Fundus autofluorescence and optical coherence tomography findings in choroidal melanocytic lesions

Imaging of Uveal Melanoma—Current Standard and Methods in Development

Simple Summary

Uveal melanoma is the most prevalent intraocular tumor in adults, derived from melanocytes; the liver is the most common site of its metastases. Due to troublesome tumor localization, different imaging techniques are utilized in diagnostics, i.e., fundus imaging (FI), ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), positron emission tomography/computed tomography (PET/CT), magnetic resonance imaging (MRI), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), or fundus autofluorescence (FAF). Specialists eagerly use these techniques, but sometimes the precision and quality of the obtained images are imperfect, raising diagnostic doubts and prompting the search for new ones. In addition to analyzing the currently utilized methods, this review also introduces experimental techniques that may be adapted to clinical practice in the future. Moreover, we raise the topic and present a perspective for personalized medicine in uveal melanoma treatment.

Abstract

Uveal melanoma is the most common primary intraocular malignancy in adults, characterized by an insidious onset and poor prognosis strongly associated with tumor size and the presence of distant metastases, most commonly in the liver. Contrary to most tumor identification, a biopsy followed by a pathological exam is used only in certain cases. Therefore, an early and noninvasive diagnosis is essential to enhance patients’ chances for early treatment. We reviewed imaging modalities currently used in the diagnostics of uveal melanoma, including fundus imaging, ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), as well as positron emission tomography/computed tomography (PET/CT) or magnetic resonance imaging (MRI). The principle of imaging techniques is briefly explained, along with their role in the diagnostic process and a summary of their advantages and limitations. Further, the experimental data and the advancements in imaging modalities are explained. We describe UM imaging innovations, show their current usage and development, and explain the possibilities of utilizing such modalities to diagnose uveal melanoma in the future.

Fundus Autofluorescence Imaging in Patients with Choroidal Melanoma

Simple Summary

The ocular fundus contains molecules that emit fluorescence when excited with light of an appropriate wavelength. Fundus autofluorescence imaging is based on the in vivo detection of intrinsic fluorescence and results in topographic autofluorescence mapping of the ocular fundus. In contrast to fluorescence angiography, where the fluorescing agents need to be administered intravenously, autofluorescence imaging is a non-invasive technique. Even though choroidal melanomas do not contain significant autofluorescent molecules themselves, they may lead to secondary alterations in neighbouring tissues with an impact on the autofluorescence signal recording. Fundus autofluorescence imaging in the context of choroidal melanoma is helpful for differential diagnosis and for monitoring variations over time in affected patients before and after treatment.

Abstract

Choroidal melanocytic lesions require reliable and precise clinical examination and diagnosis to differentiate benign choroidal nevi from choroidal melanoma, as the latter may become life-threatening through metastatic disease. To come to an accurate diagnosis, as well as for monitoring, and to assess the efficacy of therapy, various imaging modalities may be used, one of which is non-invasive fundus autofluorescence (FAF) imaging using novel high-resolution digital imaging technology. FAF imaging is based on the visualization of intrinsic fluorophores in the ocular fundus. Lipofuscin and melanolipofuscin within the postmitotic retinal pigment epithelium (RPE) cells represent the major fluorophores that contribute to the FAF signal. In addition, the presence or loss of absorbing molecular constituents may have an impact on the FAF signal. A choroidal melanoma can cause secondary retinal and RPE alterations that affect the FAF signal (e.g., occurrence of orange pigment). Therefore, FAF imaging supports multimodal imaging and gives additional information over and above conventional imaging modalities regarding retinal metabolism and RPE health status. This article summarises the features of FAF imaging and the role of FAF imaging in the context of choroidal melanoma, both before and following therapeutic intervention.

Multimodal imaging of optic disc melanocytoma

PURPOSE

To describe the findings of four patients (four eyes) with optic disc melanocytoma (ODM), using multimodal imaging.

