Long-Term Results of Full Macular Translocation for Choroidal Neovascularization in Age-Related Macular Degeneration

Macular neovascularization

Neovascularization of the macula, a common complication of many chorioretinal diseases such as neovascular age-related macular degeneration, polypoidal choroidal vasculopathy, and pathologic myopia results from increased synthesis of vascular endothelial growth factor (VEGF) by the retinal pigment epithelium and/or Müller cells because of localized ischemia and inflammation. The Consensus on Neovascular AMD Nomenclature (CONAN) study group acknowledged that these vessels may originate from either the choriocapillaris or the retinal microvasculature, prompting them to propose the term 'macular neovascularization' (MNV) to include intraretinal, subretinal, and sub-pigment epithelial neovascularization localized to the macula. MNV frequently appears as a grey-green macular lesion with overlying intraretinal thickening and/or subretinal exudation, causing metamorphopsia, reduced central vision, relative central scotoma, decreased reading speed, and problems with color recognition. Multimodal imaging with optical coherence tomography (OCT), OCT angiography, dye-based angiographies, fundus autofluorescence, and multiwavelength photography help establish the diagnosis and aid in selecting an appropriate treatment. The standard of care for MNV is usually intravitreal anti-VEGF injections, though thermal laser photocoagulation, verteporfin photodynamic therapy, and vitreoretinal surgery are occasionally used. This current review discusses the etiology and clinical features of MNV, the role of multimodal imaging in establishing the diagnosis, and the available therapeutic options.

Induced retinal pigment epithelial cells with anti-epithelial-to-mesenchymal transition ability delay retinal degeneration

The hostile microenvironment of the retina in patients with age-related macular degeneration (AMD) may trigger epithelial-to-mesenchymal transition (EMT) of grafted retinal pigment epithelial (RPE) cells, thus attenuating the therapeutic outcome. Here, we transformed human dedifferentiated induced pluripotent stem cell-derived RPE (iPSC-RPE) cells into induced RPE (iRPE) cells using a cocktail of four transcription factors (TFs)—CRX, MITF-A, NR2E1, and C-MYC. These critical TFs maintained the epithelial property of iRPE cells by regulating the expression of bmp7, forkhead box f2, lin7a, and pard6b, and conferred resistance to TGF-β-induced EMT in iRPE cells by targeting ppm1a. The iRPE cells with Tet-on system-regulated c-myc expression exhibited EMT resistance and better therapeutic function compared with iPSC-RPE cells in rat AMD model. Our study demonstrates that endowing RPE cells with anti-EMT property avoids the risk of EMT after cells are grafted into the subretinal space, and it may provide a suitable candidate for AMD treatment.

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CRX, MITF-A, NR2E1, and C-MYC transform De-iPSC-RPE cells into iRPE cells

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iRPE cells have resistance to TGF-β-induced EMT

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BMP7, FOXF2, LIN7A, PARD6B, and PPM1A mediate the functions of TFs in iRPE cells

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iRPE cells have better retinal protective function than iPSC-RPE cells

Destructive inflammatory reaction after an autologous retinal pigment epithelium and choroid transplantation: no detection of an auto-immune response

Purpose

Five patients who underwent uncomplicated retinal pigment epithelium (RPE)-choroid transplantation for neovascular age-related macular degeneration developed a destructive inflammatory reaction causing subretinal fluid accumulation and extensive RPE atrophy in the graft. We hypothesized that this inflammation could be caused by an auto-immune response against the graft, resulting in circulating auto-antibodies. The aim of our study was to examine a potential autoimmune origin, which would allow a more targeted therapy approach.

Methods

Five above-mentioned patients and four control groups of five patients each were included: 1) after uncomplicated RPE-choroid transplantation, 2) after full macular translocation, 3) treated with anti-vascular endothelial growth factor, and 4) healthy controls. Histopathology of rejected graft tissue was performed using standard procedures. Presence of RPE-choroid autoantibodies in serum was examined by indirect immunofluorescence and Western blot, and human leukocyte antigen (HLA) typing was performed.

