimal gland after SCOP treatment. The disordered structures of the ocular surface and lacrimal glands were also observed. CONCLUSIONS: This study showed that repeated subcutaneous SCOP injections successfully elicited some of the typical dry eye symptoms commonly seen in humans.

Pediatric Chemical and Thermal Ocular Injuries Requiring Hospitalization in South China.

PURPOSE: To study the clinical characteristics of children with severe ocular chemical or thermal injuries in South China and evaluate prognostic factors affecting final visual acuity (VA). METHODS: A five-year retrospective study was conducted on pediatric patients who were first admitted to Zhongshan Ophthalmic Center with severe chemical or thermal ocular injuries. Data collected and analyzed comprised socioeconomic and socio-demographic data, details regarding their injury, subsequent treatment, and visual outcomes. RESULTS: Of the 105 children (121 eyes), severe ocular chemical and thermal injuries in South China were prevalent in preschool children (n = 51, 58.1%), predominantly male (n = 82, 78.1%), and primarily children in rural areas (n = 98, 93.3%). Seventy-one eyes (78.9%) had a final VA <0.05, and multivariate logistic regression analysis revealed that initial VA after injury (OR = 0.47), the maternal education level (OR = 0.23), and monthly household income (OR = 0.31) were significantly associated with final VA. CONCLUSION: Final VA was associated with the initial VA, the maternal level of education, and family income; necessitating an increased provision of public education to children from low-income families, especially in rural areas.

In Vivo Bioimaging and Photodynamic Therapy Based on Two-Photon Fluorescent Conjugated Polymers Containing Dibenzothiophene-S,S-dioxide Derivatives.

As a critical component for photodynamic therapy toward cancer treatment, photosensitizers require high photoinduced reactive oxygen species generation efficiency, good biocompatibility, and high phototoxicity. Herein, a series of donor-acceptor conjugated polymers containing dibenzothiophene-S,S-dioxide derivatives are designed and synthesized, which can be used as effective photosensitizers. The resulting copolymer PTA5 shows strong green light emission with high photoluminescence quantum yields owing to the intercrossed excited state of local existed and charge transfer states. The PTA5 nanoparticles can be fabricated by encapsulation with a biocompatible polymer matrix. Upon excitation at 800 nm, these nanoparticles present a relatively large two-photon absorption cross section of 3.29 × 106 GM. These nanoparticles also exhibit good photostability in water and thus can be utilized for bioimaging. The tissue-penetrating depths of up to 170 µm for hepatic vessels and 380 µm for blood vessels of mouse ear were achieved using PTA5 nanoparticles. Furthermore, PTA5 nanoparticles show impressive reactive oxygen species generation capability under the irradiation of a white light source. This can be attributed to the effective intersystem crossing between high-level excited state. Upon irradiation with white light (400-700 nm) at 50 mW cm-2 for 5 min every other day, the tumor growth can be effectively suppressed in the presence of PTA5 nanoparticles. These findings demonstrate that PTA5 nanoparticles can be used as a photosensitizer for photodynamic therapy.

Efficient near-infrared anionic conjugated polyelectrolyte for photothermal therapy.

In this work, an anionic conjugated polyelectrolyte (PCP-SO3K), in which the backbone contains alternating 4,4-bis-alkyl-4H-cyclopenta-[2,1-b;3,4-b']-dithiophene and benzene structural units and the charges are provided by pendant sulfonate groups, was synthesized. The ionic nature of PCP-SO3K renders it soluble in water, and PCP-SO3K aqueous solution exhibits good photostability, with two main absorbance bands centered at 490 nm and 837 nm before and after laser irradiation. Its NIR absorption in water, negligible photoluminescence and insignificant intersystem crossing endow PCP-SO3K with efficient photothermal therapy performance, and an effective photothermal conversion efficiency of 56.7% was realized. Thus, PCP-SO3K aqueous solution can be used as an effective photothermal agent for in vivo applications as its photoactivity can be triggered by NIR light and can convert laser energy into thermal energy in a water environment. Of particular importance is the fact that complete tumor remission without recurrence in 4T1 tumor-bearing mice was realized after intravenous injection of PCP-SO3K aqueous solution and laser irradiation (2.0 W cm-2, 808 nm). The results indicate that the application of anionic conjugated polyelectrolytes as photothermal agents in photothermal therapy provides a new platform for the design of photothermal agents for clinical cancer treatment.

Healing characteristics of acellular porcine corneal stroma following therapeutic keratoplasty.

BACKGROUND: Acellular porcine corneal stroma (APCS) has proven to be a promising alternative to traditional corneal grafts. This prospective case series was conducted to further investigate the healing characteristics of APCS following keratoplasty. METHODS: Twenty-seven patients undergoing APCS implantation to treat infectious keratitis were included. The patients were followed up for 12 months after surgery. The main outcome measures included visual acuity, corneal transparency, graft thickness, and cellular and nerve regeneration. RESULTS: In the operated eyes, the best-corrected visual acuity (BCVA, in logarithm of the minimal angle of resolution [logMAR] units) increased from 1.23 ± 0.95 logMAR before surgery to 0.23 ± 0.18 logMAR at 12 months after surgery (P < .001). The contrast sensitivity was still evidently reduced, especially at higher spatial frequencies. Gradual transparency improvement was observed in APCS grafts post-operatively. After implantation, the APCS graft thickness initially increased (day 1 = 592.41 ± 52.69 µm) but then continuously decreased until 3 months after surgery (1 month = 449.26 ± 50.38 µm; 3 months = 359.63 ± 34.14 µm, P < .001). Graft reepithelialization was completed within 1 week. In the in vivo confocal microscopy scans, host keratocytes began to repopulate the APCS grafts between 3 and 6 months post-operatively; subbasal nerve regeneration was only noted in 18.52% (5/27) of the eyes by 12 months after surgery. CONCLUSIONS: Acellular porcine corneal stroma functions as an effective alternative to human corneal tissue in lamellar keratoplasty. However, APCS is somewhat different from fresh human cornea in term of the post-operative healing process, which warrants the attention of both clinicians and patients.

The lived experiences of patients undergoing acellular porcine corneal stroma transplantation.

To explore the lived experiences of patients undergoing acellular porcine corneal stroma (APCS) transplantation, a descriptive, qualitative design was performed. A purposive sample of 13 patients who underwent APCS transplantation to treat progressive infectious keratitis were enrolled in the semi-structured, open-ended interviews. The taped and transcribed interviews were analyzed using a thematic analysis approach. Alterations in the transparency of APCS grafts were accompanied by a gradual improved visual acuity (before surgery: 1.38± 0.91 logMAR; 3mo postoperatively: 0.40±0.24 logMAR, respectively). Accordingly, in terms of lived experiences, the patients generally reported "negative" experiences before the operation and during the early postoperative period, but this was greatly improved 3mo after surgery. Four main themes were derived: anxiety and fear, stigma, lifestyle change, and gratitude and insights. Conclusively, health care professionals should provide holistic care for patients, proactively promoting patients' physical and mental health.

Safety of antivascular endothelial growth factor administration in the ocular anterior segment in pterygium and neovascular glaucoma treatment: Systematic review and meta-analysis.

BACKGROUND: Anti-VEGF agents has been widely used in ocular diseases, but its safety for treating anterior segment disorders, the conclusions are controversial. METHODS: Several major databases, including CENTRAL, MEDLINE, and EMBASE, were searched. Safety data from 18 randomized controlled trials (RCTs) were used to compare anti-VEGF treatment in the ocular anterior segment in pterygium and neovascular glaucoma treatment with placebo/sham treatment for eye diseases. A meta-analysis for adverse events was performed. RESULTS: Eighteen RCT studies with 955 eyes were included in the meta-analysis. Significant difference in conjunctival disorders (OR: 1.62; 95% CI, 1.01-2.59; P = .05) was noted among the included studies, but not in ocular intolerance (odds ratio [OR]: 0.75; 95% CI, 0.34-1.62; P = .46), corneal disorders (OR: 0.71; 95% CI, 0.37-1.37; P = .31), or the subgroup analysis of conjunctival disorders. CONCLUSIONS: The administration of anti-VEGF agents in the ocular anterior segment for patients with pterygium and glaucoma was tolerable in tolerance and cornea, but was the risk factor of conjunctival disorders. The healing of corneal epithelium may be delayed in patients with primary corneal epithelial defects after anti-VEGF application. However, due to the limited evidence, further research should be performed on the safety of anti-VEGF administration in patients with different corneal disorders.

Hyaluronate Acid-Dependent Protection and Enhanced Corneal Wound Healing against Oxidative Damage in Corneal Epithelial Cells.

Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA) in promoting corneal wound healing. Methods. Human corneal epithelial cells (HCECs) were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-α and MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined. Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1ß and MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group. Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses.

Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus.

Objective. To compare fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT (TD-OCT) in the determination of thinnest corneal thickness (TCT). Methods. This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT) and Visante-OCT (TD-OCT) were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by paired t-test, the Pearson correlation, intraclass correlation coefficient (ICC), and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation (S (w)), coefficient of variation (CV(w)), and ICC. Results. The TCT value of normal corneas was higher by RTVue-OCT (530.4 ± 19.7 µm) than Visante-OCT (521.5 ± 18.3 µm) (p < 0.001). For keratoconus eyes, the TCT was 425.0 ± 58.2 µm and 424.4 ± 55.7 µm (difference being 0.6 ± 10.2 µm, p = 0.604). Strong correlation (r = 0.938∼0.985) (ICC = 0.915-0.984) was observed between the two OCTs, and each OCT exhibited excellent repeatability in determining the TCT in all subjects (ICC = 0.984-0.994). Conclusions. The values of TCT obtained from RTVue-OCT and Visante-OCT were highly correlated; however, the two values were different. Both OCT instruments exhibited good intraobserver reliability. The existence of systematic differences suggested that the two instruments cannot be used interchangeably.

[Management of Lamellar Keratoplasty in Day-care Unit].

PURPOSE: The management and efficacy of lamellar keratoplasty of 8 patients in day-care unit were summarized. METHODS: The work flow and medical record of 8 cases undergoing corneal transplantation in day-care unit were retrospectively analyzed. RESULTS: Eight patients were fully recovered. One case with fungal keratohelcosis was re-infected at post-operative 2 months and hospitalized. CONCLUSION: During lamellar keratoplasty in day-care unit, the work flow should be explicitly established and modified. The quality of patient selection, preoperative and postoperative nursing, follow-up after discharge should be carefully assured. In addition, nursing paperwork should be simplified, psychological nursing should be strengthened, and doctors and nurses should cooperate closely to enhance work efficiency.

[Nursing Experience of Corneal Collagen Cross-linking in Treating Keratoconus].

PURPOSE: To summarize the nursing experience and clinical efficacy of corneal collagen cross-linking in treating keratoconus. METHODS: Preoperative and postoperative nursing and medical record of 30 patients (31 eyes) undergoing corneal collagen cross-linking were retrospectively analyzed. RESULTS: The the severity of diseases in all 30 patients (31 eyes) was properly controlled. All cases were fully recovered. The visual acuity at postoperative one month was improved in all cases. CONCLUSION: Assistance in terms of preoperative examination, education of health knowledge and effective psychological nursing play a pivatol role in the nursing before and after corneal collagen cross-linking. Following surgery, postoperative changes in the the severity of diseases should be strictly observed. Much attention should be diverted to ease patients' pain, prevent infection and accelerate the healing of corneal epithelium.

Surgical cooperation during implantation of a Boston type-I keratoprosthesis.

This study was designed to summarize the key points of surgical cooperation involving penetrating corneal transplantation combined with implantation of keratoprosthesis. Preoperative preparation and intraoperative procedures were fully implemented to ensure cooperation with the physicians, to observe the the severity of the disease, and to guarantee the success of the surgery.

ES micro-environment enhances stemness and inhibits apoptosis in human limbal stem cells via the maintenance of telomerase activity.

Our previous work had found that telomerase rejuvenated in the cytoplasm of corneal epithelial cells cultured in embryonic stem cell-conditioned medium, the functional properties of stem-like corneal epithelial cells can be enhanced by co-culturing with embryonic stem cells (ESCs) via activation of the integrinß1-FAK-PI3K/Akt signaling pathway. The goal of this study was to explore the potential molecular mechanisms of the ES micro-environment that enhance the stem cell-like phenotype and inhibit apoptosis in human limbal stem cells (LSC). The LSC were cultured in different media, either CnT-20 medium or CnT-20 +20% ES culture supernatant (ESC-CM). We observed that LSC cultured in ESC-CM had an increased proliferative capacity, greater serial passage capacity, higher colony-forming efficiency (CFE) and higher levels of stem cell-associated marker than those cultured in CnT-20. Compared with CnT-20, ESC-CM enhanced the undifferentiated status and inhibited apoptosis in the LSC by promoting the maintenance of telomerase activity, which could reduce the generation of reactive oxygen species (ROS), maintain the membrane potential (Δψm) at higher levels and reduce the expression of the p21 protein. Our findings indicated that ESC-CM system induced LSC to maintain a stem cell phenotype and inhibit the process of apoptosis. These effects might partially be achieved via the telomerase-p21-mitochondrial axis and the activation of the FAK/Wnt signaling pathways. This study may have high impact and clinic implication on the expansion of LSC in regenerative medicine, especially for ocular surface reconstruction.