The dose-dependent macular thickness changes assessed by fd-oct in patients with retinitis pigmentosa treated with ciliary neurotrophic factor.

PURPOSE: To evaluate the effect of intravitreal ciliary neurotrophic factor (CNTF) implant on mean macular thickness (MMT) in eyes with retinitis pigmentosa using high-resolution Fourier domain optical coherence tomography imaging. METHODS: A cohort of 8 patients (CNTF-3: n = 5; CNTF-4: n = 3) enrolled in Neurotech sponsored Phase 2 clinical trial underwent Fourier domain optical coherence tomography imaging. A ≥3% change in MMT from baseline or fellow eye was considered as a measurable change. RESULTS: Two patients enrolled in the CNTF-3 study received low-dose implant. At 18 months, a change in MMT from -4.47 µm to 6 µm from baseline was noted. Six patients received high-dose implant (CNTF-3: n = 3; CNTF-4: n = 3). In CNTF-3 group, 1 eye showed an increase in MMT by 19.25 µm (+7.6%) from baseline at 18 months. In CNTF-4 group, 1 eye had an increase in MMT of 27.08 µm (+11%) from baseline at 30 months; second eye had increase in MMT of 31.36 µm (+12%) from contralateral eye. Amongst these 3 responsive high-dose implant eyes, overall thickening of the retina could not be attributed to any specific retinal layer. CONCLUSION: A heterogeneous dose-dependent response on MMT was noted in eyes treated using intravitreal CNTF implant for retinitis pigmentosa. We recommend corroboration of our findings with Neurotech sponsored clinical trial results.

METformin for the MINimization of Geographic Atrophy Progression (METforMIN): A Randomized Trial.

Purpose: Metformin use has been associated with a decreased risk of age-related macular degeneration (AMD) progression in observational studies. We aimed to evaluate the efficacy of oral metformin for slowing geographic atrophy (GA) progression. Design: Parallel-group, multicenter, randomized phase II clinical trial. Participants: Participants aged ≥ 55 years without diabetes who had GA from atrophic AMD in ≥ 1 eye. Methods: We enrolled participants across 12 clinical centers and randomized participants in a 1:1 ratio to receive oral metformin (2000 mg daily) or observation for 18 months. Fundus autofluorescence imaging was obtained at baseline and every 6 months. Main Outcome Measures: The primary efficacy endpoint was the annualized enlargement rate of the square root-transformed GA area. Secondary endpoints included best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) at each visit. Results: Of 66 enrolled participants, 34 (57 eyes) were randomized to the observation group and 32 (53 eyes) were randomized to the treatment group. The median follow-up duration was 13.9 and 12.6 months in the observation and metformin groups, respectively. The mean ± standard error annualized enlargement rate of square root transformed GA area was 0.35 ± 0.04 mm/year in the observation group and 0.42 ± 0.04 mm/year in the treatment group (risk difference = 0.07 mm/year, 95% confidence interval = -0.05 to 0.18 mm/year; P = 0.26). The mean ± standard error decline in BCVA was 4.8 ± 1.7 letters/year in the observation group and 3.4 ± 1.1 letters/year in the treatment group (P = 0.56). The mean ± standard error decline in LLVA was 7.3 ± 2.5 letters/year in the observation group and 0.8 ± 2.2 letters/year in the treatment group (P = 0.06). Fourteen participants in the metformin group experienced nonserious adverse events related to metformin, with gastrointestinal side effects as the most common. No serious adverse events were attributed to metformin. Conclusions: The results of this trial as conducted do not support oral metformin having effects on reducing the progression of GA. Additional placebo-controlled trials are needed to explore the role of metformin for AMD, especially for earlier stages of the disease. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Anti-EMP2 diabody blocks epithelial membrane protein 2 (EMP2) and FAK mediated collagen gel contraction in ARPE-19 cells.

