Indocyanine green angiography in Vogt-Koyanagi-Harada-type disease

Choroidal circulation impairment during the anterior recurrence of Vogt-Koyanagi-Harada disease confirmed with indocyanine green angiography and laser speckle flowgraphy

PURPOSE

To assess choroidal inflammation-related circulatory changes associated with the anterior recurrence of Vogt-Koyanagi-Harada (VKH) disease, using indocyanine green angiography (ICGA) and laser speckle flowgraphy (LSFG).

METHODS

This retrospective case series included 17 eyes of 11 patients with VKH disease showing recurrent inflammatory findings in the anterior, but not posterior, segment (i.e. anterior recurrence). Indocyanine green angiography (ICGA) and LSFG were performed at the time of recurrence and one month after the initiation of corticosteroid therapy. The number and total area of hypofluorescent dark dots (HDDs) on ICGA were independently counted by three physicians and measured with ImageJ, respectively. Mean blur rate (MBR), a quantitative index of relative blood flow velocity, was calculated via the LSFG Analyzer software.

RESULTS

Hypofluorescent dark dots (HDDs) were identified on ICGA in 13 of 17 eyes (76%) with the anterior recurrence of VKH disease. The number and total area of HDDs significantly decreased from 203 ± 101 dots to 59 ± 51 dots and from 48 789 ± 24 251 pixels to 15 664 ± 13 254 pixels, respectively. The change ratio of MBR significantly increased by 17.9 ± 16.3% after the treatment. Importantly, there was no significant association between the change ratios of HDDs and MBR.

CONCLUSIONS

These findings on LSFG and ICGA clearly demonstrated subclinical involvement as well as post-treatment improvement of choroidal circulation impairment due to granulomatous inflammation in eyes with the anterior recurrence of VKH disease. The present data suggest the validity of using these two examinations, capable of detecting different circulatory changes, in the management of recurrent VKH disease.

Elevated choroidal blood flow velocity during systemic corticosteroid therapy in Vogt-Koyanagi-Harada disease

PURPOSE

Laser speckle flowgraphy (LSFG) can be used to non-invasively visualize the haemodynamics of choroidal circulation and the vascular pattern. The purpose of this study was to examine the ability of LSFG to quantitatively evaluate blood flow velocity at the macula in patients with Vogt-Koyanagi-Harada (VKH) disease before and after systemic corticosteroid therapy.

METHODS

Prednisolone (200 mg/day) was systemically administered in 10 VKH disease patients with serous retinal detachment at the macular area. The drug was gradually tapered to zero over a 6-month period. Laser speckle flowgraphy measurements were taken in the 20 eyes of these patients at their initial visit and at 1, 4 and 12 weeks after the onset of therapy. Square blur rate (SBR), a quantitative index of relative blood flow velocity, was calculated using LSFG.

RESULTS

Serous retinal detachment resolved within 4 weeks after treatment and visual acuities improved to > 1.0 in almost all cases. There were significant increases in average SBR at the macula at 4 weeks after treatment compared with at 1 week after treatment, and also at 12 weeks after treatment compared with at 4 weeks after treatment.

CONCLUSIONS

These results suggest that systemic corticosteroid therapy improves inflammation-related impairment in choroidal blood flow velocity at the macula. Laser speckle flowgraphy can evaluate the effect of systemic corticosteroid therapy by enabling comparisons between measurements of blood flow velocity, which is considered to reflect inflammation activity in the choroid.

Choroidal dye filling velocity in patients with Vogt–Koyanagi–Harada disease

PURPOSE

To evaluate quantitative choroidal dye filling velocity in patients with Vogt-Koyanagi-Harada disease (VKH) before and after corticosteroid treatment using indocyanine green (ICG) angiography.

METHODS

ICG angiography was performed in seven VKH patients before and after systemic corticosteroid treatment. Choroidal dye curves were obtained by image analysis software and analyzed using an exponential model. The model's time constant (tau) was used to evaluate choroidal dye filling velocity.

