Faculty Bibliography

Indocyanine-green angiography represents a major advance in imaging of the choroidal circulation. Recent technical innovations have permitted this diagnostic technique to find clinical application in many chorioretinal conditions. The indocyanine-green molecule has proven to be safe for human study. In age-related macular degeneration, indocyanine-green angiography may play an important role in the diagnosis of patients with occult choroidal neovascularization, leading to eventual increased efficacy with laser photocoagulation treatment. Histopathologic confirmation of a lesion noted by ICG angiography has been made. In multiple inflammatory conditions, as well as with central serous chorioretinopathy, distinct ICG patterns have emerged that may facilitate better understanding of the disease processes. With greater experience, ICG angiography may provide improved imaging, a better understanding of the pathogenesis, and new treatment approaches for various chorioretinal conditions

PURPOSE: To identify the precise choroidal abnormalities associated with idiopathic polypoidal choroidal vasculopathy (IPCV), patients with IPCV were examined with indocyanine green (ICG) videoangiography. METHODS: Twelve patients with IPCV were examined using standard clinical, fluorescein, and ICG videoangiographic techniques. RESULTS: Indocyanine green videoangiography showed two basic choroidal vascular changes: a branching network of vessels in the inner choroid, and vascular dilations at the border of the network of vessels. The vascular dilations appeared to be associated with the exudative and hemorrhagic manifestations of IPCV. CONCLUSION: The choroidal vasculopathy seen in IPCV is distinct from the changes seen in other choroidal abnormalities. Recognition of these changes aids in diagnosis and patient management, since the clinical implications of IPCV differ from those of other similar entities

A pair-matched, case-control design was used to study exposure to Histoplasma capsulatum and other environmental factors, and to determine various host characteristics including human leukocyte antigen (HLA) typings in 94 young patients with macular choroidal neovascularization (CNV) and in 94 controls with other eye diseases. Patients with two types of retinal patterns were studied: Type I, or those with CNV with one or no chorioretinal atrophic spots in the posterior pole or periphery (n = 51), and Type II, or those with CNV and 2 or more chorioretinal atrophic spots (n = 43). Our purpose was to explore whether these two variants of idiopathic CNV have different and distinguishable epidemiologies which may or may not be related to prior exposure to Histoplasma. We found that histoplasmin skin tests were negative in all but two Type I cases. The combination of the HLA-B7 and HLA-DR2 markers (but not either marker alone) was significantly increased in Type I cases. Among Type II cases, HLA-B7, HLA-DR2, HLA-DQ1, a positive histoplasmin skin test, myopic refractive error, prior residence in a histoplasmosis endemic area, occupations involving exposure to animals, and hypertension were all significantly increased. Histoplasmin skin test responses were positive in 18 Type II cases (45%). In the multivariate analysis, only DR2 and the combined presence of DQ1 and a positive histoplasmin skin test remained predictive of Type II disease. Our findings suggest that histoplasmin sensitivity is associated with some, but not all, cases of Type II disease. However, histoplasmin sensitivity appears to have no relationship to Type I disease. HLA factors may play a role in both disease types, possibly by producing a modified immune response to Histoplasma and/or other unidentified agents

PURPOSE: A case-control study was conducted to identify possible risk factors for idiopathic macular holes. METHODS: One hundred ninety-eight patients with idiopathic macular holes and 1,023 control subjects were identified at five clinical centers. Data were obtained through interviews, clinical examinations, and laboratory analyses of blood specimens. RESULTS: One hundred forty-three (72%) affected patients were women. Very few of a broad array of possible risk factors were statistically significant. In a logistic regression model that included both genders, higher plasma fibrinogen levels (P = .0007) and a history of glaucoma (P = .04) were associated with an increased risk of idiopathic macular holes. When the same model was used for women, with estrogen use and parity added as variables, a higher fibrinogen level (P = .002) was positively associated, and estrogen use (P = .04) was negatively associated with risk of macular holes. CONCLUSIONS: Of the two factors that stood out as possible risk factors for idiopathic macular holes, the increased risk for women has long been recognized. The association with fibrinogen level was unexpected, and it is unclear whether this is a chance finding or whether higher levels of fibrinogen can increase susceptibility to the forces of vitreous traction, perhaps by compromising the macular blood supply or by some yet unexplained mechanism.

BACKGROUND: Occult choroidal neovascularization (CNV) secondary to age-related macular degeneration occurs in the majority of patients with exudative maculopathy. Since occult CNV cannot be imaged clearly by fluorescein angiography, this condition is untreatable. The authors performed digital indocyanine-green videoangiography (ICG-V) on 657 consecutive eyes with occult CNV by fluorescein angiography to determine if this technique could be useful in enhancing the imaging of the neovascularization, and thus increasing treatment eligibility. MATERIALS AND METHODS: Six hundred fifty-seven consecutive eyes with occult CNV were studied. The fluorescein and ICG angiograms were compared, and the percentage of patients potentially eligible for laser therapy based on ICG findings was calculated. RESULTS: Of 413 eyes with occult CNV without pigment epithelial detachments, focal areas of neovascularization were noted in 89 (22%). Overall, 142 (34.3%) eyes had lesions that were potentially treatable by laser photocoagulation based on additional information provided by ICG-V. Of the 235 eyes with occult CNV and vascularized pigment epithelial detachments, 98 (42%) were eligible for laser therapy based on ICG-V findings. The authors calculate that ICG-V enhances the treatment eligibility by approximately one third. CONCLUSIONS: In diagnosing occult CNV, ICG-V is an important adjunctive technique to fluorescein angiography. This technique is especially useful in delineating occult neovascularization, neovascularization with overlying subretinal hemorrhage or serosanguineous fluid, and neovascularization associated with pigment epithelial detachments. The authors currently suggest that ICG-V be performed in eyes in which well-delineated neovascularization cannot be identified by fluorescein angiography. Based on their preliminary study, it can be expected that one in three patients with occult CNV potentially will be eligible for laser photocoagulation based on ICG-V. Further studies are necessary to confirm these findings

BACKGROUND: The pathogenesis of central serous chorioretinopathy (CSC) is poorly understood. Abnormalities in the choroidal circulation have been hypothesized to be causative factors. Fluorescein angiography has not been particularly useful in identifying specific choroidal defects in CSC, largely because of inherent limitations in imaging with this technique. Recent technologic advances in digital indocyanine green videoangiography allow enhanced imaging of the choroid and other subretinal structures in comparison with fluorescein angiography. METHODS: We performed digital indocyanine green videoangiography in 29 consecutive eyes with CSC and compared our results with clinical and fluorescein angiographic findings. RESULTS: Several newly recognized subretinal abnormalities in CSC were noted with digital indocyanine green videoangiography, including (1) presumed hyperpermeability of the choroidal circulation surrounding active retinal pigment epithelial leaks, (2) additional focal and multifocal areas of presumed choroidal hyperpermeability not associated with abnormalities detectable by fluorescein angiography or clinical examination, and (3) multiple presumed 'occult' serous retinal pigment epithelial detachments with a characteristic indocyanine green videoangiographic pattern. CONCLUSION: We suggest that the pathogenesis of CSC may be due to a choroidal vascular hyperpermeability with and without associated active pigment epithelial leaks and multiple presumed 'occult' serous retinal pigment epithelial detachments. Based on these findings, a hypothetical model can be constructed related to the pathogenesis of CSC, beginning with choroidal abnormalities that secondarily affect the retinal pigment epithelium and neurosensory retina