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Background/aims: Voretigene neparvovec (VN) is the first and only subretinal gene therapy approved by the Food and Drug Administration and European Medicines Agency. Real-world application has started in 2018 in patients with vision impairment due to biallelic retinal pigment epithelium ( RPE ) 65 mutation-associated inherited retinal degenerations. Herein, we evaluated the development of retinal atrophy within in a single-centre patient cohort treated with VN., Methods: 13 eyes of eight patients treated with VN were retrospectively analysed for areas of retinal atrophy over a period of 6-24 months following surgery. Ultrawide field images were used to measure the area of atrophy. Fundus autofluorescence imaging is presented as an instrument for early detection of signs of retinal atrophy in these patients., Results: Atrophic changes beyond the retinotomy site were observed in all eyes. Areas of atrophy developed within the area of detachment (bleb) in all eight patients and outside the bleb in three patients. Changes in autofluorescence preceded the development of retinal atrophy and were already evident 2 weeks after surgery in the majority of patients. The areas of atrophy increase with time and progression continued over year 1. Functional outcomes remained stable (VA, FST, visual field)., Conclusion: Subretinal injection of VN can lead to RPE atrophy with consequent photoreceptor loss in and outside of the bleb area. Fundus autofluorescence is an important tool to monitor atrophic changes in patients after gene therapy. Interestingly, while areas of atrophy also included central areas, the functional benefits of the treatment did not appear to be affected and remained stable., Competing Interests: Competing interests: DF is on the advisory board of and/or consulting and/or receiving honoraria/grant money/travel support from following companies: Adelphi Values, Advent France Biotechnology, Alphasights, Arctos Medical, Atheneum, Axiom Healthcare Strategies, Biogen, Cambridge Consultants, Decision Resources, Dialectica, Frontera Therapeutics, Janssen Research & Development, Navigant, Novartis, Roche, RegenxBio, Sirion, System Analytic, and STZeyetrial. He is director of Fischer Consulting Limited and holds a patent (50%) on a gene therapy product for X-linked Retinitis Pigmentosa. FW reports personal fees from Novartis, outside the submitted work. KS reports personal fees from Novartis, outside the submitted work. SK reports grants from Charlotte & Tistou Kerstan Foundation, during the conduct of the study; personal fees from Novartis, outside the submitted work. No other disclosures were reported., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: An active microelectronic subretinal implant, developed to replace the photoreceptive function in hereditary degenerations of the outer retina, has been applied in a pilot and clinical study in patients with end-stage retinal degeneration., Methods: The study population comprised 20 blind patients, all of whom lost vision as result of a hereditary retinal disease. An active visual implant was placed surgically within the subretinal space of each patient: subfoveal placement in eight patients (group 1) and parafoveal placement in 12 (group 2). Standardized low-vision tests, including light perception, light localization, movement detection, grating acuity, and visual acuity by Landolt C-rings, were used under masked, randomized implant-OFF and implant-ON conditions. For the chip-mediated vision functional results of both subject groups were compared., Results: Three of 20 patients were excluded from analysis because of surgical or technical implant issues. Among patients with nonfoveal placement of the implant, 80% could perceive light, 10% recognized location, and 10% correctly distinguished stripe patterns up to a resolution of 0.33 cycles/degree. No nonfoveal placement patient passed the motion or Landolt C-ring tests. When the implant was placed subfoveally, 100% of patients could perceive light and determine light localization, 75% could resolve motion up to 35°/s, 88% correctly distinguished stripe patterns up to a resolution of 3.3 cycles/degree, and 38% passed a Landolt C-ring test with a decimal visual acuity of up to 20/546 (logMAR 1.43)., Conclusions: Subfoveal placement of active subretinal visual implants allows superior measurable outcomes compared to para- or nonfoveal placement locations. (ClinicalTrials.gov numbers, NCT01024803, NCT00515814.).

