The effects of simultaneous operation on dissociated vertical deviation with horizontal and torsional strabismus.

AIM: To investigate the therapeutic effects of simultaneous horizontal and vertical operations on dissociated vertical deviation (DVD) associated with other deviations. METHODS: Forty-five cases of DVD with horizontal and torsional strabismus underwent combined operation were collected retrospectively. All clinical records were analyzed. All patients were followed up for 6 to 24mo. Wilcoxon signed-ranks test was performed to evaluate the changes of vertical and horizontal deviation. χ 2 test was used to evaluate the changes of binocular visual function. RESULTS: Forty-five cases included 36 patients with intermittent exotropia and binocular inferior oblique overaction (IOOA), 5 patients with concomitant esotropia and binocular IOOA, 4 patients with intermittent exotropia and monocular superior oblique palsy. The superior rectus recession (SRR) combined with horizontal rectus recession and the myectomy of inferior oblique or anterior transposition were operated simultaneously to correct all types of strabismus. There were 43 cases who achieved normal eye position in vertical direction, while 2 cases were with undercorrection of 5Δ to 6Δ. In patients with horizontal strabismus, 2 cases of exotropia were with overcorrection of 6Δ to 8Δ, 1 case of esotropia was with undercorrection of 6Δ, and 1 case of monocular superior oblique palsy with compensatory head posture was not significantly improved. The binocular visual function of most patients recovered after operation. The difference of the binocular visual function and eye position were significant compared with that before operation (P<0.05). CONCLUSION: The simultaneous operation on DVD with horizontal and torsional strabismus is successful.

[Palisade endings of extraocular muscles in eyes with congenital nystagmus].

OBJECTIVE: To evaluate the morphology, distribution and function of palisade endings (PE) in human extraocular muscles (EOM), and observe the alterations in eyes with congenital nystagmus (CN). The etiology and pathogenesis of CN were also investigated. METHODS: It was a experimental study. The distal myotendinous junctions of the EOM were obtained during operation for CN (CN group) and concomitant strabismus (control group). The samples from patients with similar age and same extraction sites in the two groups were compared. The muscles cut during operation were immediately put into 4% glutaraldehyde fixative solution. And 1-2 transverse bands of tissue were cut every 1 mm from tendon insertion for specimens processing. The ultrastructure of EOM and PE in the two groups was observed by transmission electron microscopy. The distal parts of EOM cut during operation were put into 4% paraformaldehyde promptly. Myotendinous junction region whole mounts were labeled with antibodies against choline acetyltransferase (ChAT). Muscle fibers were counterstained with phalloidin. And longitudinal and transverse cryostat serial sections were cut at 25 µm and analyzed by confocal laser scanning microscopy. The ChAT expression, morphology and distribution of PE were observed. The same fragment of myotendinous junction in the two groups was selected. After the total protein was extracted, ChAT was detected by western blot. The expression level of ChAT was analyzed. RESULTS: Compared with the controls, the ultrastructure in the CN group had considerable variations. The axon of PE was swelled and deformed partly. The electron density was increased and presented as addicted to osmic acid. In the muscle cells, mitochondria was swelled, and sarcoplasmic reticulum was dilated. All PE exhibited ChAT immunoreactivity in human EOM. In the longitudinal section, nerve fibers extended from the muscle into the tendon, looped back and divided into several terminal arborizations (palisade endings) around the muscle fiber tip. The PE of medial rectus were richest at the location 3 - 4 mm from tendon insertion. In the cross section, the amount of PE in the CN group was higher than the control group (t = -5.613, P < 0.05). The expression level of ChAT in the CN group was higher than the control group (t = -3.730, P < 0.05). CONCLUSIONS: Palisade endings in myotendinous junction of human EOM are cholinergic nerves, which might innervate the contraction of EOM. Significant changes of palisade endings in the EOM of the CN subjects may affect eye movement.

Lymphocyte infiltration and activation in iris-ciliary body and anterior chamber of mice in corneal allograft rejection.

