Selective use of indocyanine green angiography for occult choroidal neovascularization

INDOCYANINE GREEN ANGIOGRAPHY OF TYPE 1 MACULAR NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION AND CENTRAL SEROUS CHORIORETINOPATHY REVEALS DIFFERENT DISEASE MECHANISMS

PURPOSE

To assess the rate of late phase hyperfluorescent plaque (LPHP) in Type 1 macular neovascularization (MNV) in central serous chorioretinopathy (CSCR) and age-related macular degeneration (AMD) and to evaluate its prognostic value.

METHODS

Retrospective study including Type 1 MNV in AMD and CSCR, from 2012 to 2020. Eyes with a late indocyanine green angiography image (>20 minutes) and clear visualization of MNV on optical coherence tomography angiography (OCTA) were included. Quantitative and qualitative parameters on optical coherence tomography and best-corrected visual acuity were recorded at baseline and after three monthly antivascular endothelial growth factor injections.

RESULTS

Eighty-three eyes were included, 35 with CSCR and 48 with AMD. Patients in the CSCR group were significantly younger than in the AMD group (61.3 ± 10.4 vs. 80.2 ± 6.8 years, respectively, P < 0.001), predominantly male (68.6% CSCR vs. 35.4% AMD; P = 0.003), and with a thicker choroid (379 ± 93.3 µ m vs. 204.2 ± 93.2 µ m; P < 0.001). Type 1 MNV in CSCR showed fewer LPHP compared with AMD (31.4% vs. 77.1%; P < 0.001). The baseline visual acuity was lower in patients with LPHP (0.37 ± 0.22 vs. 0.27 ± 0.28 logarithm of the minimum angle of resolution, P = 0.03). On multivariate analysis, AMD was associated with the presence of LPHP ( P < 0.001). No significant difference in the response to antivascular endothelial growth factor was observed.

CONCLUSION

Leakage of macromolecules from MNV and accumulation in the retinal pigment epithelium and/or in the stroma imaged by the LPHP is less common in eyes with Type 1 MNV in CSCR than in AMD. Late phase indocyanine green angiography imaging offers an insight into the metabolism of the dye and the environment surrounding the neovascular membrane.

ICG Angiography-Guided Photodynamic Therapy for Large Pigment Epithelial Detachments in Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE

To evaluate the role of photodynamic therapy (PDT) in the management of vascularized pigment epithelial detachment in age-related macular degeneration (AMD) when the pigment epithelial detachment is the predominant component of the neovascular complex.

PATIENTS AND METHODS

Seventeen eyes of 17 patients underwent indocyanine green angiography-guided PDT and had at least 6 months of follow-up. Data retrieved included visual acuity and angiographic features prior to the treatment, number of PDT sessions, visual acuity, angiographic outcomes at the end of the follow-up, length of follow-up, and status of the fellow eye. in the series, with an average age of 77 years and a mean follow-up time of 11 months. Six (35%) of the patients lost less than 3 lines of visual acuity, 6 (35%) lost between 3 and 6 lines, and 5 (30%) lost 6 or more lines. Angiographic outcomes were categorized as failures in 14 (82%) of the treated eyes and successful in 3 (17%) eyes.

CONCLUSIONS

In 82% of the eyes, PDT failed to flatten the pigment epithelial detachment or prevent growth of the choroidal neovascular membrane. Visual acuity outcomes correlated poorly with angiographic outcomes. PDT does not seem to improve the prognosis of eyes with large pigment epithelial detachments in AMD.

Indocyanine green angiography in chorioretinal diseases: indications and interpretation: an evidence-based update

TOPIC/PURPOSE: To assess the clinical usefulness and relevance of indocyanine green angiography (ICG) in the investigation of chorioretinal disorders and assess specifically in what conditions it may add useful information to that obtained using standard fluorescein angiography.

CLINICAL RELEVANCE

Many publications on ICG have appeared in recent years touting its use in ophthalmology. These publications have led to increasing use of this technique and to its application in numerous retinal diseases in which the fluorescein angiographic findings have been thoroughly described.

METHODS/LITERATURE REVIEWED

During this systematic literature review, we identified and reviewed a total of 376 articles, from among which we selected 92 that we considered most relevant to our purpose of evaluating published evidence as to the efficacy of ICG. We excluded many articles with weak study designs and those that simply duplicated previously published information. Our literature search used PubMed and was confined to articles in English or that included an English abstract.

