Volume 39 ·  Issue 09 ·  2003

To evaluate the efficacy of using porous polyethylene sheets as orbital implants in late surgical intervention for orbital blowout fractures (BOF).

CT scan and 3-D reconstruction were used for the diagnosis of BOF. Hertel exophthalmometer was used for the measurement of enophthalmos. Lancaster test was used for examination of diplopia. Porous polyethylene sheets were used for the repair of orbital defects and the correction of orbital volume expansion on 42 patients with enophthalmos of BOF. The time of surgeries perform was from one month to two years post-injury, and the average duration was six months. The mean follow up time was 7 months.

Enophthalmos of BOF was corrected in 32 of 42 cases and improved in the rest 10 patients. Twenty-five of 42 patients had diplopia preoperatively. The diplopia disappeared in 5 patients and improved in 10 patients postoperatively. The rest 10 patients had no significant change. Preoperatively 19 of 42 patients had restriction of ductions. Postoperatively, the limited ductions were recovered in 7 cases, improved in 4 cases and no change in 8 cases. No patient had infection and dislocation of implants.

Porous polyethylene sheets are safe and effective when used for orbital reconstruction.

To evaluate the roles of diagnosing intraocular foreign body (IOFB) and their complications with CT, B-scan, X-ray film, MRI and UBM.

Retrospective study of 103 clinic inpatient cases.

CT showing rate was 100% (103/103), CT scan could identify positions of high density IOFB, and define metal or non-metal. But for the size and shape of metal IOFB, the low density IOFB and complications of IOFB, the showing rate was lower. The total showing rate of B-scan for IOFB was 93.2%, but the discovering rates were only 68.7% and 66.7% for anterior segment and retrobulbar IOFB, but the showing rate was high to the vitreous opacity and retinal detachment caused by IOFB. X-ray film can clearly show the size and shape of the metal IOFB. MRI can show the low density IOFB and orbital FB. UBM has a good image for the low density and small IOFB at the anterior segment of globe.

In the diagnosis and localization of IOFB, CT can well identify the IOFBs and show their relation with globe wall. B-scan can show even more clearly the relation between IOFB and globe wall, and complications of IOFB. X-ray film can distinctly reveal the size and shape of metal IOFB. MRI is good at showing low density, non-magnetic IOFB. UBM is only used in small or low density IOFB at the anterior segment of globe. The combination of multiple image-related methods can provide the required information on diagnosis and surgery design of IOFB.

To investigate surgical correction of orbital and periorbital deformities in orbital and periorbital region.

In order to reconstruct orbital deformities such as orbital hypertelorism, orbital dystopia, radiated orbit, and secondary deformities of traumatic orbit, lamella osteotomies of either orbital rim and wall or complex osteotomies of both adjacent orbital rims and walls using bicoronal or galea aponeurotica incision were employed. The reconstructed complex was placed in new position with rigid fixation. Clinic evaluations were performed before and after operative osteotomies such as cephalometry (measurement of interorbital distance, IOD), exophthalmos (measurement with Hetel exophthalmometer), the angle (between orbital horizontal level and bilateral tragus linkage, A-OT), and the linear distance (between lateral canthus and tragus, LC-T), then the gap differences were analyzed before and after operation.

Nearly normal orbital volumes, better contour of orbit and midface, improved eyelids and visions were achieved in total 44 cases. There were 5 cases of supraorbital osteotomy (intracranial routine), 8 cases of medial orbital osteotomy, 3 cases of inferior orbital osteotomy, and 28 cases of both lateral and inferior orbital osteotomy in these series. No complications were found after surgery. The orbital and midfacial appearances were improved significantly.

Lamella and complex osteotomies of orbital rim and wall are proved to be safe and effective to correct most deformities of orbital and periorbital region and various kinds of orbital malposition.

The aim was to identify whether interleukin-1 receptor antagonist (IL-1ra) inhibits interleukin-1α (IL-1α)-induced intercellular adhesion molecule-1 (ICAM-1) expression on cultured orbital fibroblasts, and adhesion of peripheral blood mononuclear cells (PBMC) to orbital fibroblasts, and to investigate the clinical application potential of IL-1ra in the treatment of Graves' ophthalmopathy (GO).

Cultured orbital fibroblasts from patients with GO and controls were challenged with IL-1α or/and IL-1ra. Immunocytochemical staining was used to examine the changes of ICAM-1 in response to IL-1ra treatment; fluorescent photomicroscope was used to measure the adhesion between the labeled PBMC and orbital fibroblasts. Neutralizing antibody against ICAM-1 was used to demonstrate the role of ICAM-1 in the IL-1α-induced adhesion.