RESULTS

Compared with controls, acute phase choroidal tau values in VKH patients were significantly longer, suggesting choroidal circulation disturbance. During the recovery phase, choroidal tau values were significantly shortened, suggesting choroidal circulatory disturbance improvement.

CONCLUSION

Choroidal dye filling velocity may be useful for VKH diagnosis and verification of corticosteroid treatment effectiveness.

Subtraction ICG angiography in Harada's disease

BACKGROUND/AIM

The significance of indocyanine green (ICG) angiography (ICGA) in Harada's disease still awaits clarification in many respects. This study investigates the details of choroidal lesions observed in Harada's disease by the subtraction method.

METHODS

Eight patients with Harada's disease were followed with ICGA. ICG angiograms were obtained with a Topcon high resolution digital fundus camera and processed with a Topcon IMAGEnet computer system. Image subtraction was conducted for analysing serial angiograms taken at about 2 second intervals during the dye transit phase and those taken in the early and middle phases of angiography.

RESULTS

Standard ICG images of acute stage disease showed delayed choroidal filling in the early phase. Mid phase angiograms showed areas with bright fluorescence of variable intensity, indicating intrachoroidal ICG leakage. With image subtraction of angiograms with an interval of seconds the choroidal vessels could be imaged sequentially, with the choroidal arteries visualised first, followed by the definition of the choriocapillaris and then the choroidal veins. The choroidal veins with delayed filling were visualised as positive images in serial subtraction angiograms. Subtraction with an interval of minutes showed uneven background fluorescence and bright fluorescence corresponding to the areas of intrachoroidal ICG leakage. After the disease subsided with steroid therapy, angiography revealed an improvement in delayed choroidal filling. Image subtraction by the second allowed a clear visualisation of improved choroidal venous filling, while subtraction by the minute showed homogeneous background fluorescence, eliminating brighter areas.

CONCLUSION

Subtraction ICGA demonstrated that delayed filling of the choroidal veins of varying severity occurs in association with hyperpermeability of the choroidal vessels in the course of Harada's disease.

Videofunduscopy and videoangiography using the scanning laser ophthalmoscope in Vogt-Koyanagi-Harada syndrome

AIM

To observe pathophysiological changes in patients with Vogt-Koyanagi-Harada (VKH) syndrome using the scanning laser ophthalmoscope (SLO) to perform videofunduscopy, and indocyanine green (ICG) and fluorescein videoangiography.

METHODS

18 patients diagnosed with VKH syndrome were studied. 15 patients were examined in both acute and convalescent phases, and three patients were examined in the convalescent phase only. Retrospective review of charts was performed to obtain data on visual acuities, clinical findings, and results of cerebrospinal fluid cytology and histocompatibility leucocyte antigen D locus testing.

RESULTS

Videofunduscopy revealed abnormalities in the central macula at the level of the retinal pigment epithelium or choroid in 40% of patients in the acute phase and 83% of patients in the convalescent phase. ICG videoangiography showed irregular hypofluorescence (80%), slow or patchy filling (67%), indistinct or fewer choroidal vessels (73%), filling defects (73%), and focal leakage (33%) in patients in the acute phase. These changes improved with systemic corticosteroid treatment, although at least one ICG videoangiographic abnormality persisted into the convalescent phase in 83% of patients in the absence of clinical inflammation. In contrast, fluorescein videoangiography revealed fewer and decreased severity of abnormalities, with greater resolution in the convalescent phase when compared with ICG videoangiography.

CONCLUSIONS

SLO videofunduscopy and videoangiography revealed numerous abnormalities in patients with VKH syndrome, many of which persisted well after clinical recovery, suggesting the development of permanent morphological changes in the fundus. ICG videoangiography was more sensitive than fluorescein videoangiography in delineating abnormalities in layers deep to the sensory retina.