Epithelial membrane protein 2 (EMP2) regulates collagen gel contraction by the retinal pigment epithelium cell line ARPE-19 by modulating FAK activation. Collagen gel contraction is one in vitro model for an aberrant wound healing response, proliferative vitreoretinopathy (PVR), which occurs as a complication of severe ocular trauma. The purpose of this study is to investigate whether EMP2 specific recombinant diabody decreases activation of FAK and collagen gel contraction in ARPE-19. Anti-EMP2 diabody was recombinantly constructed from a human phage library-derived clone selected for reactivity against an extracellular domain of human EMP2. ARPE-19 cells were exposed to an anti-EMP2 or control diabody, and toxicity, adhesion, and migration were assessed respectively through toluidine blue exclusion, binding to collagen type 1, and a migration assay. Collagen gel contraction was assessed using an in vitro assay. FAK activation was evaluated using Western blot. Exposure to anti-EMP2 diabody, resulted in a 75% reduction in EMP2 protein levels at 4 h. No significant toxicity was observed with anti-EMP2 diabody at levels that maximally reduced EMP2. Anti-EMP2 diabody, but not control diabody, significantly reduced collagen gel contraction (p < 0.001), without changes in adhesion or migration. Concordantly, anti-EMP2 diabody as compared to a control diabody reduced collagen stimulated FAK activation (p = 0.01). Anti-EMP2 diabody decreases EMP2 protein levels, FAK activation, and collagen gel contraction by ARPE-19 cells without an adverse effect on cell survival. Modulation of EMP2 using anti-EMP2 diabody could be a new approach for targeting EMP2 and pathologic consequences associated with EMP2.

B-cell lymphoma line (Raji) viability and surface marker expression minimally affected by 20- and 25-gauge vitrectomy systems analyzed by flow cytometry.

PURPOSE: The purpose of this study was to evaluate the effect of 20-gauge (20-G) and 25-gauge (25-G) vitrectomy on cell viability and diagnostic yield (surface marker expression) using flow cytometry and human lymphoma cells in culture. METHODS: Cultured human Burkitt lymphoma cells (Raji B-cell lymphoma line) were allocated into five study groups in Roswell Park Memorial Institute media. By using manual aspiration, cells were then processed by aspiration alone, by 20-G vitrectomy at 600 cuts per minute (cpm) and 1,500 cpm, or by 25-G vitrectomy at both 600 and 1,500 cpm. To assess cell viability and cell surface marker expression, samples underwent standard flow cytometry analysis for suspected lymphoma using 7-amino-actinomycin D and antibodies against CD45, CD19, lambda, and kappa light chains. RESULTS: Twenty-five samples were processed after being divided into four vitrectomy groups and one nonvitrectomy group (control). The mean cell viability was 98.5 for both the nonvitrectomized and vitrectomized specimens. The percentage of cells positive for CD45 or kappa light chain was the same in the nonvitrectomized and vitrectomized groups. In addition, the level of expression of these molecules was not significantly different in all five groups. Similarly, no difference was seen for these markers between 20-G and 25-G vitrectomy at either a cut rate of 600 or 1,500 cpm. The percentage positive for CD19 was significantly lower for the 20-G vitrectomy at 1,500 cpm compared with the 25-G vitrectomy at both 600 and 1,500 cpm. Percentage of CD19 cells was greater for the 25-G vitrectomy at 600 cpm than the nonvitrectomy group. CONCLUSION: Compared with simple aspiration, both 20-G and 25-G vitrectomy seem to have no significant effect on cell viability or diagnostic yield for B-cell lymphoma cells (Raji cell line) in suspension based on flow cytometry. Further studies need to be conducted to study and compare 20-G versus 25-G vitrectomy on lymphoma cells in human vitreous or in an animal model.

Comparison of macular thickness measurement and segmentation error rate between stratus and fourier-domain optical coherence tomography.

BACKGROUND AND OBJECTIVE: To compare macular thickness measurements and segmentation error rates between Stratus optical coherence tomography (OCT) (Carl Zeiss Meditec, Inc., Dublin, CA), and Fourier-domain OCT (RTVue, Optovue, Inc., Fremont, CA). PATIENTS AND METHODS: A retrospective study was performed of 93 normal and pathologic eyes from 79 subjects imaged with both OCT instruments on the same day. Both the macular thickness measurement for each Early Treatment Diabetic Retinopathy Study (ETDRS) zone and the incidence of segmentation error in the central macula between the two instruments were compared. RESULTS: Macular thickness measurements for all nine ETDRS zones were higher with RTVue compared with Stratus OCT (P < .01). Linear regression analysis showed the highest correlation in the central macula (R(2) = 0.88), with progressively lower correlation peripherally. The overall segmentation error rate was 29% with Stratus OCT versus 32% with RTVue (P > .05). CONCLUSION: Macular thickness measurement was greater with RTVue than with Stratus OCT in all ETDRS areas, with the best correlation seen in the central macula. No difference in segmentation error rate was noted between the two instruments.