IL-1ra inhibits IL-1α-induced ICAM-1 expression in cultured orbital fibroblasts both from GO patients and controls; IL-1ra inhibits IL-1α-induced adhesion of PBMC to orbital fibroblasts in a concentration and time dependent manner. Moreover, a monoclonal anti-human ICAM-1 antibody produced a concentration dependent inhibition of the IL-1α-induced adhesion of PBMC to the fibroblasts.

IL-1ra inhibits IL-1α-induced ICAM-1 expression in cultured orbital fibroblasts and the adhesion of PBMC to fibroblasts. IL-1α-induced ICAM-1 expression may play an important role in the adhesion process. IL-1ra may be useful in the prevention or treatment of GO.

To study the therapeutic effects of Nd: YAG laser on obstructive diseases of the lacrimal passage.

693 eyes in 603 cases with obstructive diseases of lacrmal passage, including obstruction of lacrimal puncta (23 eyes), lacrimal duct (192 eyes), nasolacrimal duct (227 eyes), chronic dacryocystitis (231 eyes), and traumatic laceration of lacrimal canaliculus (20 eyes), were treated by lacrimal plastic operation with Nd: YAG laster and the therapeutic effects were compared among the groups.

The cure rates and effective rates of the five diseases were 86.9% and 95.7%, 89.1% and 93.8%, 93.0% and 96.0%, 78.4% and 82:7%, 40.0% and 65.0%, respectively. By Ridit analysis, R ± S_R values for each group were 0.921 ± 0.023, 0.914 ± 0.009, 0.927 ± 0.007, 0.856 ± 0.013, 0.749 ± 0.055.

The therapeutic effect on chronic dacryocystitis is less than those of obstruction of nasolacrimal duct and lacrimal duct (P<0.05). The therapeutic effect on traumatic laceration of lacrimal canaliculus is less than that of the other four groups (P< 0.05). Therefore, it should be restricted on indication for the cases of chronic dacryocystitis and traumatic laceration of lacrimal canaliculus.

A prospective study was performed to analyze the visual outcome and factors related to the visual outcome in cataract patients with extreme myopia, in order to provide a principle for intraocular lens (IOL) diopter chosen.

43 cases were included in the present series (myopia over 10.00 D, axial length over 27.00 mm, with clear cornea and slight or moderate opacity of the lens). Distance and near visual acuity (NVA), best corrected visual acuity and the fundus were examined before and after the phacoemulsification and implantation of IOL. χ² test and stepwise regression analysis were used to identify the predictive factors.

(1) Distance visual acuity, NVA and best corrected visual acuity were markedly improved in most cases. (2) NVA and fundus pathologic changes were two important factors for predicting post-operative visual acuity. (3) The prognosis was better in cases with NVA better than 20/200, and in cases with axial length below 29.00 mm. (4) Some cases with postoperative NVA worse than 20/80 complained of difficulty in reading.

NVA is an important factor influencing the outcome of vision and is an important parameter for predicating the outcome of vision in cataract patients with extreme myopia. IOL diopter should be determined carefully by preoperative NVA and the patients' demand for near work.

To determine the visual and refractive outcome of photorefractive keratectomy (PRK) in patients with anisometropia after cataract surgery.

We studied a series of 31 eyes of 24 patients who underwent PRK for the correction of anisometropia after cataract surgery. Pre- and post-operative vision, refraction, anisometropia and surgical complications were observed. These patients were followed-up at 12.2 months after laser ablation.

One week following PRK, the uncorrected visual acuity (UCVA) and the best correct visual acuity (BCVA) were improved significantly (P<0.01). Mean spherical equivalent refraction (MSER) was decreased significantly to (1.12 ± 0.55) D after PRK. The MSER was (1.27 ± 0.56) D in myopia eyes and (0.81 ± 0.38) D in hyperopia eyes one week after PRK, the difference between these two groups was statistically significant (P<0.01). Astigmatism was decreased significantly after PRK (P< 0.01), the mean astigmatism was (0.49 ± 0.38) D one week after the operation. Anisometropia was decreased from (3.44 ± 1.07) D to (0.58 ± 0.31) D after PRK, the difference between the pre-operative and post-operative anisometropia was statistically significant (P<0.01). No serious complications occurred during or after the operation.

PRK is a safe, reliable and effective method for correction of anisometropia after cataract surgery.

