Intravitreal triamcinolone, bevacizumab and pegaptanib for occult choroidal neovascularization

VR-10 polypeptide interacts with CD36 to induce cell apoptosis and autophagy in choroid-retinal endothelial cells: Identification of VR-10 as putative novel therapeutic agent for choroid neovascularization (CNV) treatment

Choroid neovascularization (CNV) is important adverse pathological changes that contributes to the aggravation of hypoxic-ischemic eye diseases, and our preliminary work evidences that the thrombospondin-1 (TSP-1) synthetic polypeptide VR-10 may be the candidate therapeutic agent for the treatment of CNV, but its detailed effects and molecular mechanisms are not fully delineated. In this study, the CNV models in BN rats were established by using the laser photocoagulation method, which were further subjected to VR-10 peptide treatment. The RNA-seq and bioinformatics analysis suggested that VR-10 peptide significantly altered the expression patterns of genes in the rat ocular tissues, and the changed genes were especially enriched in the CD36-associated signal pathways. Next, by performing the Real-Time qPCR and Western Blot analysis, we expectedly found that VR-10 upregulated the anti-angiogenesis biomarker (PEDF) and downregulated pro-angiogenesis biomarkers (VEGF, HIF-1 and IL-17) in rat tissues. In addition, we evidenced that VR-10 downregulated CDK2, CDK4, CDK6, Cyclin D1 and Cyclin D2 to induce cell cycle arrest, upregulated cleaved Caspase-3, Bax and downregulated Bcl-2 to promote cell apoptosis, and increased LC3B-II/I ratio and facilitate p62 degradation to promote cell autophagy in RF/6A cells, which were all reversed by knocking down CD36. Moreover, VR-10 upregulated PEDF, and decreased the expression levels of VEGF, HIF-1 and IL-17 to block angiogenesis of RF/6A cells in a CD36-dependent manner. Taken together, VR-10 peptide interacts with its receptor CD36 to regulate the biological functions of RF/6A cells, and these data suggest that VR-10 peptide may be the putative therapeutic drug for the treatment of CNV in clinic.

Cyclic RGD Peptide Targeting Coated Nano Drug Co-Delivery System for Therapeutic Use in Age-Related Macular Degeneration Disease

Vascular endothelial growth factor (VEGF) expression increased significantly in the pathogenesis of age-related macular degeneration, which induced the formation of pathological blood vessels. Dexamethasone is an exogenous anti-angiogenic drug while bevacizumab is an endogenous anti-angiogenic drug. They both have been widely used in ophthalmology. However, independent administration is not enough to completely block the development of choroidal neovascularization (CNV), and the number of eyes vitreous injections is limited. Reasonable combination of drugs may produce significantly better therapeutic effect than single drug treatment. The cyclic RGD (cRGD) peptide has a particularly high affinity with retinal pigment epithelial cells, where VEGF secretes from. In this study, we prepared nanoparticles of bevacizumab and dexamethasone with cRGD peptide as the target (aBev/cRGD-DPPNs). The particle size of the aBev/cRGD-DPPNs was 213.8 ± 1.5 nm, SEM results showed that the nano-carriers were well dispersed and spherical. The cell uptake study demonstrated the selectivity of the aBev/cRGD-DPPN to ARPE-19 with α_Vβ₃ over expressed. The aBev/cRGD-DPPNs had a better apoptosis induction effect and an obvious inhibitory effect on migration, invasion, and capillary-like structures formation of human umbilical vein epithelial cells. The fluorescein fundus angiography study, immunohistochemistry and histopathological evaluation showed the aBev/cRGD-DPPNs greatly reduced the development of CNV on a rabbit model.

KH902 suppresses high glucose-induced migration and sprouting of human retinal endothelial cells by blocking VEGF and PIGF

AIMS

Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are upregulated in many ocular neovascular diseases such as diabetic retinopathy (DR). KH902 is a recombinant fusion protein with its binding ligand taken from the domains of VEGF receptor-1 (VEGFR-1) and VEGF receptor-2 (VEGFR-2) and can bind all VEGF-A isoforms and PlGF. The aim of this study was to investigate the underlying mechanisms of anti-angiogenic effects of KH902.

METHODS

The toxic effect of KH902 on cultured human retinal endothelial cells (HRECs) was measured by Annexin V/PI staining and MTT assay. The concentrations of secreted VEGF and PlGF were measured by ELISA. The migration of HRECs was assessed by scratch wound and transwell assay. The sprouting of HRECs was determined by tube formation assay. The protein levels of Src, p-Src, PI3K, Akt1, p-Akt1, Erk1/2 and p-Erk1/2 were measured by Western blot.