METHODS

Retrospective case series.

RESULTS

On ocular ultrasonography ODMs appeared as hyperechogenic lesions with moderate-to-high internal reflectivity. On blue-light fundus autofluorescence, ODMs showed total hypoautofluorescence, while, on infrared reflectance images appeared as bright and well-marginated lesions. MultiColor composite images showed reddish-brown lesions with well-defined margins. Swept-source optical coherence tomography revealed elevated lesions covering the optic disc with an irregular hyperreflective surface, dishomogeneous internal structure with hyperreflective dots, and posterior shadowing. In all cases optical coherence tomography angiography detected intratumoral blood vessels which were not detectable with fluorescein angiography.

CONCLUSION

Multimodal imaging in ODM might be useful both at presentation, increasing the diagnostic accuracy, and at follow-up, providing helpful details, that can help to rule out the possibility of malignant transformation and other ocular complications.

Choroidal nevus and polypoidal vasculopathy: case series

BACKGROUND

To report an association between choroidal nevus and polypoidal choroidal vasculopathy (PCV) in three patients.

CASE PRESENTATION

We have encountered 3 isolated patients in our center presenting with subretinal exudation and a choroidal nevus that were thoroughly evaluated by slit lamp biomicroscopy, fundus photos, Fluorescein angiography (FA), indocyanine green angiography (ICG), B-scan ultrasound, and optical coherence tomography (SD-OCT-Heidelberg). The classic features of choroidal neovascularization seen on PVC were present in all 3 patients, all of whom had a substantial response to intravitreous antiangiogenic agent. OCT, Fluorescein and ICG Angiography, and Fundus autofluorescence (FAF) revealed similar findings in all cases.

DISCUSSION AND CONCLUSIONS

We have identified a clinical pattern of PCV and choroidal nevus that can be diagnosed early using fluorescein angiography, ICG and OCT.

Multimodal imaging of suspicious choroidal neoplasms in a primary eye-care clinic

Small suspicious choroidal neoplasms commonly present a diagnostic challenge in primary eye-care clinics, where they are most likely to present. Differentiating benign from malignant choroidal neoplasms is essential for facilitating early diagnosis and treatment, potentially decreasing the risk of metastasis and vision loss in some cases. The purpose of this review is to describe the clinical, spectral-domain optical coherence tomography and fundus autofluorescence features of suspicious choroidal neoplasms in a case series of patients presenting to a primary eye-care clinic at the Veterans Health Administration, Cleveland, Ohio, USA.

Optical Coherence Tomography Angiography of Polypoidal Neovascularization Associated with Choroidal Nevus

Purpose

To report a case of juxtapapillary polypoidal choroidal neovascularization (PCNV) associated with choroidal nevus investigated by means of optical coherence tomography angiography (OCT-A).

Methods

Case report.

Results

A 72-year-old woman presented with visual loss and metamorphopsia in her left eye for 5 days secondary to PCNV that developed on the border of a juxtapapillary choroidal nevus. Fluorescein angiography, indocyanine green angiography, and spectral-domain OCT confirmed the diagnosis. En face OCT-A disclosed a large tangled hyperreflective PCNV spreading from the optic disc at different levels of the choriocapillaris; the polyp lumina appeared hyporeflective. The patient was treated with 3 intravitreal injections of anti-vascular endothelial growth factor with partial functional recovery.

Conclusions

Our case showed the application of OCT-A in the diagnosis of a case of active PCNV complicating a benign intraocular tumor.

Clinical, optical coherence tomography, and fundus autofluorescence findings in patients with intraocular tumors

PURPOSE

To describe clinical, optical coherence tomography (OCT) and fundus autofluorescence (FAF) findings in patients with intraocular tumors and determine if OCT and FAF could be helpful in the differential diagnosis and management of different choroidal tumors.

