Retinal choroidal anastomosis in classic choroidal neovascularization demonstrated by indocyanine green angiography

Pathologic retinal choroidal anastomoses are relatively rare. Until now, they have been described in age-related macular degeneration only in occult pigment epithelial detachments or following fibrous scarring. We report the occurrence of a retinal choroidal anastomosis with blood flow from an actively proliferating classic choroidal neovascular membrane into a retinal vein in a 72-year-old male with age-related macular degeneration. Indocyanine green videoangiography performed by scanning laser ophthalmoscope demonstrated the anastomosis, whereas it could not be identified clinically or with fluorescein videoangiography.     

External beam radiotherapy and choroidal neovascularization

Triglyceride metabolism is complex and still poorly understood. Hypertriglyceridemia seems to enhance the risk for the development of coronary heart disease, but it cannot be regarded as a counterpart of hypercholesterolemia as a risk factor. The relevance of reduction of triglycerides in the prevention of coronary heart disease is still unclear. This is related to a number of problems, such as the lack of adequate clinical trials, heterogeneity in the abnormalities of triglyceride metabolism and unknown atherogenic threshold levels for serum triglycerides.     

Indocyanine green angiographic findings in idiopathic choroidal neovascularization

PURPOSE: Evaluation of choroidal alterations associated with idiopathic choroidal neovascularization (ICNV) and the possible relation between this affection and Multifocal Choroidopathies (MC). METHODS: The authors analysed, using high definition videoangiography, the choroidal findings in 21 consecutive patients affected by ICNV (7 males and 14 females; 19-46 years; mean age: 31.8 years); with a follow-up at 5-30 months (mean 13 months). Moreover, a retrospective study of 20 cases of ICNV (11 males and 9 females; age: 17-39 years; mean age: 29.3 years) with a follow-up at 6-11 years (mean 8.9), was performed. RESULTS: In 7 eyes, the indocyanine green angiography (ICGA) showed choroidal hypofluorescent spots similar to those observed in MC (in 3 cases even in the fellow unaffected eye), in 2 of them the regression of the spots was observed after steroid therapy. In 2 eyes, the ICGA revealed hyperfluorescent spots; in one of them the complete regression of the spots after oral cyprofloxacine was observed. In 6 patients (10 eyes), choroidal permeability alterations could be visualized (in 4 cases even in the unaffected eye). CONCLUSIONS: The indocyanine green angiographic findings (hypo and hyperfluorescent spots, choroidal permeability alterations) could support the theory of Gass which considers that ICNV is not idiopathic but secondary to a widespread choroidal inflammatory disease. The similarity of the ICGA alterations in ICNV and MC, the observation that cases of ICNV would become MC in the follow-up, could allow the hypothesis of a close connection between these two affections.     

Indocyanine green angiographic features of idiopathic submacular choroidal neovascularization

A portable and closed-loop system is described for the paralysed hand using transcutaneous electrical stimulation. It is implemented using a modest microprocessor which receives data from force sensors mounted in a glove on the users hand. A display shows parameter values and a menu for the user to sequentially select controller states. For the grip state, the control loop is basically proportional plus a two stage integral response (gain adaptation). Eight channels can be accommodated in the stimulator. The system was evaluated with the help of a tetraplegic who managed to hold everyday objects in a stable grip.     

Digital subtraction indocyanine green angiography of occult choroidal neovascularization

OBJECTIVE: This study aimed to use a new technique for ocular imaging, digital subtraction indocyanine green angiography (DS-ICGA), to evaluate patients with occult choroidal neovascularization (CNV). DESIGN: The design was a cross-sectional study of patients with occult CNV. PARTICIPANTS: A total of 31 eyes of 31 patients were studied. INTERVENTION: Digital subtraction of sequentially acquired indocyanine green angiographic frames was used to image the progression of the dye front in eyes with occult CNV. A method of pseudocolor imaging of the choroid was developed that allows differentiation and identification of underlying choroidal arteries and veins. RESULTS: The DS-ICGA of occult CNV showed consistent findings. Occult CNV was imaged with greater detail and in a shorter period of time than with conventional indocyanine green angiography. The fundus landmarks were retained with DS-ICGA much better than with conventional indocyanine green angiography. CONCLUSIONS: The DS-ICGA uses time to dissect the choroidal circulation. With DS-ICGA, occult CNV could be imaged more quickly and in greater detail than with conventional imaging techniques. The DS-ICGA may improve the authors ability to image, and subsequently treat, occult CNV.     

A long-term course of experimentally produced choroidal neovascularization in the rat

We studied morphologically a long-term course of experimental choroidal neovascularization (ChNV) induced by krypton laser photocoagulation in the rat retina. Fifty-two weeks after photocoagulation, ChNV was enveloped completely by the retinal pigment epithelium. Vascular endothelial cells of ChNV were thin, with many fenestrations and wide lumen. The ChNV maintained the morphological characteristics of mature leaky capillaries similar to choriocapillaris. The lumen of the neovascularizations tended to be compressed by massive collagen fibers produced by the retinal pigmented epithelium. We found that experimental ChNV in the rat retina retains the characteristics of leaky capillaries for a long time unlike that in the monkey ChNV.     

