Evaluation of focal damage in the retinal pigment epithelium layer in serous retinal pigment epithelium detachment.

The purpose of this study was to evaluate focal damage in the retinal pigment epithelium (RPE) layer in serous retinal pigment epithelium detachment (PED) with multi-contrast optical coherence tomography (OCT), which is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT and standard OCT images. We evaluated 37 eyes with age-related macular degeneration that had serous PED. Focal RPE damage was indicated by hyper-transmission beneath the RPE-Bruch's membrane band in standard OCT images. Distribution of RPE melanin was calculated using the dataset from multi-contrast OCT. Twenty-four points with hyper-transmission were detected in 21 of the 37 eyes. Standard OCT images failed to show disruption of the RPE-Bruch's membrane band at 5 of the 24 hyper-transmission points. Conversely, multi-contrast OCT images clearly showed melanin defects in the RPE-Bruch's membrane band at all points. Areas of melanin defects with disruption of the RPE-Bruch's membrane band were significantly larger than those without disruption. The volume of intraretinal hyper-reflective foci was significantly larger in eyes with hyper-transmission than that in eyes without hyper-transmission. Multi-contrast OCT is more sensitive than standard OCT for displaying changes at the RPE-Bruch's membrane band when there are small areas of RPE damage.

The effect of the acceleration/deceleration trauma in angioid streaks: A pathogenic hypothesis. / Efecto del traumatismo por aceleración/desaceleración en estrías angioides: hipótesis patogénica.

CASE REPORT: A 59-year-old male with acceleration/deceleration cranial trauma (ADT), caused by a car accident. After one month, he presented with loss of visual acuity in the right eye. A fluorescein angiography test was performed and it detected centrifugal hyperfluorescent lines from the optic nerve head, a characteristic compatible with the diagnosis of angioid streaks. The loss of visual acuity was demonstrated by the discovery of a juxtafoveal choroidal neovascular membrane (CNV). CONCLUSION: ADT can cause hyper-extension of the eyeball in its equator line, producing the rupture of fragile structures such as the Bruch membrane (MB) in patients with angioid streaks and the subsequent formation of CNV.

Hallazgos con la SD-OCT en vasculopatía coroidea polipoidea / SD-OCT findings in polypoidal choroidal vasculopathy

OBJETIVO: Examinar a los pacientes con vasculopatía coroidea polipoidea (VCP), usando la tomografía de coherencia óptica de dominio espectral (SD-OCT) para caracterizar y localizar las lesiones en la VCP. PACIENTES Y MÉTODOS: Se estudió una serie de 15 ojos de 10 pacientes diagnosticados de VCP. Todos los ojos fueron explorados con SD-OCT. RESULTADOS: Con cortes transversales de la SD-OCT se encontraron desprendimientos del epitelio pigmentario (DEP) típicos y atípicos. Los pólipos y la neovascularización se localizaron encima de la membrana de Bruch. Los 15 ojos (100%) mostraron líquido subretiniano (LSR) en asociación con los DEP. CONCLUSIÓN: Los hallazgos de la SD-OCT localizan las lesiones vasculares de la VCP en el espacio sub-EPR e indican fuertemente que la VCP es una variante de neovascularización tipo 1

OBJECTIVE: To examine patients with polypoidal choroidal vasculopathy (PCV), using spectral-domain optical coherence tomography (SD-OCT) to characterise and locate the PCV lesions. PATIENTS AND METHODS: A series of 15 eyes of 10 patients diagnosed with PCV were examined. All eyes were imaged with macular SD-OCT. RESULTS: SD-OCT cross-sectional scan findings included atypical and typical pigment epithelial detachments (PEDs). Polyps and neovascularisation were located above Bruch membrane. All 15 eyes (100%) showed sub-retinal fluid (SRF) in association with PEDs. CONCLUSION: These SD-OCT findings located the vascular lesions of PCV in the sub-retinal pigment epithelium (RPE) space, and strongly suggest that PCV is a variant of type 1 neovascularization

Serum inflammatory markers after rupture retinal laser injury in mice.

BACKGROUND AND OBJECTIVE: To characterize the cellular, immunological, and inflammatory response to retinal photocoagulation of intense rupture laser lesions as a model of retinal degenerative diseases. MATERIALS AND METHODS: Seven C57BL/6 mice were irradiated using a 532-nm laser to induce 10 retinal burns per eye that ruptured Bruch's membrane. Blood was drawn from the saphenous vein before and 2 months after laser treatment. The serum was run on antigen microarrays with 85 molecular markers associated with retinal degenerative diseases. RESULTS: Rupture laser resulted in dramatic changes in the immunoglobulin reactivity of most inflammatory markers 2 months after laser injury. Approximately two-thirds increased expression and one-third decreased expression. Notable markers that were increased included complement C3, CRP, PKM2, and aldolase. CONCLUSION: Rupture laser injury causes a change in the serum inflammatory markers after 2 months similar to macular degeneration, diabetic retinopathy, and cancer-associated retinopathy. This animal model could be used as a biomarker for disease stage and activity in retinal degenerations.

Tissue inhibitor of metalloproteinases-3 peptides inhibit angiogenesis and choroidal neovascularization in mice.

Tissue inhibitors of metalloproteinases (TIMPs) while originally characterized as inhibitors of matrix metalloproteinases (MMPs) have recently been shown to have a wide range of functions that are independent of their MMP inhibitory properties. Tissue inhibitor of metalloproteinases-3 (TIMP-3) is a potent inhibitor of VEGF-mediated angiogenesis and neovascularization through its ability to block the binding of VEGF to its receptor VEGFR-2. To identify and characterize the anti-angiogenic domain of TIMP-3, structure function analyses and synthetic peptide studies were performed using VEGF-mediated receptor binding, signaling, migration and proliferation. In addition, the ability of TIMP-3 peptides to inhibit CNV in a mouse model was evaluated. We demonstrate that the anti-angiogenic property resides in the COOH-terminal domain of TIMP-3 protein which can block the binding of VEGF specifically to its receptor VEGFR-2, but not to VEGFR-1 similar to the full-length wild-type protein. Synthetic peptides corresponding to putative loop 6 and tail region of TIMP-3 have anti-angiogenic properties as determined by inhibition of VEGF binding to VEGFR-2, VEGF-induced phosphorylation of VEGFR-2 and downstream signaling pathways as well as endothelial cell proliferation and migration in response to VEGF. In addition, we show that intravitreal administration of TIMP-3 peptide could inhibit the size of laser-induced choroidal neovascularization lesions in mice. Thus, we have identified TIMP-3 peptides to be efficient inhibitors of angiogenesis and have a potential to be used therapeutically in diseases with increased neovascularization.

Choroidal rupture and optic nerve injury with equipment designated as 'child-safe'.

Blunt ocular trauma from a child's plastic foam-covered toy baseball bat caused traumatic optic neuropathy and choroidal rupture in a 9-year-old child. The examination revealed a visual acuity of 6/60, a relative afferent pupillary defect, optic nerve swelling, commotio retinae and retinal haemorrhages. There was no orbital fracture or intraorbital haematoma on CT scanning. Optical coherence tomography showed macular oedema and disruption of the retinal pigment epithelium and Bruch's membrane. The child was admitted for intravenous methylprednisolone and discharged on topical steroid treatment. At 1 month follow-up, visual acuity had improved to 6/12. Optic nerve swelling had resolved and the fundus had two crescent-shaped choroidal rupture scars. Choroidal rupture and optic neuropathy can be secondary to indirect trauma, and even when the mechanism of injury is with a piece of equipment designated as suitable for children, serious ocular injury can occur.

Therapeutic window of retinal photocoagulation with green (532-nm) and yellow (577-nm) lasers.

BACKGROUND AND OBJECTIVE: The 577-nm (yellow) laser provides an alternative to the 532-nm (green) laser in retinal photocoagulation, with potential benefits in macular treatment and through ocular opacities. To assess relative risk of thermomechanical rupture of Bruch's membrane with yellow laser in photocoagulation, the therapeutic window, the ratio of threshold powers for mild coagulation and rupture, was measured. MATERIALS AND METHODS: Retinal coagulation and rupture thresholds, visualized ophthalmoscopically, were measured with 577- and 532-nm lasers using 10- to 100-ms pulses in 34 rabbit eyes. Lesions at 1 and 7 days were assessed histologically. RESULTS: Coagulation threshold with yellow laser was 26% lower than with green laser. The therapeutic window increased linearly with log-duration for both wavelengths with a difference in parallel-slope intercept of 0.36 ± 0.20, corresponding to 8% to 15% wider therapeutic window for yellow wavelength. CONCLUSION: The therapeutic window of retinal photocoagulation in rabbits at 577 nm is slightly wider than at 532 nm, whereas histologically the lesions are similar.

[Use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to choroidal rupture]. / Bevacizumab intravítreo en el tratamiento de la neovascularización subretiniana secundaria a rotura coroidea.

CASE REPORT: A 28 year-old male attended our Emergency Department with a traumatic choroidal rupture and macular haemorrhage. After pneumatic displacement of the haemorrhage with C(3)F(8) and tissue plasminogen activator, the haemorrhage was reabsorbed and visual acuity (VA) improved. Three months later the patient presented with decreased VA and a juxtafoveal choroidal neovascularisation (CNV) that was treated with intravitreal bevacizumab. One year after a single bevacizumab injection the CNV remained inactive, with a final VA of 0.5. DISCUSSION: Intravitreal bevacizumab injection is a new and effective treatment for traumatic CNV. In our patient, in contrast to other aetiologies, the CNV needed no more than one Avastin(®) injection to be inactivated, after one year of follow-up.

Bevacizumab intravítreo en el tratamiento de la neovascularización subretiniana secundaria a rotura coroidea / Use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to choroidal rupture

Caso clínico: Paciente varón de 28 años que presenta rotura coroidea y hemorragia macular postraumáticas de 24 horas de evolución acude al servicio de urgencias. Se realizó desplazamiento neumático de la hemorragia mediante inyección intravítrea de C3F8 y activador tisular del plasminógeno (rTPA), consiguiéndose la reabsorción de la hemorragia y mejora de la agudeza visual (AV). Al cabo de 3 meses, el paciente acude por empeoramiento de la visión con metamorfopsia, diagnosticándose de neovascularización (NVC) yuxtafoveal en la zona de la rotura, que se trata con una inyección de bevacizumab intravítreo. Un año después, la NVC permanece inactiva y la AV se mantiene en 0,5. Discusión: La inyección intravítrea de bevacizumab representa una nueva forma efectiva de tratamiento de la NVC postraumática. A diferencia de lo descrito en otras etiologías, la NVC secundaria a rotura coroidea en nuestro paciente requirió solamente una dosis de Avastin® para su inactivación, en un periodo de seguimiento de un año(AU)

Case report: A 28 year-old male attended our Emergency Department with a traumatic choroidal rupture and macular haemorrhage. After pneumatic displacement of the haemorrhage with C3F8 and tissue plasminogen activator, the haemorrhage was reabsorbed and visual acuity (VA) improved. Three months later the patient presented with decreased VA and a juxtafoveal choroidal neovascularisation (CNV) that was treated with intravitreal bevacizumab. One year after a single bevacizumab injection the CNV remained inactive, with a final VA of 0.5. Discussion: Intravitreal bevacizumab injection is a new and effective treatment for traumatic CNV. In our patient, in contrast to other aetiologies, the CNV needed no more than one Avastin® injection to be inactivated, after one year of follow-up(AU)

Intravitreal ranibizumab for choroidal neovascularization related to traumatic Bruch's membrane rupture.

PURPOSE: Choroidal neovascularization (CNV) secondary to traumatic rupture of Bruch's membrane is a rare condition, without standardized treatment. Here we describe one case of CNV related to traumatic rupture of Bruch's membrane which was successfully treated with intravitreal injection of ranibizumab. METHODS: A 14-year-old patient was referred for ocular contusion, complicating interpapillomacular rupture of Bruch's membrane in left eye. Indeed, a correct initial visual acuity, juxtafoveolar CNV appeared 4 months later on the border of Bruch's membrane rupture. The patient was treated with an off-label intravitreal ranibizumab because of worsening of visual acuity. RESULTS: One month after intravitreal injection, visual acuity improved, from 20/40 to 20/25. At 12-month follow-up, visual acuity remained at 20/25, fundus examination. Fluorescein angiography, indocyanine green angiography and optic coherence tomography showed fibrotic evolution of CNV. The Bruch's membrane rupture remained stable. No side-effect of intravitreal injection of ranibizumab was observed. CONCLUSION: For this patient affected with CNV secondary to traumatic Bruch's membrane, one single intravitreal ranibizumab injection was efficient, with 1-year follow-up.

