Epibulbar osseous choristoma: Two case reports.

BACKGROUND: Choristoma is a rare, benign, congenital proliferative tumor, with osseous choristoma being the rarest. Although the tumor is benign, effective identification is needed for its diagnosis and treatment. Here, we report the diagnosis and successful surgical treatment of two patients with osseous choristoma. CASE SUMMARY: Two patients, a young female and young male patient, were found to have a mass on the ocular surface. The tumor presented on the superior temporal bulbar conjunctiva in the first patient and on the upper eyelid in the second patient. Ultrasound biomicroscopy detected a strong echo with clear boundaries covering the lower echo, and computed tomography examination revealed calcification. Both patients underwent surgery, and histopathological evaluation of the mass showed osseous choristoma. They were treated by excision and subsequently cured. CONCLUSION: Osseous choristomas are usually asymptomatic. Our patients were cured immediately after surgery, suggesting that surgical treatment is an effective strategy.

Preliminary studies of constructing a tissue-engineered lamellar corneal graft by culturing mesenchymal stem cells onto decellularized corneal matrix.

AIM: To construct a competent corneal lamellar substitute in order to alleviate the shortage of human corneal donor. METHODS: Rabbit mesenchymal stem cells (MSCs) were isolated from bone marrow and identified by flow cytometric, osteogenic and adipogenic induction. Xenogenic decellularized corneal matrix (XDCM) was generated from dog corneas. MSCs were seeded and cultured on XDCM to construct the tissue-engineered cornea. Post-transplantation biocompatibility of engineered corneal graft were tested by animal experiment. Rabbits were divided into two groups then underwent lamellar keratoplasty (LK) with different corneal grafts: 1) XDCM group (n=5): XDCM; 2) XDCM-MSCs groups (n=4): tissue-engineered cornea made up with XDCM and MSCs. The ocular surface recovery procedure was observed while corneal transparency, neovascularization and epithelium defection were measured and compared. In vivo on focal exam was performed 3mo postoperatively. RESULTS: Rabbit MSCs were isolated and identified. Flow cytometry demonstrated isolated cells were CD90 positive and CD34, CD45 negative. Osteogenic and adipogenic induction verified their multipotent abilities. MSC-XDCM grafts were constructed and observed. In vivo transplantation showed the neovascularization in XDCM-MSC group was much less than that in XDCM group postoperatively. Post-transplant 3-month confocal test showed less nerve regeneration and bigger cell-absent area in XDCM-MSC group. CONCLUSION: This study present a novel corneal tissue-engineered graft that could reduce post-operatively neovascularization and remain transparency, meanwhile shows that co-transplantation of MSCs may help increase corneal transplantation successful rate and enlarge the source range of corneal substitute to overcome cornea donor shortage.

[Studies on vision mediated behavioral changes of rat with photic injury].

OBJECTIVE: To evaluate the relationship of visual function and photoreceptor cell loss, and to establish a visual function assessment system based on the observation of optokinetic behavior in rat with photic injury. METHODS: SD rats were exposed to (950 +/- 50) lux green light for 3 hours, 12 hours and 24 hours respectively after 24-hour dark adaptation. Then 24-hour dark recovery was followed by 48-hour observation before the eyes were enucleated. Frozen sections were obtained. Slides were stained by HE and rhodopsin immunofluorescent stainings. Vision mediated disturbance of consciousness and pre-pulse response were used to assess the visual function. Optokinetic behavior test was conducted 2 days before and after photic injury. Average velocity of motion were analyzed. RESULTS: Vision mediated disturbance of consciousness response are gradually weakened; while pre-pulse response is reinforced as the photic injury time increases. The relationship of optokinetic behavior and rat visual function is statistically significant. Optokinetic behavior test shows the average velocity of motion gradually decreases as the injury is aggravated. CONCLUSIONS: Longer light exposure time leads to increased photoreceptor injury, which in turn, causes decrease of visual function in SD rat. Optokinetic behavior test, represented by average velocity of motion, is correlated with rat visual function. Thus, optokinetic behavior test can be used to assess the visual function of SD rat quantitatively.

[Differentiation of human embryonic retinal cells in vitro].

OBJECTIVE: To study the conditions to induce differentiation of human embryonic retinal cells (HRCs) in vitro. METHODS: HRCs were isolated from neural retinas of 16th-20th week of gestation embryo and cultured in serum-free media. Retinal cell differentiation was induced by serum-containing media and by the mouse retinal pigment epithelium (RPE) eye cup whick mimic the retinal environment in vivo. The expression of Nestin and several differentiated retinal cell markers was investigated by immunostaining. Real time RT-PCR analysis was used to evaluate the mRNA level of nestin gene in HRCs and differentiated retinal cells. RESULTS: HRCs cultured in serum-containing medium can differentiate into glial cell (GFAP positive), ganglion cell (Thy1 positive) and bipolar cell (PKCalpha positive). HRCs cultured in mouse RPE eye cup can also express photoreceptor marker rhodopsin and amacrine marker syntaxin. Nestin downregulate significantly in differentiated HRCs. CONCLUSION: RPE appeares to play an important role in the differentiation of retinal photoreceptors and amacrine cells in vitro.