Abstract:

Abstract:Diabetic retinopathy (DR) is a sight-threatening chronic complication of diabetes mellitus and is the leading cause of acquired blindness in adults. Long-term exposure to the hyperglycemia of diabetes patients leads to the development of DR. Several studies have provided evidence that good diabetes control is important to prevent DR. However, emerging evidence suggests that genes are a significant contributor to an individual's risk of retinopathy. This evidence is from evalu- ations of familial aggregation and different incidence of DR in racial and ethnic groups. Some groups of patients develop DR despite good control and some escape retinopathy despite poor control. This suggests that the genes are involved in the susceptibility to DR. Genes suggested as having a role include those encoding aldose reductase, nitric oxide synthase, receptor for advanced glycation end products, angiotensin converting enzyme, vascular endothelial growth factors and pigment epithelium-derived factor. An understanding of the role of susceptibility genes will ultimately allow the development of novel therapeutic strategies. This article reviews the role of genetic factors in the etiology and progression of DR.

Abstract:AIM: The effects of ZX-5, as nitric oxide (NO) donor, on ocular blood flow has been investigated using colored microsphere technique in previous study. The relationship between the production of NO by ZX-5 and ocular blood flow has been evaluated. ZX-5 has been shown to have strong positive effect on increasing choroidal blood flow. However, the effect of ZX-5 on retinal function recovery, the effects of its optical isomers, (R, R)-ZX-5 and (S, S)-ZX-5, on choroidal blood flow and retinal function recovery have not been studied and merit investigation. · METHODS: Colored microsphere technique was used for in vivo experiments to determine choroidal blood flow of ocular hypertension (40mmHg) in rabbit eyes. Electroretinography was used to measure the b-wave recovery as an indication of retinal function recovery. · RESULTS: (R, R)-ZX-5 increased choroidal blood flow at 10g/L, 50μL instillation into eyes at all time points (P <0.05). (S, S)-ZX-5 was not effective in increasing choroidal blood flow. ZX-5 and (R, R)-ZX-5 showed significant effects in retinal function recovery after ischemia of the retina at all time points (P <0.05); whereas (S, S)-ZX-5 did not show significant effect on recovery of b-wave after ischemia at most time points except at 120 and 240 minutes. · CONCLUSION: ZX-5 and (R, R)-ZX-5 have high potency in increasing the choroidal blood flow and improving the retinal function recovery. It is hoped that they could be used for the prevention/treatment of ocular blood flow related eye diseases.

Abstract:AIM: To investigate the expression and the possible implication of CD40/CD40L costimulatory molecules in erythema nodosum of patients with BehÇet's disease. METHODS: Sampling was done from erythema nodosum of 5 patients with BehÇet's disease and normal skin of 2 healthy individuals. Immunohistochemical staining was performed to examine the expression of CD4, CD8, CD19, CD68, HLA-DR, CD40 and CD40L molecules in the obtained tissues.
RESULTS: Approximately 90% of epidermic cells in erythema nodosum expressed CD40 moleculeIn the dermis and subcutaneous tissue, a significantly increased number of CD4⁺Tcells, CD8⁺Tcells, CD19⁺cells, CD68⁺cells, HLA-DR⁺cells, CD40L⁺cells, and CD40+cells were observed in the erythema nodosum as compared with that in normal skin. Double staining showed that CD40L molecules were expressed on 45% of CD4⁺ T cells. CD40 molecules were expressed on 100% CD68⁺ cells and 59.2% of HLA-DR⁺cells respectively. CONCLUSION: A number of CD40/CD40L costimulatory molecules are upregulated in the erythema nodosum of patients with BehÇet's disease.

Abstract:AIM: To construct and analyze eukaryotic expression plasmid inserted by Cx50 with V64G mutation through bioinformatics software. METHODS: The full coding domain sequence of Cx50 with V64G mutation was acquired from the blood of patients with cataract and was cloned into pcDNA3.1/Amp (+).The constructed plasmid was identified with PCR , enzyme digestion and sequencing. The analysis of Cx50 with V64G mutation was performed with bioinformatics software. RESULTS: Cx50 with V64G mutation was successfully amplified and its eukaryotic expression plasmid was constructed. Valine-64 is well conserved in the first extracellular loop of connexin 50 in different species and also in different human α-type gap junctional proteins. CONCLUSION: The successive reconstruction and verification of eukaryotic expression plasmid containing Cx50 with V64G mutation established the foundation for further studying the mechanism of cataract.

