Abstract:AIM: To investigate the therapeutic effects of nanophtha- locyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs). METHODS: Two types of photosensitizers, G1-ZnPc(COOH)8 and G1-ZnPc(COOH)8/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (△Ψm) were conducted on HRPE and HRECs after initial uptake of the two drugs. RESULTS: Both photosensitizers demonstrated an improve- ment of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G1-ZnPc(COOH)8/m showed a better CNV closure effect versus G1-ZnPc(COOH)8 (P<0.05). A significant difference (P＜0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs(P＞0.05). Both photosensitizers showed cytotoxicity on HRPE, but G1-ZnPc(COOH)8/m induced a lower cell viability. CONCLUSION: G1-ZnPc(COOH)8/m mediated PDT is better than G1-ZnPc(COOH)8 in CNV closure and also have the advantage of fast metabolism leading to less side effect.

Abstract:AIM: To investigate the antifibrotic effect of freeze-dried bilayered fibrin-binding amniotic membrane on trabeculectomy in a rabbit model. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with natural bilayered fibrin-binding amniotic membrane) and the blank group (single trabeculectomy). Clinical observation, hematoxylin-eosin staining, Massion staining, real-time PCR and immunohistochemistry for α-SMA were performed on days 7, 14, 21 and 30 following surgery. RESULTS: Statistical differences were noted in survival analysis and intraocular pressure(IOP) among groups on days 7, 14, 21 and 30 following surgery. Histology, immunoh- istochemistry and real-time PCR further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane resulted in good wound healing and no scar formation. CONCLUSION: Self-made freeze-dried bilayered fibrin- binding amniotic membrane may inhibit the formation of scarring in glaucoma after trabeculectomy.

Abstract:AIM: To investigate changes in immunogenicity of cryopreserved limbal stem cells. METHODS: Cryopreserved limbal stem cells, fresh primary limbal stem cells and blank controls were inoculated subcutaneously in C57BL-6 mice and the percentage of CD25 cells in limbal explants was determined by flow cytometry at day 21 post inoculation. Morphological studies were performed by light and electron microscopy of limbal explant sections. RESULTS: The number of regional and systemic lymphocytes derived from cryopreserved limbal stem cells was lower than that from fresh primary limbal stem cells. CONCLUSION: Lymphocytes derived from cryopreserved limbal stem cells showed changes in immunogenicity, but the significance is unknown. The cryopreservation and thawing methods await further study.

Abstract:AIM: To explore the effect of immunization with copolymer-1 (COP-1) and retinal stem cells (RSCs) transplantation on interferon-gamma (IFN-γ) levels in a rat experimental glaucoma model. METHODS: An experimental glaucoma was induced by argon laser photocoagulation of the episcleral veins and limbal plexus in the right eye of rats. Immediately following glaucoma induction, rats were immunized with COP-1. RSCs were cultured and transplanted intravitreally into the eyes of glaucoma model animals 1 week post-laser treatment. Six experimental groups were used: COP-1/RSC, PBS/RSC, COP-1/PBS, PBS/PBS, glaucoma model group, and a normal control group. The concentration of IFN-γ in aqueous humor (AH) and serum was measured by enzyme-linked immunosorbent assay (ELISA) in each of the six groups. Retinal ganglion cell (RGC) survival was assessed by quantifying apoptosis using Hoechst staining. RESULTS: Concentrations of IFN-γ in AH and serum of rats that had undergone glaucoma induction were higher than those of non-induced control rats. The concentrations of IFN-γ in AH and serum of the COP-1/RSCs treated group were determined to be 2371.9ng/L and 710.9ng/L, respectively, which were significantly lower than those in the other treated groups (P<0.05). In fact, IFN-γ levels in the dual treated group were reduced to background levels. The COP-1/RSC group had lower number of apoptotic RGCs than the other three experimental groups (P<0.05). CONCLUSION: The reduced levels of IFN-γ in AH and serum of the COP-1/RSC group may be related to synergistic effects between RSCs transplantation and COP-1 immune modulation. It is likely that the lower levels of IFN-γ prevented RGCs glaucomatous apoptosis.