Purpose: To examine the effects of transcorneal electrical stimulation (TES) on retinal degeneration of light-exposed rats., Methods: Thirty-three Sprague Dawley albino rats were divided into three groups: STIM (n = 15) received 60 minutes of TES, whereas SHAM (n = 15) received identical sham stimulation 2 hours before exposure to bright light with 16,000 lux; healthy animals (n = 3) served as controls for histology. At baseline and weekly for 3 consecutive weeks, dark- and light-adapted electroretinography was used to assess retinal function. Analysis of the response versus luminance function retrieved the parameters Vmax (saturation amplitude) and k (luminance to reach ½Vmax). Retinal morphology was assessed by histology (hematoxylin-eosin [HE] staining; TUNEL assay) and immunohistochemistry (rhodopsin staining)., Results: Vmax was higher in the STIM group compared with SHAM 1 week after light damage (mean intra-individual difference between groups 116.06 μV; P = 0.046). The b-wave implicit time for the rod response (0.01 cd.s/m²) was lower in the STIM group compared with the SHAM group 2 weeks after light damage (mean intra-individual difference between groups 5.78 ms; P = 0.023); no other significant differences were found. Histological analyses showed photoreceptor cell death (TUNEL and HE) in SHAM, most pronounced in the superior hemiretina. STIM showed complete outer nuclear layer thickness preservation, reduced photoreceptor cell death, and preserved outer segment length compared with SHAM (HE and rhodopsin)., Conclusions: This sham-controlled study shows that TES can protect retinal cells against mild light-induced degeneration in Sprague Dawley rats. These findings could help to establish TES as a treatment in human forms of retinal degenerative disease.

Purpose: To determine the potential of adenovirally transduced bone marrow stromal cells (BMSCs) to differentiate into retinal pigment epithelial-like cells and to evaluabe possible rescue effects after transplantation into the retinas of Royal College of Surgeons (RCS) rats., Methods: Through a high-capacity adenoviral vector expressing either green fluorescent protein (GFP) or pigment epithelial-derived factor (PEDF), rat MSCs were transduced in vitro before subretinal transplantation into Wistar rats or, alternatively, RCS rats. Two months after cell injection, the rats were killed and the eyes enucleated. The eyes were then investigated light microscopically or processed for electron microscopic investigations. Cell differentiation and integration were analyzed immunocytochemically using antibodies against cytokeratin and the tight junction protein ZO-1. Electroretinography was performed 16 days after injection of cells, to check whether a functional rescue could be detected., Results: In vitro experiments in cocultured human MSCs and human RPE cells showed that MSCs adopted RPE-like characteristics. In grafting experiments, some rat MSCs integrate into the host RPE cell layer of Wistar and RCS rats, indicated by their hexagonal morphology. Subretinally transplanted cells express the epithelial marker cytokeratin and establish tight junctions with the host RPE cells. Furthermore, rescue effects can be demonstrated after grafting of vector-transduced and nontransduced MSCs in semithin sections of dystrophic retinas. Ultrastructurally, MSCs can be detected on top of host RPE and in close contact with photoreceptor outer segments phagocytosing rod outer segments., Conclusions: Taken together, these results raise the possibility that MSCs have the potency to replace diseased RPE cells and deliver therapeutic proteins into the subretinal space to protect photoreceptor cells from degeneration.

Purpose: Successful engraftment of retinal pigment epithelial cells (RPE) to treat RPE-related retinopathy will depend, at least in part, on controlling the immune response. In order to understand this process we evaluated the fate of RPE xenografts in the subretinal space, anterior chamber, and subcutis of nonimmunosuppressed Royal College of Surgeons rats., Methods: Freshly isolated adult porcine RPE cells were used as xenografts and implanted when recipients were 17 to 21 days old. The extent of photoreceptor rescue by subretinal transplants was determined by counting the maximum layers of surviving photoreceptor nuclei in histologic sections. Cellular immune response was evaluated by immunohistochemistry., Results: Compared to non- or sham-injected eyes, subretinal xenografts in RPE-transplanted eyes were able to induce a dramatic rescue effect (P <.01). However, the effect was not absolute and photoreceptor cell degeneration was only delayed. Xenografts both in the anterior chamber and in the subcutaneous tissue led to an inflammatory cellular infiltration., Conclusion: RPE xenografts in subcutaneous space and in the anterior chamber are rejected by a delayed but vigorous inflammatory cell infiltration. Subretinal RPE xenografts are protected from a strong cellular rejection, but seem to undergo a slow functional deterioration, reflected by a decline in their capability to rescue adjacent photoreceptors.

In the pursuit of identifying the underlying pathways of ocular diseases, the use of cell lines such as (retinal ganglion cell-5) RGC-5 and 661W became a valuable tool, including pathologies like retinal degeneration and glaucoma. In 2001, the establishment of the RGC-5 cell line marked a significant breakthrough in glaucoma research. Over time, however, concerns arose about the true nature of RGC-5 cells, with conflicting findings in the literature regarding their identity as retinal ganglion cells or photoreceptor-like cells. This study aimed to address the controversy surrounding the RGC-5 cell line's origin and properties by comparing it with the 661W cell line, a known cone photoreceptor model. Both cell lines were differentiated according to two prior published redifferentiation protocols under the same conditions using 500 nM of trichostatin A (TSA) and investigated for their morphological and neuronal marker properties. The results demonstrated that both cell lines are murine, and they exhibited distinct morphological and neuronal marker properties. Notably, the RGC-5 cells showed higher expression of the neuronal marker β-III tubulin and increased Thy-1-mRNA compared with the 661W cells, providing evidence of their different properties. The findings emphasize the importance of verifying the authenticity of cell lines used in ocular research and highlight the risks of contamination and altered cell properties. [ABSTRACT FROM AUTHOR]

Purpose: To assess the efficacy and safety of systemic interferon alpha-2a (IFN) for refractory pseudophakic cystoid macular edema (PCME).Methods: Retrospective observational study. The primary outcome was the decrease of central retinal thickness (CRT). Secondary endpoints were the improvement of best-corrected visual acuity (BCVA) and the assessment of IFN-related side effects.Results: Twenty-four eyes of 20 patients were included. The median CRT was 513 µm (range 220-980 µm) at baseline and decreased to 190 µm (range 140-520 µm) at the last follow-up visit (p < 0.001). Reduction of CRT greater than 100 µm was observed in 22 eyes (92%). The median BCVA (logMAR) increased statistically significant from 0.5 (range 0.2-1.5) at baseline to 0.3 (0-0.8) at the last follow-up (p < 0.001). The BCVA improved in 18 eyes (75%) and remained stable in five eyes (21%). No severe treatment-related side effects occurred.Conclusion: IFN is a very effective agent for treatment of refractory PCME. [ABSTRACT FROM AUTHOR]

Purpose: To report the visual and morphological outcomes following intravitreal bevacizumab in neovascular age-related macular degeneration (nAMD) with submacular, predominantly hemorrhagic, lesions. Methods: Retrospective study of patients with a follow-up after 1 year. All eyes with submacular hemorrhages larger than 50% of the total lesion size and received only anti-VEGF (vascular endothelial growth factor) monotherapy (intravitreous administration of 1.25 mg bevacizumab, PRN). The primary endpoint was the change in hemorrhage size and time to resolution, in association with the mean best-corrected visual acuity (BCVA). The eyes were grouped based on the size of the hemorrhage: group A (≥1 to, 4 disc area [DA]), group B (≥4 to, 9 DA), and group C (≥9 DA). Results: Forty-six consecutive eyes were included. The mean area of the hemorrhage was 6 DA at baseline. Eyes with smaller bleeding (group A) had better chances of stabilized or improved vision. Complete resolution of the hemorrhage was seen in 96% of the eyes within 1 year. The mean BCVA increased from 0.81 logarithm of the minimum angle of resolution (logMAR) (95% confidence interval [CI]: 0.70'0.92) (Snellen 20/125) at baseline to 0.75 logMAR (95% CI: 0.62'0.88) (20/125) after 1 year (P=0.11). BCVA improved (one or more ETDRS [Early Treatment of Diabetic Retinopathy Study] lines) in 57% of the eyes (13/23) in group A; 53% (8/15) in group B; and 38% (3/8) in group C. Conclusion: Many of the eyes with hemorrhagic lesions showed stabilization or improvement of the mean BCVA after treatment within 1 year. Anti-VEGF treatment can be considered as a useful treatment option in eyes with hemorrhages secondary to nAMD. [ABSTRACT FROM AUTHOR]

A subretinal visual implant (Alpha IMS, Retina Implant AG, Reutlingen, Germany) was implanted in 29 blind participants with outer retinal degeneration in an international multicenter clinical trial. Primary efficacy endpoints of the study protocol were a significant improvement of activities of daily living and mobility to be assessed by activities of daily living tasks, recognition tasks, mobility, or a combination thereof. Secondary efficacy endpoints were a significant improvement of visual acuity/light perception and/or object recognition (clinicaltrials.gov, NCT01024803). During up to 12 months observation time twenty-one participants (72%) reached the primary endpoints, of which thirteen participants (45%) reported restoration of visual function which they use in daily life. Additionally, detection, localization, and identification of objects were significantly better with the implant power switched on in the first 3 months. Twenty-five participants (86%) reached the secondary endpoints. Measurable grating acuity was up to 3.3 cycles per degree, visual acuities using standardized Landolt C-rings were 20/2000, 20/2000, 20/606 and 20/546. Maximal correct motion perception ranged from 3 to 35 degrees per second. These results show that subretinal implants can restore very-low-vision or low vision in blind (light perception or less) patients with end-stage hereditary retinal degenerations. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the long-term functional outcome and its predictive factors of treatment of acute submacular hemorrhage secondary to age-related macular degeneration with intravitreal application of recombinant tissue plasminogen activator (rt-PA) and gas. Methods: Twenty-six patients were enrolled in the retrospective case series. A complete history and ocular examination, including fluorescein angiography, were performed. The best-corrected visual acuity was measured with a Snellen chart. Patients were followed up for 12 to 131 months (mean: 49 months). All patients underwent intravitreal injection of rt-PA (50 μg) and expansile gas. Primary outcome measures were best postoperative and final visual acuity and degree of blood displacement. Results: The size of the subretinal hemorrhage ranged from 0.5 to 28 disc diameters, and the degree of blood displacement was defined as complete (≥1 disc area from the center of the fovea), partial, or no displacement. Twenty-one (81%) patients showed partial or complete displacement of hemorrhage. Due to lack of displacement of hemorrhage in 5 patients (19%), submacular surgery was performed. In 13 of 21 (62%; P=0.0001) patients with displacement of hemorrhage, the best postoperative visual acuity improved ≥2 lines. The final visual acuity improved ≥2 lines in 42.9% (9 of 21), was stable in 23.8% (5 of 21), and worse ≥2 lines in 33.3% (7 of 21) of patients. The short duration of hemorrhage (≤4 days) and complete displacement of blood, independent of the hemorrhage size, were significantly associated with better postoperative visual acuity ( P=0.0001, P=0.0001, respectively). Conclusion: Intravitreal injection of rt-PA and gas seem to be more effective when applied within the first 4 days of acute submacular hemorrhage. Preoperative visual acuity as well as displacement of hemorrhage might be useful to predict final visual acuity. [ABSTRACT FROM AUTHOR]

Purpose Age-related macular degeneration ( AMD) is the leading cause of visual impairment in Western nations. Since the discovery of the importance of vascular endothelial growth factor ( VEGF) in the pathogenesis of neovascular AMD, anti- VEGF agents including pegaptanib, ranibizumab and bevacizumab provide a treatment option to improve vision in affected persons. VEGF Trap-Eye (Aflibercept) is a new agent available for the treatment of exudative AMD. The molecule is a receptor decoy with a longer half-life and a higher affinity to VEGF compared with ranibizumab or bevacizumab. The presented study has been designed to evaluate the short-term toxic effects of VEGF Trap-Eye on retinal function during and after direct exposure to the drug. Methods Isolated bovine retinas were perfused with an oxygen-saturated nutrient solution, and the electroretinogram ( ERG) was recorded using silver/silver chloride electrodes. A total of 0.5 mg or 2 mg VEGF Trap-Eye was added to the nutrient solution and retinas were exposed for 45 min, followed by a washout period of 100 min. The percentage of a- and b-wave reduction at the end of the washout was compared with the baseline values. Additionally, retinal whole mount cultures were exposed for 24 hr to VEGF Trap-Eye, and the amount of apoptotic cells were determined using the terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labelling ( TUNEL) assay. Results During simulation of intraocular application, no significant reduction in the a-wave amplitude for 0.5 mg (2.70%, p = 0.37) and 2 mg (3.84%, p = 0.37) VEGF Trap-Eye and b-wave amplitude for 0.5 mg (19.68%, p = 0.17) and 2 mg (24.1%, p = 0.06) VEGF Trap-Eye was observed at the end of the washout. However, there were significant changes in a-wave and b-wave amplitudes directly after exposure to 0.5 mg VEGF Trap-Eye (18.4%, p = 0.004 and 43.1%, p = 0.006, respectively). Conclusions The presented data suggest that intraocular application of up to 2 mg VEGF Trap-Eye does not induce irreversible toxic retinal damage. However, short-term results showed a negative effect directly after the application for 0.5 mg and 2 mg VEGF Trap-Eye. [ABSTRACT FROM AUTHOR]

Background/aims Vascular endothelial growth factor (VEGF) is a key factor in the pathogenesis of neovascular retinal diseases including age-related macular degeneration. VEGF inhibitors including ranibizumab, pegaptanib or bevacizumab improve retinal morphology and vision in many patients. The recently approved drug aflibercept (VEGF Trap-Eye/Eyelea, Regeneron, Tarrytown, New York, USA) offers a new therapy modality. We therefore tested for toxic and anti-proliferating effects of aflibercept. Methods The effects of aflibercept (0.125, 0.5, 2 mg), ranibizumab (0.125 mg) and bevacizumab (0.3125 mg) after 1, 24, 48 and 72 h on cell morphology via phase contrast pictures, cell viability via MTS assay, total cell amount via crystal violet staining, apoptosis induction via caspase 3/7 assay and proliferation via BrdU assay were investigated. Three ocular cell lines were chosen for toxicology testing: ARPE19 cells, RGC-5 cells and 661W cells. Results Aflibercept did not cause changes in cell morphology, induce apoptosis or cause permanent decrease in cell viability, cell density or proliferation in any cell line or concentration investigated. In general, aflibercept had fewer effects (upregulation or downregulation) compared with controls than bevacizumab or ranibizumab. Conclusions In our experiments, aflibercept did not lead to any negative effects on retinal cell lines and might therefore be used safely in clinical applications. [ABSTRACT FROM AUTHOR]

Acute macular neuroretinopathy (AMNR) is a rare disease entity, the diagnosis of which is frequently complicated by the subtlety of biomicroscopic findings. Two cases of AMNR are presented, in which the diagnosis and follow-up was enabled using the Spectralis® HRA+OCT in the absence of clear biomicroscopic findings. The typical lesions were visualized by hyporeflexion during infrared imaging and faded over time. With spectral domain optical coherence tomography, changes in the outer retina in the affected regions were documented, with no change over time. The broader availability of this technology may enhance the diagnosis and follow-up of AMNR. [ABSTRACT FROM AUTHOR]

