Bone marrow-derived cells are differentially involved in pathological and physiological retinal angiogenesis in mice.

PURPOSE: Bone marrow-derived cells have been shown to play roles in angiogenesis. Although these cells have been shown to promote angiogenesis, it is not yet clear whether these cells affect all types of angiogenesis. This study investigated the involvement of bone marrow-derived cells in pathological and physiological angiogenesis in the murine retina. MATERIALS AND METHODS: The oxygen-induced retinopathy (OIR) model was used as a retinal angiogenesis model in newborn mice. To block the influence of bone marrow-derived cells, the mice were irradiated with a 4-Gy dose of radiation from a (137)Cs source. Irradiation was performed in four different conditions with radio dense 2-cm thick lead disks; (1) H group, the head were covered with these discs to protect the eyes from radiation; (2) A group, all of the body was covered with these discs; (3) N group, mice were completely unshielded; (4) C group, mice were put in the irradiator but were not irradiated. On P17, the retinal areas showing pathological and physiological retinal angiogenesis were measured and compared to the retinas of nonirradiated mice. RESULTS: Although irradiation induced leukocyte depletion, it did not affect the number of other cell types or body weight. Retinal nonperfusion areas were significantly larger in irradiated mice than in control mice (P<0.05), indicating that physiological angiogenesis was impaired. However, the formation of tuft-like angiogenesis processes was more prominent in the irradiated mice (P<0.05), indicating that pathological angiogenesis was intact. CONCLUSIONS: Bone marrow-derived cells seem to be differentially involved in the formation of physiological and pathological retinal vessels. Pathological angiogenesis in the murine retina does not require functional bone marrow-derived cells, but these cells are important for the formation of physiological vessels. Our results add a new insight into the pathology of retinal angiogenesis and bolster the hypothesis that bone marrow cells are involved in the pathology or severity of retinal angiogenic diseases.

[Circulating bone marrow-derived stem cells in patients with polypoidal choroidal vasculopathy].

PURPOSE: The current study was designed to investigate the role of circulating bone marrow (BM)-derived stem cells in the pathogenesis of polypoidal choroidal vasculopathy (PCV), a distinct type of neovascular age-related macular degeneration (AMD). METHODS: Thirty one clinically documented PCV patients were enrolled. Circulating BM-derived stem cells were collected from the patients' peripheral blood and cultured. Colony forming capacity (Hill assay) and migration activity (Boyden chamber system) were examined and analyzed. RESULTS: Colony forming units (CFU-Hill) were significantly fewer in bilateral PCV patients than in unilateral PCV patients. CFU-Hill was impaired in patients with larger (> 5000 microm) PCV lesions compared with patients with smaller PCV lesions. Migration activity of BM-derived stem cells was also reduced significantly in the bilateral PCV patients than in the unilateral PCV patients. CONCLUSIONS: Similar to CNV associated with AMD, impaired functional activity of circulating BM-derived stem cells was observed in PCV patients with bilateral or larger lesions. Circulating BM-derived stem cells may have a role in the pathogenesis of PCV.

Central retinal sensitivity after intravitreal injection of bevacizumab for myopic choroidal neovascularization.