Results

Histopathological examination of an explanted graft showed infiltration of T-lymphocytes and macrophages in the choroid and RPE, and an increased number of B-cell lymphocytes were found in the choroid. Indirect immunofluorescence showed weak RPE-choroid autoantibody immunoreactivity in three patients of different groups. Western blot did not show specific RPE-choroid autoantibody immunoreactivity and no difference of HLA genotypes between the groups was found.

Conclusions

Although local mononuclear inflammatory cell infiltration and a high number of B-lymphocytes were observed in an explanted graft, we did not detect serological evidence of an autoimmune origin of the postoperative inflammation using direct immunofluorescence and Western Blot. Alternatively, the graft failure may have been caused by local innate inflammation, triggered by breakdown of tolerance. Based on our current findings of this small study group, we have no rationale to pursue therapies targeted towards autoreactive graft failure. More research is needed to confirm our findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12348-022-00305-2.

Suppression of choroidal neovascularization by silencing of long non-coding RNA IPW

Long noncoding RNAs (lncRNAs) have emerged as the key regulators in the pathogenesis of human disorders. This study aimed to investigate the role of lncRNA-IPW in the progression of choroidal neovascularization (CNV) and the underlying molecular mechanism. IPW was significantly up-regulated in the choroidal tissues of laser-induced CNV mice and in the endothelial cells in response to hypoxic stress. IPW silencing led to reduced formation of CNV in laser-induced CNV model and ex vivo choroidal sprouting model, which could achieve similar therapeutic effects of anti-VEGF on CNV formation. Silencing or transgenic overexpression of IPW could alter endothelial cell viability, proliferation, migration, and tube formation ability in vitro. Mechanistically, IPW silencing led to increased expression of miR-370. Increased miR-370 could mimic the effects of IPW silencing on CNV formation and endothelial angiogenic phenotypes in vivo and in vitro. This study suggests that IPW silencing is a promising strategy for the treatment of neovascular ocular diseases.

Development of Stem Cell Therapies for Retinal Degeneration

Degenerative retinal disease is the major cause of sight loss in the developed world and currently there is a lack of effective treatments. As the loss of vision is directly the result of the loss of retinal cells, effective cell replacement through stem-cell-based therapies may have the potential to treat a great number of retinal diseases whatever their underlying etiology. The eye is an ideal organ to develop cell therapies as it is immune privileged, and modern surgical techniques enable precise delivery of cells to the retina. Furthermore, a range of noninvasive diagnostic tests and high-resolution imaging techniques facilitate the evaluation of any therapeutic intervention. In this review, we evaluate the progress to date of current cell therapy strategies for retinal repair, focusing on transplantation of pluripotent stem-cell-derived retinal pigment epithelium (RPE) and photoreceptor cells.

RETINAL PIGMENT EPITHELIUM-CHOROID GRAFT WITH A PERIPHERAL RETINOTOMY FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION: Long-Term Outcome

PURPOSE

To investigate the long-term outcome of autologous retinal pigment epithelium -choroid transplantation with a peripheral retinotomy for exudative age-related macular degeneration.

METHODS

In a retrospective study, we selected all patients who underwent a retinal pigment epithelium-choroid transplantation from 2007 through 2013. Exclusion criteria were age <60 years, <12 months of follow-up, and retinal pigment epithelium-choroid graft for other diseases than age-related macular degeneration. The main outcome measure was best-corrected visual acuity converted into logarithm of the minimum angle of resolution.

RESULTS

In this study, 81 patients were included with a mean follow-up of 38 months (SD = 19). Median best-corrected visual acuity improved from 1.30 logarithm of the minimum angle of resolution (20/400 Snellen) to 0.90 logarithm of the minimum angle of resolution (20/160 Snellen) 1 year after surgery (P < 0.001). A ≥3-line gain was achieved in 43 patients (53%) 1 year postoperatively and 37 patients (46%) preserved their visual gain until last visit. Of 4 patients with an 8-year follow-up, 3 patients had a ≥6-line gain at last visit. Severe complications were submacular hemorrhage (n = 8, 10%), macular hole (n = 6, 7%), and proliferative vitreoretinopathy (n = 3, 4%).

CONCLUSION

Best-corrected visual acuity improved significantly after retinal pigment epithelium-choroid transplantation in patients with age-related macular degeneration and preservation of visual gain was possible in the long term.