METHODS

Forty-nine patients with untreated, macular, midperipheral, and extrapapillary intraocular tumors were included. All patients underwent ophthalmic examination: best-corrected visual acuity, slit-lamp biomicroscopy, funduscopy, and standardized B mode, and if possible A mode, ultrasonography, and OCT and FAF imaging of the surface of the intraocular tumors.

RESULTS

Of the 49 patients studied, 19 had choroidal nevi, ten had indeterminate choroidal melanocytic lesions (IMLs), ten had malignant melanomas, and ten had other choroidal tumors. The choroidal nevi revealed subretinal fluid (SRF) on OCT in only 11%. FAF detected isoauto-fluorescence in 42%, hypoautofluorescence in 37%, patchy FAF pattern in 16%, and a diffuse FAF pattern in 5%. Seventy percent of patients with IML showed SRF on OCT and 20% showed tumor growth on follow-up, detected only by OCT and FAF imaging. FAF revealed a patchy pattern in 50% and a diffuse pattern in 40% of cases with IML. Ninety percent of the patients with choroidal melanoma had SRF on OCT and FAF revealed a patchy pattern in 60% and a diffuse pattern in 40%. Patients with other choroidal tumors had SRF on OCT in 30% of cases and no characteristic pattern on FAF.

CONCLUSION

Both OCT and FAF were helpful in the differential diagnosis of choroidal nevi versus IMLs, choroidal melanomas, and other choroidal tumors. Also, detailed and periodical clinical evaluation of patients with intraocular tumors using OCT and FAF imaging for the detection of both SRF and FAF patterns overlying the tumor can be useful for detection of tumor growth.

Infrared autofluorescence, short-wave autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytomas

AIM

To investigate the findings of infrared fundus autofluorescence (IR-AF) and spectral-domain optical coherence tomography (SD-OCT) in eyes with optic disc melanocytoma (ODM).

METHODS

IR-AF findings and those of other ophthalmologic imaging examinations, including short-wave autofluorescence (SW-AF), fluorescein angiography (FA), fundus color photography, and SD-OCT of 8 eyes of 8 consecutive cases with ODM were assessed.

RESULTS

The ODMs in all cases (100%) presented similar IR-AF, SW-AF, and FA findings. On IR-AF images, ODMs showed outstanding hyper-AF with well-defined outline. On SW-AF images, the area of ODMs presented as hypo-AF. FA images revealed the leaking retinal telangiectasia on the surface of the ODMs. On SD-OCT images in 8 cases (100%), the ODMs were sloped with highly reflective surface, which were disorganized retina and optic nerve layers. In 7 cases (87.5%), peripapillary choroids were involved. The melanocytomas of 8 cases (100%) presented as optically empty spaces. Vitreous seeds were found in one case (12.5%).

CONCLUSION

IR-AF imaging may provide a new modality to evaluate the pathologic features of ODMs, and together with SW-AF imaging, offers a new tool to study biological characteristics associated with ODMs. SD-OCT is a valuable tool in delimitating the tumor extension and providing morphological information about the adjacent retinal tissue.

Histopathologic Findings in the Areas of Orange Pigment Overlying Choroidal Melanomas

PURPOSE

Orange pigment is an important sign of malignancy in melanocytic tumors. There is a question as to whether the pigment accumulation is inside of macrophages or retinal pigment epithelial (RPE) cells. We investigated which cells are involved with this color alteration.

METHODS

We examined enucleated specimens from two patients with choroidal melanoma and dense orange pigment on fundus examination. Color fundus and fundus autofluorescence (FAF) photographs were reviewed followed by examination with fluorescent microscopy, electron microscopy, and immunohistochemistry of enucleated eyes for the specific areas corresponding to the orange pigment.