There is an active and controversial debate about the role of intravitreal bevacizumab versus approved drugs in the treatment of neovascular agerelated macular degeneration (AMD). Because bevacizumab was available prior to the launch of ranibizumab, off-label use of the former became widespread and the cancer drug bevacizumab is the most commonly used medication in ophthalmology nowadays. This review considers every publication identified in MEDLINE using the keywords 'bevacizumab' and 'Avastin' between 1 June 2005 and 31 July 2008. The search identified 511 papers that were evaluated. In 33 studies, there was consistent and clear evidence for the efficacy of bevacizumab in neovascular AMD. However, the highest grade studies (three prospective, randomized, controlled trials) did not attain better than grade 2b level of evidence, and objective evaluation of the benefit of bevacizumab relative to representative controls was therefore not possible. Certainly, the available evidence is inferior to that obtained from the approval studies of ranibizumab and this should influence treatment selection and guidance of patients. These considerations indicate that important quality criteria need to be included in future studies to ensure more meaningful conclusions can be drawn. These include clearly defined inclusion criteria, information about the recruitment procedure (including data on withdrawals, excluded patients, concealed treatment allocation, use of intention-to-treat analyses and blinded assessment procedures). Although preclinical studies have almost exclusively found bevacizumab to be safe, the design utilized in clinical case series cannot rule out a possible increase in adverse events, which already show a high spontaneous incidence in elderly AMD patients. The superior evidence level for ranibizumab and the limited safety data for bevacizumab must be taken into consideration when evaluating the costs that a healthcare system is willing to spend. However, the superior grade of evidence for ranibizumab should not be confused with the (still missing) evidence for superior efficacy. The results of ongoing randomized, controlled, comparative trials will provide further data on the efficacy and cost effectiveness of bevacizumab and ranibizumab in the treatment of AMD. In the meantime, patients should be informed about the alternatives, the price differences and the restricted liability issue when off-label use of bevacizumab is offered. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is more prevalent among the elderly Caucasians than in Africans. A significant association between light iris colour, fundus pigmentation and incidence of AMD is reported, suggesting a possible correlation with melanin pigment. Zinc is known to bind to melanin in pigmented tissues and to enhance antioxidant capacity by function as a cofactor or gene expression factor of antioxidant enzymes in the eye. In this in vitro study, we investigated the uptake and storage of zinc in human irides. Irides of blue and brown human eyes were used. The number of melanocytes was measured. Tissues without any treatment served as controls. The irides were incubated with 100 μM zinc chloride in culture medium for 24 h. Specimens of the tissues were stored for the uptake examination. The remained pieces were further incubated for 3 and 7 d to investigate the storage of zinc. The concentration of zinc was measured by inductively coupled plasma mass spectrometry (ICP-MS). Melanocytes count was significantly higher in the brown tissues (P < 0.0001). Zinc concentration of blue coloured irides after 24 h zinc treatment was close to the controls. We did not observe any significant storing. In contrast, the concentration of zinc in brown irides was significantly increased after 24 h (P ≤ 0.01) and remained at a high level for 7 d. The uptake of zinc is likely dependent on the amount of pigmentation in human iris. Therefore, we assume that in patients suffering from AMD the degree of pigmentation of the irides and eventually fundi should be under consideration when the patients are treated with zinc supplementation. [ABSTRACT FROM AUTHOR]

Electronic implants are able to restore some visual function in blind patients with hereditary retinal degenerations. Subretinal visual implants, such as the CE-approved Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany), sense light through the eye's optics and subsequently stimulate retinal bipolar cells via ∼1500 independent pixels to project visual signals to the brain. Because these devices are directly implanted beneath the fovea, they potentially harness the full benefit of eye movements to scan scenes and fixate objects. However, so far, the oculomotor behavior of patients using subretinal implants has not been characterized. Here, we tracked eye movements in two blind patients seeing with a subretinal implant, and we compared them to those of three healthy controls. We presented bright geometric shapes on a dark background, and we asked the patients to report seeing them or not. We found that once the patients visually localized the shapes, they fixated well and exhibited classic oculomotor fixational patterns, including the generation of microsaccades and ocular drifts. Further, we found that a reduced frequency of saccades and microsaccades was correlated with loss of visibility. Last, but not least, gaze location corresponded to the location of the stimulus, and shape and size aspects of the viewed stimulus were reflected by the direction and size of saccades. Our results pave the way for future use of eye tracking in subretinal implant patients, not only to understand their oculomotor behavior, but also to design oculomotor training strategies that can help improve their quality of life. [ABSTRACT FROM AUTHOR]