High-resolution Fourier-domain optical coherence tomography and microperimetric findings after macula-off retinal detachment repair.

OBJECTIVE: To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). DESIGN: Prospective observational case series. PARTICIPANTS: Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. METHODS: FD OCT with axial and transverse resolution of 4.5 mum and 10 to 15 mum, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. MAIN OUTCOME MEASURES: Stratus OCT scans, FD OCT scans, and MP-1 data. RESULTS: Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (P<0.001, chi(2)). Both imaging modalities revealed persistent subretinal fluid in 2 eyes (12%) and lamellar hole in 1 eye. Among 7 subjects who had reliable MP-1 data, areas of abnormal function corresponded to areas of photoreceptor layer disruptions or persistent subretinal fluid in 5 subjects (71%); one subject had normal FD OCT and MP-1. CONCLUSIONS: Photoreceptor disruption after macula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair.

Cystoid macular edema with docetaxel chemotherapy and the fluid retention syndrome.

Docetaxel (Taxotere) is an anticancer agent used to treat a wide range of malignancies including breast, lung, and prostate cancer. In this report, we describe a patient with bilateral vision loss due to cystoid macular edema (CME) associated with docetaxel therapy. This report documents for the first time the optical coherence tomography (OCT) findings of CME despite the lack of leakage with flourescein angiography and its association with the Fluid Retention Syndrome (FRS). Successful management of CME with oral acetazolamide is also discussed.

Rubeosis and anterior segment ischemia associated with systemic cryoglobulinemia.

PURPOSE: To report two cases of iris neovascularization associated with systemic cryoglobulinemia. DESIGN: Retrospective case report. METHODS: Patient chart review and review of literature. RESULTS: Two patients with iris neovascularization in the absence of retinal ischemia were subsequently found to have systemic cryoglobulinemia. Successful treatment of one patient's underlying lymphoma led to stabilization and resolution of neovascularization. CONCLUSIONS: Systemic cryoglobulinemia may be associated with anterior segment ischemia and neovascularization, and should be considered in the differential diagnosis of iris neovascularization in the absence of apparent retinal ischemia.

Comparison of In Vivo Gene Expression Profiling of RPE/Choroid following Intravitreal Injection of Dexamethasone and Triamcinolone Acetonide.

Purpose. To identify retinal pigment epithelium (RPE)/choroid genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care. Methods. Differential gene expression of over 34,000 well-characterized mouse genes in the RPE/choroid of 6-week-old C57BL/6J mice was analyzed after intravitreal steroid injections at 1 week and 1 month postinjection, using Affymetrix Mouse Genome 430 2.0 microarrays. The data were analyzed using GeneSpring GX 12.5 and Ingenuity Pathway Analysis (IPA) microarray analysis software for biologically relevant changes. Results. Both triamcinolone and dexamethasone caused differential activation of genes involved in "Circadian Rhythm Signaling" pathway at both time points tested. Triamcinolone (TAA) uniquely induced significant changes in gene expression in "Calcium Signaling" (1 week) and "Glutamate Receptor Signaling" pathways (1 month). In contrast, dexamethasone (Dex) affected the "GABA Receptor Signaling" (1 week) and "Serotonin Receptor Signaling" (1 month) pathways. Understanding how intraocular steroids affect the gene expression of RPE/choroid is clinically relevant. Conclusions. This in vivo study has elucidated several genes and pathways that are potentially altering the circadian rhythms and several other neurotransmitter pathways in RPE/choroid during intravitreal steroid injections, which likely has consequences in the dysregulation of RPE function and neurodegeneration of the retina.

Epithelial Membrane Protein-2 in Human Proliferative Vitreoretinopathy and Epiretinal Membranes.