PURPOSE: To evaluate retinal sensitivity in the macular area after intravitreal injection of bevacizumab in eyes with myopic choroidal neovascularization (mCNV). DESIGN: Prospective interventional case series. METHODS: Twenty-two eyes of 21 patients with mCNV were treated with intravitreal injections of bevacizumab. Microperimetry in the macular area was performed with a Micro Perimeter-1 (Nidek, Vigonza, Italy) before, and at 1 month and 6 months after treatment. RESULTS: After treatment, visual acuity (VA) and central retinal sensitivity were improved significantly. Mean VA in logarithm of the minimal angle of resolution (logMAR) fashion improved from 0.67 +/- 0.34 to 0.43 +/- 0.33 at 1 month, and to 0.34 +/- 0.26 at 6 months [P < .01, respectively]. Mean retinal sensitivity within the central 10 degree field improved from 4.8 +/- 2.8 decibels (dB) to 6.5 +/- 3.2 dB at 1 month and to 7.4 +/- 4.4 dB at 6 months [P < .01, respectively]. These improvements were more prominent in eyes with juxtafoveal mCNV than in eyes with subfoveal mCNV. With treatment, the mean number of measurement points within the scotomas decreased significantly; the absolute scotoma was reduced substantially in 15 (68%) eyes at 6 months. Unfortunately, the absolute scotoma was significantly enlarged in 1 eye (5%) at 1 month and in 4 eyes (18%) at 6 months. Also at 6 months, chorioretinal atrophy had developed in the macular area in 4 eyes (18%). CONCLUSIONS: Although intravitreal injection of bevacizumab improved retinal sensitivity in the macular area, some eyes showed enlargement of the scotoma after this treatment.

Circulating hematopoietic stem cells in patients with idiopathic choroidal neovascularization.

PURPOSE: In a prior study, the correlation was investigated between circulating hematopoietic stem cells (HSCs) and the activity or severity of choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD). The present study was designed to explore the role of circulating HSCs in the pathogenesis of CNV in patients with idiopathic (i)CNV. METHODS: Thirteen patients with clinically documented iCNV and 10 age-sex matched patients without iCNV or systemic disease were enrolled in a case-control study. Circulating HSCs were collected from the patients' peripheral blood and cultured. Colony-forming capacity, migration activity, and invasion activity of HSCs were experimentally analyzed. RESULTS: Colony-forming units by Hill's assay (CFU-Hill) were markedly lower (P<0.001) in patients with iCNV (12.8+/-3.2) than in healthy patients (67.6+/-12.6). Invasion activities of HSCs were reduced significantly in patients with iCNV. CFU-Hill was impaired in the patients (4.0+/-1.2) with CNV more than 1500 microm compared with the patients (20.3+/-4.0) with CNV less than 1500 microm (P=0.006). CONCLUSIONS: Similar to the previous finding of CNV associated with AMD, impaired functional activities of circulating HSCs were observed in patients with iCNV, which correlated with the size of iCNV. These results in young patients provide evidence to support the role of circulating HSCs in the pathogenesis of CNV.

[Two-year results of photodynamic therapy for choroidal neovascularization in young patients].

PURPOSE: To study the safety and efficacy of photodynamic therapy (PDT) with verteporfin in treating choroidal neovascularization (CNV) in young Japanese patients. METHODS: Ten eyes of 10 patients aged 50 years or younger with the diagnosis of CNV were retrospectively analyzed. CNV was of idiopathic origin in 8 eyes and of myopic origin in 2. Five eyes were treated with PDT. The visual, clinical, and angiographic responses and complications were investigated. Mean follow-up period was 33.2 months. RESULTS: The initial mean best-corrected visual acuity (BCVA) was significantly worse in the PDT treated group than in the non-PDT treated group (0.55 vs. 0.21, p = 0.029). The mean CNV size was significantly larger in the PDT treated group (1752 microm vs. 782 microm, p = 0.014). BCVA improved in 40% (2 eyes), unchanged in 40% (2 eyes), and worsened in 20% (1 eye) in both PDT-treated and non-treated groups. No significant complications were observed. CONCLUSIONS: PDT seems to be a good treatment strategy in achieving a stable or improved vision for young CNV patients, even if they had very poor visual acuity at their initial visits. Further prospective studies are needed.

Granulocyte colony-stimulating factor protects retinal photoreceptor cells against light-induced damage.