Abstract:AIM: To study the effects of danhong huayu koufuye (DHK) on fasting blood glucose (FBG) and diabetic retinopathy (DR) in streptozotocin (STZ)-induced type 1 diabetic rats to facilitate the rational usage of this drug. METHODS: Diabetic rats were induced by injection of a single dose of STZ intraperitoneally at 50mg/kg. Flash electroretinogram (FERG) and oscillatory potentials (OPs) were used to measure retinal function. The microvascular perfusion of ears was performed to study the microcirculation in rats. FBG, body-weight, and 24-h urine volume, water intake and diet intake were also assessed. RESULTS: DHK had no effect on FBG in normal rats. However, STZ + DHK group were significantly different from those of Model and moved toward those of normal control. It reversed the increase in diet intake(P≤0.05 vs model control) and the loss in body-weight(P≤0.05 vs model control) in diabetic rats. DHK decreased the FBG of diabetic rats by 25.6% (P≤0.05) and 37.9% (P ≤0.01) after 14 and 21 days administration as compared with the model control, respectively. Moreover, DHK significantly increased the FERG b-wave amplitude by 80% (P≤0.05 vs model control) and decreased the FERG b-wave latency by 15.3% (P≤0.01 vs model control) after 24 days administration. The OP1 and OP2 amplitudes in DHK group were 2.6 (P≤0.01) and 2.0 (P≤0.01) times of model group after 24 days of DHK treatment, respectively. At the same time, OP1 and OP2 latencies in DHK group reduced by 16.0% (P≤0.001) and 14.7% (P≤0.001) as compared with the model control, respectively. Furthermore, the microvascular perfusion of DHK group was 2.4 times of model group (P≤0.001) after 21 days administration. CONCLUSION: DHK had no effect on normal FBG. But it had antihyperglycemic activity, and had a preventive and therapeutic effect on DR in diabetic rats.

Abstract:AIM: To explore if peroxyntrite （ONOO－) induced iNOS via Fas/ Fas/L pathway in diabetic rats and the effection of cholecystokinin octapeptide-8 (CCK-8) as therapeutic agent for decrease diabetic retinopathy. METHODS: Thirty-six rats were taken as control group, seventy two were given (streptozotocin) STZ (45mg/kg) and then divided into ONOO－group and CCK-8 group (peritoneal injection CCK-8). STZ-induced diabetic rats were treated with CCK-8 for 60 days. Western blotting analysis, DNA ladder, RT-PCR, immunohistochemistry and flow cytometry were used for determining the expression of nitrotyrosine (NT, the foot print of ONOO－); apoptosis and inducible nitric oxide synthase (iNOS) mRNA as well as Fas/Fasl signal transduction in RPE cells. RESULTS: Both RPE cells in ONOO－ and CCK-8 group developed apoptosis and expressed NT, iNOS mRNA and Fas/Fasl. But latter delayed the all changes in a time-dependent manner compared with control and ONOO－ group (P＜0.001). iNOS and Fas/Fasl were up-regulated and associated with an increase of expression of ONOO－in vivo. CONCLUSION: The study suggested that apoptosis of RPE was partly induced by ONOO－ may be the new way of oxidative damage to the RPE cells. CCK-8 decreased RPE cells apoptosis partly induced by ONOO－ and is a potential drug for therapy of diabetic retinopathy. The mechanism of CCK-8 dealing with RPE cells may be related to its direct inhibition of the formation of iNOS to produce ONOO－ and antagnism of damage of ONOO－ to RPE cells.

Abstract:AIM: To quantify the changes in the lens profile with accommodation in different age groups. METHODS: The Pentacam HR system was used to obtain the images of the anterior eye segment from 23 young and 15 presbyopic emmetropic subjects in unaccommodated (with an accommodation stimulus of 0.0D) and accommodated (with an accommodation stimulus of 5.0D for the young group and 1.0D for the presbyopic group) states. The phakic crystalline lens shape, including curvature of crystalline lens and central lens thickness (CLT), and the measurements of anterior segment length (ASL), central anterior chamber depth (CACD) were investigated. The anterior chamber volume (ACV) was also measured. RESULTS: The reduction of CACD and ACV were significant in both groups after accommodation stimulus. From the profile of anterior eye segment, a significant decrease in anterior crystalline lens radii of curvature (-2.52mm) and a mean increase in CLT (0.222mm) and ASL (0.108mm) were found in the young group with an accommodation stimulus of 5.0D. However, no statistically significant changes of CLT, ASL, or crystalline lens radii of curvature were found in the presbyopic group. CONCLUSION: Our data showed that the shallowing of anterior chamber during accommodation was caused by the forward bulging of the anterior lens surface, rather than by anterior shifting of lens position in either young or presbyopic subjects.