Abstract:AIM: To investigate the antioxidant effect of hydralazine under hypoxia-induced damage on retinal pigment epithelial (ARPE-19) cells and the role of reactive oxygen species (ROS) in this effect. ·METHODS: Human retinal pigment epithelial (hRPE) cells were used to investigate the effect of hydralazine on oxidative stress, including tert-butyl hydroxyperoxide (t-BHP), H2O2, sodium azide (NaN3), and hypoxia induced cell damage. Cell viability was determined by MTT assay. RESULTS: When ARPE-19 cells were treated with oxidative stress induced by ROS, hydralazine showed concentration-dependent protection against t-BHP, H2O2 and hypoxia induced cell damage but not NaN3. Nitric oxide (NO) was not involved in this effect. ·CONCLUSION: Hydralazine showed antioxidant potential against oxidative stress induced damage in ARPE-19 cells. These effects might be caused through scavenger of ROS. Thus, hydralazine could be used for the treatment of age-related macular degeneration (AMD).

Abstract:AIM: To detect the gene expression of TGF-β2 in retinas of diabetic rats at different stages, to observe and analyze the effect of TGF-β2 on the retinas of diabetic rats, to explore the role of TGF-β2 in pathogenesis of diabetic retinopathy (DR), and to provide experiment data and experience for further clinic studies. METHODS: Sprague-Dawley (SD) rats were used and retinas were dissected. The total RNA was isolated from which the first strand of cDNA was prepared. Diabetes mellitus was induced by a single intraperitoneal injection of 60mg/kg streptozotocin (STZ) and the rats were held without insulin treatment until sacrifice. Besides, age-matched rats treated with saline were used as controls. Tail vein blood glucose was measured after 2 days and rats were considered hyperglycemic if blood glucose reading >16.7mmol/L. Animals with blood glucose level <16.7mmol/L were excluded from the study. The rats were killed at the 4th, 8th, 12th, 16th, 20th and 24th week respectively after hyperglycemic models were established. The retinas were separated and preserved in liquid nitrogen. The expressions of TGF-β2 gene mRNA were detected by reverse transcription PCR (RT-PCR). RESULTS: The RNA of rat retina was integrative enough to be used to further carry out PCR analysis. Compared with control groups, the expression of TGF-β2 mRNA in retinas of diabetic rats was up-regulated at the 4th week, but there was no statistical difference (P >0.05); it was down-regulated at the 8th week, and there was statistical difference (P<0.05); it was also down-regulated at the 12th week, and there was statistical difference (P<0.05); at the 16th week there was no statistical difference (P >0.05); it was up-regulated at the 20th week, but there was no statistical difference (P>0.05); it continued to be up-regulated at the 24th week, and there was statistical difference(P <0.05). CONCLUSION: Since the expression of TGF-β2 mRNA in retinas of diabetic rats was down-regulated at the 8th week and 12th week statistically, up-regulated at the 24th week statistically, it has obviously shown that TGF-β2 was down- and up-regulated through the period of DR. That is, its changes are diphasic with time. It may confirm that TGF-β2, with the characteristic of diphasic regulation, played an important role in DR. It is necessary to study it furthermore.

Abstract:AIM: To test the expression of erythropoietin (Epo) and its receptor EpoR in normal and neovascularized murine corneas induced by alkali burns, and to investigate whether Epo/EpoR is involved in the process of corneal angiogenesis. METHODS: The expression of Epo/EpoR was tested in normal and neovascularized murine corneas induced by alkali burns through immunohistochemistry of corneal frozen sections. Epo cloning, expression, and purification were carried out. Then Epo protein (6μL, 1μg) and control (6μL of vector control or saline) were injected into the corneal stroma respectively, and the corneas were checked at the 14th day after injection to see whether corneal neovascuarization occurred. RESULTS: Epo/EpoR was expressed in epithelial cells, endothelial cells and stromal cells in normal and neovascularized corneas induced by alkaline burns, and also expressed strongly in neovascularized cornea. They were expressed at the same time in stromal inflammatory cells and new vessels. Corneal neovascularization was induced by Epo intrastromal injection in 5 out of 6 eyes , but no new vessels were observed in all controls (n =6) at day 14 after vector control or saline intrastromal injection in normal corneas. CONCLUSION: This paper first reported the expression of Epo and its receptor in normal and neovascularized cornea. Injection of Epo into the corneal stroma may induce the corneal neovascularization Epo/EpoR is associated with the formation of corneal neovascularization.

