Correction: The Tight Junction Associated Signalling Proteins ZO-1 and ZONAB Regulate Retinal Pigment Epithelium Homeostasis in Mice.

[This corrects the article DOI: 10.1371/journal.pone.0015730.].

Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT.

BACKGROUND: Cataract surgery is one of the most common operations. Femtosecond laser-assisted cataract surgery (FLACS) is a technique that automates a number of operative steps. OBJECTIVES: To compare FLACS with phacoemulsification cataract surgery (PCS). DESIGN: Multicentre, outcome-masked, randomised controlled non-inferiority trial. SETTING: Three collaborating NHS hospitals. PARTICIPANTS: A total of 785 patients with age-related cataract in one or both eyes were randomised between May 2015 and September 2017. INTERVENTION: FLACS (n = 392 participants) or PCS (n = 393 participants). MAIN OUTCOME MEASURES: The primary outcome was uncorrected distance visual acuity in the study eye after 3 months, expressed as the logarithm of the minimum angle of resolution (logMAR): 0.00 logMAR (or 6/6 if expressed in Snellen) is normal (good visual acuity). Secondary outcomes included corrected distance visual acuity, refractive outcomes (within 0.5 dioptre and 1.0 dioptre of target), safety and patient-reported outcome measures at 3 and 12 months, and resource use. All trial follow-ups were performed by optometrists who were masked to the trial intervention. RESULTS: A total of 353 (90%) participants allocated to the FLACS arm and 317 (81%) participants allocated to the PCS arm attended follow-up at 3 months. The mean uncorrected distance visual acuity was similar in both treatment arms [0.13 logMAR, standard deviation 0.23 logMAR, for FLACS, vs. 0.14 logMAR, standard deviation 0.27 logMAR, for PCS, with a difference of -0.01 logMAR (95% confidence interval -0.05 to 0.03 logMAR; p = 0.63)]. The mean corrected distance visual acuity values were again similar in both treatment arms (-0.01 logMAR, standard deviation 0.19 logMAR FLACS vs. 0.01 logMAR, standard deviation 0.21 logMAR PCS; p = 0.34). There were two posterior capsule tears in the PCS arm. There were no significant differences between the treatment arms for any secondary outcome at 3 months. At 12 months, the mean uncorrected distance visual acuity was 0.14 logMAR (standard deviation 0.22 logMAR) for FLACS and 0.17 logMAR (standard deviation 0.25 logMAR) for PCS, with a difference between the treatment arms of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.17). The mean corrected distance visual acuity was 0.003 logMAR (standard deviation 0.18 logMAR) for FLACS and 0.03 logMAR (standard deviation 0.23 logMAR) for PCS, with a difference of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.11). There were no significant differences between the arms for any other outcomes, with the exception of the mean binocular corrected distance visual acuity with a difference of -0.02 logMAR (95% confidence interval -0.05 to 0.00 logMAR) (p = 0.036), which favoured FLACS. There were no significant differences between the arms for any health, social care or societal costs. For the economic evaluation, the mean cost difference was £167.62 per patient higher for FLACS (95% of iterations between -£14.12 and £341.67) than for PCS. The mean QALY difference (FLACS minus PCS) was 0.001 (95% of iterations between -0.011 and 0.015), which equates to an incremental cost-effectiveness ratio (cost difference divided by QALY difference) of £167,620. LIMITATIONS: Although the measurement of outcomes was carried out by optometrists who were masked to the treatment arm, the participants were not masked. CONCLUSIONS: The evidence suggests that FLACS is not inferior to PCS in terms of vision after 3 months' follow-up, and there were no significant differences in patient-reported health and safety outcomes after 12 months' follow-up. In addition, the statistically significant difference in binocular corrected distance visual acuity was not clinically significant. FLACS is not cost-effective. FUTURE WORK: To explore the possible differences in vision in patients without ocular co-pathology. TRIAL REGISTRATION: Current Controlled Trials ISRCTN77602616. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 6. See the NIHR Journals Library website for further project information. Moorfields Eye Charity (grant references GR000233 and GR000449 for the endothelial cell counter and femtosecond laser used).

Cataract is a condition in which the natural lens inside the eye becomes cloudy, leading to loss of vision. In cataract surgery, the cloudy lens is replaced by a clear, artificial one. The standard surgical method (phacoemulsification) is carried out manually by the surgeon using ultrasound. Part of the procedure can now be automated using a computer-controlled laser. This is called femtosecond laser-assisted cataract surgery (FLACS). The potential advantages of FLACS include greater precision reproducibility, but this new technique is more expensive than the standard surgery. We performed a randomised controlled trial comparing the two techniques. We assessed vision, surgical complications, patient-related quality of life and cost-effectiveness at 3 and 12 months. We found that the outcomes were almost identical for eyesight, quality of life and complications. Overall, the evidence suggests that the new technique is not worth the additional costs.