Intravitreal Recombinant Tissue Plasminogen Activator and Sulphur Hexafluoride Gas for Submacular Haemorrhage Displacement in Age-Related Macular Degeneration: Looking behind the Blood

PURPOSE

To evaluate the effectiveness of recombinant tissue plasminogen activator (rtPA) and sulphur hexafluoride gas (SF6) intravitreal injection for the displacement of large submacular haemorrhages (SMH) secondary to neovascular age-related macular degeneration and for guiding the selection of additional treatments or observations for choroidal neovascularization (CNV).

METHODS

The medical records of consecutive patients with recent-onset, large SMH, treated at Sacro Cuore Hospital from January 2004 to May 2016, were retrospectively analysed. All eyes underwent a 0.05-mL intravitreal injection of 50 μg rtPA, 0.3 mL of 100% SF6, and then face-down positioning. Afterwards, the eyes received additional treatments for CNV or observation, based on the severity and extent of the underlying pathology. The multimodal imaging features revealed after blood displacement were analysed and then correlated to the treatment selected as a second therapeutic option.

RESULTS

A total of 96 eyes met the inclusion criteria and was evaluated in this study. SMH was displaced from the fovea in the majority of the eyes (76%), allowing several diagnostic tools to evaluate the underlying macular features. In 19 cases (19.8%) exhibiting severe macular damage, no additional treatment was applied. In the remaining eyes, subsequent treatments included anti-vascular endothelial growth factor injections (44.8%), photodynamic therapy (n = 2), and submacular surgery (35.4%). Statistically significant correlations were found between the macular findings revealed after blood displacement and the additional treatments or observations selected for the underlying disease. The mean follow-up was 35 months. Improvements in visual acuity were statistically significant up to 3 years.

CONCLUSION

Intravitreal rtPA and gas injection was found to be effective for the displacement of large SMH, allowing postoperative diagnostic testing, and thus guiding the opportunity to apply further treatments. The addition of subsequent individualized treatments may allow long-term visual gain in selected cases.

Dysregulated claudin-5 cycling in the inner retina causes retinal pigment epithelial cell atrophy

Age-related macular degeneration (AMD) is the leading cause of central retinal vision loss worldwide, with an estimated 1 in 10 people over the age of 55 showing early signs of the condition. There are currently no forms of therapy available for the end stage of dry AMD, geographic atrophy (GA). Here, we show that the inner blood-retina barrier (iBRB) is highly dynamic and may play a contributory role in GA development. We have discovered that the gene CLDN5, which encodes claudin-5, a tight junction protein abundantly expressed at the iBRB, is regulated by BMAL1 and the circadian clock. Persistent suppression of claudin-5 expression in mice exposed to a cholesterol-enriched diet induced striking retinal pigment epithelium (RPE) cell atrophy, and persistent targeted suppression of claudin-5 in the macular region of nonhuman primates induced RPE cell atrophy. Moreover, fundus fluorescein angiography in human and nonhuman primate subjects showed increased retinal vascular permeability in the evening compared with the morning. These findings implicate an inner retina-derived component in the early pathophysiological changes observed in AMD, and we suggest that restoring the integrity of the iBRB may represent a novel therapeutic target for the prevention and treatment of GA secondary to dry AMD.

Morphological changes in the diseased retina on a healthy choroid-retinal pigment epithelial complex after full macular translocation for exudative age-related macular degeneration

PURPOSE

To describe the change in the retinal morphology after full macular translocation (FMT) for exudative age-related macular degeneration (AMD) and identify predictive factors for the visual outcome.

METHODS

All patients who underwent FMT from December 2008 through July 2013 were selected. Exclusion criteria were FMT for other disease than AMD, age <60 years, <12 months of follow-up or no available images. Spectral domain optical coherence tomography, fundus autofluorescence, fluorangiography and indocyanine green angiography were evaluated.

RESULTS

In total, 51 patients were included with a mean follow-up of 30 months. The presence of the external limiting membrane (ELM) was a significant predictor for a favourable visual outcome 1 year after FMT (OR = -0.30). Other significant predictive factors were the absence of intraretinal fluid (OR = 0.28) and the mixed choroidal neovascularization type (OR = -0.47), whereas nonresponders (OR = 0.41) and fibrotic lesions (OR = 0.35) were less likely to have a good visual function after surgery.