PURPOSE: Granulocyte colony stimulating factor (G-CSF) has been shown to have neuroprotective and anti-inflammatory effects in cerebral damage models. In addition, bone-marrow-derived hematopoietic cells, which can be mobilized with G-CSF, have a neuroprotective effect in hereditary retinal cell death. The present study was conducted to investigate whether G-CSF protects photoreceptors from light-induced cell death. METHODS: G-CSF or vehicle was systemically injected before the light exposure and for four consecutive days after the exposure. Morphologic and electrophysiologic examinations were performed 1 week after the exposure to light. Gamma ray irradiation (6.5 Gy) was used to examine the involvement of bone marrow-derived cells increased by G-CSF injection. The expression of G-CSF receptor in the retina was analyzed by immunohistochemistry and quantitative RT-PCR. RESULTS: The outer nuclear layer thickness was partially preserved in G-CSF-treated mice (measured at 300 microm superior from the optic disc, G-CSF: 14.9 +/- 6.3 microm versus control: 6.7 +/- 2.5 microm), and an electroretinogram confirmed the preservation of wave amplitudes (maximum scotopic a-wave G-CSF: 97.7 +/- 48.0 microV versus control: 14.4 +/- 21.9 microV, maximum scotopic b-wave G-CSF: 298.1 +/- 145.3 microV versus control: 33.2 +/- 50.1 microV). The effect was not lost, even with leukocyte depletion by irradiation. G-CSF receptor was expressed in retinal cells and upregulated by the light exposure (1.8-fold upregulation 2 hours after light exposure). CONCLUSIONS: G-CSF protects photoreceptor cells against light-induced damage, possibly via G-CSF receptor expressed on retinal cells. These findings may lead to a novel treatment strategy for neural degenerating diseases of the retina.

Two-year results of photodynamic therapy for polypoidal choroidal vasculopathy.

PURPOSE: To report on the two-year visual outcomes of indocyanine green angiography-guided photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV) patients. DESIGN: Retrospective case study. METHODS: A retrospective analysis that examined the clinical and angiographic data related to 41 eyes of 38 PCV patients (25 males, 13 females; average age +/- standard deviation [SD], 72.9 +/- 7.4 years) with follow-up periods of 24 months or more. RESULTS: The average number of PDT treatments was 1.65. After the 12-month follow-up, 12 eyes required retreatment. Although the mean visual acuity (VA) +/- SD before PDT (0.55 +/- 0.38 logarithm of the minimum angle of resolution units) improved to 0.46 +/- 0.41 at 12 months after the initial PDT, at 24 months, it declined significantly to 0.59 +/- 0.44 (P = .0018). Although only seven of 41 eyes exhibited VA deterioration at the 12-month follow-up examination, a decreased VA was noted in 18 eyes during the period starting from the 12-month follow-up until the final examination. The cases were bilateral in 11 (61.1%) of the 18 eyes. At the final examination, the mean VA of the bilateral cases but not the unilateral cases was significantly lower than that observed for the initial VA. CONCLUSIONS: PDT is an effective treatment against PCV over the short-term for both unilateral and bilateral cases. However, the VA prognosis may not the same after 12 months, especially for those PCV patients who have exudative age-related macular degeneration in contralateral eye.

Activation of bone marrow-derived microglia promotes photoreceptor survival in inherited retinal degeneration.

The role of microglia in neurodegeneration is controversial, although microglial activation in the retina has been shown to provide an early response against infection, injury, ischemia, and degeneration. Here we show that endogenous bone marrow (BM)-derived microglia play a protective role in vascular and neural degeneration in the retinitis pigmentosa model of inherited retinal degeneration. BM-derived cells were recruited to the degenerating retina where they differentiated into microglia and subsequently localized to the degenerating vessels and neurons. Inhibition of stromal-derived factor-1 in the retina reduced the number of BM-derived microglia and accelerated the rate of neurovascular degeneration. Systemic depletion of myeloid progenitors also accelerated the degenerative process. Conversely, activation of BM-derived myeloid progenitors by systemic administration of both granulocyte colony-stimulating factor and erythropoietin resulted in the deceleration of retinal degeneration and the promotion of cone cell survival. These data indicate that BM-derived microglia may play a protective role in retinitis pigmentosa. Functional activation of BM-derived myeloid progenitors by cytokine therapy may provide a novel strategy for the treatment of inherited retinal degeneration and other neurodegenerative diseases, regardless of the underlying genetic defect.

Chorioretinal anastomosis after photodynamic therapy for polypoidal choroidal vasculopathy: CRA after PDT for PCV.

An 80-year-old woman was treated with photodynamic therapy (PDT) to the left eye for polypoidal choroidal vasculopathy (PCV). About 3 months after PDT, her left eye developed a chorioretinal anastomosis with severe atrophy of the retinal pigment epithelium in the macula; visual acuity in this eye was 20/1000. She received a second session of PDT, plus an intravitreal injection of triamcinolone acetonide. About 3 months after the second treatment, the chorioretinal anastomosis was enlarged and the retinal vessels involved in the anastomosis were more dilated. About 1 year after the first PDT, visual acuity in the left eye had stabilized at 20/400. Development of a chorioretinal anastomosis is a distinct possibility following PDT in eyes with PCV, and can lead to poor visual recovery.

Circulating hematopoietic stem cells in patients with neovascular age-related macular degeneration.

PURPOSE: Circulating hematopoietic stem cells (HSCs) appear to have roles in the formation of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). This study was conducted to investigate whether the number or function of HSCs plays a role in neovascular AMD. METHODS: Eighty-one patients with neovascular AMD who underwent comprehensive fundus examinations every 3 months were included. The number of CD34(+) HSCs isolated from peripheral blood was counted by flow cytometry. Serum cytokine levels were assessed by enzyme-linked immunosorbent assay. To examine the function of circulating HSCs, mononuclear cells were cultured and then colony forming unit (CFU-EC) and migration were measured. RESULTS: The number of circulating CD34(+) HSCs was significantly increased in the patients with active CNV without major systemic diseases (stable: 3.8 +/- 0.3 cells/microL, active: 5.5 +/- 0.7 cells/microL, stable versus active: P < 0.05). The number of HSCs correlated positively with the erythropoietin serum level (r = 0.47, P = 0.002). Although there was no significant difference in the CFU-EC between the patients with CNV and the control subjects, a significant decrease of CFU-EC was observed in the patients with bilateral or larger CNV. CONCLUSIONS: The findings suggest that CD34(+) HSCs may be recruited from bone marrow through a signal from active CNV. Furthermore, HSCs may play a role in the severity of CNV.

Indocyanine green angiography: guided photodynamic therapy for polypoidal choroidal vasculopathy.

PURPOSE: To report the 12-month follow-up results of subfoveal polypoidal choroidal vasculopathy (PCV) patients treated with indocyanine green angiography (ICGA)-guided photodynamic therapy (PDT). DESIGN: Interventional, noncomparative cases series. METHODS: A retrospective analysis of the clinical and angiographic data related to 47 PCV eyes that were followed up for 12 months was carried out. The greatest linear dimension (GLD) for PDT was determined based on the ICGA findings. Optical coherence tomography (OCT) also was used to evaluate the therapeutic effects. RESULTS: The mean logarithm of the minimum angle of resolution visual acuity (VA; 0.58 +/- 0.37) significantly improved to 0.53 +/- 0.38 at three months (P = .04) and to 0.46 +/- 0.40 at 12 months (P = .02). The average ICGA GLD (2682.3 +/- 1026.9 mm) was significantly (P = .0001) smaller than the presumed fluorescein angiography (FA) GLD (4043.6 +/- 1914.8 mm). In more than 80% of cases, complete resolution of retinal exudative changes was observed. Although polypoidal vascular lesions disappeared in 82.2% of eyes, the branched vascular networks showed little change. The initial VA and GLD had little correlation with the VA outcome. CONCLUSIONS: ICGA-guided PDT reduces the size of laser exposure and is an effective treatment for PCV. Because PCV may appear as occult choroidal neovascularization (CNV) on FA, PCV should be diagnosed using ICGA before treatment because PCV may respond differently than CNV to appropriate treatment.