PURPOSE: To determine the level of epithelial membrane protein-2 (EMP2) expression in preretinal membranes from surgical patients with proliferative vitreoretinopathy (PVR) or epiretinal membranes (ERMs). EMP2, an integrin regulator, is expressed in the retinal pigment epithelium and understanding EMP2 expression in human retinal disease may help determine whether EMP2 is a potential therapeutic target. METHODS: Preretinal membranes were collected during surgical vitrectomies after obtaining consents. The membranes were fixed, processed, sectioned, and protein expression of EMP2 was evaluated by immunohistochemistry. The staining intensity (SI) and percentage of positive cells (PP) in membranes were compared by masked observers. Membranes were categorized by their cause and type including inflammatory and traumatic. RESULTS: All of the membranes stained positive for EMP2. Proliferative vitreoretinopathy-induced membranes (all causes) showed greater expression of EMP2 than ERMs with higher SI (1.81 vs. 1.38; P = 0.07) and PP (2.08 vs. 1.54; P = 0.09). However all the PVR subgroups had similar levels of EMP2 expression without statistically significant differences by Kruskal-Wallis test. Inflammatory PVR had higher expression of EMP2 than ERMs (SI of 2.58 vs. 1.38); however, this was not statistically significant. No correlation was found between duration of PVR membrane and EMP2 expression. EMP2 was detected by RT-PCR in all samples (n = 6) tested. CONCLUSIONS: All studied ERMs and PVR membranes express EMP2. Levels of EMP2 trended higher in all PVR subgroups than in ERMs, especially in inflammatory and traumatic PVR. Future studies are needed to determine the role of EMP2 in the pathogenesis and treatment of various retinal conditions including PVR.

GSTM1 and GSTM5 Genetic Polymorphisms and Expression in Age-Related Macular Degeneration.

PURPOSE: Previously, two cytosolic antioxidant enzymes, Glutathione S-transferase Mu 1 (GSTM1) and Mu 5 (GSTM5), were reduced in retinas with age-related macular degeneration (AMD). This study compared genomic copy number variations (gCNV) of these two antioxidant enzymes in AMD versus controls. METHODS: Genomic copy number (gCN) assays were performed using Taqman Gene Copy Number Assays (Applied Biosystems, Darmstadt, Germany) in technical quadruplicate for both GSTM1 and GSTM5. Peripheral leukocyte RNA levels were compared with controls in technical triplicates. Statistical comparisons were performed in SAS v9.2 (SAS Institute Inc., Cary, NC). RESULTS: A large percentage of patients in both AMD and age-matched control groups had no copies of GSTM1 (0/0). The mean gCN of GSTM1 was 1.40 (range 0-4) and 1.61 (range 0-5) for AMD and control, respectively (p = 0.29). A greater percentage of control patients had > 3 gCNs of GSTM1 compared with AMD, respectively (15.3% versus 3.0%, p = 0.004). The gCN of GSTM5 was 2 in all samples except one control sample. The relative quantification of GSTM1 and GSTM5 mRNA from peripheral blood leukocytes in patients showed significant differences in relative expression in AMD versus control (p < 0.05). Peripheral blood leukocyte mRNA and gCN were not significantly correlated (p = 0.27). CONCLUSION: Since high copy numbers of GSTM1 are found more frequently in controls than in AMD, it is possible that high copy number leads to increased retinal antioxidant defense. Genomic polymorphisms of GSTM1 and GSTM5 do not significantly affect the peripheral blood leukocyte mRNA levels.

Reprint of: Survey of patients with age-related macular degeneration: knowledge and adherence to recommendations.

OBJECTIVE: To evaluate the patient's understanding of the importance and adherence to the various lifestyle and Age-Related Eye Disease Study (AREDS) supplement recommendations for age-related macular degeneration (AMD). DESIGN: Cross-sectional study. PARTICIPANTS: Patients with AMD treated at the vitreoretinal service clinic. METHODS: Telephone questionnaire survey was administered to assess knowledge and adherence to various recommendations made to patients with AMD about lifestyle and AREDS supplements in this single-institution study. RESULTS: Among 92 patients with AMD contacted, dietary modification, exercise and weight reduction, smoking cessation, and AREDS supplementation recommendations were recalled by 47 (51%), 21 (23%), 5 (5%), and 90 (98%) patients, respectively. The necessity of making these interventions was believed by 29 (62%), 16 (76%), 4 (80%), and 67 (74%) patients, respectively. Patient adherence to dietary modification was 81%, to exercise and weight reduction was 76%, to smoking cessation was 0%, and to AREDS supplementation was 88% (71% on correct dose). Financially, 29% of the patients noted a mean increase of $88 per month in expenditure because of making dietary modifications, but most reported such as justified; 61% noted a mean increase of $25 per month in expenditure from consumption of AREDS supplements, and most (96%) believed this was justified. CONCLUSIONS: Patients with AMD recalled recommendations for AREDS supplementation more often than other lifestyle changes but generally felt recommendations were necessary and affordable. Adherence to smoking cessation recommendation was poor (0%), but to other recommendations was good.