Abstract:AIM: To investigate the expression of EMMPRIN, MMP1, MMP9 and TIMP2 in retinoblastoma (RB) and normal retinal tissues and their clinicopathological significance and interrelationship. METHODS: Envision immunohistochemistry stainings of EMMPRIN, MMP1, MMP9 and TIMP2 were performed in 30 enucleated eyeballs with retinoblastoma and 15 specimens of normal retina tissue, which had been routinely imbedded with paraffin. RESULTS: Positive rate of EMMPRIN, MMP1, MMP9 expression was higher in RB tissue than in normal control ( P<0.01), while TIMP2 expression was lower in RB than in normal retinal tissue ( P<0.01). Samples from RB cases of clinical stage I, differentiated type, and life span ≥ 2 years had lower positive rate in expression of EMMPRIN, MMP1, MMP9 than those from RB cases of clinical stage III, undifferentiated type, andP life span<2 years ( P<0.05 or <0.01), while samples from RB cases of differentiated type, optic nerve unaffected, and life span ≥ 2 years had markedly higher positive rate in expression of TIMP2 than those from RB cases of undifferentiated type, optic nerve involved and life span<2 years ( P<0.05 or P<0.01). In RB tissues, EMMPRIN, MMP1, MMP9 expressions were highly consistent ( P<0.05), whereas TIMP2 expression is highly inconsistent with EMMPRIN,MMP1,MMP9 expression levels( P<0.05). CONCLUSION: The expression level of EMMPRIN, MMP1, MMP9 and TIMP2 may be an important marker of RB progression, invasion and prognosis. There exist internally mutual regulation relations among them."

Abstract:AIM: To investigate the effect of PEDF on retinal neovascularization in mice. METHODS: 40 7-day-old C57BL/6J mice was exposed to 750mL/L oxygen for 5 days and then to normal situation to produce the murine model of oxygen-induced retinopathy(OIR). One eye of the mouse was regarded as experimental one and the other served as control. Eyes in experimental group received intravitreal injection of PEDF and eyes in control group received intravitreal injection of PBS at postnatal day 12. All mice were executed at postnatal day 17. The changes of retinal vessels of mice were observed by ADPase histochemical technique. The inhibitory effect of PEDF on retinal neovascularization was evaluated by counting the endotheliocyte nuclei of new vessels which extended from retina to vitreous in the tissue slice of HE staining. RESULTS: Neovascularization was reduced, retinal blood vessels distributed regularly and non-perfusion areas were not found in eyes of experimental group compared with control group. The number of endotheliocyte nuclei of new vessels extending from retina to vitreous was significantly less in the eyes of experimental group (10.18±1.74) than that in control group (38.89±2.98) (P <0.01). Retinal toxicity and inflammatory reactions were not found in tissue slice. CONCLUSION: PEDF inhibits retinal angiogenesis in OIR and the feasibility should be determined for use of PEDF in ocular angiogenesis treatment.

Abstract:AIM: To investigate whether potassium cyanate can inactivate glyceraldehydes 3-phosphate dehydrogenase (GAPDH) and thioltransferase (TTase) in bovine lens. METHODS: Fresh intact bovine lenses were incubated with 100mmol/L potassium cyanate(KCNO) for 7 and 12 days respectively. Then all lens were incubated in 50mmol/L DMEM solution. The proteins in the water-soluble fractions from the normal control and the cyanate-modified lens were extracted. The activity of GAPDH and TTase in the water-soluble fraction after incubation at 37℃ was measured by spectrophotometer. RESULTS: GAPDH activity was significantly lower in the cyanate-modified lens proteins than that of the normal control(P <0.01), and considerably diminished in protein incubated with 100mmol/L potassium cyanate for 12 days. There were statistically significant differences in the activity of TTase between the normal control lenses and the carbamylated lenses incubated for 7 days(P <0.05) and 12 days(P <0.01). However, there was no statistical difference between the samples incubated with 100mmol/L KCNO for 7 and 12 days (P =0.19296). CONCLUSION: This study provides evidence to show carbamylation is able to inactivate GAPDH and TTase in bovine lenses. This may have implications for the susceptibility of lenticular GAPDH and TTase to carbamylation, and also for the research on pathogenesis of cataract.

