Indocyanine green and fluorescein hyperfluorescence at the site of occlusion in branch retinal vein occlusion

Arteriovenous crossing associated with branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is defined as the focal occlusion of a first or second-order branch of retinal vein, which occurs most frequently at an arteriovenous (AV) crossing. Direct ophthalmoscopy, color fundus photography, and fluorescein angiography facilitate observation of AV crossings parallel to the retinal plane. Optical coherence tomography (OCT), with its high-depth resolution, enables observation of retinal lesions perpendicular to the retinal plane. OCT angiography (OCTA) provides depth-resolved images of the retinal vasculature by segmenting three-dimensional data. In this review, we discuss novel findings related to affected AV crossings associated with BRVO obtained via OCT and OCTA. The high-depth resolution of OCT or OCTA is useful for observation of the narrowed vein and determination of the vessel position of the affected AV crossing. Studies using OCT and OCTA have shown that BRVO caused by a venous overcrossing is more prevalent than previously reported, and that venous narrowing was significantly greater in instances caused by a venous overcrossing than in those caused by an arterial overcrossing. Moreover, OCTA also revealed that the retinal nonperfusion area size was larger in eyes with BRVO caused by a venous overcrossing than in those with BRVO caused by an arterial overcrossing. This contrasts with earlier findings obtained by conventional imaging modalities predating OCT, which showed that an arterial overcrossing was more common than a venous overcrossing at the causative venous occlusion site in eyes with BRVO. This review discusses these findings and their significance in the study of AV crossing associated with BRVO.

Evaluation of Navigated Laser Photocoagulation (Navilas 577+) for the Treatment of Refractory Diabetic Macular Edema

Purpose

To evaluate navigated laser photocoagulation for the treatment of refractory diabetic macular edema (DME).

Methods

Retrospective study of 25 eyes (21 patients) treated with Navilas 577+ focal laser system. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (OCT) parameters were measured at baseline, 1, 3, and 6 months, and final visit.

Results

The mean follow-up period was 12.8 ± 2.4 (7–16 months). All subjects had history of previous treatment which was injection of triamcinolone acetonide or antivascular endothelial growth factor (VEGF) agents. The navigated laser photocoagulation was delivered to the microaneurysms on indocyanine green angiography (ICGA) in 21 of 25 eyes (84%), fluorescein angiography (FA) guided in 3 eyes, and OCT angiography guided in 1 eye. After initial navigated laser treatment, 16 of 25 eyes (64%) were needed additional navigated laser photocoagulation, injection of triamcinolone acetonide, and/or injection of VEGF agents. Although median BCVA remained stable, the central retinal thickness and macular volume were significantly decreased over 6 months (p < 0.05). All patients were treated without complications.

Conclusions

Focal photocoagulation using Navilas 577+ showed to be effective in treating DME with improvement in macular edema on OCT over 6 months. Navilas 577+ was beneficial to perform navigated laser photocoagulation based on three modalities (ICGA, FA, and OCT angiography).

Usefulness of indocyanine green angiography to depict the distant retinal vascular anomalies associated with branch retinal vein occlusion causing serous macular detachment

PURPOSE

To report the usefulness of indocyanine green angiography (ICGA) to depict the retinal vascular anomalies associated with distant branch retinal vein occlusion resulting in serous retinal detachment at the macula.

METHODS

This was a retrospective, case series of 6 patients (6 eyes) with serous retinal detachments. Fluorescein angiography and ICGA showed that those 6 eyes had a distant branch retinal vein occlusion. The characteristics in ophthalmic examinations such as fundus appearance, fluorescein angiography, ICGA, optical coherence tomography, and clinical courses were evaluated.

RESULTS

In addition to serous retinal detachments, five eyes exhibited hard exudates around the macula. Fluorescein angiography and ICGA clearly showed the vessel occlusion; however, no apparent abnormalities appeared in the macular area in any of the eyes. In four eyes, early-phase ICGA depicted the retinal vascular anomalies within the area of venous occlusion and those were seen as hyperfluorescent patches on late-phase ICGA. In two eyes, punctate hyperfluorescent spots were seen in the area of venous occlusion on late-phase ICGA. Optical coherence tomography depicted a serous retinal detachment at the macula and retinal swelling in the outer nuclear layer from the macula to the hyperfluorescent abnormalities on ICGA. The macular serous retinal detachments were resolved within 3 months after laser photocoagulation was applied to the hyperfluorescent areas on ICGA.

CONCLUSION

Leakage from subsequent vascular anomalies after branch retinal vein occlusion can cause submacular fluid. Indocyanine green angiography is useful for detecting the causative vascular regions of the fluid.