Abstract:AIM: To establish and compare serum proteomic of diabetic retinopathy(DR) patients in various phases and discuss pathogenesis of DR so as to find out possible serum specific molecular markers for early diagnosis of DR. METHODS: Thirty-two subjects were divided into four groups: one group of eight type 2 diabetes mellitus (T2DM) patients without apparent DR (No-DR, NDR), one group of eight T2DM patients with non-proliferative diabetic retinopathy(NPDR), one group of eight T2DM patients with proliferative diabetic retinopathy(PDR) and one group of eight healthy volunteer participants. Two dimensional fluorescence difference gel electrophoresis (2D-DIGE) was applied to establish differential protein expression profiles in four groups. Matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI-TOF-TOF MS) was applied to identify mass spectrometry of differential proteins and analyze follow-up bioinformatics. RESULTS: 2D-DIGE maps of serum protein were satisfactory obtained from NDR, NPDR, PDR and normal control groups. Twenty-six different proteins spots were screened(the volume ratio was ＞1.5 based on DeCyder software analysis). Twenty-four of them were verified and two of them were not. Fifteen proteins were verified. Most of them were high-abundant proteins in serum. The four relatively low-abundant ones were beta 2-glycoprotein I (β2-GPI), alpha2-HS-glycoprotein(AHSG), alpha1-acid glycoprotein(α1-AGP) and apolipoprotein A-1(apo A-1). β2-GPI expression was gradually increased in the development of DR but unrelated to the severity of DR. The volume ratio of β2-GPI is 1.54, 2.43, and 2.84 in NDR, NPDR and PDR group respectively compared with normal control group. CONCLUSION: Serum proteomic analysis of 2D-DIGE combined with MALDI-TOF-TOF MS is feasible to be applied in the study of DR. β2-GPI probably takes part in the process of DR occurrence and development and it could be a candidate biomarker on DR diagnosis in early phase.

Abstract:AIM: To evaluate the frequency of blue-on-yellow perimetry (B/YP) deficits in ocular hypertension (OHT) patients and to correlate these findings with central corneal thickness (CCT), and to investigate the influence of age, refraction and gender on the B/YP results in OHT patients. METHODS: The B/YP and CCT were checked respectively in 72 OHT patients with normal white-on-white perimetry(W/WP) and normal optic nerve head. The B/YP was tested by Octopus 101 automated perimetry using G2 strategy, while the CCT was checked with DGH-550 ultrasound pachymeter. All patients were chosen randomly one eye for statistical analysis, a binary regression model was used to determine the independent contribution of variables included in the model, and the differences of the intraocular pressure (IOP), CCT, age, refraction and gender between the normal B/YP group and abnormal B/YP group were compared. RESULTS: Forty-nine out of 72 patients with OHT showed normal B/YP results, whereas 23 of 72 patients(31.9%) demonstrated abnormal B/YP results. CCT showed a correlation with the B/YP results (B=-0.038, SE=0.019, P=0.044), whereas none of the IOP, age, refraction and gender was found to be correlated with the B/YP results. The mean CCT in OHT patients with abnormal B/YP group was lower than that with normal B/YP group(t =2.066, P=0.043).There was a significant positive correlation between IOP and CCT (R2=0.513, P= 0.000). CONCLUSION: The mean CCT in OHT patients with abnormal B/YP results was lower than that with normal B/YP results. There was a significant positive correlation between IOP and CCT in OHT patients. The age, refraction and gender didn't influence the B/YP results in OHT patients.

Abstract:AIM: To study macular features in patients with congenital nystagmus and to assess the utility of spectral-domain optical coherence tomography (SD-OCT) in nystagmus. METHODS: The macular areas of 51 outpatients with congenital nystagmus were examined using SD-OCT. Morphological changes in the retinal layers of the macular area were analysed. RESULTS: Macular images were successfully obtained with SD-OCT from 50 (98%) patients. Patients with ocular albinism mainly have macular hypoplasia, abnormal foveal depression, and increased foveal thickness with persistence of an inner nuclear layer, an inner plexiform layer, a ganglion cell layer and a nerve fiber layer. Macular morphology similar to albinism was observed in three patients with idiopathic macular hypoplasia. The OCT findings of cone dystrophy included unclear, disrupted or invisible photoreceptor outer segment/inner segment in the fovea; fusion, thickening and uneven reflection of the outer segment/inner segment with external limiting membrane. Some patients with congenital idiopathic nystagmus showed normal macular morphology and structure, and others showed indistinct macular external limiting membrane reflection. CONCLUSION: SD-OCT is an effective and reliable method to detect the macular morphology of congenital nystagmus patients. This technique has diagnostic value in particular for patients with macular hypoplasia and cone cell dystrophy with no distinct abnormality on fundoscopy.