RESULTS

Our systematic review suggests that ICG has relatively few specific indications for use as justified by previously published peer-reviewed studies. In keeping with the requirements for this Journal's evidence-based articles, we have divided our clinical recommendations for the use of ICG into three categories: (A) strongly recommended and supported by strong evidence; (B) recommended with moderately strong supporting evidence; (C) not recommended at present because supported only by anecdotal or group consensus evidence. We highly recommended ICG for (1) identification of polypoidal choroidal vasculopathy, (2) occult choroidal neovascularization, (3) neovascularization associated with pigment epithelial detachments, and (4) recurrent choroidal neovascular membranes. These are all conditions in which ICG contributes to the identification of lesions that may be treatable. We recommend ICG with some enthusiasm for identifying feeder vessels in age-related macular degeneration, choroidal neovascular membranes, chronic central serous retinopathy, multiple evanescent white dot syndrome, vasculitis, acute multifocal placoid pigment epitheliopathy, Vogt-Koyanagi-Harada syndrome, macular lesions associated with angioid streaks, and birdshot retinopathy. In all these conditions, ICG may help establish a diagnosis and provide some useful guidance for therapy. At present, we do not recommend ICG for scleritis and posterior scleritis, drusen differentiation, Behçet's disease, or sarcoidosis, because it has not been demonstrated to add useful clinical information.

CONCLUSIONS

ICG, although now a well established technique, has clear advantage over fluorescein angiography in relatively few chorioretinal disorders. It has, however, contributed to the understanding of pathologic processes in many ocular diseases. As yet, no published randomized controlled clinical trials show any benefit to the use of ICG in the management of any specific ocular disease.

Eligibility for treatment and angiographic features at the early stage of exudative age related macular degeneration

AIMS

To determine the eligibility for laser photocoagulation treatment or for photodynamic therapy (PDT) with verteporfin in eyes at the earliest stage (first month of symptoms) of exudative age related macular degeneration (AMD) based on fluorescein angiographic (FA) features; to evaluate the potential contribution of indocyanine green angiography (ICG-A) for occult choroidal neovascularisation (CNV) at this stage.

METHODS

Retrospective review of 252 consecutive patients (269 eyes) examined within the first month of symptoms of exudative AMD.

RESULTS

On FA, 97 eyes (36%) had classic CNV alone. Occult CNV associated with fibrovascular retinal pigment epithelium detachments (PEDs) was observed in 71 eyes (26%) and without fibrovascular PED in 101 eyes (38%). 91 eyes (34%) met the Macular Photocoagulation Study criteria for laser photocoagulation. 53 eyes (20%) met the Verteporfin In PDT (VIP) or Treatment of AMD with PDT (TAP) studies criteria. By ICG-A, occult CNV was visualised as focal spots in 49% of eyes examined within 15 days v 32% of eyes examined between 16 and 30 days after the onset of symptoms (p=0.07). 8.5% of late staining plaques disclosed in eyes examined within 15 days were combined with focal spots v 36% in eyes examined between 16 and 30 days (p<0.01).

CONCLUSIONS

Early examination of eyes with exudative AMD would allow the treatment of 47% of eyes. 60% of eyes with subfoveal CNV would be eligible for PDT with verteporfin. Up to half of eyes with occult CNV would be converted by ICG-A into well delineated focal spots.

Indocyanine green angiography in the presence of subretinal or intraretinal haemorrhages: clinical and experimental investigations

PURPOSE

The absorption and emission characteristics of indocyanine green are associated with better penetration through ocular pigments, including melanin and blood, in comparison with fluorescein. Therefore, it has been assumed that indocyanine green angiography (ICG-A) allows better delineation of fluorescent structures including choroidal neovascularization in the presence of haemorrhages. The degree and frequency of blockage by haemorrhages during ICG-A and fluorescein angiography (Fl-A) were compared and absorption characteristics by blood were experimentally determined.

METHODS

Simultaneous confocal scanning laser ophthalmoscopy was performed in patients with intraretinal or sub-retinal haemorrhages associated with various retinal diseases including neovascular age-related macular degeneration. Areas of blocked choroidal fluorescence were compared in Fl-A and ICG-A using a standardized classification system by two independent readers. Experimental absorption measurements were performed using blood-filled quartz cuvettes and laser light with 488 and 790 nm, respectively.

RESULTS

Sixty eyes of 59 patients were analysed. Twelve eyes (20%) showed blockage in Fl-A only corresponding with funduscopically visible blood. In 35 eyes (58%) the extent of absorption was greater in Fl-A compared with ICG-A. An identical area of blockage in both Fl-A and ICG-A was noted in 13 eyes (22%). The coefficient of absorption was 18.4 mm(-1) for Fl-A (488 nm) and 5.4 mm(-1) for ICG-A (790 nm).

CONCLUSIONS

In contrast to previous assumptions, the findings indicate that clinically intraretinal or subretinal haemorrhages are frequently associated with blockage not only in Fl-A but also in ICG-A. This is in accordance with the experimentally determined coefficient of absorption. Apparently, haemorrhages occurring in association with retinal and choroidal diseases commonly have a thickness sufficient enough to induce relevant absorption during ICG-A, and thus impair delineation of fluorescent structures in planes posterior to the haemorrhage. Therefore, the diagnostic value of ICG-A in presence of subretinal or intra-retinal bleedings is limited.

Retinal choroidal anastomoses and occult choroidal neovascularization in age-related macular degeneration

OBJECTIVE

This study was designed to identify the incidence of retinal choroidal anastomoses in patients with occult choroidal neovascularization (CNV) and focal hot spots on indocyanine green (ICG) angiography, to identify the clinical and angiographic features that would assist in their identification, and to determine if the presence of these anastomotic lesions affect the outcome of laser therapy.

DESIGN

Combined prospective and retrospective cross-sectional study.

PARTICIPANTS

One hundred fifty consecutive patients with newly diagnosed occult CNV secondary to exudative age-related macular degeneration and focal hot spots on ICG angiography were evaluated prospectively. In addition, a retrospective review was performed on 79 eyes previously reported to have undergone laser photocoagulation treatment with ICG guidance. METHODS AND TESTING: In all cases, stereo color and red-free photographs, and stereo fluorescein and digital ICG angiograms were obtained for evaluation.

MAIN OUTCOME MEASURES

Images obtained by all four techniques were evaluated for the presence of a retinal choroidal anastomosis. Associated clinical and angiographic findings were noted. In the retrospective review, the success rate of laser treatment was correlated with the presence or absence of a retinal choroidal anastomosis.

RESULTS

Of the 150 eyes evaluated prospectively, 31 (21%) were found to have a retinal choroidal anastomosis. Retinal choroidal anastomoses were found in 27% of patients with associated serous pigment epithelial detachment (PED), whereas 13% were found in those without an associated elevation of the retinal pigment epithelium. Seventy-one percent of eyes had multiple anastomotic connections. Ninety percent of eyes had at least one retinal vein involved in the anastomotic connection. Clinical evidence of preretinal and intraretinal hemorrhage and cystic edema coupled with angiographic evidence of intraretinal dye leakage were key features of retinal choroidal anastomoses. In the retrospective review, seven patients were found to have retinal choroidal anastomoses with associated serous PED and demonstrated a very low (14%) success rate for laser treatment.

CONCLUSIONS

Retinal choroidal anastomoses can present as a primary manifestation of the exudative process in age-related macular degeneration. They may be seen in eyes with and without detachment of the retinal pigment epithelium. Specific clinical and angiographic features have been identified that can aid in the diagnosis of these vascular anomalies. Their presence represents a poor prognostic sign for successful ICG-guided laser treatment.

The present role of indocyanine green angiography in ophthalmology

Recent developments in the clinical application of indocyanine green angiography have mainly concerned refining its role as an adjunct to fluorescein angiography in detecting and guiding the treatment of choroidal neovascularization. We now have a better understanding of the different patterns of abnormal hyperfluorescence seen with indocyanine green angiography in eyes with both wet and dry forms of macular degeneration. In exudative cases, the success rate of laser treatment guided by indocyanine green angiographic findings can vary considerably, and it is now known which angiographic presentations are not as likely to benefit. In dry macular degeneration, indocyanine green angiography appears to add clinically useful information, such as helping to identify plaques in fellow eyes with choroidal neovasculrization or watershed zones that may be predictive of future exudative transformation. In certain circumstances, indocyanine green angiography can be valuable in detecting choroidal neovascularization in other macular diseases or in helping to diagnose other choroidal conditions, especially when the clinical presentation is atypical, such as central serous chorioretinopathy in elderly patients.

Evaluating persistent and recurrent choroidal neovascularization. The role of indocyanine green angiography

OBJECTIVE

To evaluate the clinical utility of routinely using indocyanine green angiography (ICGA) with fluorescein angiography (FA) in detecting persistent or recurrent choroidal neovascularization (CNV).

DESIGN

Prospective, consecutive case series.

PARTICIPANTS

Twenty-four eyes of 21 patients with exudative age-related macular degeneration (AMD) that had conventional laser treatment for CNV were examined.

INTERVENTION

Fluorescein angiography and ICGA were performed together on all eligible eyes at the first post-treatment visit and all subsequent follow-up visits in which persistent or recurrent CNV was suspected clinically.

