ICG Videoangiography Research Articles

The influence of dressings and ointments on the qualitative and quantitative evaluation of burn wounds by ICG video-angiography: an experimental setup

Burn wound depth is difficult to determine. Even for experienced investigators the exact differentiation between superficial and deep dermal burns is not always possible. Therefore, methods for objective and reproducible measurements estimating the depth of burn wounds are of great clinical interest. One technique that appears to be able to differentiate between superficial and deep dermal burn wounds is ICG video-angiography. Since burn wounds are often covered with dressings and ointments or soiled with blood, it is necessary to evaluate the influence of these substances on ICG video-angiography and its performance as a measurement method. The most commonly used ointments and dressings were tested. All studied substances had a massive influence on ICG video-angiography and its measurements. They caused decreases by absorption of up to 63±36% and thereby falsely reported deeper burn wounds. The results of this study, suggest that in clinical practice, all dressings, ointments and blood should be completely removed at least 10 min prior to measurement by ICG video-angiography to gain exact and reproducible results.

Simultaneous digital ICG and fluorescein videoangiography with the personal computer

Since the invention of the simultaneous ICG and fluorescein (SIF) videoangiography in 1995 none of the available SLOs were significantly improved. Digital video recording with a PC can simplify and improve the quality of the angiography. SIF angiography images of a two-wavelength scanning laser ophthalmoscope were digitized with a personal computer and written to disk with at rate of 25 images/s as a non-compressed digital video file. The digitized image sequence could be replayed with any standard video player and converted to different image and video file formats with a file conversion utility, developed specifically for the needs of SIF angiography. Recording of digital SIF videoangiograms with a personal computer is not more complicated than the conventional video method. Since most of the parameters of the recording software are customizable, processing methods can be tailored to individual needs. Off-line processing and/or storage of the images in a digital database are possible immediately after recording. To facilitate localization of the pathological landmarks on the fundus the two channels of the SIF angiograms can be observed as combined red-green images. Compared to conventional videoangiography, digital SIF videoangiography has only advantages: the image quality is better, it is less complicated and not more expensive than the conventional one. Digital recording should replace the conventional one.

Hereditary retinal dystrophies and choroidal neovascularization

Choroidal neovascularization infrequently occurs in patients affected by hereditary retinal dystrophies. We studied eight patients suffering from different hereditary retinal dystrophies (Best's disease, reticular dystrophy, butterfly-shaped dystrophy, gyrate atrophy, and retinitis pigmentosa) who developed choroidal neovascularization. All patients underwent complete ophthalmic evaluation, electrophysiology, colour vision testing, and fluorescein angiography. In some patients, ICG video-angiography was also performed. Laser treatment was carried out in only one patient. The mean duration of follow-up was 41.7 months (range 6-148 months). At CNV diagnosis, the mean VA was 0.23 (range 0.02-0.6). At the last follow-up, mean VA was 0.34 (range HM to 0.9). At the last follow-up, fluorescein angiography showed a focal, atrophic scar in seven eyes, a fibrotic membrane in two eyes and a still active membrane in two cases. We emphasize the relatively favourable visual prognosis in patients suffering from inherited retinal dystrophies complicated with choroidal neovascularization. Therapeutic approaches other than laser treatment could be attempted in these patients.

Choroidal Osteoma

The choroidal osteoma is a benign, ossifying tumor of the choroid that typically is found in young, healthy women in the second or third decade of life. Its pathogenesis is unknown. This tumor is clinically unilateral in 75% of cases and tends to be located in the juxtapapillary region. Choroidal neovascularization may occur in up to one-third of cases. The choroidal osteoma must be differentiated from other intraocular tumors as well as cases of dystrophic and metastatic calcification. Ultrasonography and computed tomography may help in the diagnosis by demonstrating a calcified plaque at the level of the choroid. Fluorescein angiography and ICG videoangiography may demonstrate choroidal neovascularization, which may be amenable to treatment by laser photocoagulation.