Abstract:AIM: To analyze the incidence and risk factors for retinopathy of prematurity (ROP). METHODS: A retrospective analysis was conducted on 568 premature infants from September 2005 to December 2010 with birth weight(BW) equal to or less than 2 500g or a gestational age(GA) at birth of 34 weeks or less. All of the members were examined by indirect binocular ophthalmoscopy. RESULTS: ROP occurred with an incidence rate of 10.7% among 568 premature infants, and stages 3 and above ROP occurred with an incidence rate of 2.5%. This study showed the infants were more prone to develop ROP with short geststional age, low BW, long time of oxygen inhalation, and severe infants diseases. Twins had a significantly higher rate of ROP(18.3%) than singleton babies(9.8%), ROP were severer in twins than singleton babies . CONCLUSION: Short GA, low BW, long time of oxygen inhalation, severe infants diseases, and non-singleton babies were the most significant risk factors associated with ROP.

Abstract:AIM: As a result of the increase in premature births and the advances in neonatal intensive care, retinopathy of prematurity (ROP) remains one of the most important causes of childhood blindness worldwide. The main factors in the development of ROP are gestational age, birth weight and oxygen therapy. ROP continues to gain importance due to the increasing survival rates of more immature babies. METHODS: Between January 2007 and October 2008, 203 premature infants treated at the Neonatal Intensive Care Unit (NNICU) were prospectively enrolled and the relationship between known risk factors and the occurance of ROP was studied. RESULTS: ROP in various stages developed in 86 cases (42.4%). Statistically significant correlations were found between the development of ROP and birth weight (P<0.0001) gestational age (P<0.0001), oxygen treatment and its duration (P<0.0001 and P=0.002), mechanical ventilation (MV) and its duration (P=0,0001 and P=0.0001), apnea(P=0.001), intraventricular hemorrhage (IVH) (P=0.046), sepsis (P=0.0001), use of erythropoietin (EPO) (P=0.003), the number of blood transfusions and frequency (P=0.0001 and P=0.0001), surfactant application (P=0.0001), the presence of patent ductus arteriosus (PDA) (P=0.001) or bronchopu- lmonary dysplasia (BPD) (P=0.0001). No significant correlations were found between the occurance of ROP and maternal pre-eclampsia (P=0.293), multiple pregnancy (P=0.218), or hyperbilirubinemia (P=0.494). Severity of ROP was related significantly with birth weight (P=0.0001), but no significant correlation between severity of ROP and gestational age was present. CONCLUSION: Early description and reduction of the risk factors related with the occurance of ROP with the help of routine screening programs may warrant the prevention of visual loss, however early ophthalmic diagnosis and treatment are still mandatory to provide better visual rehabilitation.

Abstract:AIM: To investigate the fundus findings of patients infected with human immunodeficiency virus (HIV) in correlation to Highly Active Antiretroviral Therapy (HAART) and CD4 count. METHODS: Two hundred and two patients of the three major races (Chinese, Malay and Indian) in Malaysia were recruited in this population-based cross-sectional study. This consisted of confirmed HIV sero-positive patients with HAART treatment (n=95) or without HAART therapy (n=107) from December 2007 to March 2008. They were further classified into the HIV infected group, AIDS related complex (ARC) group and AIDS group. Each group was then subdivided according to their CD4 count. Clinical fundus findings were recorded. RESULTS: Sixty six patients (32.7%) showed presence of fundus manifestation, majority of which was HIV microangiopathy (89%) and the rest being Cytomegalovirus (CMV) retinitis (11%). The most common fundus lesion was cotton wool spot (34%). There was a higher incidence of fundus manifestation in the non HAART group than the HAART group (P=0.04) and in patients with CD4 count less than 200 cells/ml in both groups (P=0.01). The HAART therapy had remarkably reduced the percentage of fundus manifestation by 20% but CD4 count remains the marker for fundus manifestations. There were no significant differences noted in the retinal manifestation among the different races. (ANOVA, P=0.25). CONCLUSION: The fundus manifestations were higher in patients with CD4<200 cells/ml and in the non HAART group. Hence the HAART therapy is capable of reducing the incidence of fundus manifestations, however the CD4 count determines the occurrence of fundus manifestations.

Abstract:AIM: To compare the corneal endothelial cell density (ECD) of clear grafts after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). METHODS: The study included 44 and 54 patients treated with PK and DALK, respectively, between March 2006 and April 2010. Corneal ECD was examined using specular microscopy at postoperative 1, 3, 6, 12, and 18 months, and the values were compared. RESULTS: Corneal ECD reduction in the PK group was 7.4%, 15.2%, 23.5%, and 28.9% at 3, 6, 12 and 18 months respectively after surgery, compared with 4.2 % in the first month (P<0.01). These figures were 3.0%, 6.7%, 7.2%, and 7.7% at 3, 6, 12 and 18 months respectively, compared with 2.2 % in the first month in the DALK group (P>0.05). CONCLUSION: Compared with DALK,PK significantly reduced ECD of the clear grafts. These results suggest that survival of endothelial cells in grafts is better after DALK than after PK.