RESULTS

KH902 at the concentrations from 100 ng/ml to 100 µg/ml had no cytotoxicity to cultured HRECs. KH902 bound not only VEGF165, but also PlGF that were secreted by HRECs under high glucose condition. A 500 ng/ml of KH902 significantly suppressed high glucose-induced migration and sprouting of HRECs through downregulating the expression of PI3K and inhibiting the activation of Src, Akt1 and Erk1/2.

CONCLUSION

Our study indicates that KH902 suppresses high glucose-induced migration and sprouting of HRECs through not only binding VEGF, but also PlGF to inhibit the activation of Src-Akt1-Erk1/2 pathway. KH902 is a drug that potentially inhibits angiogenic pathways involving in DR or other ocular neovascular diseases.

Low luminance visual acuity in patients with central serous chorioretinopathy

BACKGROUND

The aim was to determine the low luminance visual acuity in eyes with central serous chorioretinopathy.

METHODS

Seven eyes of seven patients with central serous chorioretinopathy and six eyes of six age-matched normal volunteers were examined. Low luminance visual acuity charts were created by an Apple Power Mac G5 computer and displayed on a cathode ray tube monitor (SONY GDM-F500). The background luminance was set at six different levels from 78.20 cd/m(2) to 0.37 cd/m(2). The visual acuities of the eyes with central serous chorioretinopathy at each of the six luminance levels were compared to those from their fellow eyes and to normal eyes.

RESULTS

The mean visual acuities varied from 0.13, 0.23, 0.29, 0.42, 0.62 to 0.70 logMAR units as luminance varied from high to low. At the lowest luminance (0.37 cd/m(2)), five of the seven eyes could not read any character. The mean visual acuities of the fellow eyes at the same luminance levels were 0.03, 0.06, 0.11, 0.20, 0.27 and 0.45 logMAR units and those of the normal volunteers were 0, 0.03, 0.08, 0.14, 0.23 and 0.38 logMAR units, respectively. The visual acuities of the eyes with central serous chorioretinopathy were significantly poorer than those of the normal eyes at all luminance levels except 0.37 cd/m(2) (p < 0.05 for all).

CONCLUSIONS

Although the eyes from all three groups had 0 logMAR units visual acuity under standard testing condition, the visual acuity of the eyes with central serous chorioretinopathy were significantly worse at low luminance levels. The low luminance visual acuity may provide information on the visual disturbances reported by central serous chorioretinopathy patients with 0 logMAR units visual acuity.

Low-fluence photodynamic therapy combinations in the treatment of exudative age-related macular degeneration

AIM

To compare the efficacy of low-fluence photodynamic therapy (PDT) combinations in the treatment of age-related macular degeneration (AMD).

METHODS

Forty-five previously untreated eyes of 45 patients with exudative AMD whose best-corrected visual acuity (BCVA) was ≥0.3 (Snellen) were enrolled. 15 patients in Group I underwent low-fluence PDT (25J/cm(2)-300mW/cm(2)-83sec) and intravitreal pegaptanib combination, 15 patients in Group II underwent PDT (50J/cm(2)-600mW/cm(2)-83sec) and intravitreal pegaptanib combination while, 15 patients in Group III underwent intravitreal pegaptanib monotherapy. Complete ophthalmologic examinations were performed in pre and post treatment visits, and the results were statistically analised. A clinical activity score (CAS) was calculated by using changes in lesion size, amount of hemorrhage, staining pattern in FA and OCT measurement of intra/subretinal fluid. ≤ 3 logMAR lines of decrease in BCVA and decrease in CAS were considered as successful treatment.

RESULTS

The mean age of 19 female (42.2%) and 26 male (57.8%) patients was 72.82±8.02 years. Mean follow-up was 13.93±5.87 months. Lesion type was occult in 28 eyes (62.2%). Treatment success rates according to BCVA assessments were 86.7%, 80%, 60% and mean BCVA decrease were 0.3, 1.0, 2.2 logMAR lines in Group I, II and III, respectively (P>0.05). According to the changes in central macular thickness and CAS, no difference was found among the study groups (P=0.850 and P=0.811, respectively). Patients treated with combination regimens had lower intravitreal injection frequencies (P=0.015).

CONCLUSION

Combination regimen with intravitreal pegaptanib and low-fluence PDT seems to be safe and effective in stabilizing the clinical activity and BCVA in exudative AMD.

Natural history of age-related retinal lesions that precede AMD in mice fed high or low glycemic index diets

PURPOSE

Epidemiologic data indicate that people who consume low glycemic index (GI) diets are at reduced risk for the onset and progression of age-related macular degeneration (AMD). The authors sought corroboration of this observation in an animal model.