MAIN OUTCOME MEASURES

Choroidal neovascularization detection and delineation by each angiographic technique were measured.

RESULTS

Of the 54 FA-ICGA study pairs performed over a 20-month investigation period, FA showed well-defined, ill-defined, and no CNV in 10 (19%), 19 (35%), and 25 (46%) eyes, respectively. Indocyanine green angiography had a high concordance rate at 70% and 88% when persistent or recurrent CNV was well-defined and absent, respectively, on FA and rarely added additional, clinically useful information in these settings, particularly in the former presentation. Of the 29 eyes that showed some evidence of CNV by FA, the neovascular complex was ill-defined in 19 (66%) eyes. When CNV was ill-defined by FA, the corresponding ICGA showed well-defined CNV in 9 (47%) of 19 eyes, in 5 of which the CNV was nonsubfoveal in location.

CONCLUSIONS

Persistent or recurrent CNV in AMD was frequently ill-defined by FA. Indocyanine green angiography was a valuable adjunct to FA by better delineating CNV in this specific setting. However, ICGA was not useful when the post-treatment FA showed well-defined CNV. Furthermore, ICGA was not helpful when the first post-treatment FA was negative and there were no ophthalmoscopic signs of exudation.

Treatment options In subfoveal choroidal neovascularization secondary to age-related macular degeneration

Laser photocoagulation of the entire area of the neovascular lesion is the only proven treatment for subfoveal choroidal neovascularization secondary to age-related macular degeneration with a poor natural history. However, there are some limiting factors such as patient eligibility, a significant decline in visual acuity after treatment, and a very low possibility of a final vision of 20/100 or better. Although no large benefit of other treatment modalities, such as indocyanine green videoangiography-guided laser photocoagulation, surgical removal of neovascular membranes, and radiation therapy, has yet been proven, carefully selected patients may be suitable candidates for such treatments. This article reviews the status of treatment modalities for subfoveal choroidal neovascularization secondary to age-related macular degeneration, including laser photocoagulation of the entire area of the neovascular lesion, and discusses factors prognostic of visual outcome in these treatment options.

Indocyanine green hyperfluorescence associated with serous retinal pigment epithelial detachment in age-related macular degeneration

PURPOSE

Indocyanine green (ICG) angiography may improve visualization of choroidal neovascularization (CNV) associated with serous retinal pigment epithelial detachment (RPED) in age-related macular degeneration (AMD). The features of ICG hyperfluorescence associated with serous RPED and therapeutic effect of ICG-directed laser photocoagulation in eyes with serous RPED is evaluated.

DESIGN

Retrospective review of all simultaneous fluorescein/ICG angiograms (n = 918) performed over an 18-month period to identify 44 eyes in 39 patients with serous RPED secondary to AMD on fluorescein angiography.

PARTICIPANTS

Thirty-nine patients with AMD, aged 53 to 89 years, participated.

INTERVENTION

Eyes were nonrandomly treated with ICG-directed laser photocoagulation or observation.

MAIN OUTCOME MEASURES

Characteristics of ICG hyperfluorescence associated with a serous RPED are reviewed. Final visual acuity and anatomic appearance of the serous RPED are given.

RESULTS

Twenty-three (52%) of the 44 eyes had an isolated serous RPED without obvious CNV, and 21 (48%) of the 44 eyes had a serous RPED associated with occult CNV on fluorescein angiography. Indocyanine green angiography demonstrated underlying CNV in 19 eyes (83%) with an isolated serous RPED and in all 21 eyes (100%) with serous RPED and occult CNV. The pattern of ICG hyperfluorescence revealed focal CNV in 15 eyes and plaque CNV in 4 eyes with an isolated serous RPED. In eyes with serous RPED and occult CNV, focal CNV and plaque CNV were noted with ICG in 8 and 13 eyes, respectively. No follow-up was available for two eyes. Twenty eyes were treated with ICG-directed laser photocoagulation. In these eyes, the visual acuity remained stable in 6 eyes (30%) and decreased in 14 eyes (70%). Twenty-two eyes were observed, and the visual acuity remained stable in 8 (36%), improved in 2 (9%), and decreased in 12 eyes (55%).

CONCLUSIONS

Although ICG angiography may enhance visualization of CNV associated with serous RPED in AMD, ICG-directed laser treatment did not appear to improve visual acuity when compared with observed eyes in this series.

Indocyanine green angiography-guided photocoagulation of choroidal neovascularization associated with retinal pigment epithelial detachment

PURPOSE

To determine visual acuity outcome after indocyanine green angiography-guided laser photocoagulation of choroidal neovascularization associated with pigment epithelial detachment in eyes with age-related macular degeneration.