Abstract:AIM:To determine whether the multifocal visual evoked potential (mfVEP) can be used as a clinical method to assess the patients with optic nerve disease. METHODS:Fifteen patients with optic nerve disease were examined in this study. All patients underwent visual acuity examination, slit-lamp inspection, ophthalmoscopy, Goldmann perimeter, fundus fluorescein angiography, visual field and mfVEP. Although these patients with unilateral optic nerve damage,data from both eyes were included in the analysis. RESULTS:In all patients the visual fields defect was demonstrated on the mfVEPand showed good correspondence in location of the scotoma. However, we also found some slight difference between visual field and mfVEP. In some locations, when the local visual fields were normal, mfVEP showed that its amplitude reduced. In reverse, when the local mfVEPseemed normal, visual field showed abnormity. CONCLUSION:Multifocal visual evoked potential could be used as a clinical diagnosis option in patients with optic nerve disease. Local monocular damage to the optic nerve can be measured by an interocular comparison of the mfVEP

Abstract:AIM: To determine the long-term efficacy of transpupillary thermotherapy (TTT) in the treatment of subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (AMD). METHODS: Fourteen eyes of 14 patients with subfoveal CNV secondary to AMD were treated with diode laser (810nm) TTT. The mean age was 67.1 years. Complete ophthalmic examination was done, color fundus photographs and macular optical coherence tomography scans were taken, fluorescein and indocyanine green angiography were performed during initial and at subsequent follow-up examinations. Treatment was given in one minute using 2-3mm spot sizes, and laser power settings were between 650-800mW. The follow-up period was between 5 and 64 months and the mean was 28.6 months. RESULTS: There was subfoveal classic CNV in 10, predominantly classic CNV in 2, minimally classic CNV in 1, and type 1 occult CNV in one of the fourteen eyes. Four patients were noted to have post-treatment hemorrhage which was absorbed in a short time. Macular non-perfusion occurred in one patient immediately after treatment. Most of the eyes demonstrated a decrease in exudation during the follow-up. With a mean follow-up of 28.6 months, visual acuity improved in 5, remained the same in 8 and decreased in 1 of the 14 eyes. CONCLUSION: Transpupillary thermotherapy is shown to close subfoveal CNV with rapid resolution of subretinal fluid while maintaining visual function in patients with AMD. It may be performed as an alternative laser treatment in classic and predominantly classic subfoveal choroidal neovascularization due to AMD.

Abstract:AIM: To evaluate correlation of retinopathy and diabetic peripheral neuropathy (DPN) as microvascular complications of diabetes and also to identify their risk factors in patients with type 2 diabetes. METHODS: We conducted a cross-sectional study in an outpatient diabetes clinic during an 18-month period. 100 patients (51 male and 49 female), all affected by non-insulin- dependent diabetes mellitus (NIDDM), were examined for the presence of diabetic neuropathy and diabetic retinopathy. RESULTS: 78.1% of patients with retinopathy had DPN; and 79.1% of patients with DPN had retinopathy. Analysis of the association between DPN and retinopathy showed no significant correlation between them. 90.9% of patients with proliferative diabetic retinopathy (PDR) had DPN; and 27.8 % of patients with DPN had PDR. Both the univariate analysis and multiple logistic regression analysis revealed significant correlation between them (r =0.42, P =0.02). CONCLUSION: A severe diabetic retinopathy is associated with diabetic neuropathy. Our study further supports that diabetic neuropathy might be used as a tell-tale sign of diabetic retinopathy, necessitating more intensive ophthalmic care, especially in long-lasting diabetes.