Falciform macular folds and chromosome 22q11.2: evidence in support of a locus for familial exudative vitreoretinopathy (FEVR).

BACKGROUND: Familial exudative vitreoretinopathy (FEVR) is a genetic disease caused by abnormal retinal vascular development. New additional genetic loci for FEVR have recently been identified. Microduplication of 22q11.2 has been reported with a heterogeneous phenotype and microdeletion of 22q11.2 has been associated with FEVR. We describe a case of a girl with microduplication of 22q11.2 and falciform macular folds. MATERIALS AND METHODS: The infant and first-degree relatives were examined. A dilated fundus examination was performed. Genetic screening was done by chromosomal microarray analysis and confirmed by fluorescent in situ hybridization (FISH). RESULTS: Bilateral macular folds were found with temporal fibrosis in the proband. A chromosomal microarray revealed a 2.21 Mb microduplication of the 22q11.2 region. CONCLUSION: This is the first report to associate microduplication of 22q11.2 with macular folds, supporting the potential for a FEVR locus on chromosome 22q11.2. We encourage full ophthalmological examination for patients with microduplication of 22q11.2 to identify ocular associations.

Improving visual outcomes by preserving outer retina morphology in eyes with resolved pseudophakic cystoid macular edema.

PURPOSE: To use ultra-high-resolution optical coherence tomography (OCT) subclinical anatomic alterations to explain suboptimum vision despite pseudophakic cystoid macula edema (CME) resolution. SETTING: University of California-Davis, Sacramento, California, USA. DESIGN: Case study. METHODS: This study comprised patients who had cataract phacoemulsification surgery. Cases of resolved postoperative CME (diagnosed postoperatively by 1 month and resolved by 1 year) were included. Exclusion criteria included any other cause for decreased vision or compounding factors. Patients with a history of resolved pseudophakic CME were imaged using a purpose-built ultra-high-resolution OCT system with 4.5 µm axial resolution and an acquisition speed of 9 frames/sec (1000 A-scans/frame). The corrected distance visual acuity (CDVA) was determined by Early Treatment Diabetic Retinopathy Study standards. Statistical analysis was by the unpaired t test. A P value less than 0.05 was considered significant. RESULTS: The review identified 56 patients with a pseudophakic CME diagnosis at least 1 month postoperatively. Fifteen eyes (26.8%) had less than 20/20 CDVA despite resolution of CME; 7 participated. Four patients with 20/20 CDVA after resolution of pseudophakic CME participated. Eyes with reduced CDVA after macula edema showed ultra-high-resolution OCT evidence of blurring of outer segments of photoreceptors, while controls showed normal outer retina morphology (P<.05). CONCLUSIONS: Persistent anatomic alteration of photoreceptors visualized by ultra-high-resolution OCT correlated with reduced CDVA in patients with pseudophakic CME compared with patients who had 20/20 CDVA after macula edema. This anatomic alteration in outer photoreceptor morphology is a plausible explanation for the reduced CDVA in this disease. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Macular edema in the era of spectral-domain optical coherence tomography.

The development of spectral-domain optical coherence tomography (OCT) allows for the highest commercially available resolution of in vivo retinal anatomic details to date. The ability to see the macula with ever increasing detail is dramatically improving our understanding of the pathogenesis of retinal disease. However, the only prospective study that partially evaluated spectral-domain OCT versus time-domain OCT failed to show any clinical benefit of increased OCT resolution. Clinical outcomes, eg, best-corrected visual acuity, central macular thickness and number of injections, with "newer" OCT technologies remain an unproven advantage.

Survey of patients with age-related macular degeneration: knowledge and adherence to recommendations.

