Case Report: A Case of Cystoid Macular Edema in Retinitis Pigmentosa With Central Retinal Vein Occlusion.

Significance: Cystoid macular edema (CME) is a common complication of retinitis pigmentosa (RP). However, CME in RP with central retinal vein occlusion (CRVO) is rare. Prompt administration of anti-vascular endothelial growth factor (anti-VEGF) medication can achieve a satisfactory prognosis. Purpose: This report describes a case of using anti-VEGF medication to treat CME secondary to RP with impending or mild CRVO. Case Report: A 26-year-old female presented for blurred vision in both eyes. Best-corrected visual acuity (BCVA) was 20/50 in the right eye and finger-counting in the left eye. According to ophthalmic examinations, CME secondary to RP in the right eye and CME secondary to RP with impending or mild CRVO in her left eye can be diagnosed. Central macular thickness (CMT) was 554 µ m in the right eye and 831 µm in the left eye. Only the left eye was treated with a single intravitreal injection of anti-VEGF medication. One month later, BCVA increased to 20/200 and CMT decreased to 162 µm in the left eye. Interestingly, BCVA in the right eye also had an improvement (20/40) and intraretinal fluid decreased significantly. However, 3 months after injection, these improvements of both eyes were not maintained. Conclusion: This is the second case of RP with CRVO. Intravitreal injection of anti-VEGF medication for addressing CME secondary to RP with CRVO is an effective treatment, but it needs to be reinjected.

Yes-associated protein promotes endothelial-to-mesenchymal transition of endothelial cells in choroidal neovascularization fibrosis.

AIM: To reveal whether and how Yes-associated protein (YAP) promotes the occurrence of subretinal fibrosis in age-related macular degeneration (AMD). METHODS: Cobalt chloride (CoCl2) was used in primary human umbilical vein endothelial cells (HUVECs) to induce hypoxia in vitro. Eight-week-old male C57BL/6J mice weighing 19-25 g were used for a choroidal neovascularization (CNV) model induced by laser photocoagulation in vivo. Expression levels of YAP, phosphorylated YAP, mesenchymal markers [α smooth muscle actin (α-SMA), vimentin, and Snail], and endothelial cell markers (CD31 and zonula occludens 1) were measured by Western blotting, quantitative real-time PCR, and immunofluorescence microscopy. Small molecules YC-1 (Lificiguat, a specific inhibitor of hypoxia-inducible factor 1α), CA3 (CIL56, an inhibitor of YAP), and XMU-MP-1 (an inhibitor of Hippo kinase MST1/2, which activates YAP) were used to explore the underlying mechanism. RESULTS: CoCl2 increased expression of mesenchymal markers, decreased expression of endothelial cell markers, and enhanced the ability of primary HUVECs to proliferate and migrate. YC-1 suppressed hypoxia-induced endothelial-to-mesenchymal transition (EndMT). Moreover, hypoxia promoted total expression, inhibited phosphorylation, and enhanced the transcriptional activity of YAP. XMU-MP-1 enhanced hypoxia-induced EndMT, whereas CA3 elicited the opposite effect. Expression of YAP, α-SMA, and vimentin were upregulated in the laser-induced CNV model. However, silencing of YAP by vitreous injection of small interfering RNA targeting YAP could reverse these changes. CONCLUSION: The findings reveal a critical role of the hypoxia-inducible factor-1α (HIF-1α)/YAP signaling axis in EndMT and provide a new therapeutic target for treatment of subretinal fibrosis in AMD.

Silencing of YAP attenuates pericyte-myofibroblast transition and subretinal fibrosis in experimental model of choroidal neovascularization.

Age-related macular degeneration (AMD) is the main reason of irreversible vision loss in the elderly. The subretinal fibrosis subsequent to choroidal neovascularization (CNV) is an important feature in the late stage of wet AMD and is considered to be one reason for incomplete response to anti-VEGF drugs. Recent studies have shown that pericyte-myofibroblast transition (PMT) is an important pathological process involving fibrotic diseases of various organs. However, the specific role and mechanism of PMT in the subretinal fibrosis of CNV have not been clarified. It has been clear that the Hippo pathway along with its downstream effector Yes-associated protein (YAP) plays an important role in both epithelial and endothelial myofibroblast development. Therefore, we speculate whether YAP participates in PMT of pericytes and promotes fibrosis of CNV. In this study, experimental CNV was induced by laser photocoagulation in C57BL/6J (B6) mice, and aberrant YAP overexpression was detected in the retinal pigment epithelial/choroid/sclera tissues of the laser-injured eyes. YAP knockdown reduced the proliferation, migration, and differentiation of human retinal microvascular pericytes in vitro. It also reduced subretinal fibrosis of laser-induced CNV in vivo. Moreover, by proteomics-based analysis of pericyte conditioned medium (PC-CM) and bioinformatic analyses, we identified that the crosstalk between Hippo/YAP and MAPK/Erk was involved in expression of filamin A in hypoxic pericytes. These findings suggest that Hippo/YAP and MAPK/Erk are linked together to mediate pericyte proliferation, migration as well as differentiation, which may embody potential implications for treatment in diseases related to CNV.