METHODS

We retrospectively reviewed pretreatment and posttreatment visual acuity after laser photocoagulation to well-demarcated hyperfluorescent areas seen with indocyanine green angiography adjacent to or within pigment epithelial detachments in 20 eyes of 20 patients with age-related macular degeneration and suspected choroidal neovascularization.

RESULTS

Visual acuity before and after laser photocoagulation was followed up for 3 to 24 months (median, 9 months). At 3 months after laser photocoagulation, visual acuity had improved 2 or more Snellen lines in two eyes (10%), worsened by 2 or more lines in 10 (50%), and remained unchanged in eight of 20 (40%). By 6 months after laser photocoagulation, visual acuity had improved by 2 or more lines in two eyes (12%), worsened by 2 or more lines in nine (53%), and remained unchanged in six of 17 (35%). At 9 months after laser photocoagulation, visual acuity had improved by 2 or more lines in one eye (9%), worsened by 2 or more lines in nine (82%), and remained unchanged in one of 11 (9%).

CONCLUSIONS

Indocyanine green angiography-guided laser photocoagulation may temporarily stabilize visual acuity in some eyes with choroidal neovascularization associated with pigment epithelial detachments, but final visual acuity decreases with time.

ICG videoangiography of occult choroidal neovascularization in age-related macular degeneration

Digital indocyanine green videoangiography has recently been reported to improve the imaging of occult choroidal neovascularization. In this study, 44 eyes with occult choroidal neovascularization in age-related macular degeneration were studied with fluorescein and indocyanine green videoangiography. On indocyanine green videoangiographic examination, 6 of the 44 eyes (13.6%) with occult choroidal neovascularization had vascularized pigment epithelial detachment and 27 (61.4%) had vascularized retinal pigment epithelium. In the remaining 11 (25%) eyes which had previous laser photocoagulation, indocyanine green videoangiography confirmed the presence of recurrence while fluorescein revealed no demonstrable neovascularization. The findings in our study indicate that patients with occult choroidal neovascularization have manifestations that are more clearly demonstrated with indocyanine green videoangiography and improved imaging of these abnormal vessels could potentially increase the number of patients eligible for photocoagulation treatment.

Classification of choroidal neovascularization by digital indocyanine green videoangiography

PURPOSE

The majority of patients with exudative maculopathy due to age-related macular degeneration present with poorly defined or occult choroidal neovascularization (CNV) that cannot be imaged adequately by fluorescein angiography. Digital indocyanine green (ICG) videoangiography is a new technique that allows enhanced imaging of these poorly defined or occult vessels. The authors studied 1000 consecutive cases of occult CNV using digital ICG angiography to describe the various types of neovascularization observed by this technique and to determine the frequency and natural history of the various lesions.

MATERIALS AND METHODS

Digital ICG videoangiography was performed as described previously on 1000 consecutive eyes with occult CNV by fluorescein angiography.

RESULTS

One thousand consecutive eyes with occult CNV by fluorescein angiography were imaged using digital ICG videoangiography. Three morphologic types of CNV were noted by ICG videoangiography, which included focal spots, plaques (well-defined or poorly defined), and combination lesions (in which both focal spots and plaques are noted). Combination lesions can be subdivided into marginal spots (focal spots at the edge of plaques of neovascularization), overlying spots (hot spots overlying plaques of neovascularization), or remote spots (a focal spot remote from a plaque of neovascularization). The relative frequency of these lesions was as follows: there were 283 cases (29%) of focal spots; 597 cases (61%) of plaques, consisting of 265 cases (27%) of well-defined plaques and 332 cases (34%) of poorly defined plaques; and 84 cases (8%) of combination lesions, consisting of 35 cases (3%) of marginal spots, 37 cases (4%) of overlying spots, and 12 cases (1%) of remote spots. In seven additional cases (1%), a mixture of the above lesions was noted. In 13 additional eyes (1%), no lesions were noted on the ICG angiogram. The studies of 16 eyes were unreadable or unobtainable.

CONCLUSIONS

There are three types of CNV that can be observed by digital ICG videoangiography. Plaques are the most common type and have a poor natural history. Focal spots or hot spots are the next most frequently seen lesion and can potentially be treated by ICG-guided laser photocoagulation. Combination lesions, in which both focal spots and plaques are present, are rare. This study of 1000 consecutive cases of eyes with occult neovascularization that were imaged with digital ICG videoangiography serves to classify the various types of neovascularization observed by this technique. Digital ICG videoangiography is an important tool in better delineating eyes with occult CNV. Future studies are necessary to validate our findings.