OBJECTIVE: To evaluate the patient's understanding of the importance and adherence to the various lifestyle and Age-Related Eye Disease Study (AREDS) supplement recommendations for age-related macular degeneration (AMD). DESIGN: Cross-sectional study. PARTICIPANTS: Patients with AMD treated at the vitreoretinal service clinic. METHODS: Telephone questionnaire survey was administered to assess knowledge and adherence to various recommendations made to patients with AMD about lifestyle and AREDS supplements in this single-institution study. RESULTS: Among 92 patients with AMD contacted, dietary modification, exercise and weight reduction, smoking cessation, and AREDS supplementation recommendations were recalled by 47 (51%), 21 (23%), 5 (5%), and 90 (98%) patients, respectively. The necessity of making these interventions was believed by 29 (62%), 16 (76%), 4 (80%), and 67 (74%) patients, respectively. Patient adherence to dietary modification was 81%, to exercise and weight reduction was 76%, to smoking cessation was 0%, and to AREDS supplementation was 88% (71% on correct dose). Financially, 29% of the patients noted a mean increase of $88 per month in expenditure because of making dietary modifications, but most reported such as justified; 61% noted a mean increase of $25 per month in expenditure from consumption of AREDS supplements, and most (96%) believed this was justified. CONCLUSIONS: Patients with AMD recalled recommendations for AREDS supplementation more often than other lifestyle changes but generally felt recommendations were necessary and affordable. Adherence to smoking cessation recommendation was poor (0%), but to other recommendations was good.

The comparative histologic effects of subthreshold 532- and 810-nm diode micropulse laser on the retina.

PURPOSE: Therapeutic retinal laser photocoagulation can damage the neurosensory retina and cause iatrogenic visual impairment. Subthreshold micropulse photocoagulation may decrease this risk by selective tissue treatment. The aim of this study was to compare subthreshold 810-nm diode micropulse laser and subthreshold 532-nm micropulse laser on the retina by histologic examination and differential protein expression. METHODS: Fourteen Dutch-belted rabbits received subthreshold 810-nm diode micropulse laser photocoagulation in their right eye and subthreshold 532-nm micropulse laser photocoagulation in their left eye. Histology and immunohistochemical detection of stromal cell-derived factor-1 (SDF-1), ß-actin, vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP), and insulin-like growth factor 1 (IGF-1) were analyzed 12 hours, 3 days, 14 days, and 28 days post-laser photocoagulation. RESULTS: Histologically, all time points produced a similar degree of retinal disruption in both wavelengths. Immunohistochemically, SDF-1 expression was greatest at the 12-hour time point and decreased thereafter. SDF-1, VEGF, and ß-actin up-regulation was detected at early time points in both the 810- and 532-nm micropulse laser-treated animals. CONCLUSIONS: Subthreshold micropulse retinal laser photocoagulation caused equivalent histologic changes from both 532- and 810-nm diode lasers. Differential protein expression was not evident between the different laser conditions.

Epithelial membrane protein 2 controls VEGF expression in ARPE-19 cells.

PURPOSE: VEGF production by RPE cells has been shown to be important in regulating aberrant angiogenesis in the retina, which is responsible for multiple types of ocular pathology. EMP2 is highly expressed in the RPE and has been shown to regulate FAK activation, which is implicated in VEGF expression in other cell lines. The purpose of this study was to determine whether EMP2 regulates VEGF expression in the RPE cell line, ARPE-19. METHODS: ARPE-19 cells were engineered to overexpress EMP2. EMP2 siRNA was used to decrease EMP2 expression. The small molecule inhibitor PP2 was used to inhibit FAK activation. VEGF levels were measured by Western blot and ELISA. Functional differences in secreted VEGF were assayed using HUVEC migration. RESULTS: VEGF expression levels correlated with levels of EMP2. An increase of VEGF by 150% was observed in EMP2 overexpressing cells as compared with ARPE-19 cells. Concordantly, EMP2 knockdown resulted in a 57% decrease in VEGF expression. HUVEC migration (P = 0.01) and vessel tube formation (P < 0.01) were significantly increased when exposed to cell culture supernatants from EMP2 overexpressing cells. CONCLUSIONS: This study establishes a novel connection between EMP2 and VEGF and may reflect either a direct effect through the tetraspan web or an indirect change through FAK activation. This connection is functionally significant. In addition to the direct use of anti-VEGF antibodies, modulation of EMP2 with impact on VEGF is potentially a distinct therapeutic target for the treatment of neovascularization associated with retinal diseases that involve pathologic angiogenesis.