To examine whether adult human retinal cells can be maintained in vitro over long time periods and to study the effects of brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT-4), epidermal growth factor (EGF), fibroblast growth factor (FGF), and retinoic acid (RA) on growth, proliferation, and apoptosis of the cultured adult human retinal cells.

Adult retinal cells were isolated from donor eyes and cultured. BDNF, NT-4, EGF, FGF, and RA were added individually to the cultures. The cells were identified by morphologic criteria, growth patterns, and immunocytochemical staining. The number of neurons in each group was compared. Expression levels of c-fos, c-jun, Bcl-2, and Bax were examined.

Adult human retinal cells survived for 240 days in vitro. The addition of BDNF and FGF promoted survival of adult retinal neurons, increased the number of cells positive for neuron specific enzyme (NSE), Thy1.1, c-fos, c-jun, and Bcl-2. More c-fos and c-jun positive cells were observed in cell cultures containing medium with RA. However, NT-4 and EGF treatment groups showed no significant difference from control groups in that neuron cell survival was low and fewer cells were positive for NSE, Thy1.1, c-fos, c-jun, and Bcl-2.

BDNF, FGF and RA improve survival of adult human retinal neurons in vitro via a mechanism that may involve c-fos, c-jun, and Bcl-2 expression, However, EGF and NT-4 do not improve surival of the adult human retinal neurons.

To evaluate the general cause of limbal allograft transplantation rejection and the effects of the immunosuppressant FK506.

Limbal deficiency models were established in 48 New Zealand rabbits, which were randomized into three groups of 16 rabbits each. Limbal allograft transplantation was performed one month later. After transplantation, the FK506 group, the CsA group and the untreated group were treated with FK506 eye drops (0.5 g/L), 1% CsA eye drops and physiological saline, respectively. Graft survival and ocular surface were observed clinically for 10 weeks. Impression cytology was performed on the central cornea of the rabbit one month after limbal ablation, 1 day before allograft transplantation, and two and four weeks after transplantation. The expression of CD25 in peripheral T cells was identified dynamically one day before and one and eight weeks after transplantation. The expression of CD25 on the limbal allograft and lymphocyte infiltration was also identified dynamically the fourth, eighth and tenth week after transplantation.

Conjunctivalization of corneal epithelium was found in the limbal deficiency model by impression cytology. Two weeks after limbal allograft transplantation, the central corneal epithelium regained corneal phenotype. Four weeks later, the ocular surface of FK506 group and CsA group continued to express corneal phenotype. Epithelium rejection appeared first in the untreated group (P<0.05), which had the highest level of the lymphocyte infiltration and the expression of CD25 in peripheral blood and allografts after limbal allograft transplantation(P<0.05). Epithelium rejection occurred next with the CsA group. FK506 group epithelium rejection occurred last and had the lowest level of the lymphocyte infiltration and the expression of CD25 in peripheral T cell and limbal allografts.

Topically administered FK506 eye drops early after limbal allograft transplantation can delay allograft rejection by effectively inhibiting the expression of CD25 in peripheral T cells and limbal allografts. Also, FK506 is more effective than CsA.

To investigate the effect of antioxidants N-acetyl-L-cysteine and catalase on H₂O₂-induced apoptosis of lens epithelial cells and the activity of caspase-3.

Rat lenses were incubated in MEM with 2 mmol/L H₂O₂(H₂O₂ groups) or without H₂O₂ (control groups), antioxidants 100 μmol/L N-acetyl-L-cysteine and 900 U/ml catalase were used to block the oxidative injury of lens epithelial cells respectively. Lens opacification and apoptosis of lens epithelial cells were detected using transmission electron microscope and AnnexinV-PI staining after 24 hours incubation. The activity of caspase-3 was analyzed by Western blot at the same time.

The observations revealed that 2 mmol/L H₂O₂ could apparently induce lens opacification and lens epithelial cell apoptosis in vitro, the apoptosis rate increased to (31.20 ± 3.31)% after 24 hours incubation, which is also the time caspase-3 was activated. Treatment with N-acetyl-L-cysteine and catalase could inhibit lens opacification, apoptosis and caspase-3 activation induced by H₂O₂. The apoptosis rate decreased to (20.90 ± 3.16)% and (15.02 ± 2.41)% respectively (P<0.01).

These data indicate that antioxidants N-acetyl-L-cysteine and catalase, possibly through regulation of the activity of caspase-3, can prevent lens opacification and apoptosis of lens epithelial cells.