AIM: To investigate the infiltration and activation of lymphocyte in iris-ciliary body and anterior chamber after allogenic penetrating keratoplasty (PK), for further revealing the role of iris-ciliary body in corneal allograft immune rejection. METHODS: In the mice models of PK, BALB/C mice received orthotopic isografts (n =35) or C57BL/6 donor allografts (n =25). Grafts were examined daily for 3 weeks by slit-lamp microscopy and scored for opacity. The infiltration of CD4(+) T lymphocyte in iris-ciliary body and anterior chamber was examined by immunohistology and the mRNA of CD80 and CD86 in both cornea graft and iris-ciliary body by RT-PCR was analyzed in allograft recipient at days 3, 6, 10 and the day when graft rejection occurred. Isograft recipients were examined as control at the corresponding time points. Transmission electron microscope was used to study the ultrastructure, especially cell infiltration, of iris-cilary body and corneal graft at day 3, 7 and the day when rejection occurred after allogenic PK. RESULTS: Rejection was observed in all the allograft recipients followed more than 10 days, at a median time of 15 days (range 12-18 days), but not in any of isografts. CD4(+) T cells were first detected at day 6 after transplantation in limbus and Ciliary body, and then in the stroma of recipient, iris, anterior chamber and corneal allograft with an increased number until graft rejection occurred. CD80 and CD86 mRNA were detected under RT-PCR examination in both graft and iris-ciliary body of allograft recipient, but not in any of isograft recipient. Three days after operation, lymphocytes and monocytes macrophages were visible in iris blood vessels and the anterior chamber, and vascular endothelial cell proliferation and activation were significant under transmission electron microscopy examination. At day 7, corneal endothelial cells became thinner. Lymphocytes and mononuclear macrophages were found with great number in the anterior chamber and adhered to the corneal endothelium. Blood vessels in iris increased and were filled with lymphocytes. And lymphocytes were detected to migrate through endothelial cell gap out of vessels. When allograft rejection occurred, macrophages attached to endothelial cells with large number of lymphocytes and macrophages infiltrating in iris. CONCLUSION: Lymphocyte infiltration and activation occurred in iris-ciliary body after allogenic PK, and the lymphocytes could migrate from iris blood vessel to the anterior chamber, which might play an important role in corneal allograft immune rejection.

[The preliminary study of establishing animal model of chronic allograft dysfunction after penetrating keratoplasty].

OBJECTIVE: To establish a murine model of chronic corneal allograft dysfunction (CCAD) after penetrating keratoplasty (PK). METHODS: Experimental study. PK model in mice: Semiallogeneic CB6F1 mice were obtained from matching of female BALB/c and male C57BL/6 mice. C57BL/6 (allogeneic group), CB6F1 (semiallogeneic group) and BALB/c (syngeneic group) grafts were transplanted orthotopically to BALB/c recipients respectively, and BALB/c mice as a control group. The follow-up time was more than 100 d, and graft survival time and corneal opacity score were monitored, and corneal endothelium were examined by alizarin red and PI/Hoechst stain. CD4(+) and CD8(+) T lymphocytes were examined by immunohistochemistry. Ultrastructure changes of the grafts were examined by electronmicroscopy. Log-rank test were used to compare survival curves. RESULTS: (1) Graft examination:Median graft survival times were 17.0 d, 85.5 d, > 100 d and > 100 d in allogeneic, semiallogeneic, syngeneic and control groups, respectively (F = 344.0, P < 0.01). (2) Immunohistochemistry examination: There were large amount of CD4(+) and CD8(+) T lymphocyte infiltration in allografts in allogeneic group at 3 weeks after PK; Few CD4(+) and CD8(+) T lymphocytes were observed in semiallogeneic group and syngeneic groups at 3 weeks after PK; CD4(+) and CD8(+) T lymphocyte infiltration was not observed in the control group. (3) Endothelium examination: The endothelium can not be counted because the blurred image after the alizarin red combined PI/Hoechst stain and apoptotic and necrotic cells can be seen in allogeneic group; the endothelial cell density decreased and few apoptosis can be detected in semiallogeneic and syngeneic groups; no apoptotic and necrotic endothelial cells were found in the control group. (4) Ultrastructural characteristic changes mainly include fibrosis formation and endothelium atrophy and degeneration in failed grafts in all transplanted groups by electron microscopy examination. Inflammation cells can only be found in the allogeneic group. CONCLUSIONS: Semiallogeneic and syngeneic transplantation groups present the changes similar to CCAD in clinical study, and both can be regarded as the model that permits molecular evaluation of CCAD.

Minimally invasive botulinum toxin type A injection from the ocular surface to extraocular muscles.

AIM: To investigate a new, safe and effective injection method for strabismus patients. Botulinum toxin type A (BTXA) was injected by pulling the extraocular muscles with a minimally-invasive technique into the ocular surface, and it was ensured that the extraocular muscles was maintained in the suspended state. METHODS: A total of 32 patients with different types of strabismus were treated at our institution from February to October 2010. A small conjunctival incision (≤2mm) was made under a microscope. The extraocular muscles were pulled out with a hook to ensure an elevated position compared with the wall of eyeball. The muscle fiber was clearly seen through the conjunctiva and BTXA was injected at a small angle under the microscope. The deviation angles before and after the injection were recorded. All patients were followed up at 5 and 30 days after the operation. Recovery was defined as abolition of diplopia in straight-ahead gaze and anteroinferior gaze and the symptoms of giddiness disappeared thoroughly. Eyeball position was essentially normal. Improvement was defined as basic disappearance of diplopia in straight-ahead gaze and anteroinferior gaze; restriction of action of paralytic muscle improved. If most of the symptoms and signs still existed and disturbed normal work and life, the treatment was determined to be invalid. The injection dose for patients of 5 to 10 prism diopter (PD), 11 to 20PD, and ≥21PD was 1u, 3u and 4u to 5u, respectively. RESULTS: Of the 32 treated patients, 11(34.4%) were cured, and 18(56.3%) were improved at 5 days after the operation; 12(40%) were cured, and 15(46.9%) were improved at 30 days. Five patients (15.6%) who had unsatisfactory response after BTXA injection at 30 days received repeated injections or underwent strabismus surgery. Ptosis was present in 2.5% of the injected eyes. No retrobulbar hemorrhage or ocular perforation was found in any eye. CONCLUSION: It is safe and efficient to inject BTXA by pulling extraocular muscles with a minimally-invasive technique under the microscope to make the muscles separated from the wall of eyeball.

[Experimental study of low molecular weight heparin drug delivery system for prevention of posterior capsular opacification in rabbit eyes].

OBJECTIVE: To investigate the safety and efficacy of low-molecular-weight heparin drug delivery system (LMWH DDS) for prevention of posterior capsular opacification (PCO) in rabbit eyes. METHODS: (1) To prepare the LMWH DDS by freeze-drying way with Polylactic-co-glycolic acid (PLGA) as the carrier, and evaluate its release properties in vitro. (2) Fifty New Zealand albino rabbits (50 eyes) undergoing phacoemulsification were equally divided into five groups: receiving normal saline eye drops (group A), 3 different dose (1 mg, 0.5 mg and 0.25 mg) of LMWH DDS respectively implanted into the posterior chamber (group B, C and D), and a carrier DDS implanted into the posterior chamber (group E). All the 50 eyes were examined by slit-lamp microscopy. The low-molecular-weight heparin levels in aqueous humor were measured, and the wet posterior capsules were weighed. RESULTS: The LMWH DDS prepared with a freeze-dried way has high encapsulation efficiency, and the equation of 49-day release curve fitting in vitro were were similar to zero order. The fibrin exudation in group B, C and D were lower than in Group A and E during the first postoperative day. There were 10, 2, 3, 9 and 10 eyes that developing PCO in the group A, B, C, D and E, respectively. The mean wet-weight of the posterior capsule were (114.59 +/- 14.58) mg, (24.14 +/- 6.08) mg, (39.23 +/- 17.13) mg, (99.35 +/- 29.37) mg, (115.29 +/- 19.87) mg respectively in 5 trial groups. There were stable and high concentration of low molecular weight heparin in aqueous of group B and C during the 4 weeks (> 20 mg/L), while a instable and lower concentrations in group D. The result of optical microscopy and electron microscopy examination indicated that fibroblast proliferation was quite active in groups A, D and E, but inactive in group B and C. Neither infiltration of inflammatory cells at the cornea, iris, trabecular meshwork and ciliary body nor retinal degeneration or necrosis was found in any group at 12 weeks. There was no intraocular bleeding in all the five groups in the following 12 weeks. CONCLUSIONS: The LMWH DDS prepared by freeze-drying way with PLGA as the carrier has good slow-release and biological tolerance. Implantation of LMWH DDS into the posterior chamber of experimental animals can significantly reduce postoperative fibrin exudation, and can safe and effective prevent the occurrence of PCO, and also there were some dose-effect relationship.

[Ultrastructure changes in chronic corneal allograft dysfunction after penetrating keratoplasty].

OBJECTIVE: To study the ultrastructure changes of failed graft caused by chronic corneal allograft dysfunction (CCAD) after penetrating keratoplasty (PK), and to reveal the possible mechanism of these changes. METHODS: In CCAD group, corneas of 12 patients fulfilling the diagnostic criteria for CCAD who underwent repeated PK operation were studied. The average interval of these 12 patients between two PK operations was 69 months. All but two patients suffered at least once acute rejection episode during follow-up period. The mean time that the first acute immune rejection occurred was 39.4 months. Five healthy donor corneas were also studied as the control group. Both failed corneal grafts and healthy corneas were examined by light and electron microscopy. RESULTS: Compared with normal cornea, the cornea epithelium of CCAD became thinner, the quantity of microvillus apparently reduced, number of dark cells was increased, fibers of cornea stroma arranged disorderly, and there was no obvious invasion of inflammation cell into the stroma. The thickness of Descemet's membrane was uneven, abnormal lacuna and red cell could be seen between the Descemet's membrane and the endothelium. The number of cornea endothelial cells was decreased, cells became thinner, the organelle was reduced obviously, notch appeared in the cell nucleus, chromatin was condensed and inflammatory cells was adherent to the endothelium. CONCLUSIONS: The special ultrastructure changes of CCAD grafts consist of atrophic changes of the endothelium and fibrosis without inflammatory cells. Chronic subclinical alloantigen specific and non-alloantigen specific factors are both contributed to the CCAD process. Acute immune rejection perhaps induces and accelerates the occurrence and development of CCAD.