Abstract:AIM: To analyze the postoperative anatomical and functional outcomes as well as complications after combined phacoemul- sification, pars plana vitrectomy (PPV), removal of the intraocular foreign body (IOFB) and intraocular lens (IOL) implantation in patients with traumatic cataract and intraocular foreign body. METHODS: Medical records of 13 patients(13 eyes) with traumatic cataract and IOFB who had undergone combined phacoemulsification, PPV, foreign body extraction and IOL implantation were retrospectively analyzed. The postoperative follow-up ranged from 2 to 12 months. The main measure- ments of outcomes were the extraction success of cataract and intraocular foreign body, intraoperative and postoperative complications and the final best corrected visual acuity (BCVA). ·RESULTS: The mean age of 13 patients(10 male, 3 female )was 36.8 years (range: 17-65 years). All eight IOFBs were removed. Four intraocular lenses were implanted after vitrectomy intraoperatively. In 5 cases, intraocular lenses were implanted during the second operation. Intraocular lenses were not implanted in 4 cases. BCVA at last ranged from 0.8 to hand movement. BCVA was 0.5 or better in four eyes, 0.1 to 0.4 in five eyes, less than 0.1 in four eyes. Intraoperative complications were encountered in 3 patients. They had vitreous hemorrhage. Postoperative complications were encounter- ed in 2 patients. They had retinal detachment. The reoperations of the two patients were successful. CONCLUSION: The combined phacoemulsification, PPV, removal of IOFB and IOL implantation is safe and effective for patients with traumatic cataract and intraocular foreign body. The visual outcome depended primarily on the corneal or scleral wound and underlying posterior segment pathology and sites.

Abstract:AIM: To assess the biocompatibility of bovine bone as orbital implants in rabbits. METHODS: Bovine bone graft was used as an ocular im- plant in rabbits to determine whether it could be successfully used in the anophthalmic socket as an alternative to the expensive synthetic alloplastics. Evisceration of eyes with and without bovine bone orbital implantation was performed in the right eyes of 12 New Zealand white rabbits. Group Y (n = 6) was eviscerated without implant, meanwhile Group X (n = 6) was eviscerated with insertion of an orbital implant using bovine bone. Observation was carried out on day 1, day 7, day 14, day 28 and day 42. Serial clinical examination was carried out based on a few fixed criteria, which included rate of infection, implant migration, evidence of wound breakdown and any restriction of intraocular movements. The implanted eyes were then enucleated on day 42. The enucleated eyes were sent for histopathological evaluation to record the type of inflammatory reaction and rate of fibrovascular ingrowth. RESULTS : Serial clinical examination showed presence of mini- mal infection in all eyes, both in Group X (implanted) and Group Y (control) on first postoperative day, which responded well with antibiotics. Infection occurred in the implanted group after first postoperative day, but there was no evidence of orbital migration or extrusion of implant, wound breakdown, restriction of extraocular movement, severe infection or any physical abnormality. Histopathological examination revealed good fibrovascular ingrowth in the implanted group, with minimal rejecting reaction of rabbit eye towards bovine bone implant. CONCLUSION: This study shows that bovine orbital implant has a good biocompatibility in rabbit eyes and its cost is acceptable.

Abstract:AIM: To compare the success rates of probing for the treatment of congenital nasolacrimal duct obstruction in children divided into three age groups. METHODS: One hundred and eighty children with uncomplicated congenital nasolacrimal duct obstruction underwent probing in Eye Hospital of Liaquat University of Medical and Health Sciences Hyderabad, Sindh, Pakistan from March 2005 to January 2008. The children were divided into three groups: Group I (aged 4-6 months), Group II (aged 7-12 months) and Group III (aged 13-24 months). Success was defined as complete resolution of signs and symptoms. The chi-square test was used to analyze the results. RESULTS: The success rate was 100.0% in Group I, 88.5% in Group II and 82.3% in Group III. The overall cure rate for the entire study was 90.7%. CONCLUSION: The efficacy of probing decreases with the increasing age. However, when probing is done within six months of age, it is highly effective and results in complete resolution of symptoms.