CONCLUSION

Full macular translocation (FMT), that permits to relocate the diseased macula onto an area of unaffected retinal pigment epithelial and choroid, can restore the anatomy and visual function in some patients with AMD when the outer retina layers are not irreversibly damaged. The presence of the ELM seems to be the most reliable factor in predicting the functional outcome.

In situ regeneration of retinal pigment epithelium by gene transfer of E2F2: a potential strategy for treatment of macular degenerations

The retinal pigment epithelium (RPE) interacts closely with photoreceptors to maintain visual function. In degenerative diseases such as Stargardt disease and age-related macular degeneration, the leading cause of blindness in the developed world, RPE cell loss is followed by photoreceptor cell death. RPE cells can proliferate under certain conditions, suggesting an intrinsic regenerative potential, but so far this has not been utilised therapeutically. Here, we used E2F2 to induce RPE cell replication and thereby regeneration. In both young and old (2 and 18 month) wildtype mice, subretinal injection of non-integrating lentiviral vector expressing E2F2 resulted in 47% of examined RPE cells becoming BrdU positive. E2F2 induced an increase in RPE cell density of 17% compared with control vector-treated and 14% compared with untreated eyes. We also tested this approach in an inducible transgenic mouse model of RPE loss, generated through activation of diphtheria toxin-A gene. E2F2 expression resulted in a 10-fold increase in BrdU uptake and a 34% increase in central RPE cell density. Although in mice this localised rescue is insufficiently large to be demonstrable by electroretinography, a measure of massed retinal function, these results provide proof-of-concept for a strategy to induce in situ regeneration of RPE for the treatment of RPE degeneration.

Recent developments in age-related macular degeneration: a review

Background

Visual impairment in elderly people is a considerable health problem that significantly affects quality of life of millions worldwide. The magnitude of this issue is becoming more evident with an aging population and an increasing number of older individuals.

Objective

The objective of this article was to review the clinical and pathological aspects of age-related macular degeneration (AMD), diagnostic tools, and therapeutic modalities presently available or underway for both atrophic and wet forms of the disease.

Methods

An online review of the PubMed database was performed, searching for the key words. The search was limited to articles published since 1980 to date.

Results

Several risk factors have been linked to AMD, such as age (>60 years), lifestyle (smoking and diet), and family history. Although the pathogenesis of AMD remains unclear, genetic factors have been implicated in the condition. Treatment for atrophic AMD is mainly close observation, coupled with nutritional supplements such as zinc and antioxidants, whereas treatment of wet AMD is based on targeting choroidal neovascular membranes.

Conclusion

Identification of modifiable risk factors would improve the possibilities of preventing the progression of AMD. The role of anti-vascular endothelial growth factor (anti-VEGF) agents has transformed the therapeutic approach of the potentially blinding disease “wet AMD” into a more favorable outcome.

OCT angiography documented reperfusion of translocated autologous full thickness RPE-choroid graft for complicated neovascular age-related macular degeneration

PurposeThe purpose of this study is to investigate the reperfusion of translocated retinal pigment epithelium (RPE)-choroid graft in the treatment of patients with neovascular age-related macular degeneration (nAMD), using OCT angiography (OCTA), a novel non-invasive, high-resolution imaging modality.Patients and methodsEighteen eyes of 18 consecutive patients suffering from complicated nAMD underwent RPE-choroid patch graft translocation surgery using a peripheral retinotomy and flap-over technique. We analyzed functional and anatomical outcome using visual acuity, Spectral Domain OCT and OCTA.ResultsWith a mean follow-up of 11 months, out of 18 patients, 15 gained vision, 1 remained stable, and 2 lost vision. Overall, the visual acuity improved with a mean of 30 letters. Perfusion of the graft tissue was confirmed in all patients. Two patients developed signs of a recurrent neovascular membrane during follow-up. No cases of proliferative vitreoretinopathy occurred in this series.ConclusionsOCTA images show signs of perfusion in all grafts. Encouraging functional results and low risk of severe complications suggest that RPE-choroid graft translocation is a valid option in patients with complicated nAMD.