Image enhancement of color fundus photographs for age-related macular degeneration: the Shanghai Changfeng Study.

AIM: To develop and evaluate a new fundus image optimization software based on red, green, blue channels (RGB) for the evaluation of age-related macular degeneration (AMD) in the Chinese population. METHODS: Fundus images that were diagnosed as AMD from the Shanghai Changfeng Study database were analyzed to develop a standardized optimization procedure. Image brightness, contrast, and color balance were measured. Differences between central lesion area and normal retinal area under different image brightness, contrast, and color balance were observed. The optimal optimization parameters were determined based on the visual system to avoid image distortion. A paired-sample diagnostic test was used to evaluate the enhancement software. Fundus optical coherence tomography (OCT) was used as the gold standard. Diagnostic performances were compared between original images and optimized images using McNemar's test. RESULTS: A fundus image optimization procedure was developed using 86 fundus images of 74 subjects diagnosed with AMD. By observing gray-scale images, choroid can be best displayed in red channel and retina in green channel was found. There was limited information in blue channel. Totally 104 participants were included in the paired sample diagnostic test to assess the performance of the optimization software. After the image enhancement, sensitivity increased from 74% to 88% (P=0.008), specificity decreased slightly from 88% to 84% (P=0.500), and Youden index increased by 0.11. CONCLUSION: The standardized image optimization software increases diagnostic sensitivity and may help ophthalmologists in AMD diagnosis and screening.

Measurement of the Lid Margin Thickness in Meibomian Gland Dysfunction with Vernier Micrometer.

INTRODUCTION: To investigate the lid margin thickness (LMT) from the posterior lash line to the mucocutaneous junction at the middle position in adults with and without meibomian gland dysfunction (MGD) by vernier micrometer (VM). METHODS: This is a cross-sectional, observational study. A hundred eyes from 100 volunteers aged 20 to 79, including 56 normal participants and 44 participants with MGD, were recruited. Measurements of the LMT by VM were performed by the same person. RESULTS: The mean age of 56 normal subjects (24 males and 32 females) and 44 MGD subjects (16 males and 28 females) was 40.0 ± 13.2 years and 42.7 ± 17.1 years, respectively. There was a significant difference in the upper LMT between normal and MGD subjects (1.36 ± 0.25 vs. 1.60 ± 0.27 mm, P < 0.001), but not in the lower LMT (1.0 ± 0.23 vs. 1.10 ± 0.28 mm, P = 0.07). In both normal and MGD subjects, the upper or lower LMT was significantly positively correlated with age (P < 0.05), and the upper LMT was greater than the lower LMT (P < 0.001). In addition, the lower LMT in MGD subjects was significantly positively correlated with meibum expressibility (rs = 0.35, P = 0.02). CONCLUSIONS: The LMT was closely related to age and could be an important indicator for detecting MGD. Furthermore, we found that the upper LMT was greater than the lower LMT, and the lower LMT in MGD subjects seemed to be related to meibum expressibility.

Platelet-derived growth factor-BB promotes proliferation and migration of retinal microvascular pericytes by up-regulating the expression of C-X-C chemokine receptor types 4.

Stromal cell-derived growth factor (SDF)-1α acts as a ligand to C-X-C chemokine receptors 4 (CXCR4) and 7 (CXCR7), which are involved in the formation of choroidal neovascularization. Previous studies have demonstrated crosstalk between the platelet-derived growth factor (PDGF)-BB/PDGF receptor (PDGFR)-ß and SDF-1α/CXCR4 axes during tumor neovascularization by increasing the recruitment of pericytes. However, the effects of interactions between these two signaling pathways in retinal microvascular pericytes remain poorly understood. Western blotting and reverse transcription-quantitative PCR were used to measure CXCR4 and CXCR7 expression in PDGF-BB-treated pericytes, whilst Cell Counting Kit-8 and Transwell migration assays were used to investigate cell viability and migration following PDGF-BB pretreatment on SDF-1α-treated pericytes. Exogenous PDGF-BB enhanced CXCR4 and CXCR7 expression through PDGFR-ß in a dose- and time-dependent manners. In addition, PDGF-BB increased cell viability and migration in SDF-1α-treated pericytes, which were inhibited by AMD3100 and niclosamide, inhibitors for CXCR4 and STAT3 respectively. Crosstalk between PDGF-BB/PDGFR-ß and SDF-1α/CXCR4/CXCR7 were involved in the JAK2/STAT3 signaling pathway. PDGF-BB treatment enhanced CXCR4, CXCR7 and PDGFR-ßexpression, which may be associated with the phosphorylation of STAT3. siRNA-PDGFR-ß transfection reduced CXCR4 and CXCR7 expression in pericytes. Therefore, PDGF-BB directly targets PDGFR-ß and serves an important role in regulating CXCR4 and CXCR7 expression, ultimately affecting viability and migration in SDF-1α-treated pericytes. Therefore, targeting CXCR4/CXCR7 may serve as a potential therapeutic strategy for fundus diseases.