RESULTS

Orange pigment was observed on color fundus photography and correlated with areas of hyperautofluorescence on FAF. Fluorescent microscopy of sections of the enucleated eyes showed autofluorescence in the RPE, which were most pronounced where there was a localized retinal detachment and reactive hyperplasia of the RPE. Immunohistochemical studies were done with keratin (OSCAR and AE1/AE3) and S-100 stained RPE cells, which still were attached to Bruch's membrane. Histiocytes present in the detached retina stained with anti-CD163 antibody and did not show autofluorescence. Electron microscopy studies of the same areas showed the presence of lipofuscin and melanolipofuscin within the clustered RPE cells.

CONCLUSIONS

Orange pigment in choroidal melanocytic lesions originates from the RPE cells, rather than macrophages, and is most abundant where there is proliferation of the RPE.

TRANSLATIONAL RELEVANCE

The orange pigment tumoral biomarker arises and is in the retinal pigment epithelium.

Choroidal nevus in an eye with polypoidal choroidal vasculopathy

Purpose

To report an eye with polypoidal choroidal vasculopathy (PCV) and a choroidal nevus.

Methods

This is an observational case report.

Results

A healthy 69-year-old woman was referred to the Osaka University Hospital with a diagnosis of a macular tumor. She complained of having distorted vision in her left eye. The medical history of the patient was unremarkable. At the initial examination, her best-corrected visual acuity (BCVA) was 20/20 in both eyes, and the intraocular pressure was 18 mm Hg in both eyes. A slit-lamp examination showed no abnormalities in the anterior segment of both eyes and a fundus examination of the left eye showed a slightly elevated juxtafoveal chorioretinal lesion and polyp-like reddish-orange lesions. The juxtafoveal choroidal lesion was located beneath a choroidal neovascularization (CNV). An optical coherence tomography confirmed CNV with pigment epithelial detachment (PED). Fluorescein angiography showed juxtafoveal hyperfluorescence due to CNV. Indocyanine green angiography demonstrated a branching choroidal vascular network that resembled polypoidal lesions. A fundus autofluorescence showed a mosaic pattern and a slight hyperautofluorescence at the CNV. We diagnosed the patient as having PCV. Aflibercept was injected intravitreally because of her PED. After the injection, PED improved and her visual acuity remained stable during the 12-month follow-up period.

Conclusions

In cases of PCV, FAF images are helpful in determining the status of the posterior pole. Intravitreal injections of aflibercept can improve PED associated with CNV, and the BCVA will remain stable for at least 12 months.

Role of wide-field autofluorescence imaging and scanning laser ophthalmoscopy in differentiation of choroidal pigmented lesions

AIM

To evaluate the diagnostic properties of wide-field fundus autofluorescence (FAF) scanning laser ophthalmoscope (SLO) imaging for differentiating choroidal pigmented lesions.

METHODS

A consecutive series of 139 patients were included, 101 had established choroidal melanoma with 13 untreated lesions and 98 treated with radiotherapy. Thirty-eight had choroidal nevi. All patients underwent a full ophthalmological examination, undilated wide-field imaging, FAF and standardized US examination. FAF images and imaging characteristics from SLO were correlated with the structural findings in the two patient groups.

RESULTS

Mean FAF intensity of melanomas was significantly lower than the FAF of choroidal nevi. Only 1 out of 38 included eyes with nevi touched the optic disc compared to 31 out of 101 eyes with melanomas. In 18 out of 101 melanomas subretinal fluid was seen at the pigmented lesion compared to none seen in eyes with confirmed choroidal nevi. In "green laser separation", a trend towards more mixed FAF appearance of melanomas compared to nevi was observed. The mean maximal and minimal transverse and longitudinal diameters of melanomas were significantly higher than those of nevi.

CONCLUSION

Wide-field SLO and FAF imaging may be an appropriate non-invasive diagnostic screening tool to differentiate benign from malign pigmented choroidal lesions.

Treatment of vascular activity secondary to atypical choroidal nevus using intravitreal bevacizumab

Objective

To report the optical coherence tomography (OCT) findings of 27 eyes treated with intravitreal bevacizumab for intraretinal and subretinal vascular activity associated with atypical choroidal nevi.