Management of Neovascular Age-related Macular Degeneration: A Review on Landmark Randomized Controlled Trials

In the last decade, a number of prospective clinical trials with carefully designed study protocols have been conducted for the treatment of neovascular age-related macular degeneration (AMD). These landmark clinical trials such as ANCHOR and MARINA and, more recently, the Comparison of AMD Treatment Trials and VIEW studies have revolutionized the management of neovascular AMD. While AMD continues to remain a leading cause of severe visual loss worldwide, advances in pharmacotherapeutics have led to substantial improvements in the outcome of these patients. The introduction of anti-vascular endothelial growth factor agents has resulted in improvement of visual outcomes and has had a positive impact on the quality of life among elderly population. While the contemporary management of neovascular AMD has been successful in tremendously reducing the visual morbidity, the financial burden of therapy has increased exponentially. To overcome these challenges, newer pharmacologic agents are evaluated for their efficacy and safety in AMD. Ground-breaking advances in bench to bedside research have led to discovery of new pathways that appear to be viable targets for preventing visual loss in AMD. In this review, study designs and results of landmark clinical trials in AMD from the past decade have been summarized.

miRNA involvement in angiogenesis in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Late-stage AMD is characterized by choroidal neovascularization (CNV). miR-93 appears to play a role in regulating vascular endothelial growth factor-A (VEGF-A), a known factor involved in neovascularization. Understanding its biological significance might enable development of therapeutic interventions for diseases like AMD. We aimed to determine the role of miR-93 in AMD using a laser-induced CNV mouse model. CNV was induced by laser photocoagulation in C57BL/6 mice. The CNV mice were transfected with scrambled miR or miR-93 mimic. The treatment effect was assessed by fundus photography and fluorescein angiography and confirmed by choroidal flatmount. The expression of miR-93 and VEGF-A in ocular tissues was analysed by quantitative polymerase chain reaction (qPCR) and Western blot. The overexpression effects of miR-93 were also proved on human microvascular endothelial cells (HMECs). Significantly decreased expression of miR-93 was observed by qPCR analysis in CNV mice compared to untreated mice (p < 0.05). VEGF-A messenger RNA (mRNA) and protein expression were upregulated with CNV; these changes were ameliorated by restoration of miR-93 (p < 0.05). CNV was reduced after miR-93 transfection. Transfection of miR-93 reduced the proliferation of HMECs (p < 0.01), but no significant changes were observed in 2D capillary-like tube formation (p > 0.05) and migration (p > 0.05) compared with that in the untreated cells. miR-93 has been shown to be a negative modulator of angiogenesis in the eye. All together, these results highlight the therapeutic potential of miR-93 and suggest that it may contribute as a putative therapeutic target for AMD in humans.

miR-126 Regulation of Angiogenesis in Age-Related Macular Degeneration in CNV Mouse Model

miR-126 has recently been implicated in modulating angiogenic factors in vascular development. Understandings its biological significance might enable development of therapeutic interventions for diseases like age-related macular degeneration (AMD). We aimed to determine the role of miR-126 in AMD using a laser-induced choroidal neovascularization (CNV) mouse model. CNV was induced by laser photocoagulation in C57BL/6 mice. The CNV mice were transfected with scrambled miR or miR-126 mimic. The expression of miR-126, vascular endothelial growth factor-A (VEGF-A), Kinase insert domain receptor (KDR) and Sprouty-related EVH1 domain-containing protein 1 (SPRED-1) in ocular tissues were analyzed by qPCR and Western blot. The overexpression effects of miR-126 were also proven on human microvascular endothelial cells (HMECs). miR-126 showed a significant decrease in CNV mice (p < 0.05). Both mRNA and protein levels of VEGF-A, KDR and SPRED-1 were upregulated with CNV; these changes were ameliorated by restoration of miR-126 (p < 0.05). CNV was reduced after miR-126 transfection. Transfection of miR-126 reduced the HMECs 2D-capillary-like tube formation (p < 0.01) and migration (p < 0.01). miR-126 has been shown to be a negative modulator of angiogenesis in the eye. All together these results high lights the therapeutic potential of miR-126 suggests that it may contribute as a putative therapeutic target for AMD in humans.