Femtosecond laser-assisted cataract surgery compared with phacoemulsification cataract surgery: randomized noninferiority trial with 1-year outcomes.

PURPOSE: To report the 1-year outcomes of a randomized trial comparing femtosecond laser-assisted cataract surgery (FLACS) and phacoemulsification cataract surgery (PCS). SETTING: Moorfields Eye Hospital, New Cross Hospital, and Sussex Eye Hospital, United Kingdom. DESIGN: Multicenter, randomized controlled noninferiority trial. METHODS: Patients undergoing cataract surgery were randomized to FLACS or PCS. Postoperative assessments were masked. Outcomes included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), complications, corneal endothelial cell count, and patient-reported outcomes measures. RESULTS: The study enrolled 785 participants. A total of 311 of 392 (79%) participants were allocated to FLACS and 292 of 393 (74%) participants were allocated to PCS attended follow-up at 1 year. Mean UDVA was 0.14 (SD = 0.22) for FLACS and 0.17 (0.25) for PCS with difference of -0.03 logarithm of the minimum angle of resolution (logMAR) (95%, -0.06 to 0.01, P = .17). Mean CDVA was 0.003 (0.18) for FLACS and 0.03 (0.23) for PCS with difference of -0.03 logMAR (95% CI, -0.06 to 0.01, P = .11); 75% of both FLACS (230/307) and PCS (218/290) cases were within ±0.5 diopters (D) refractive target, and 292 (95%) of 307 eyes of FLACS and 279 (96%) of 290 eyes of PCS groups were within ±1.0 D. There were no significant differences between arms for all other outcomes with the exception of binocular CDVA mean difference -0.02 (-0.05 to 0.002) logMAR (P = .036) favoring FLACS. Mean cost difference was £167.62 per patient greater for FLACS (95% iterations between -£14.12 and £341.67). CONCLUSIONS: PCS is not inferior to FLACS regarding vision, patient-reported health, and safety outcomes after 1-year follow-up. A difference was found for binocular CDVA, which, although statistically significant, was not clinically important. FLACS was not cost-effective.

Femtosecond Laser-Assisted Cataract Surgery Versus Phacoemulsification Cataract Surgery (FACT): A Randomized Noninferiority Trial.

PURPOSE: To report the 3-month results of a randomized trial (Femtosecond Laser-Assisted Cataract Trial [FACT]) comparing femtosecond laser-assisted cataract surgery (FLACS) with standard phacoemulsification cataract surgery (PCS). DESIGN: Multicenter, randomized controlled trial funded by the UK National Institute of Health Research (HTA 13/04/46/). PARTICIPANTS: Seven hundred eighty-five patients with age-related cataract. METHODS: This trial took place in 3 hospitals in the UK National Health Service (NHS). Randomization (1:1) was stratified by site, surgeon, and 1 or both eyes eligible using a secure web-based system. Postoperative assessments were masked to the allocated intervention. The primary outcome was unaided distance visual acuity (UDVA) in the study eye at 3 months. Secondary outcomes included corrected distance visual acuity, complications, and patient-reported outcomes measures. The noninferiority margin was 0.1 logarithm of the minimum angle of resolution (logMAR). ISRCTN.com registry, number ISRCTN77602616. MAIN OUTCOME MEASURES: We enrolled 785 participants between May 2015 and September 2017 and randomly assigned 392 to FLACS and 393 to PCS. At 3 months postoperatively, mean UDVA difference between treatment arms was -0.01 logMAR (-0.05 to 0.03), and mean corrected distance visual acuity difference was -0.01 logMAR (95% confidence interval [CI], -0.05 to 0.02). Seventy-one percent of both FLACS and PCS cases were within ±0.5 diopters (D) of the refractive target, and 93% of FLACS and 92% of PCS cases were within ±1.0 D. There were 2 posterior capsule tears in the PCS arm and none in the FLACS arm. There were no significant differences between arms for any secondary outcome. CONCLUSIONS: Femtosecond laser-assisted cataract surgery is not inferior to conventional PCS surgery 3 months after surgery. Both methods are as good in terms of vision, patient-reported health, and safety outcomes at 3 months. Longer-term outcomes of the clinical effectiveness and cost-effectiveness are awaited.