The Relationship between Visual Field Global Indices and Retinal Nerve Fiber Layer Thickness in Healthy Myopes.

The aim of the current study was to investigate the association between the thickness of the retinal nerve fiber layer (RNFL) and central visual field indices in otherwise healthy myopes. In total, 57 otherwise healthy subjects were cross-sectionally studied. General ophthalmic examinations, refractive measurements, RNFL thickness by spectral domain optical coherence tomography (OCT), and central visual fields were examined. Linear models were used to assess the associations. In this young and mid-aged population, the mean spherical equivalent was -4.79 (SD 1.66) and -4.59 (SD 1.88) diopters in the right and left eyes, respectively. Approximately 7% to 14% of the eyes showed the average RNFL thickness out of the normal range. The temporal RNFL was remarkably thicker, whereas the nasal RNFL was thinner. The higher the refractive error, the thinner the RNFL thickness. A thicker overall RNFL was significantly associated with decreased mean sensitivity and increased mean defect, and further adjustments for age, sex, refractive error, optic disk area, or ocular magnification did not change the association. Although nonpathologic myopia does not significantly affect central visual field global indices, its effects on the RNFL may be linked with performance on the central visual field test.

Analysis of corneal astigmatism in cataract surgery candidates at a teaching hospital in Shanghai, China.

PURPOSE: To describe and quantify the pattern of corneal astigmatism in cataract surgery candidates and to provide information for cataract surgeons and intraocular lens (IOL) manufacturers. SETTING: Zhongshan Hospital, Fudan University, Shanghai, China. DESIGN: Cross-sectional study. METHODS: The datasets of cataract surgery candidates acquired between November 1, 2009, and November 30, 2011, were collected and analyzed. Keratometry values were optically measured by partial coherence interferometry (IOLMaster) before cataract extraction. Spearman rank correlation coefficients were used to estimate bivariate correlations. The power vector method, J(0) and J(45) values, and linear regression models were used to assess the association between age and astigmatism. RESULTS: The study evaluated the keratometry values in 1430 eyes (827 patients) with a median age of 75 years (range 16 to 98 years). The corneal astigmatism was 1.00 diopter (D) or higher in 45.45% of eyes. The magnitude of corneal astigmatism was positively correlated with age (ρ = 0.126, P = .000). A trend toward increasing against-the-rule astigmatism with age was found by linear regression models; the per-year increase in age was associated with a J(0) decrease of 0.016 D in right eyes and 0.018 D in left eyes (both P = .000). No association was found between age and J(45). CONCLUSIONS: Most eyes having corneal astigmatism of 1.00 D or greater could be covered by the range of the cylindrical power of the toric IOLs available on the market. Against-the-rule corneal astigmatism of relatively younger cataract surgery candidates should be managed more aggressively. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

[Anti-angiogenesis effect of AMD3100 in oxygen-induced retinopathy mice].

OBJECTIVE: To observe the inhibition of neovascularisation in the oxygen-induced retinopathy (OIR) mice by a stromal cell-derived factor 1 (SDF-1) antagonist. METHODS: Experimental study. Fifty-eight 7-day-old C57BL/6 mice were divided into 3 groups randomly, the control group (n = 17), the test group (n = 17) and the medication group (n = 24). According to the dosage of AMD3100, the medication group (n = 24) were divided into low dose group, high dose group, low dose control group, and high dose control group (each group n = 6). Each group (19-day-old) was sacrificed to perform ADPase staining, paraffin sections and immunohistochemical staining (anti-VEGF and anti-SDF-1). The average positive staining area percentage (APSAP) was measured as the outcomes and processed with the Students' t-test. RESULTS: Real-time PCR showed expression of both VEGF mRNA (0.080 ± 0.022 vs. 0.123 ± 0.032) and SDF-1 mRNA (0.731 ± 0.099 vs.0.544 ± 0.108) in retinas from the control group and test group, respectively. The expression of these factors in the test group was significantly higher (t = 2.488, P = 0.038;t = 2.864, P = 0.021). The number of neovascular endothelial nuclear that broke through the retinal internal limiting membrane in the paraffin section in the high dose group and the low dose group was significantly less than that in the self-control group (t = -9.507, P = 0.000; t = -10.761, P = 0.000). The appearance of ADPase staining sections in the medication group was more similar to the simple control group than that of the test group. Immunohistochemical staining sections showed that VEGF and SDF-1 expressed in neuroepithelial cells in each group. APSAP in the high dose group and the low dose group was significantly lower than that in the self-control group (VEGF: t = -7.249, P = 0.000; t = -9.02, P = 0.000; SDF-1: t = -5.246, P = 0.000; t = -5.216, P = 0.000). CONCLUSION: These results indicate that AMD3100 block the SDF-1 receptor to reduce the effect of SDF-1, decrease the production of VEGF protein and inhibite neovascularization.