Abstract:Glaucoma is one of the leading causes of visual impairment and blindness. Improved knowledge of the pathogenesis of this disease has allowed the exploration of new therapeutic methods. In general, elevated intraocular pressure (IOP), oxidative stress, and vascular insufficiency are accepted as the major risk factors for the progression of glaucoma. Many natural compounds have been found beneficial for glaucoma. Nutritional therapies are now emerging as potentially effective in glaucomatous therapy. One nutritional supplement with potential therapeutic value is cod liver oil, a dietary supplement that contains vitamin A and omega-3 polyunsaturated fatty acids (PUFAs). Vitamin A is important for preserving normal vision and it is a well-known antioxidant that prevents the oxidative damage that contributes to the etiology and progression of glaucoma. Vitamin A is also a crucial factor for maintaining the integrity of conjunctival and corneal ocular surfaces, and preventing the impairment of ocular epithelium caused by topical antiglaucomatous drugs. Omega-3 fatty acids are beneficial for glaucoma patients as they decrease IOP, increase ocular blood flow, and improve optic neuroprotective function. In this article, we propose that cod liver oil, as a combination of vitamin A and omega-3 fatty acids, should be beneficial for the treatment of glaucoma. However, further studies are needed to explore the relationship between cod liver oil and glaucoma.

Abstract:Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous system (CNS) disorders, and involved in many aspects of neuronal functions including neurite outgrowth and retraction. In the adult CNS, the damaged neuron regeneration is very difficult due to the presence of myelin-associated axon growth inhibitors such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp), etc. The effects of these axon growth inhibitors are reversed by blocking the Rho/ROCK pathway in vitro, and the inhibition of Rho/ROCK pathway can promote axon regeneration and functional recovery in the injured CNS in vivo. In addition, the therapeutic effects of the Rho/ROCK inhibitors have also been demonstrated in some animal models and the Rho/ROCK pathway becomes an attractive target for the development of drugs for treating CNS disorders. In this review, we summarized on the effect of the Rho and the downstream factor ROCK in neural regeneration, and the potential therapeutic effect of Rho/ROCK inhibitors in the survival and axonal regeneration of retinal ganglion cells was also discussed.

Abstract:Myopia is a significant public health problem and its prevalence is increasing over time and genetic factors in disease development are important. The prevalence and incidence of myopia within sampled population often varies with age, country, sex, race, ethnicity, occupation, environment, and other factors. Myopia growth is under a combination of genes and their products in time and space to complete the coordination role of the guidance. Myopia-related genes include about 70 genetic loci to which primary myopias have been mapped, although the number is constantly increasing and depends to some extent on definition. Of these, several are associated with additional abnormalities, mostly as part of developmental syndromes. These tend to result from mutations in genes encoding transcriptional activators, and most of these have been identified by sequencing candidate genes in patients with developmental anomalies. Currently, COL1A1(collagen alpha-1 chain of type I), COL2A1 (collagen alpha-1 chain of type II), ACTC1 (actin, alpha, cardiac muscle 1), PAX6 (paired box gene 6) and NIPBL (nipped-B homolog), and so on have been mapped. Myopia is most commonly treated with spectacles or glasses. The most common surgical procedure performed to correct myopia is laser in situ keratomileusis (LASIK). This review of the recent advances on epidemiology, genetic locations and treatments of myopia are summarized.

Abstract:The prevalence of diabetic retinopathy (DR) is increasing dramatically as the population of patients with diabetes continues to rise. This paper wants to investigate the prevalence and risk factors of DR in China through reviewing the research from Pubmed about population-based epidemic studies. The results of observational studies suggested that the overall prevalence of DR was 1.6%-6.5% in population, 19.9%-43.1% in diabetes and 13.6% in population without diabetes, most of the DR were the mild type, macular edema and vision-threatening were 5.2% and 1.2%. The risk factors for DR were longer duration of diabetes, plasma glucose concentration, concentrations of HbA1c level, higher systolic blood pressure(BP), higher diastolic BP, male gender, rural region, and methods of diabetic treatment and so on. The prevalence of DR which was strongly related to duration of diabetes was higher with the increase of diabetes. DR would be the major leading cause of visual impairment in China, it is very important to prevent DR by early screening and any other methods.

Abstract:

Abstract:

Abstract: