Xiao-Wei Gao

Mechanism of immune tolerance induced by donor derived immature dendritic cells in rat high-risk corneal transplantation

AIM To study the role of immature dendritic cells (imDCs) on immune tolerance in rat penetrating keratoplasty (PKP) in high-risk eyes and to investigate the mechanism of immune hyporesponsiveness induced by donor-derived imDCs. METHODS Seventy-five SD rats (recipient) and 39 Wistar rats (donor) were randomly divided into 3 groups: control, imDC and mature dendritic cell (mDC) group respectively. Using a model of orthotopic corneal transplantation in which allografts were placed in neovascularized high-risk eyes of recipient rat. Corneal neovascularization was induced by alkaline burn in the central cornea of recipient rat. Recipients in imDC group or mDC group were injected donor bone marrow-derived imDCs or mDCs of 1×10(6) respectively 1 week before corneal transplantation via tail vein. Control rat received the same volume of PBS. In each group, 16 recipients were kept for determination of survival time and other 9 recipients were executed on day 3, 7 and 14 after transplantation. Cornea was harvested for hematoxylin-eosin staining and acute rejection evaluation, Western blot was used to detect the expression level of Foxp3. RESULTS The mean survival time of imDC group was significantly longer than that of control and mDC groups (all P<0.05). The expression level of Foxp3 on CD4(+)CD25(+)T cells of imDC group (2.24±0.18) was significantly higher than that in the control (1.68±0.09) and mDC groups (1.46±0.13) (all P<0.05). CONCLUSION Donor-derived imDC is an effective treatment in inducing immune hyporesponsiveness in rat PKP. The mechanism of immune tolerance induced by imDC might be inhibit T lymphocytes responsiveness by regulatory T cells.

Posterior chamber phakic intraocular lens implantation for high myopia

AIM To evaluate the efficacy, safety and stability of posterior chamber phakic intraocular lens implantation for the correction of high myopia. METHODS Retrospective case review of 82 eyes (43 patients) undergoing implantable Collamer lens (ICL) placement by a single surgeon (Xiao-Wei Gao) to correct preoperative mean spherical equivalents between -9.00 diopter (D) and -23.00D. Main outcome measures included uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), intraocular pressure (IOP), lens transparency, postoperative uveitis. Visante anterior segment optical coherence tomography (AS-OCT) was used to measure anterior chamber depth (ACD) and the position of ICL. RESULTS Mean follow-up was 6.54±3.26 months (range 3-12 months). Predictability of the manifest spherical equivalent (SE) refraction to within ±1.00D was achieved in 88% of eyes and ±0.50D in 72.5% of eyes. The mean postoperative manifest SE refraction was -1.85±0.72D, with 96.34% of eyes maintaining or gaining ≥1 line(s) of BSCVA. The mean 3-month postoperative ECD decreased but had no statistically difference compared with the preoperative ECD. Of the 7 eyes (8.54%) with a mild transient increase in intraocular pressure (up to 30mmHg), none required a second surgical procedure or prolonged topical medication. There was no loss of lens transparency. Pigmented precipitates were observed in 5 eyes (6.09%). The mean preoperative ACD measured with AS-OCT was 3.28±0.14mm, three months after surgery, the mean ACD was 2.45±0.22mm. Anterior chamber depth showed a statistically significant reduction. One eye (1.22%) had ICL spontaneous rotation, 81 eyes (98.78%) of the lens remained correctly centered. CONCLUSION The implantation of ICL is an effective surgical option for the management of high myopia. But its long time effect and safety still need more time to prove.

Effects of aminoguanidine on retinal apoptosis in mice with oxygen-induced retinopathy.

AIM To explore the protective effects of aminoguanidine (AG) on retinal apoptosis in mice with oxygen-induced retinopathy (OIR). METHODS A total of 80 C57BL/6J mice, aged 7 days, were randomly divided into four groups: normal, high oxygen, high oxygen saline and high oxygen treated with AG. In the normal group, mice were housed in normoxic conditions from postnatal day P7 to P17. Mice in the other 3 groups were placed under hyperoxic conditions (75±2%O2) in an oxygen-regulated chamber for 5 days and subsequently placed in normoxic conditions for 5 days. Mice in the AG group were treated once daily, from P12 to P17, with AG hemisulfate (100mg/kg body weight, intraperitoneally) dissolved in physiological saline. An equivalent amount of 0.9% physiological saline was administered, as above, to mice in the high oxygen saline group. Ten mice were randomly selected from each group on P14 and on P17, euthanized and the retinas examined. Apoptotic cells in the retina were detected using the terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. The expression of nitric oxide synthase (iNOS) in the retina was detected by immunohistochemistry and changes in rod cells were observed using electron microscopy. RESULTS TUNEL-positive cells and iNOS immunoreactive neurons were present in the inner nuclear and ganglion cell retinal layers of mice in the high oxygen group. The number of TUNEL-positive cells was significantly greater in the high oxygen group compared with the normal group (t=-20.81, P 14d <0.05; t=-15.05, P 17d <0.05). However, the number of TUNEL-positive cells in the AG treatment group was significantly lower (t=-13.21, P 14d<0.05; t=-6.61, P 17d <0.05) compared with the high oxygen group. The expression of iNOS was significantly higher in the high oxygen group compared with the normal group (t=-21.95, P 14d<0.05; t=-17.30, P 17d<0.05). However, the expression of iNOS in the AG treatment group was significantly lower (t=-12.17, P 14d<0.05; t=-10.30, P 17d<0.05) compared with the high oxygen group. The outer segments of the rods were disorganized and short in the high oxygen group. Rod morphology appeared to be slightly improved in the AG group. CONCLUSION AG may protect retinal neurons in OIR by inhibiting apoptosis. The mechanism may be related to iNOS.

Inhibition of retinopathy of prematurity in rat by intravitreal injection of sorafenib.

AIM To investigate the effect of intravitreal injection administered sorafenib, a multikinase inhibitor, in a rat model of oxygen-induced retinopathy (OIR). METHODS Seven-day-old Sprague-Dawley rats (n=144) were randomly assigned to six groups. Group A received normal partial oxygen pressure and groups B, C, D, E and F were exposed to hyperoxia (75±2)% from postnatal 7d (P7) to P12 to induce retinopathy of prematurity. The rats in groups C, D, E and F were received intravitreal injections of either vehicle (DMSO) or sorafenib at P12 (5, 20 and 80 µg, respectively). Then they returned to normoxia after P12. The retinas were whole-mounted and imaged with a confocal microscopy. The vascular branching points were counted to quantify neovascularization at P17. Cross-sections of the retina were stained with hematoxylin and eosin (HE). The nuclei of new vessels breaking the internal limiting membrane were counted to quantify the proliferative neovascular response. RESULTS The retinal vessel in groups B and C turned into tortuosity and a great deal of neovascularization were observed. Sorafenib-treated rats had significantly less neovascularization as compared with vehicle-treated and control rats in a dose dependent manner (P<0.05). The number of vascular branching points in A, B, C, D, E and F were 16.50±3.90, 37.44±6.47, 37.08±5.10, 30.80±6.85, 26.08±5.08 and 19.83±3.51, respectively. The number of the nuclei of retinal new vessel in A, B, C, D, E and F were 0.22±0.42, 35.66±4.70, 35.30±4.54, 27.30±4.28, 21.41±3.53, and 7.41±2.87, respectively. There were significant difference between each group (P<0.05) except groups B and C. CONCLUSION In the rat OIR model, sorafenib could inhibit retinal neovascularization in a dose dependent manner.

