Indocyanine green angiographic and multifocal electroretinographic features in the diffuse and regional form of Bietti's crystalline retinopathy.

PURPOSE

To observe different features of indocyanine green angiography (ICGA) and multifocal electroretinography (ERG) in the diffuse and regional type of Bietti's crystalline retinopathy (BCR).

METHODS

ICGA and the multifocal ERG were performed in two cases of the diffuse and regional type of BCR respectively. These data were compared with fluorescein angiography (FA), standard Ganzfeld ERG, and visual field testing.

RESULTS

In the regional case, ICGA revealed reduced perfusion of the choroidal circulation in the early phase and multiple hypofluorescent spots in the posterior pole in the late phase, due to choriocapillaris filling defect; the extent of choroiocapillaris loss was shown in early phase of ICGA and there were multifocal hyperfluorescent dots surrounding hypofluorescent spots in late phase in the diffuse case. The multifocal ERG showed that the central responses were markedly depressed, corresponding to the visual field defects, while the findings of Ganzfeld ERG were normal in the regional BCR; however, both the multifocal ERG and Ganzfeld ERG were severely subnormal in the diffuse case.

CONCLUSIONS

The features of ICGA and multifocal ERG are different between the diffuse and regional BCR. In the meantime, the two tools are also useful to differentiate the type and assess the extent of evolution in BCR.