Hemorrhagic complications after photodynamic therapy for polypoidal choroidal vasculopathy.

PURPOSE: To evaluate the clinical features and risk factors of hemorrhagic complications in eyes with polypoidal choroidal vasculopathy (PCV) after photodynamic therapy (PDT). METHODS: We retrospectively reviewed data for 91 consecutive eyes of 85 patients who underwent PDT for the treatment of PCV. The diagnosis of PCV was based on indocyanine green angiographic findings, showing a branching vascular network terminating in polypoidal swelling. The greatest linear dimension included all polypoidal lesions, leaking vascular network, and type 2 choroidal neovascularization. RESULTS: During the follow-up period after PDT, postoperative subretinal hemorrhage was seen in 28 (30.8%) of 91 eyes. In 22 (78.6%) of these 28 eyes, subretinal hemorrhage was absorbed without treatment. In 6 eyes (21.4%), however, bleeding resulted in vitreous hemorrhage, and 2 eyes underwent pars plana vitrectomy. Although visual acuity was maintained or increased in 18 (81.8%) of 22 eyes with subretinal hemorrhage alone, it decreased significantly in 3 (50.0%) of 6 eyes with postoperative vitreous hemorrhage. Various systemic diseases and medication with an anticoagulant had no correlation with these hemorrhagic complications. Laser irradiation spot size for PDT was significantly larger in eyes with postoperative vitreous hemorrhage (P = 0.017) than in those without. CONCLUSION: Subretinal hemorrhage after PDT can be a common complication in patients with PCV and may have a minor effect on visual outcome. However, postoperative hemorrhage is occasionally so massive that it leads to vitreous hemorrhage and poor visual prognosis. When considering PDT for eyes with a large PCV lesion, ophthalmologists should be aware of the risk of serious hemorrhagic complications.

Microrips of the retinal pigment epithelium in polypoidal choroidal vasculopathy.

PURPOSE: To study the clinical characteristics of microrips of the retinal pigment epithelium (RPE) in polypoidal choroidal vasculopathy (PCV). DESIGN: Retrospective case series. METHODS: For this study, we retrospectively reviewed 156 consecutive eyes of 136 patients with PCV. The lesions were examined with fluorescein angiography and indocyanine green angiography. RESULTS: Of 156 eyes with PCV, 11 (7.1%) had microrips of the RPE at the margin of the pigment epithelial detachment. In the early phase of fluorescein angiography, the microrips showed pinpoint leakage from the RPE, which increased and pooled within the subretinal space in the late phase. Of the 11 eyes with microrips, the rip disappeared in 10 eyes (90.9%), and no eyes developed RPE tears during follow-up. The mean duration from the first detection of a microrip to resolution was 3.0 +/- 1.6 months. CONCLUSIONS: In eyes with PCV, microrips of the RPE are not uncommon, but have minimal clinical relevance.

Central retinal sensitivity measured with the micro perimeter 1 after photodynamic therapy for polypoidal choroidal vasculopathy.

PURPOSE: To evaluate central retinal sensitivity and its relation to the symptomatic change noted in central visual disturbance shortly after photodynamic therapy (PDT) in eyes with polypoidal choroidal vasculopathy (PCV). DESIGN: Retrospective interventional case series. METHODS: We reviewed retrospectively 20 eyes of 20 patients who underwent PDT for the treatment of subfoveal PCV. Microperimetry in the macular area was performed with Micro Perimeter 1 (MP1) [Nidek, Vigonza, Italy] before and at one, three, and six months after PDT. Forty measurement points were located within the central 10 degree of the macula. RESULTS: After PDT, although most eyes showed a reduction in exudation, the mean posttreatment visual acuity did not change significantly. At one month after PDT, however, retinal sensitivities within the central 2 degree, 6 degree, and 10 degree fields, which were 3.6 +/- 3.1, 5.1 +/- 3.4, and 6.2 +/- 3.6 dB [decibels] at baseline, improved to 5.9 +/- 3.8 (P = .003), 7.1 +/- 3.6 (P = .003), and 8.1 +/- 3.5 dB (P = .004). At one month after treatment, 14 patients (70%) noted subjective improvement of the central visual disturbance and mean retinal sensitivity within the central 2 degree, 6 degree, and 10 degree fields had improved more than 2 dB in 11, 10, and eight eyes, respectively. At three and six months after PDT, however, postoperative improvement of the retinal sensitivities was diminished. CONCLUSIONS: Retinal sensitivity in the macular area of eyes with subfoveal PCV improved shortly after PDT, and may account, at least in part, for the immediate subjective improvement in central vision after PDT.

