Gaiping Du

Moscow Eye Microsurgery Complex in Russia Keratoprosthesis in Beijing

PURPOSE To evaluate the efficacy and preliminary safety of the Moscow Eye Microsurgery Complex in Russia (MICOF) keratoprosthesis in eyes with complicated corneal opacities unsuitable for keratoplasty. DESIGN Retrospective review of consecutive clinical case series. PARTICIPANTS We analyzed 85 eyes of 85 patients who previously underwent MICOF keratoprosthesis implantation at the Chinese PLA General Hospital between April 1, 2000, and August 31, 2009. The mean follow-up after MICOF keratoprosthesis implantation (measured after the second stage of the implantation) was 34.7 months (range, 3-107 months). METHODS The MICOF keratoprosthesis surgery involves 2 procedures. In stage 1, a supporting titanium frame is inserted into the lamellar pocket; a polymethyl methacrylate (PMMA) optical cylinder is implanted 3 months later (stage 2). Data were collected from the preoperative, intraoperative, and postoperative courses. Statistical analysis was performed to identify factors influencing postoperative complications. MAIN OUTCOME MEASURES Visual acuity (VA), keratoprosthesis retention, and significant postoperative complications. RESULTS The MICOF keratoprosthesis dramatically improved vision in most patients. The percentage of eyes with postoperative VA of 20/100 or better was 80.7% (67/83) at 6 months after stage 2, 82.4% (61/74) at 1 year, 72.7% (40/55) at 2 years, 78.8% (26/33) at 3 years, 78.9% (15/19) at 4 years, 100% (8/8) at 5 years, 80% (4/5) at 6 years, 100% (2/2) at 7 and 8 years, and 100% (1/1) at 9 years. The most common complication, retroprosthetic membrane formation, occurred in 39 of 85 eyes. The overall keratoprosthesis retention rate was 81.2% at an average follow-up of 34.7 months (range, 3-107 months). Ten eyes presented with elevated intraocular pressure after implantation; 3 of these had underlying glaucoma. All 3 eyes received cyclocryotherapy to control intraocular pressure. Sterile vitreitis occurred in 2 eyes, and retinal detachment occurred in 1 eye. CONCLUSIONS The MICOF keratoprosthesis is an effective alternative for patients with corneal blindness and a poor prognosis for penetrating keratoplasty.

Long-term outcomes of MICOF keratoprosthesis in the end stage of autoimmune dry eyes: an experience in China

Aims To evaluate the clinical outcomes following Moscow Eye Microsurgery Complex in Russia keratoprosthesis (MICOF KPro) implantation in end-stage autoimmune dry eyes. Methods A retrospective observational case series. Fourteen patients with end-stage autoimmune dry eyes underwent MICOF KPro surgery by one surgeon (YH) in the Chinese PLA General Hospital between 2000 and 2009. Retention of the prosthesis and vision were recorded and postoperative complications were analysed. Results Preoperative diagnosis included Stevens–Johnson syndrome (n=7), ocular cicatricial pemphigoid (n=4) and Sjogrens syndrome (n=3). The mean follow-up period was 3.9 years (range 10 months–7.8 years). After surgery, 13 eyes (93%) showed a visual acuity of 20/200 or better and 6 eyes (43%) achieved excellent vision of 20/40 or better. At last visit, 69% of the eyes (9/13) maintained a visual acuity of at least 20/200. The first case retained a visual acuity of 20/80 7.8 years after the operation. The most common complication was stromal melting that threatened anatomical success. Seven of the first eight patients showed tissue melting, and four of them had leakage. All of these were repaired successfully. The latter six cases received prophylactic autologous auricular cartilage implantation to reinforce the anterior surface of recipients cornea at either stage 1 or 2. Other causes of vision loss included pre-existing glaucoma (n=6), sterile vitritis (n=5), cylinder loosening (n=1) and retroprosthetic membrane (n=4). Conclusion MICOF KPro provided useful vision for the end stage of autoimmune dry eyes in our study. Anatomical stability of KPro was achieved in all cases using repair and reinforcing surgery.

Association between vascular endothelial growth factor +936 C/T gene polymorphism and age-related macular degeneration

Objectives The pathogenesis of age-related macular degeneration (AMD) remains unknown. Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis and a target for inhibition therapy in wet AMD. This study investigated the association between the VEGF +936 C/T gene polymorphism and AMD, in a Chinese Han population. Methods Patients with AMD, and age- and sex-matched controls were enrolled. Restriction fragment length polymorphism was used to analyse the VEGF +936 polymorphism in the promoter and the 3′ untranslated region of the gene. Results The study included 200 AMD patients and 200 control subjects. There was a significantly higher prevalence of the TT genotype among AMD patients (9.0%) compared with controls (3.5%); the odds ratio for this genotype in AMD patients was 2.73 (95% confidence intervals 1.11, 6.68). There were no significant associations between any genotype and AMD subphenotypic categories (early, geographic atrophy, choroidal neovascularization). Conclusions The present study findings suggested that the VEGF +936 TT genotype was associated with AMD among Han Chinese patients.

