Treatment of upper and lower lacrimal punctal occlusion using retrograde canaliculotomy and punctoplasty.

This is a retrospective, noncomparative analysis of a case series to explore the safety and effectiveness of retrograde canaliculotomy and punctoplasty for treating epiphora due to upper and lower lacrimal punctal occlusion. During the procedure, the horizontal portion of the normal lower canaliculus was identified; the corresponding punctum was reconstructed via retrograde canaliculotomy and punctoplasty. Intubation was performed to prevent postoperative reocclusion. Patients were followed up for 12 to 24mo. A total of 16 patients with unilateral upper and lower lacrimal punctal occlusion were included. Satisfactory outcomes were achieved: all 16 patients exhibited improvement of epiphora; 31 rebuilt punctal openings and canaliculi achieved recanalization. Only one upper punctal opening could not be reconstructed because the corresponding canaliculus exhibited severe injury. No significant complications occurred as a result of the treatments. Retrograde canaliculotomy and punctoplasty appears to effective, safe, and minimally invasive for treatment of upper and lower punctal occlusion.

High glucose levels increase the expression of neurotrophic factors associated with p-p42/p44 MAPK in Schwann cells in vitro.

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus. One contributing factor to DPN is altered neurotrophism due to changes in the synthesis and expression of neurotrophins. Schwann cells (SCs) are the myelin-forming cells of the peripheral nervous system that promote nerve regeneration through the expression and secretion of neurotrophic factors (NTFs). Therefore, in this study, using SCs cultured in the presence of high levels of glucose for 24 h, with and without the p42/p44 mitogen-activated protein kinase (MAPK) inhibitor, PD98059, we investigated the effect of high glucose levels on SCs over a short period of time. The cultured cells were evaluated using 3(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst staining, immunocytochemistry, reverse transcriptase-polymerase chain reaction and western blot analysis. High glucose levels did not promote morphological abnormalities or decrease the viability of SCs. However, high glucose levels enhanced the expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and induced the activation of p42/p44 MAPK in cultured SCs in a dose-dependent manner. Additionally, the phosphorylation of p42/p44 MAPK may be associated with the expression of NTFs by SCs exposed to high glucose conditions; the excessive activation of p42/p44 MAPK inhibited the expression of NTFs. These observations demonstrate that exposure to high glucose levels lead to acutely elevated levels of NGF and BDNF in SCs over a short period of time, which may be involved in the p42/p44 MAPK pathway.

[Three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction].

OBJECTIVE: To evaluate the outcomes of the clinical application of three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction. METHODS: Thirteen patients (13 eyes) manifested with complex orbital fractures (including orbital-zygomatic-maxillary bone fracture in 6 patients, nasal-orbital-ethmoid bone fracture in 5 patients and complex multiple periorbital bone fracture in other 2 patients) underwent the reconstructive surgery by using three-dimensionally preformed titanium mesh plates. Eight cases underwent high density porous polyethylene implantation simultaneously. Evaluation of enophthalmos, eyeball movement, and orbit CT scan were taken pre- and post-operatively. RESULTS: The average enophthalmos was (3.9 ± 1.7) mm and the position of the affected eyeball was (3.1 ± 2.6) mm bellow the contralateral side preoperatively. Twelve patients suffered from eyeball movement restriction, including grade I in 4 cases, grade II in 7 cases and grade III in 2 cases. During the 3 to 6 months post operative follow-up, enophthalmos was completely corrected in 10 patients while the other 3 patients had residual 1.0 mm enophthalmos. The affected eyeballs were repositioned in 8 cases and 3 cases had residual 1 mm lower position and 2 cases with a 1 mm higher positioned eyeball. Eye movement was not restricted in 8 patients, whereas 3 patients had grade I movement restriction and 2 patients had grade II movement restriction. There were no rejection, infection and other complications during follow-up. CONCLUSIONS: Three-dimensionally preformed titanium mesh plates can be used to reconstruct posttraumatic complex orbital bone fractures in order to improve the orbital volume and to correct enophthalmos effectively.

[Pharmacologic vitreolysis in diabetic rats].