Repeatability of swept-source optical coherence tomography retinal and choroidal thickness measurements in neovascular age-related macular degeneration.

BACKGROUND: The aim was to determine the intrasession repeatability of swept-source optical coherence tomography (SS-OCT)-derived retinal and choroidal thickness measurements in eyes with neovascular age-related macular degeneration (nAMD). METHODS: A prospective study consisting of patients with active nAMD enrolled in the Distance of Choroid Study at Moorfields Eye Hospital, London. Patients underwent three 12×9 mm macular raster scans using the deep range imaging (DRI) OCT-1 SS-OCT (Topcon) device in a single imaging session. Retinal and choroidal thicknesses were calculated for the ETDRS macular subfields. Repeatability was calculated according to methods described by Bland and Altman. RESULTS: 39 eyes of 39 patients with nAMD were included with a mean (±SD) age of 73.9 (±7.2) years. The mean (±SD) retinal thickness of the central macular subfield was 225.7 µm (±12.4 µm). The repeatability this subfield, expressed as a percentage of the mean central macular subfield thickness, was 23.2%. The percentage repeatability of the other macular subfields ranged from 13.2% to 28.7%. The intrasession coefficient of repeatability of choroidal thickness of the central macular subfield was 57.2 µm with a mean choroidal thickness (±SD) of 181 µm (±15.8 µm). CONCLUSIONS: This study suggests that a change >23.2% of retinal thickness and 57.2 µm choroidal thickness in the central macular subfield is required to distinguish true clinical change from measurement variability when using the DRI OCT-1 device to manage patients with nAMD.

Spectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration.

PURPOSE: To determine the intrasession repeatability of spectral-domain OCT (SDOCT)-derived macular retinal and choroidal metrics in patients with neovascular age-related macular degeneration (nAMD) in the Distance of Choroid Study (DOCS). DESIGN: Validity and reliability analysis. METHODS: Enrolled patients underwent repeated SDOCT imaging using the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). A single technician certified for clinical trials took 3 macular volume scans. Retinal thicknesses were calculated for each of the 9 Early Treatment Diabetic Retinopathy Study (ETDRS) macular subfields. Center point thickness and total macular volume were also included in the analysis. Manual subfoveal choroidal thickness measurements were made by a masked observer. RESULTS: A total of 40 eyes of 40 patients were included in this analysis (mean [± standard deviation] age: 74.1 [± 7.2] years, 60% male). The coefficient of repeatability (CR) of the central macular subfield was 30.6 µm (95% confidence interval [CI] 29.8-1.4 µm). The CR for the other macular subfields ranged from 7.0 µm to 38.2 µm. The CR for the total macular volume was 0.212 mm(3) (95% CI 0.206-0.217 mm(3)) and the CR for the center point was 47.5 µm (95% CI 46.2-48.7 µm). Images were also reviewed for the presence of segmentation error in the central macular subfield, and after exclusion of these eyes the revised CR for this subfield was 13.7 µm (95% CI 13.3-14.1 µm). The intrasession CR of subfoveal choroidal thickness was 34.7 µm (95% CI 33.7-35.7 µm). CONCLUSIONS: This study suggests that a change of greater than 31 µm in Spectralis SDOCT-derived retinal thickness measurement of the central macular subfield and 35 µm in subfoveal choroidal thickness is necessary to detect true clinical change associated with disease progression or improvement in nAMD with a revised figure of 14 µm for central macular retinal subfield thickness in the absence of segmentation error.

Long-term effect of gene therapy on Leber's congenital amaurosis.

BACKGROUND: Mutations in RPE65 cause Leber's congenital amaurosis, a progressive retinal degenerative disease that severely impairs sight in children. Gene therapy can result in modest improvements in night vision, but knowledge of its efficacy in humans is limited. METHODS: We performed a phase 1-2 open-label trial involving 12 participants to evaluate the safety and efficacy of gene therapy with a recombinant adeno-associated virus 2/2 (rAAV2/2) vector carrying the RPE65 complementary DNA, and measured visual function over the course of 3 years. Four participants were administered a lower dose of the vector, and 8 were administered a higher dose. In a parallel study in dogs, we investigated the relationship among vector dose, visual function, and electroretinography (ERG) findings. RESULTS: Improvements in retinal sensitivity were evident, to varying extents, in six participants for up to 3 years, peaking at 6 to 12 months after treatment and then declining. No associated improvement in retinal function was detected by means of ERG. Three participants had intraocular inflammation, and two had clinically significant deterioration of visual acuity. The reduction in central retinal thickness varied among participants. In dogs, RPE65 gene therapy with the same vector at lower doses improved vision-guided behavior, but only higher doses resulted in improvements in retinal function that were detectable with the use of ERG. CONCLUSIONS: Gene therapy with rAAV2/2 RPE65 vector improved retinal sensitivity, albeit modestly and temporarily. Comparison with the results obtained in the dog model indicates that there is a species difference in the amount of RPE65 required to drive the visual cycle and that the demand for RPE65 in affected persons was not met to the extent required for a durable, robust effect. (Funded by the National Institute for Health Research and others; ClinicalTrials.gov number, NCT00643747.).

Subconjunctival bevacizumab induces regression of corneal neovascularisation: a pilot randomised placebo-controlled double-masked trial.

OBJECTIVE: To evaluate the off-label use of subconjunctival bevacizumab for corneal neovascularisation (CoNV). METHODS: 30 patients with recent-onset CoNV from various causes were randomly assigned into a double-masked, placebo-controlled trial. Each received three 0.1 ml injections containing either 2.5 mg bevacizumab or 0.9% saline at monthly intervals. Dexamethasone 0.1% drops were used four times a day for the first month, when the dose was modified if clinically indicated. The primary outcome was change in area of corneal involvement by CoNV from baseline to 3 months measured using specialised imaging technology. RESULTS: The mean area of CoNV reduced by -36% (range -92% to +40%) in the 15 eyes that received bevacizumab compared with an increase of 90% (range -58% to +1394%) in eyes that received saline placebo (analysis of covariance (ANCOVA); p=0.007). One outlier in the placebo arm developed corneal graft rejection with aggressive neovascularisation (+1384%), but even when this patient was excluded the mean reduction in CoNV in the placebo group (-3%, range -58% to +40%) was still significantly different from the treatment arm (ANCOVA; p=0.016). Changes in best-corrected visual acuity, central corneal thickness, intraocular pressure and endothelial cell counts were similar between groups. The intervention was well tolerated with no major safety concerns. CONCLUSIONS: Three subconjunctival injections of 2.5 mg bevacizumab are more effective than placebo at inducing the regression of recent-onset CoNV. Further studies are needed to confirm this effect and our data suggest that a sample size of 40 patients per treatment group is required.

Delayed cilioretinal artery occlusion after a hemiretinal vein occlusion.

The purpose of this study is to report a case of combined hemiretinal vein occlusion and cilioretinal artery occlusion (CLRAO), in which the development of the CLRAO was substantially delayed. This interventional case report illustrates the sequential development of a cilioretinal artery occlusion following a hemiretinal vein occlusion with colour fundus and fluorescein angiogram photographs. Systemic examination revealed previously unrecorded hypertension for which her general practitioner commenced treatment. The patient developed an inferior visual field defect however made a visual recovery to 20/40 at 6-month follow-up. In this report, the risk factors and the likely pathogenesis for such an event are studied.

Lentiviral vector integration profiles differ in rodent postmitotic tissues.

Lentiviral vectors with self-inactivating (SIN) long terminal repeats (LTRs) are promising for safe and sustained transgene expression in dividing as well as quiescent cells. As genome organization and transcription substantially differs between actively dividing and postmitotic cells in vivo, we hypothesized that genomic vector integration preferences might be distinct between these biological states. We performed integration site (IS) analyses on mouse dividing cells (fibroblasts and hematopoietic progenitor cells (HPCs)) transduced ex vivo and postmitotic cells (eye and brain) transduced in vivo. As expected, integration in dividing cells occurred preferably into gene coding regions. In contrast, postmitotic cells showed a close to random frequency of integration into genes and gene spare long interspersed nuclear elements (LINE). Our studies on the potential mechanisms responsible for the detected differences of lentiviral integration suggest that the lowered expression level of Psip1 reduce the integration frequency in vivo into gene coding regions in postmitotic cells. The motif TGGAA might represent one of the factors for preferred lentiviral integration into mouse and rat Satellite DNA. These observations are highly relevant for the correct assessment of preclinical biosafety studies, indicating that lentiviral vectors are well suited for safe and effective clinical gene transfer into postmitotic tissues.

GFAP-driven GFP expression in activated mouse Müller glial cells aligning retinal blood vessels following intravitreal injection of AAV2/6 vectors.

BACKGROUND: Müller cell gliosis occurs in various retinal pathologies regardless of the underlying cellular defect. Because activated Müller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy. METHODOLOGY/PRINCIPAL FINDINGS: We used adeno-associated viral AAV2/6 vectors to transduce mouse retinas. The transduction pattern of AAV2/6 was investigated by studying expression of the green fluorescent protein (GFP) transgene using scanning-laser ophthalmoscopy and immuno-histochemistry. AAV2/6 vectors transduced mouse Müller glial cells aligning the retinal blood vessels. However, the transduction capacity was hindered by the inner limiting membrane (ILM) and besides Müller glial cells, several other inner retinal cell types were transduced. To obtain Müller glial cell-specific transgene expression, the cytomegalovirus (CMV) promoter was replaced by the glial fibrillary acidic protein (GFAP) promoter. Specificity and activation of the GFAP promoter was tested in a mouse model for retinal gliosis. Mice deficient for Crumbs homologue 1 (CRB1) develop gliosis after light exposure. Light exposure of Crb1(-/-) retinas transduced with AAV2/6-GFAP-GFP induced GFP expression restricted to activated Müller glial cells aligning retinal blood vessels. CONCLUSIONS/SIGNIFICANCE: Our experiments indicate that AAV2 vectors carrying the GFAP promoter are a promising tool for specific expression of transgenes in activated glial cells.

The tight junction associated signalling proteins ZO-1 and ZONAB regulate retinal pigment epithelium homeostasis in mice.

Cell-cell adhesion regulates the development and function of epithelia by providing mechanical support and by guiding cell proliferation and differentiation. The tight junction (TJ) protein zonula occludens (ZO)-1 regulates cell proliferation and gene expression by inhibiting the activity of the Y-box transcription factor ZONAB in cultured epithelial cells. We investigated the role of this TJ-associated signalling pathway in the retinal pigment epithelium (RPE) in vivo by lentivirally-mediated overexpression of ZONAB, and knockdown of its cellular inhibitor ZO-1. Both overexpression of ZONAB or knockdown of ZO-1 resulted in increased RPE proliferation, and induced ultrastructural changes of an epithelial-mesenchymal transition (EMT)-like phenotype. Electron microscopy analysis revealed that transduced RPE monolayers were disorganised with increased pyknosis and monolayer breaks, correlating with increased expression of several EMT markers. Moreover, fluorescein angiography analysis demonstrated that the increased proliferation and EMT-like phenotype induced by overexpression of ZONAB or downregulation of ZO-1 resulted in RPE dysfunction. These findings demonstrate that ZO-1 and ZONAB are critical for differentiation and homeostasis of the RPE monolayer and may be involved in RPE disorders such as proliferative vitroretinopathy and atrophic age-related macular degeneration.

Comprehensive genomic access to vector integration in clinical gene therapy.

Retroviral vectors have induced subtle clonal skewing in many gene therapy patients and severe clonal proliferation and leukemia in some of them, emphasizing the need for comprehensive integration site analyses to assess the biosafety and genomic pharmacokinetics of vectors and clonal fate of gene-modified cells in vivo. Integration site analyses such as linear amplification-mediated PCR (LAM-PCR) require a restriction digest generating unevenly small fragments of the genome. Here we show that each restriction motif allows for identification of only a fraction of all genomic integrants, hampering the understanding and prediction of biological consequences after vector insertion. We developed a model to define genomic access to the viral integration site that provides optimal restriction motif combinations and minimizes the percentage of nonaccessible insertion loci. We introduce a new nonrestrictive LAM-PCR approach that has superior capabilities for comprehensive unbiased integration site retrieval in preclinical and clinical samples independent of restriction motifs and amplification inefficiency.

Subretinal delivery of adeno-associated virus serotype 2 results in minimal immune responses that allow repeat vector administration in immunocompetent mice.