METHODS

Five- and 16-month-old C57BL/6 mice were fed high or low GI diets until they were 17 and 23.5 months of age, respectively. Retinal lesions were evaluated by transmission electron microscopy, and advanced glycation end products (AGEs) were evaluated by immunohistochemistry.

RESULTS

Retinal lesions including basal laminar deposits, loss of basal infoldings, and vacuoles in the retinal pigment epithelium were more prevalent in the 23.5- than in the 17-month-old mice. Within each age group, consumption of a high GI diet increased the risk for lesions and the risk for photoreceptor abnormalities and accumulation of AGEs.

CONCLUSIONS

Consuming high GI diets accelerates the appearance of age-related retinal lesions that precede AMD in mice, perhaps by increasing the deposition of toxic AGEs in the retina. The data support the hypothesis that consuming lower GI diets, or simulation of their effects with nutraceuticals or drugs, may protect against AMD. The high GI-fed C57BL/6 mouse is a new model of age-related retinal lesions that precede AMD and mimic the early stages of disease and may be useful for drug discovery.

Bilateral intravitreal bevacizumab injection for exudative age-related macular degeneration: effect of baseline visual acuity

PURPOSE

To assess side differences in patients undergoing bilateral intravitreal bevacizumab injections as treatment of exudative age-related macular degeneration (AMD).

METHODS

The clinical interventional case series study included 48 patients (96 eyes) who consecutively and bilaterally received 3 intravitreal bevacizumab injections. The mean age was 76.5±7.5 years (range: 59-88 years). Follow-up was 6 months. Main outcome parameters were best-corrected visual acuity (BCVA) and measurements by optic coherence tomography. The eyes of the same patient were assigned to a study group 1 for the eye with the higher visual acuity at baseline, and study group 2 for the contralateral eye with the lower visual acuity at baseline.

RESULTS

The increase in BCVA was significantly (P=0.02) greater in group 2 (0.07±0.25 logarithm of the minimum angle of resolution, LogMAR) than in group 1 (0.05±0.29 LogMAR). The height of a detached retinal pigment epithelium, the height of subretinal fluid, and the tissue thickness of the macula decreased significantly (P<0.05) in group 2 during follow-up, whereas these parameters did not markedly change in the eyes of group 1 (P=0.96, P=0.38, and P=0.07, respectively). The reduction in the height of a detached retinal pigment epithelium and in the height of subretinal fluid was significantly more pronounced in group 2 than in group 1 (P=0.03, P=0.04, respectively).

CONCLUSIONS

After an initial set of 3 bilateral bevacizumab injections, patients with bilateral exudative AMD have a higher likelihood for an improvement in vision in the worse-seeing eye at baseline than in the better-seeing eye.

Intravitreal bevacizumab for exudative age-related macular degeneration in clinical practice

PURPOSE

The purpose of this study was to evaluate whether baseline visual acuity and baseline anatomy of the macula influence visual outcome in patients receiving intravitreal bevacizumab as treatment of exudative age-related macular degeneration (AMD) in clinical practice.

METHODS

This clinical case series study included 319 patients (406 eyes) who consecutively received intravitreal injections of bevacizumab for treatment of exudative AMD. The intervals between injections were 6 weeks and postinjection examinations were performed at 4 weeks after injection. Mean follow-up was 3.6 months.

RESULTS

After 3 injections of bevacizumab, best-corrected visual acuity (BCVA) significantly (P<0.01) improved in eyes with a baseline BCVA of less than 0.2 (group 1; 138 eyes; -0.10±0.43 LogMAR) and in eyes with a baseline BCVA ≥0.2 and <0.4 (group 2; 117 eyes; -0.06±0.24 LogMAR), but BCVA deteriorated in eyes with a baseline BCVA of ≥0.4 (group 3; 151 eyes; 0.09±0.32 LogMAR). Correspondingly, regression analysis revealed that improvement in BCVA after 3 intravitreal bevacizumab injections was significantly (P=0.001) associated with a low baseline BCVA. After the first injection of bevacizumab, changes in optical coherent tomography measurements of the macula (height of subretinal fluid, macular tissue thickness) were statistically significant for group 1 (P=0.03, P=0.03, respectively) and group 2 (P=0.01, P=0.02, respectively), but not for group 3 (P=0.85, P=0.22, respectively).

CONCLUSIONS

In clinical practice, patients with exudative AMD and a baseline BCVA of <0.2 have a better prognosis for an increase in BCVA after intravitreal bevacizumab injections than patients with a higher baseline BCVA.