Biocompatibility of helicoidal multilamellar arginine-glycine-aspartic acid-functionalized silk biomaterials in a rabbit corneal model.

Silk proteins represent a unique choice in the selection of biomaterials that can be used for corneal tissue engineering and regenerative medical applications. We implanted helicoidal multilamellar arginine-glycine-aspartic acid-functionalized silk biomaterials into the corneal stroma of rabbits, and evaluated its biocompatibility. The corneal tissue was examined after routine hematoxylin-eosin staining, immunofluorescence for collagen I and III, and fibronectin, and scanning electron microscopy. The silk films maintained their integrity and transparency over the 180-day experimental period without causing immunogenic and neovascular responses or degradation of the rabbit corneal stroma. Collagen I increased, whereas Collagen III and fibronectin initially increased and then gradually decreased. The extracellular matrix deposited on the surface of the silk films, tightly adhered to the biomaterial. We have shown this kind of silk film graft has suitable biocompatibility with the corneal stroma and is an initial step for clinical trials to evaluate this material as a transplant biomaterial for keratoplasty tissue constructs.

Changes in objective vault and effect on vision outcomes after implantable Collamer lens implantation: 1-year follow-up.

Purpose To investigate the changes in vault and the effect on visual outcomes 1 year after implantable Collamer lens (ICL) implantation. Methods In this retrospective study, 127 eyes of 66 patients undergoing ICL implantation were examined both before and up to 1 year after the surgery. The examination contents included white-to-white (WTW) diameter, central vault of the ICL (distance between posterior surface of ICL and anterior surface of crystalline lens), refractive error, and wavefront high-order aberration (HOA). All statistical analyses were performed using SPSS 13.0 software. Results A significant decrease in vault was noted up to 1 month, after which the value stabilized (p=0.001). The moderate vault decreased significantly after the first 3 months postsurgery (paired-samples t test, p<0.05). Low vault showed a tendency to increase and high vault showed a tendency to decrease, but not significantly, over time. There was no statistically significant correlation between the amount of vault and the refractive error (Pearson correlation coefficient R=0.111, p=0.473) and there was a statistically significant correlation between the vault and HOAs (R=0.304, p=0.024). Conclusions Implantable Collamer lens vault over the crystalline lens had the tendency toward a slight decrease with time and did not significantly affect the vision outcome 1 year after surgery.

Experimental study of the mechanism of tolerance induction in dexamethasone-treated dendritic cells.

Summary Background The aim of this study was to investigate the mechanisms underlying tolerance induction of dexamethasone (Dex)-treated dendritic cells (DCs). Material/Methods Well-grown DC2.4 cells were randomly assigned to receive control, 50 μg/L, 100 μg/L, or 200 μg/L of dexamethasone and then were cultured for 6 days. The expressions of CD80, CD86, galectin-9, and PD-L1 on the surface of DC2.4 cells were analyzed with flow cytometry and the level of IL-12 secreted by DC2.4 cells was determined by ELISA. The stimulating activity of DC2.4 cells on allogeneic T cells was assessed with mixed lymphocyte reaction. Dexamethasone-treated DC2.4 cells were co-cultured with allogeneic splenic lymphocytes and the Foxp3 expression in naive T lymphocytes was determined with flow cytometry. Results Compared with the control group, the expressions of CD80, CD86, galectin-9, and PD-L1 on the surface of DC2.4 cells exposed to different doses of dexamethasone showed no significant changes; however, dexamethasone treatment significantly reduced IL-12 secretion and inhibited DC2.4’s stimulation on the proliferation of allogeneic T lymphocytes. Moreover, dexamethasone-treated DC2.4 cells effectively promoted FOXP3 expression in naive T lymphocytes. Conclusions DC2.4 is a stable cell line with high expressions of CD80, CD86, and PD-L1. Dexamethasone does not significantly change the cell phenotype of DC2.4 cells, but inhibits the secretion of IL-12 cytokine and attenuates DC2.4’s stimulation of the proliferation of allogeneic T cells. Dexamethasone-treated DC2.4 cells also effectively promote FOXP3 expression in naive T lymphocytes.

Long-term outcomes and complications of Moscow Eye Microsurgery Complex in Russia (MICOF) keratoprosthesis following ocular surface burns: clinical experience in China

Objective The aim of this study was to evaluate the clinical outcomes of the implantation of MICOF keratoprosthesis (Kpro) in patients with alkaline, acid and thermal ocular burns. Methods This is a retrospective, non-competitive, interventional case series. Ninety eyes of 90 patients with ocular burns underwent MICOF KPro surgery at the Chinese People’s Liberation Army General Hospital between April 2000 and December 2012. Preoperative and postoperative findings were recorded. Retention of the prostheses and the treatment for postoperative complications were investigated. Results The mean age of patients was 40.26±12.18 years (range: 8–64 years), and the mean duration after ocular trauma was 4.8±6.2 years (range: 1.5–12 years). The mean follow-up period was 58.22±36.28 months (range: 1–145 months). Eighty patients were followed for ≥1 year and 73 eyes (81.11%) achieved the best-corrected visual acuity of 20/200 or better and 39 eyes (43.33%) achieved best-corrected visual acuity of ≥20/40. The common complications were glaucoma, corneal melt and conjunctiva overgrowth, and the incidences of these complications were 59.99%, 40% and 31.11%, respectively. One patient experienced KPro extrusion, and two patients exhibited leakage from the area of the implant. Seven with endophthalmitis eyes had final visual acuities of light perception. There was no significant difference in the effectiveness of the implants among the different causes of injuries, including acid, alkali and thermal burns. Conclusions MICOF Kpro is an effective alternative for patients with ocular burn with corneal blindness. Glaucoma and endophthalmitis were identified as significant risk factors for visual loss.

New surgical therapy for conjunctival lymphangiectasia.

AIM To report 7 cases of conjunctival lymphangiectasia, introduce a simple operation method and discuss the result of the pathological examination. METHODS Clinical data including medical history, physical examination, previous surgery history were collected in 7 patients with conjunctival lymphangiectasia. Ocular data including visual acuity, Slit-lamp biomicroscopy were released, as were results of histopathology studies. Surgical method was also introduced by video. RESULTS Seven eyes of 7 patients (4 male and 3 female) with biopsy-proven conjunctival lymphangiectasia underwent the resection. Despite different surgical intervention, the optima method has been founding to treatment conjunctival lymphangiectasia. It is to reduce recurrence that the most concerned problem. In these 7 cases reported, patients kept healthy for 18 months without any one recurrence, whose visual acuity were not affected. Pathological report showed cystic tissue consists of squamous epithelium with significant hyperplasia. CONCLUSION This operation method is simple and easy to complete, as it is deserved to accept for surgeons and patients on the basis of its advantages.

Integrin alpha v beta 6 contributes to maintaining corneal epithelial barrier function.

The corneal epithelial barrier dysfunction is associated with a number of disorders of the cornea. This study aims to investigate the role of integrin alpha v beta 6 (avb6) in maintaining the corneal epithelial barrier function. In this study, the association of avb6 and endosome/lysosome in the human corneal epithelial cell line, HCE cells, was observed with immunocytochemistry. The corneal epithelial barrier function was assessed with HCE monolayers in Transwells. The results showed that avb6 was observed attaching to endosomes in HCE cells. Knockdown of avb6 resulted in disturbing the fusion of endosome/lysosome. Tumor necrosis factor (TNF)‐α could bind avb6 to form a complex that interfered with the fusion of endosome/lysosome in HCE cells. With the HCE monolayer as a corneal epithelial barrier model, the knockdown of avb6 or exposure to TNF‐α markedly increased the epithelial barrier permeability to a macomolecular protein, ovalbumin, in Transwell system. After passing through the deficient epithelial barrier, the ovalbumin molecules still conserved the antigenicity. We conclude that the integrin avb6 plays an important role in the fusion of endosome/lysosome in corneal epithelial cells; inhibition of avb6 results in corneal epithelial barrier dysfunction.

Ocular trauma score in transferred fireworks-related ocular injuries: a case series

BACKGROUND Our aim was to review the characteristics of transferred fireworks-related ocular damage and to evaluate the prognostic value of the ocular trauma score (OTS) for these injuries. METHODS This study included 22 transferred patients (19 male, 3 female; mean age 22.6±14.9 years) (25 eyes). The data were retrospectively reviewed, including the characteristics of the geography, types of fireworks, status of injuries, therapeutic procedures, and the best-corrected visual acuity (BCVA). All the injured eyes were classified using the OTS at the time of the initial examination. RESULTS Twenty eyes (80%) were in OTS category 1, three eyes (12%) were in OTS category 2, and two eyes (8%) were in OTS category 3. All cases received surgical therapy. Six eyes (24%) were enucleated, four (16%) of which achieved an improvement in their final BCVA. There was a statistically significant improvement in final BCVA between OTS category 1 and the other two OTS categories (p=0.016). CONCLUSION The aforementioned transferred fireworks-related ocular injury cases occurred mainly in young adults, men and active participants, all of which incurred serious vision loss and blindness. The OTS is quite effective for classifying the status and estimating the prognosis of transferred fireworks-related ocular injuries.