Dark rim around choroidal neovascularization in indocyanine green angiography

Experimentally produced choroidal neovascularization (ChNV) surrounded by a dark rim in indocyanine green (ICG) angiography was studied histopathologically. Dark rims were seen in 28% of ChNVs which were detected with ICG angiography 2 weeks after photocoagulation. During the developing stage of ChNV, the dark rim around it was seen in the early phase of ICG angiography, but in the late phase, the dark rim became unclear because of extravascular dye leakage. During the regressive stage, the dark rim was seen in all phases of angiography. It was especially clear in the late phase. Histopathologically, at the site of the dark rim the retinal pigment epithelial cells proliferated to surround the ChNV in the subretinal space during both stages. These results show that proliferated retinal pigment epithelium surrounding ChNV blocks the fluorescence of the choroid, and causes the dark rim. The dark rim is helpful for diagnosis of ChNV.     

Comparison of indocyanine green and fluorescein angiography of choroidal neovascularization

We compared indocyanine green (ICG) and fluorescein angiography for evaluation of choroidal neovascularization (CNV). Cast preparations of CNV induced in monkey eyes by laser photocoagulation were correlated with ICG and fluorescein angiographies of the same CNV formations. Fluorescein angiography was more effective, in general, than ICG angiography in detecting CNV; however, CNVs with subretinal hemorrhage (2 of 35 sites) were visible only with ICG angiography. In early phase ICG angiography, CNV formations that casts showed to be dense or composed of thick vessels were seen, but less dense areas were not visible. Lesions that ICG angiography revealed as leaking were not differentiated morphologically from non-leaking areas by the CNV casts. This study confirms that only ICG angiography can identify CNV hidden by subretinal hemorrhage, although fluorescein angiography is otherwise superior. Indocyanine green angiography is indicated as a valuable complement to fluorescein angiography for evaluation of CNV.     

Immunosuppressive treatment of choroidal neovascularization associated with endogenous posterior uveitis

OBJECTIVE: To determine whether resolution of choroidal neovascularization (CNV), a recognized sight-threatening complication of endogenous posterior uveitis, and maintenance of vision could be achieved with immunosuppression. PATIENTS AND METHODS: Fourteen patients (17 eyes) with CNV associated with endogenous posterior uveitis were enrolled in an open study. Ages ranged from 5 to 51 years. Three eyes had extrafoveal CNV, 6 juxtafoveal, and 8 subfoveal. Three patients were treated with a single course of oral corticosteroids, 2 had additional cyclosporine for up to 2 years, and 9 continued to receive a low-dose regimen of a combination of immunosuppressive drugs. RESULTS: After a median follow-up of 15 months (range, 7 months to 6 1/2 years), 9 of 17 eyes had an improvement in visual acuity; 6 remained within 1 Snellen line of initial visual acuity, and 2 had lost 2 Snellen lines. Angiographically, CNV resolved in 13 eyes, resolved then recurred in 3, and improved but persisted in 4. CONCLUSION: These results support a role for immunosuppressive therapy in the treatment of CNV associated with endogenous posterior uveitis.     

Perifoveal laser treatment for subfoveal choroidal neovascularization in age-related macular degeneration

The management of subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration presents a major therapeutic dilemma. No treatment may lead to severe visual loss, and direct laser treatment to the entire subfoveal lesion results in acute loss of visual acuity. Encouraging results have been described with a foveal-sparing laser technique for subfoveal CNV. The authors performed perifoveal confluent laser treatment on a relatively well-defined occult CNV, sparing the foveal avascular zone. One month after treatment, the visual acuity had improved from 20/400 to 20/30. At 24 months, the visual acuity was 20/40 with no recurrence. Confluent perifoveal laser treatment for subfoveal CNV may be useful in preserving central visual acuity in selected patients.     

Photocoagulation of well-defined choroidal neovascularization in age-related macular degeneration: clinicopathologic correlation

PURPOSE: To present the clinicopathologic features of the eyes of a patient with age-related macular degeneration (ARMD): the right eye was treated for well-defined extrafoveal choroidal neovascularization (CNV), and the left eye had an untreated disciform scar. METHODS: The patient was studied ophthalmoscopically and by fluorescein angiography at the time of presentation and on follow-up examinations up to 54 days after laser treatment, when he died. The posterior portions of both eyes (obtained postmortem), including the macula and optic nerve head, were sectioned serially for light microscopy. Tissue sections from both eyes were removed from glass slides and studied by transmission electron microscopy. RESULTS: Histopathologic study of the right eye disclosed a thin layer of basal laminar deposit throughout the posterior pole. Two defects in Bruch's membrane without CNV were present within the area of laser photocoagulation located superior to the fovea. No CNV was present in the scar. Eleven areas of early CNV were present in the posterior pole. Histopathologic study of the left eye showed a prominent basal laminar deposit throughout the posterior pole. A 2.6 x 2.7 mm disciform scar was present that was located mostly in the subretinal space. Four sources of CNV were present. CONCLUSIONS: The clinicopathologic features of a treated eye with well-defined extrafoveal CNV, and the fellow eye with a disciform scar, both associated with ARMD, are presented. Although laser treatment obliterated a choroidal neovascular membrane, 11 additional areas of early, subclinical CNV were present.     