Abstract: Endostatin is an endogenous angiogenesis inhibitor which requires E-selectin for its antiangiogenic activity. The aim of this study was to investigate the expression of endostatin in human choroidal neovascular membranes (CNV) secondary to age-related macular degeneration (AMD) with regard to vascularization and proliferative activity. An interventional case series of 36 patients who underwent removal of CNV were retrospectively investigated. Thirty-six CNV were analyzed by light microscopic immunohistochemistry for the expression of CD34 (endothelial cells, EC), CD105 (activated EC), Ki-67 (cell proliferation), Cytokeratin 18 (epithelial cells), VEGF (vascular endothelial growth factor), E-selectin and endostatin. Donor eyes (n =7) including one with AMD were used as controls. Endostatin immunoreactivity was present in choroidal vessels of five as well as in the retinal pigment epithelium (RPE)-Bruch''s membrane complex of two donor eyes without AMD. In one eye with AMD, endostatin was detected in RPE, Bruch''s membrane and choroidal vessels. Ninety-two percent (33/36) of CNV disclosed endostatin staining. RPE-Bruch''s membrane complex, choroidal vessels and stroma were positive in 50% (18/36), 72% (26/36), and 78% (28/36) of the membranes, respectively. Both control eyes and CNV expressed all the investigated markers except E-selectin being positive only in membranes. Endostatin, an endogenous angiogenesis inhibitor, is expressed in CNV and its therapeutic up-regulation may be a new strategy in the treatment of neovascular AMD. [Copyright &y& Elsevier]

Purpose: To examine the impact of photodynamic therapy (PDT) on pigment epithelium derived factor (PEDF) expression in human choroidal neovascularization (CNV) membranes with regard to vascular endothelial growth factor (VEGF) expression. Design: Interventional case series. Methods: Retrospective review of interventional case series of 42 patients (42 eyes) who underwent removal of CNV. CNV was secondary to age-related macular degeneration (AMD) in all cases. Fifteen patients were treated with PDT, 3 to 246 days before surgery. CNV were stained for CD34, CD105, cytokeratin 18, VEGF, and PEDF. Twenty-seven CNV without previous treatment were used as control. Results: Specimens without pretreatment disclosed varying degrees of vascularization, VEGF, and PEDF expression by different cells. Specimens treated by PDT, three days previously showed mostly occluded vessels lined with damaged endothelial cells (EC). In contrast, specimens excised at later time points after PDT were highly vascularized with healthy EC. This chronology was associated with an impressive VEGF immunoreactivity increased considerably in retinal pigment epithelial cells as well as significantly reduced PEDF expression in EC and stroma. Conclusions: PDT induces a selective vascular damage in CNV. The effectiveness of PDT, however, seems to be jeopardized by a rebound effect initiated by an enhanced VEGF and reduced PEDF expression in CNV. [ABSTRACT FROM AUTHOR]

: PurposeTo evaluate the vascularization and proliferative activity in choroidal neovascular membranes due to age-related macular degeneration after verteporfin photodynamic therapy and submacular removal.: DesignInterventional case series.: MethodsIn a retrospective review of seven patients who underwent removal of subfoveal classic choroidal neovascular membranes after treatment with photodynamic therapy 3 to 146 days earlier, membranes were stained for CD 34, CD 105, and Ki-67 and correlated with clinical pictures and fluorescein angiography.: ResultsFluorescein angiography performed on the day of surgery disclosed nonperfusion of the treated area 3 days after photodynamic therapy, but perfusion and leakage were seen at greater post–photodynamic therapy intervals. Membranes excised 3 days after photodynamic therapy showed CD34 and CD105 positive, mostly occluded vessels. The endothelial cells appeared damaged. Ki-67 activity was low. In membranes excised 34 to 146 days after photodynamic therapy, all vessels appeared patent and were lined by healthy endothelial cells with strong expression of CD34 and CD105. Ki-67 expression was elevated after 34 days but decreased thereafter.: ConclusionPhotodynamic therapy did not cause a general or complete occlusion of vessels within the choroidal neovascular membranes, as suggested by fluorescein angiography 3 days postintervention, but the endothelial cells appeared to be severely damaged. Proliferative activity within these specimens was reduced. At longer intervals after photodynamic therapy, the fibrovascular tissue seemed to recover; perfusion, hyperfluorescence, and leakage of the choroidal neovascular membranes could be detected by fluorescein angiography. The clinical appearance showed a correlation with the immunohistologic characteristics of an increased proliferative activity and patent vascularization. [Copyright &y& Elsevier]