OBJECTIVE: To evaluate the efficacy and safety of plasmin or hyaluronidase in the inducing of posterior vitreous detachment in diabetic rats. METHODS: Forty SD rats were induced diabetes by Streptozotocin (STZ). Four weeks later, these rats were randomized into 4 groups: rats in group A received 5 U hyaluronidase intravitreal injection in right eyes; rats in group B received 0.5 U plasmin intravitreal injection in right eyes; rats in group C received 0.5 U plasmin +5 U hyaluronidase intravitreal injection in right eyes; rats in group D received BSS (balance salt solution) 2 microl intravitreal injection in right eyes. Clinical examination were performed at 1, 3, 7 days after injection. After 1 week, scanning electron microscope (SEM) was performed to judge whether the PVD was induced. ERG and histology were examined to evaluate the toxicity after the intravitreal injection of these two drugs. RESULTS: No PVD was found in SEM disclosed group A and group D. Forty percent eyes were induced complete PVD in groups B, and one hundred percent eyes were induced complete PVD in group C. ERG and histology showed no toxicity changes in any group. CONCLUSION: Intravitreal injection of 0.5 U plasmin + 5 U hyaluronidase can induce complete PVD without obvious toxicity in diabetic rats. Solo usage of plasmin or hyaluronidase can not induce complete PVD.

[Repairing rabbit orbital defects with human BMP-2 gene modified bone marrow stromal cells and coral].

OBJECTIVE: To investigate the efficacy of tissue-engineered bone (human BMP-2 genetic modified BMSC combined with coral) in healing the segmental orbital defect in rabbits. METHODS: Rabbit BMSC were isolated and cultured in vitro, and cells of passage 2 were infected with adenovirus-mediated transfection of human BMP-2 gene (150 pfu/cell). After infection, the expression of BMP-2 was determined by RT-PCR and Western blot analysis, and cell proliferation and osteogenic differentiation were observed by flow cytometry, ALP and Alizarin red staining. A 12 mm bone defect in the infraorbital rim was induced by surgery in both orbits of 24 New Zealand white rabbits. The defects were repaired with modified tissue-engineered bone constructed with coral plus BMP-2 transfected BMSC (Group A, n = 12), constructed by coral plus non-transfected BMSC (Group B, n = 12) and grafts of coral alone (Group C, n = 12), with untreated group (Group D, n = 12) served as control. The osteogenesis of bone defect was monitored by gross observation, micro-CT measurement, histological and histomorphologic analysis at 4, 8, and 16 weeks after the implantation. RESULTS: After transfection, the BMP-2 expression was confirmed by RT-PCR and western blot, and the osteogenesis activity of BMSC could be obviously enhanced. The 12 mm segmental defect of rabbit orbit couldn't heal alone. Gross observation and micro-CT demonstrated well the bony-union in experimental group, with higher bone mineral density and more bone volume than other control groups (F = ll.46, F = 7180.97; P < 0.05). CONCLUSION: This study demonstrated that the rabbit orbital defect could be successfully repaired by tissue-engineered bone constructed with human BMP-2 gene modified BMSC and coral.

Pharmacokinetic and toxicity study of intravitreal erythropoietin in rabbits.

AIM: To study the pharmacokinetics and toxicity of intravitreal erythropoietin (EPO) for potential clinical use. METHODS: For toxicity study, 4 groups (60 rabbits) with intravitreal injection (IVit) of EPO were studied (10 U, 100 U, or 1,000 U) per eye for single injection and 0.6 U/eye (the designed therapeutic level in rabbits) for monthly injections (6X). Eye examination, flash electroretinogram (ERG), and fluorescein angiography (FA) were carried out before and after injection. The rabbits were killed for histological study at different intervals. For the pharmacokinetic study, after IVit of 5 U EPO into left eyes, 44 rabbits were killed at different intervals, and the EPO levels in vitreous, aqueous, retina and serum were analyzed by enzyme-linked immunosorbent assay. RESULTS: At all of the time points examined, the eyes were within normal limits. No significant ERG or FA change was observed. The histology of retina remained unchanged. The pharmacokinetic profile of EPO in ocular compartments was summarized as follows. The half-life times of EPO in vitreous, aqueous and serum were 2.84, 3.24 and 2.12 d, respectively; and Cmax were 4615.75, 294.31 and 1.60 U/L, respectively. EPO concentrations in the retina of the injected eye peaked at 1.36 U/g protein at 6 h following injection, with the half-life observed to be 3.42 d. CONCLUSIONS: IVit of EPO in a wide range is well tolerated and safe for rabbit eyes. At doses up to 10-fold higher than therapeutic levels, EPO has a pharmacokinetic profile with faster clearance, which is favorable for episodic IVit.