Targeted disruption of the FGF2 gene does not prevent choroidal neovascularization in a murine model

Choroidal neovascularization (CNV) is the major cause of severe visual loss in patients with age-related macular degeneration. Laser treatment is helpful for a minority of patients with CNV, and development of new treatments is hampered by a poor understanding of the molecular signals involved. Several lines of evidence have suggested that basic fibroblast growth factor (FGF2) plays a role in stimulating CNV. In this study, we tested this hypothesis using mice with targeted disruption of the FGF2 gene in a newly developed murine model of laser-induced CNV. One week after krypton laser photocoagulation in C57BL/6J mice, 34 of 60 burns (57%) showed fluorescein leakage and 13 of 16 (81%) showed histopathological evidence of CNV. At 2 weeks, CNV was detected in 9 of 10 burns (90%) in which a bubble had been observed at the time of the laser treatment. Electron microscopy showed fenestrated vessels with large lumens within choroidal neovascular lesions. Two weeks after laser-induced rupture of Bruch's membrane, 27 of 36 burns (75%) contained CNV in FGF2-deficient mice compared with 26 of 30 (87%) in wild-type control mice, a difference that is not statistically significant. This study demonstrates that FGF2 is not required for the development of CNV after laser-induced rupture of Bruch's membrane and provides a new model to investigate molecular mechanisms and anti-angiogenic therapy in CNV.     

Specificity of chromosome damage caused by the Rex element of Drosophila melanogaster

Alkylresorcinols, natural amphiphilic compounds commonly found in cereal grains, markedly decreased mutagenic activity of four standard mutagens examined in the Ames test. The effect was the strongest in the case of indirect-acting mutagens, benzo[a]pyrene and 2-aminofluorene. In the case of direct-acting mutagens, daunorubicin and methyl methanesulfonate, the diminution of the mutagenic activity by the alkylresorcinols was smaller but still noticeable. In the Sister Chromatid Exchanges test (SCEs) with cultured in vitro human blood-derived lymphocytes, a significant decrease of SCEs frequency induced by benzo[a]pyrene was observed in the presence of alkylresorcinols. These preliminary results seem to be important in the aspect of possible antimutagenic and anticarcinogenic potency of alkylresorcinols found in cereal grains.     

Deliberately caused bodily damage

Meaning has the power to drastically modify our experience of pain. It also can dramatically affect our health, both positively and negatively--a phenomenon I explored previously in this column. Spiritual meanings may be the most powerful forms of meaning, because they can provoke healing responses that appear miraculous, such as in DCBD. DCBD bridges medicine, neuroscience, religion, and anthropology. Consequently, it is regarded as too sprawling by scientists who prefer to work in a confined, limited area. DCBD also carries the stigma of being "weird" and "foreign." So it isn't surprising that researchers have given it a wide berth over the years. At long last, however, this attitude is changing, and a few brave investigators are coming forward. In my imagination I see DCBD as a territory marked by bold signs: ATTENTION PROSPECTIVE NOBLE PRIZE WINNERS: LOOK HERE! Is anybody out there up to the challenge?     

Evaluation of choroidal neovascularization in age-related macular degeneration with fluorescein and indocyanine green videoangiography

375 Individuals from 23 HBsAg positive families were investigated in the study. The results showed that HBsAg carrier rate among blood relatives was significantly higher than non-blood relatives (P < 0.01); HBsAg carrier rate decreased with the order of the first, second and third degree relatives (P < 0.01); and the rate in the individuals living together with the probands was higher than those living apart (P < 0.01). However, the other two markers of HBV infectivity, anti-HBs and anti-HBc, did not show any differences mentioned above. The results analysed by means of dichotomy and Logistic regression model, showed that blood relationship played an important role in HBsAg carrier state. In addition, the history of sharing living facilities was related to HBsAg carrier state. The average heritability in the first, second and third degree relatives was 79.68%. The analysis of genetic model showed that HBsAg carrier state was corresponded to the characteristic of multifactorial genetic disease, excluding the possibility of genetic disease due to single gene.     

Progressive cerebral parenchyma damage caused by recurrent arterial hypotension

To date clinical and experimental investigations have focused on acute strokes and complete infarctions. Histological and immunological staining in animal experiments and improved imaging techniques in patients suggest that selective or incomplete infarction is a common pathomechanism. Incomplete infarction can manifest as laminar necrosis at autopsy and as leukoaraiosis in imaging studies. An important mechanism in the genesis of leukoaraiosis is vascular pathology of the long penetrating arteries of the deep white matter combined with episodes of decreased perfusion pressure or hypotension. We demonstrate that the cumulative effect of repetitive, moderate hypotensive episodes on cognitive performance or cerebral tissue has not been adequately studied and appreciated.