BACKGROUND: Adeno-associated virus serotype 2 (AAV2) vectors show considerable promise for ocular gene transfer. However, one potential barrier to efficacious long-term therapy is the development of immune responses against the vector or transgene product. METHODS: We evaluated cellular and humoral responses in mice following both single and repeated subretinal administration of AAV2, and examined their effects on RPE65 and green fluorescent protein transgene expression. RESULTS: Following subretinal administration of vector, splenocytes and T-cells from draining lymph nodes showed minimal activation following stimulation by co-culture with AAV2. Neutralizing antibodies (NAbs) were not detected in the ocular fluids of any mice receiving AAV2 or in the serum of mice receiving a lower dose. NAbs were present in the serum of a proportion of mice receiving a higher dose of the vector. Furthermore, no differences in immunoglobulin titre in serum or ocular fluids against RPE65 protein or AAV2 capsid between treated and control mice were detected. Histological examination showed no evidence of retinal toxicity or leukocyte infiltration compared to uninjected eyes. Repeat administration of low-dose AAV.hRPE65.hRPE65 to both eyes of RPE65(-/-) mice resulted in transgene expression and functional rescue, but re-administration of high-dose AAV2 resulted in boosted NAb titres and variable transgene expression in the second injected eye. CONCLUSIONS: These data, which were obtained in mice, suggest that, following subretinal injection, immune responses to AAV2 are dose-dependent. Low-dose AAV2 is well tolerated in the eye, with minimal immune responses, and transgene expression after repeat administration of vector is achievable. Higher doses lead to the expression of NAbs that reduce the efficacy of repeated vector administration.

Effect of gene therapy on visual function in Leber's congenital amaurosis.

Early-onset, severe retinal dystrophy caused by mutations in the gene encoding retinal pigment epithelium-specific 65-kD protein (RPE65) is associated with poor vision at birth and complete loss of vision in early adulthood. We administered to three young adult patients subretinal injections of recombinant adeno-associated virus vector 2/2 expressing RPE65 complementary DNA (cDNA) under the control of a human RPE65 promoter. There were no serious adverse events. There was no clinically significant change in visual acuity or in peripheral visual fields on Goldmann perimetry in any of the three patients. We detected no change in retinal responses on electroretinography. One patient had significant improvement in visual function on microperimetry and on dark-adapted perimetry. This patient also showed improvement in a subjective test of visual mobility. These findings provide support for further clinical studies of this experimental approach in other patients with mutant RPE65. (ClinicalTrials.gov number, NCT00643747 [ClinicalTrials.gov].).

Aqueous misdirection syndrome after pars plana vitrectomy for retinal detachment.

BACKGROUND: Aqueous misdirection syndrome (AMS) typically occurs after surgery for angle closure glaucoma, or surgery in hyperopic eyes with narrow angles. Pars plana vitrectomy (PPV) is often considered the definitive treatment for AMS. The authors describe a rare case of AMS developing de novo after PPV in an eye without any prior history of AMS, angle closure glaucoma, or narrow angles. METHODS: Interventional case report. RESULTS: A 72-year-old woman with vitreomacular traction syndrome developed an acute rhegmatogenous retinal detachment and underwent an uneventful PPV, posterior hyaloid peel, cryopexy, and C3F8 gas insertion. Initial postoperative raised intraocular pressure (IOP) was successfully managed medically. She returned 6 days postoperatively with a highly elevated IOP refractory to medical treatments, and signs of AMS. She therefore underwent emergency C3F8 removal, phacoemulsification, posterior chamber IOL insertion, anterior vitrectomy, peripheral irido-capsulo-hyaloidectomy, and retamponade with 30% SF6. In 2 years of follow-up, there has been no recurrence of AMS and her IOP has remained normal. CONCLUSION: This case demonstrates that AMS can develop in vitrectomized eyes without a pre-existing history of AMS, angle closure glaucoma, or narrow angles. AMS should therefore be considered as a potential cause of raised IOP in association with a shallow anterior chamber following vitrectomy.

Gene transfer of an engineered zinc finger protein enhances the anti-angiogenic defense system.

Zinc finger protein transcription factors (ZFP TFs) have been shown to positively or negatively regulate the expression of endogenous genes involved in a number of different disease processes. In this study we investigated whether gene transfer of an engineered ZFP TF designed to up-regulate expression of the chromosomal pigment epithelium-derived factor (Pedf) gene could suppress experimentally induced choroidal neovascularization (CNV). Transient transfection with engineered ZFP TFs significantly increased both Pedf messenger RNA (mRNA) and secreted PEDF protein levels in cell culture. Six weeks after intravitreous or subretinal injection of an adeno-associated viral (AAV) vector expressing the PEDF-activating ZFP TF in mice, we observed increased retinal Pedf mRNA, and a significant reduction in the size of CNV at Bruch's membrane rupture sites, assessed in vivo by fluorescein angiography or by postmortem measurements on choroidal flat mounts. Importantly, the anti-angiogenic activity persisted at 3 months after intravitreous injection. These data suggest that ZFP TF-driven enhancement of the endogenous anti-angiogenic defense system may provide a new approach for prophylaxis and treatment of neovascular diseases of the eye.