Effect of Fufang Xueshuantong Capsule on a rat model of retinal vein occlusion.

OBJECTIVE: To establish a retinal vein occlusion (RVO) animal model and observe the therapeutic effect of a Chinese herbal composition (Fufang Xueshuantong Capsule, , FXC)inischemicinischemic) in ischemic retinal disease. METHODS: Fifteen adult male Sprague-Dawley rats underwent laser photothrombosis to induce RVO on their right eyes and were subsequently randomized to receive FXC (the intervention group, n=7) or placebo treatment (the control group, n=8). Fundus fluorescein angiography was performed after 2, 4 and 8 weeks of treatment. Real-time reverse transcription-PCR was used to quantify the mRNA expression of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1). The main outcomes were the mRNA copies of VEGF and SDF-1 and the counts of RVO signs. RESULTS: Laser photothrombosis procedure induced typical lesions of RVO, including hemorrhage, leakage, retinal detachment, capillary non-perfusion, filling defect of retinal vessels, and lateral circulation/dilation of small vessels. The retinal lesions were associated with an increased expression of VEGF (P<0.05). No significant change of SDF-1 expression was noticed. Compared with the control group, the intervention group had numerically fewer RVO lesions at week 2 (1.71±0.76 vs. 3.50±1.51, t=-2.82, P<0.05). The benefit of intervention remained at weeks 4 and 8. CONCLUSIONS: A rat model of laser photothrombosis-induced RVO was established and an increase in the VEGF expression was observed in the retinal lesion. The FXC had therapeutic benefit in improving retinal lesions in the rat model of RVO.

[Expression of stromal cell-derived factor 1 is increased in the retina of experimental diabetic rats].

OBJECTIVE: To investigate the expression of stromal cell-derived factor 1 (SDF-1) in retina of experimental diabetic rats. METHODS: Thirty four healthy male Wistar rats of six to eight weeks old were chosen and divided randomly into 3 groups: normal control (CON, n = 8), diabetes mellitus 2 months (DM2M, n = 14) and 3 months (DM3M, n = 12). Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) (60 mg/kg). At the end point, immunochemistry and digital photomicrography analysis were employed to localize and quantitate the expression of SDF-1 in the retinas. The ratios of integrated optical density (IOD) to area of interest (AOI) were calculated to evaluate the intensities of positive staining. Values of z and t, as well as P value of each, were determined by Wilcoxon-Mann-Whitney test and Student's t-test, respectively. Immunofluorescent double-staining was used to indicate the co-expression of SDF-1 and hypoxia-inducible factor-1 (HIF-1), a pivotal transcription factor activated by hypoxia. The SDF-1 mRNA of the retina from DM2M (n = 4) and CON (n = 2) was detected by real-time RT-PCR. Copies of SDF-1 mRNA were then adjusted by the copies of beta-actin mRNA in each sample. Differences between groups were compared by a Student's t test. RESULTS: Positive immunohistochemical staining for SDF-1 was found in each group, most of which located in the inner part of the retina, especially at the inner nuclear layer (INL) and ganglion cell layer (GCL). The inter-quartile range of IOD/AOI of SDF-1 was between 0.6 x 10(-2) to 1.5 x 10(-2) in diabetic group, and 1.1 x 10(-3) to 2.4 x 10(-3) in control group (z = -3.359, P < 0.001). There was no significant difference between DM2M and DM3M (t = 0.952, P > 0.05). Co-expression of SDF-1 and HIF-1 was found in some cells in the inner part of the retina of diabetic rats. Copies of SDF-1 mRNA in DM2M were 2.3 x 10(-4) +/- 1.2 x 10(-4), and those in CON were 2.9 x 10(-4) +/- 1.0 x 10(-4). The ratios of them to beta-actin were 3.3 x 10(-2) +/- 8.5 x 10(-3) for DM2M and 1.7 x 10(-2) +/- 5.7 x 10(-3) for CON (t = 2.33, P < 0.05). CONCLUSION: Possibly promoted by HIF-1, expression of SDF-1 is increased in the retinas of diabetic rats, which may play an important role in the mechanism of diabetic retinopathy.