Effects of minocycline on expression of bcl-2, bax in early retinal neuropathy of diabetes in rats

AIM To study the effect of the minocycline (MNC) on expression of bcl-2, bax in retinal nerve cells of rat with diabetes. METHODS Male SD rats were randomly divided into negative control group, model control group and MNC treated group. Diabetes model was established by intraperitoneal injection of 60 mg/kg streptozotocin (STZ). The protein expressions of bcl-2 and bax in retina were detected by immunohistochemistry method. RESULTS Compared with the negative control group, bax immunoreactive neurons in retina were increased significantly (P<0.01) in model control group. However, bax immunoreactive neurons in retina in MNC treated group were significantly decreased (P<0.01). Compared with the model control group, bcl-2 immunoreactive neurons in retina were increased significantly(P<0.01) in MNC treated group. CONCLUSION MNC can obviously decreased expression of bax and increased expression of bcl-2 in retina with DR. It is one of path of inhibiting impairment on retinal nerve cells with DR.

Clinical Observation on Removal of Small Foreign Bodies Touching the Optic Nerve in the Deep Orbital Region: A Case Series

Abstract Purpose: Five patients presented to our institution with deep intraorbital foreign bodies adjacent to the optic nerve. We removed all foreign bodies by lateral orbitotomy to evaluate the treatment and the benefits of their extraction. Methods: The clinical outcomes of the five patients were retrospectively analyzed. Results: Radiology in all five patients revealed small foreign bodies touching the optic nerve in the deep orbital region. All patients also suffered from significant secondary psychological disturbances, these including anxiety and altered sleep patterns. They had become preoccupied with a strong desire to remove the intraorbital foreign bodies [IFB]. In this cohort, two had no light perception before surgery, another two had light perception, and one had hand motion perception as well as vitreous hemorrhage that had been plugged with silicone oil in other hospital. All foreign bodies were removed via lateral orbitotomy. Visual acuity improved after the operation in only three cases. However, the psychological well-being of all five patients improved. Conclusions: Consideration should be given to removal of intraorbital foreign bodies adjacent to the optic nerve, even where a significant degree of vision has already been lost. Furthermore some patients can achieved vision improvement and such surgery can frequently address the significant psychological disturbance that can be associated with such orbital foreign bodies.

Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns

AIM To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty. METHODS The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups, Group A (16 eyes) with femtosecond laser-assisted deep lamellar keratoplasty 24h after burn and Group B (16 eyes) without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy (TEM) at 1, 2, 3, and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology. RESULTS The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached. CONCLUSION Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes.

Eye and appearance characteristics of encephalocraniocutaneous lipomatosis

Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous syndrome. The unique clinical manifestations of the disease include ocular edema or hamartoma, abnormal skin on the head and neck, and corresponding hair loss on the scalp. Historical literature on ECCL consists mainly of case reports and does not present the common features of the disease. We present the characteristic manifestations of the eye and skin to provide ophthalmologists with a fuller understanding of in ECCL.

Comparative study of modified and conventional secondary hydroxyapatite orbital implantations

AIM To compare the clinical effects of the modified and conventional secondary hydroxyapatite orbital implantations. METHODS A total of 40 patients who had received eye enucleation were equally randomized into the modified and conventional groups. Twenty patients were treated by conventional method. The four rectus muscles were separated, and then an orbital implant wrapped with xenogenous sclera was implanted. Twenty patients were treated by modified method. An implant unwrapped with xenogenous sclera was directly implanted into the muscle pyramid. The operating time, costs, clinical effects, and complications of the two groups were compared. RESULTS The average operating time of the modified group was 20.5±5.6min, whereas that of the conventional group was 56.8±14.6min (P<0.01). The average cost of the modified group was 7 800±340RMB (1 274±55.6USD), whereas that of the conventional group was 9 800±660RMB (1 601±107.8USD) (P<0.01). The two groups did not show significant difference in orbital implant mobility or postoperative complications. CONCLUSION The modified secondary hydroxyapatite orbital implantation has advantages in operating time, surgery cost, and complication reducing. It is worthy for wide clinical application and further study.