Abstract:AIM: To report the demographic characteristics of a sample of population affected by exudative age-related macular degeneration (AMD) in the region of Castilla-Leon (North- Central Spain), and to compare them with a group of population of the same age and from the same geographic area. METHODS: In this observational, prospective study, AMD patients attending a regional reference clinic for photodynamic therapy were interviewed. The patients reported their medical history for high blood pressure, hyperlipemia and smoking habit. Iris color was examined and classified as light (green, blue and grey) or dark (hazel, brown, black). RESULTS: A total of 343 patients were interviewed. Mean age at onset was 74.9 years (range 55 to 93), among whom 64.5% were female and 35.5% male. Iris color was rated as light in 45.1% of the patients. Arterial hypertension (AH) was present in 50% of the cases and 15.3% were on treatment for hypercholesterolemia, and 30.2% of the patients were smokers or had quit smoking (80.9% of males). CONCLUSION: The frequency of light colored iris is higher among patients with exudative AMD. In our series, other risk factors for exudative AMD were smoking habit in males, not being on treatment for hypercholes-terolemia and being female.

Abstract:Submacular Hemorrhage (SMH) in age-related macular degeneration (AMD) represents a challenging disorder for vision protection. Varied surgical interventions have been suggested in its management. The author herein reviewed some aspects related to SMH in AMD such as its risk factors, secondary damages, natural course and surgical management including different techniques, outcomes and complications.

Abstract:Pterygium is a common disorder of ocular surface with unknown etiology and pathogenesis. The epidemiological studies around the world have shown that the prevalence rates range from 0.3% to 37.46%. Pterygium is related to geographic setting, sunlight and ultraviolet exposure, age, gender, economic situation, dry eye syndrome and others. The purpose of this review is to present a summary of the more recent literature about the epidemiological study, paying particular attention to prevalence and risk factors of pterygium.

Abstract:AIM: To report a case of unilateral optic neuritis with multiple sclerosis in an Asian child. METHODS: A case report. RESULTS: A 10-year-old Chinese girl presented with history of sudden loss of vision of the right eye for 3 days’ duration. It was associated with pain in eye movement. She gave history of fever associated with ataxic gait a year ago. She had been diagnosed to have acute disseminated encephalomyelitis (ADEM). Visual acuity in the right eye was 'counting finger' with positive afferent pupillary defect. The optic disc was swollen and hyperemic. The colour vision was severely impaired. Visual field showed central scotoma and enlarged blind spot. Magnetic resonance imaging (MRI) of the brain revealed multiple intense lesions in the left occipital lobe, basal ganglia and periventricular regions suggesting multiple sclerosis. She was treated with intravenous methylprednisolone for 3 days, followed by oral prednisolone for 11 days. She had excellent recovery and her visual acuity improved to 6/9. She remained asymptomatic for 3 years. CONCLUSION: The simultaneous occurrence of optic neuritis and multiple sclerosis is less common in children and seldom reported. We presented this case to highlight the possibility of this disease occurring in Asian population in a younger age group.

Abstract:AIM: To report a rare case of melioidosis presenting as orbital abscess, who was successfully treated with high dose of intravenous ceftazidime. METHODS: A case report. RESULTS: A 55-year-old Malay gentlemen who was newly diagnosed with diabetes mellitus, presented with prolonged low grade fever for three weeks and left eye swelling for five days duration. Initial CT scan of brain and orbit showed left periorbital cellulitis and acute left sphenoidal sinusitis. Initial swab culture grew Pseudomonas sp. His general condition improved with regular antibiotics. However, upon completion of intravenous therapy his condition worsened and the left eye became more proptosed. Repeat CT scan of the brain and orbit showed left eye orbital abscess with intracranial exten-sion. Swab culture from fistula of the lateral part of upper eyelid showed Burkholderia pseudomallei. He was treated with high dose of intravenous ceftazidime, oral co-trimoxazole for the acute management and on maintenance dose of oral co-trimoxazole for 2 months. He responded well to treatment and had no relapse up to one year post treatment. Unfortunately his left eye vision was not salvageable. CONCLUSION: This case illustrates a rare presentation of orbital abscess due to melioidosis which was complicated with cerebral abscess and septicemia. An accurate diagnosis was essential and high dose of susceptible antibiotics was important for the institution of therapy to successfully treat this potentially fatal condition.