Clinical and histological aspects of CNV formation: studies in an animal model.

The purpose of the present thesis was to develop an animal model of CNV in order to study the early formation of CNV and to test the effects of an anti-angiogenic treatment. Porcine eyes were chosen as a substrate for CNV induction, since they are similar to human eyes in terms of both macroscopic and microscopic morphology. However, a major difference is that pigs lack a fovea; instead they have a visual streak, with a relatively stable and high concentration of cones. By surgical perforation of Bruch's membrane we were able to induce formation of CNV membranes. The morphology and cellular composition of these membranes varied with the surgical technique employed. When RPE cells were locally removed at the time of perforation, the resulting CNV was thinner, contained fewer blood vessels and was less prone to leak on fluorescein angiography than when RPE cells were left intact at induction. The neuroretina overlying the perforation site was not damaged by any of the surgical techniques, thus allowing the subsequent retinal damage to be ascribed to the actual process of CNV formation. Using this animal model allowed us to directly map histological findings onto fluorescein angiograms and thereby perform meaningful correlations between histopathologic and photographic features. Such correlations have been hampered in human subjects, since human eyes are not enucleated as a consequence of CNV and are therefore only available for post-mortem studies. In such studies there often is a considerable time-gap between the death of the patient and the latest available fluorescein angiogram, thereby allowing macular pathology to evolve in the interim. Histological examination of the porcine membranes demonstrated that they were composed of RPE cells, glial cells, macrophages, endothelial cells, collagen and smooth muscle fibres, which are the same cellular and fibrillar elements that dominate human CNV membranes. The porcine model was applied to test the effects, in a randomized and masked fashion, of intravitreally injected bevacizumab. Bevacizumab, a pan VEGF A antibody, was found to reduce both the proliferation of endothelial cells in CNV membranes and the propensity to leak in fluorescein angiograms. Immunohistochemically, bevacizumab was detected in the inner limiting membrane, in retinal blood vessels and binding uniformly to the entire CNV membrane without any cellular predisposition. Based on the above findings we believe that the porcine CNV model shows a bearing to human disease and therefore might be used as a tool to obtain improved treatments for this debilitating condition.

Surgical induction of choroidal neovascularization in a porcine model.

PURPOSE: To develop a reproducible surgical technique for the induction of choroidal neovascularization (CNV) in the subretinal space of porcine eyes and to analyse the resulting CNV clinically and histologically. METHODS: Two different modifications of a surgical technique previously described were compared with the original method. In ten porcine eyes retinal pigment epithelial (RPE) cells were removed using a silicone tipped cannula, in ten porcine eyes Bruch's membrane was perforated once with a retinal perforator without prior RPE removal and in ten eyes RPE removal was followed by a single perforation of Bruch's membrane. Fifteen of the eyes, five from each group, were enucleated 30 minutes after surgery, while the remaining eyes were enucleated after 14 days. Prior to enucleation, at day 14, fundus photographs and fluorescein angiograms were obtained. Eyes were examined by light microscopy and by immunohistochemical staining. In addition to these 30 eyes, two eyes underwent surgery with the purpose of subsequent scanning electron microscopic (SEM) examination. RESULTS: In eyes enucleated immediately after surgery neuroretinas overlying the induced lesions were intact without apparent atrophy of cells regardless of the surgical technique applied. The process of RPE removal was found to induce breaks in Bruch's membrane and both the size and the number of breaks varied between eyes. CNV membranes were identified in 15 of 15 eyes enucleated after 14 days. CNV membranes induced by perforation of Bruch's membrane without prior RPE removal were significantly thicker than membranes from eyes undergoing both RPE removal and Bruch's perforation (p = 0.03) and also thicker than membranes from eyes with only RPE-removal (p < 0.01). CNV membranes from eyes with perforation of Bruch's membrane without prior RPE removal had a higher cellular content and were more richly vascularized and also exhibited the highest propensity to leak in fluorescense angiograms. CONCLUSION: All three surgical techniques were capable of inducing CNV, but the one applying perforation of Bruch's membrane without RPE removal was easier to reproduce and involved fewer variables than the techniques utilizing RPE removal. The presence of RPE cells seems to affect both the morphology and cellular composition of induced CNV.

Trans-scleral delivery of polyamine analogs for ocular neovascularization.

Periocular injections of the polyamine analog CGC-11144 three times a week causes regression of choroidal neovascularization. This regimen was selected to maximize chances of success for proof of concept, but is not ideal for clinical application. In this study we explored other regimens for periocular delivery of CGC-11144, and 2 other polyamine analogs, CGC-11047 and CGC-11093. A single periocular injection of 200 microg of CGC-11144, 2 mg of CGC-11047, or 1.5 mg of CGC-11093 caused significant suppression and regression of laser-induced choroidal neovascularization. An injection of 2 mg of CGC-11047 or 1.5 mg of CGC-11093 one or two weeks before, but not 3 weeks before, rupture of Bruch's membrane also caused significant suppression. Periocular injection of polyamine analogs also caused strong inhibition of retinal or subretinal neovascularization in mice with oxygen-induced ischemic retinopathy or Rhodopsin promoter/VEGF transgenic mice, respectively. These data suggest that periocular injection of one of 3 different polyamine analogs inhibits retinal or choroidal neovascularization and a single injection provides inhibitory activity for at least 2 to 3 weeks, which could provide the basis for a feasible treatment regimen for clinical trials.

Bone marrow-derived cells home to and regenerate retinal pigment epithelium after injury.

PURPOSE: To determine whether hematopoietic stem and progenitor cells (HSCs/HPCs) can home to and regenerate the retinal pigment epithelium (RPE) after induced injury. METHODS: Enriched HSCs/HPCs from green fluorescent protein (gfp) transgenic mice were transplanted into irradiated recipient mice to track bone marrow-derived cells. Physical damage was induced by breaching Bruch's membrane and inducing vascular endothelial growth factor A (VEGFa) expression to promote neovascularization. RPE damage was also induced by sodium iodate injection (40 mg/kg) into wild-type or albino C57Bl/6 mice. Cell morphology, gfp expression, the presence of the Y chromosome, and the presence of melanosomes were used to determine whether the injured RPE was being repaired by the donor bone marrow. RESULTS: Injury to the RPE recruits HSC/HPC-derived cells to incorporate into the RPE layer and differentiate into an RPE phenotype. A portion of the HSCs/HPCs adopt RPE morphology, express melanosomes, and integrate into the RPE without cell fusion. CONCLUSIONS: HSCs/HPCs can migrate to the RPE layer after physical or chemical injury and regenerate a portion of the damaged cell layer.

A new animal model of choroidal neovascularization.

PURPOSE: The purpose of this study was to evaluate the ability of different methods to induce choroidal neovascularization (CNV) in the domestic pig. METHODS: A total of 26 Danish landrace pigs was used. A sample of 22 eyes in 12 pigs underwent retinal photocoagulation with a xenon lamp, six eyes in four pigs underwent retinal photocoagulation with a diode laser, and mechanical rupture of Bruch's membrane (BM) was induced in 12 pigs following surgical debridement of the retinal pigment epithelium without damage to the neuroretina. RESULTS: All 12 pigs (100%) in the group with mechanical rupture of BM developed CNV. The induced membranes were morphologically similar to CNV membranes in humans. Induced CNV was found in 13 of 22 (54%) xenon lamp-treated animals and in five of six (83%) diode laser-treated animals. The CNV in these groups was small and the morphology of the induced lesions was dominated by retinal gliosis and retinal neovascularization, probably due to a marked destruction of the neuroretina. CONCLUSIONS: Surgical debridement of the retinal pigment epithelium followed by mechanical rupture of BM is a reproducible method of producing CNV in the domestic pig, whereas photocoagulation gives rise to glially derived subretinal fibrovascular membranes and primarily retinal neovascularization.