Polypoidal choroidal vasculopathy appearing as classic choroidal neovascularisation on fluorescein angiography.

AIMS: To study the visual prognosis and ocular characteristics of eyes with polypoidal choroidal vasculopathy (PCV) that appear to have classic choroidal neovascularisation (CNV) on fluorescein angiography (FA). METHODS: The authors reviewed retrospectively 38 eyes with PCV that appear to have classic CNV on FA. Lesions were examined with indocyanine green angiography, FA and optical coherence tomography (OCT). RESULTS: In all cases OCT showed subretinal material with moderate reflectivity that corresponded in location to classic CNV. At the final visit, the subretinal material resolved completely in 14 eyes (36.8%, resolved group), but resolved only incompletely in 24 eyes (63.2%, persisted group) after photodynamic therapy (PDT). Mean (standard deviation) visual acuity in the resolved group (0.35 (0.41) in log MAR) was significantly better than that in the persisted group (0.84 (0.24)) at the final visit (p<0.001). The subretinal material seen before treatment was more frequently seen in subfovea in the persisted group (87.5% vs 42.9%, p = 0.007). Also, this material was located adjacent to polypoidal lesions more often in the resolved group (92.9% vs 58.3%, p = 0.030). CONCLUSIONS: Eyes with PCV sometimes show classic CNV with subretinal material apparent on OCT, and PCV is thus attributed to type 2 CNV or to pure fibrinous tissue without CNV. Visual prognosis in eyes with type 2 CNV is poor, and although it is difficult to discriminate type 2 CNV from pure fibrin deposition before treatment, type 2 CNV is seen more often in the subfovea and is typically separate from the polypoidal lesions.

Pigment epithelial detachment in polypoidal choroidal vasculopathy.

PURPOSE: To study the morphological features of serosanguineous pigment epithelial detachments (PEDs) with accompanying polypoidal lesions in eyes with polypoidal choroidal vasculopathy (PCV). DESIGN: Retrospective observational case series. METHODS: For this observational case study, we retrospectively reviewed 93 consecutive eyes of 85 patients with PCV. The lesions in eyes with PCV were examined with indocyanine green angiography (IA) and optical coherence tomography (OCT). RESULTS: Of 93 eyes with PCV, 51 eyes (55%) had serous or hemorrhagic PEDs. Of these 51 eyes, a notch in the PED was found in 27 eyes (53%) by angiography, most of which showed polypoidal lesions by IA that corresponded in location to the notch observed by angiography. Polypoidal lesions were detected outside the PED in one eye (2%), at the margin of the PED in 33 eyes (65%), and inside the PED in 12 eyes (24%). OCT revealed that PED had a notch observed tomographically in 29 eyes (57%), most of which corresponded in location to polypoidal lesions seen by IA. In eight eyes, polypoidal lesions, which were adherent to the inner surface of the serous PED, appeared to be detached from the Bruch membrane and the choroid. CONCLUSIONS: Polypoidal lesions are located at the margin of PED and make a notch in the accompanying PED that is visible by angiography and tomographically. When the polypoidal lesions have increased exudate, the fluid from the lesions infiltrates under the polypoidal lesions themselves, which results in the lesions detaching from the Bruch membrane and appearing to be located inside the PED.