Methods

This was an Internal Review Board-approved retrospective review of 27 eyes of 27 patients with choroidal nevus treated for secondary vascular activity with intravitreal injections of bevacizumab, performed by a single surgeon (TGM) at the Bascom Palmer Eye Institute. All patients were rigorously evaluated before the procedure and followed thereafter with ophthalmic examinations, refractive analysis, fundus photos, optical coherence tomography (OCT), and ocular echography. Patient demographics, tumor characteristics, dates of bevacizumab injections, and spectral-domain (SD)-OCT findings at each injection were recorded. Macular edema was graded as per SD-OCT findings for the initial and final visit.

Results

The mean age was 66.6 years (range, 40–86 years), with ten males and 17 females. Mean, median, and range baseline best corrected visual acuity (BCVA) were 20/53, 20/40, and 20/20–4/200, respectively. After a mean follow up of 29 months, the final BCVA mean, median, and range were 20/50, 20/40, and 20/20–20/400, respectively. The final BCVA ranged from 20/20 to 20/25 in nine eyes, while only six eyes had an initial BCVA within the same range. All patients demonstrated OCT findings of vascular activity suggestive of choroidal neovascularization (CNV). Initial SD-OCT findings included intraretinal cysts in eleven eyes, intraretinal fluid in six eyes, subretinal fluid in 14 eyes, pigment epithelial detachment in six eyes, epiretinal membrane in five eyes, and subretinal neovascularization in 14 eyes. On fundus photos, four eyes presented retinal hemorrhage. A mean of eight (range of 1–31) intravitreal bevacizumab (1.25 mg/0.05 cc) injections were given in all cases. A total of 37% (10/27) of eyes had complete or partial regression of vascular activity. The mean initial OCT classification for macular edema was 3 and a mean grade of 3 was maintained at the final follow-up OCT. All 27 choroidal nevi remained stable, and there were no adverse effects from the bevacizumab injections.

Conclusion

To our knowledge, this is the largest published case series of eyes treated with intravitreal bevacizumab for vascular activity associated with choroidal nevus. Intravitreal bevacizumab seems to be effective in the treatment of CNV secondary to choroidal nevus, and OCT can be a useful tool in the follow up of these patients, to assess the regression of CNV and to monitor macular edema.

Long-term echographic surveillance of elevated choroidal nevi

PURPOSE

To report the outcomes of choroidal nevi monitoring and to compare the detection of ultrasonographic hollowness, a risk factor of malignant transformation, from a B-scan with results from an A-scan examination.

DESIGN

Retrospective cohort study.

METHODS

Standardized A- and B-scan echography and ophthalmoscopy in 358 consecutive patients with median age 69 years and baseline choroidal nevus higher or lower than 1.5 mm in 51 (14%) and 307 (86%) eyes, respectively.

RESULTS

No growth or change in echographic or ophthalmoscopic features were found in 307 nevi with a median elevation of 0.9 mm (range, 0.7 to 1.5 mm) and a median follow-up of 6 years (range, 4 to 9 years). After 2 to 6 years, decreased internal reflectivity on standardized A-scan and ultrasonographic hollowness on B-scan were detected in 7 (18%) of 38 initially highly reflective choroidal nevi (thickness, 1.98 ± 0.37 mm); 2 (5%) nevi grew into melanoma 15 years after the first observation. Of 13 choroidal nevi (thickness, 2.75 ± 0.66 mm), with initial atypical medium to high reflectivity on standardized A-scan (100%) and hollowness on B-scan (85%), 6 (46%) were plaqued 6 to 15 months later because of the presence of multiple risk factors.

CONCLUSIONS

No changes in thickness or echographic features of choroidal nevi elevated up to 1.5 mm were recorded during the follow-up period. In initially typical choroidal nevi higher than 1.5 mm, strong agreement was detected between decreased reflectivity on standardized A-scan and ultrasonographic hollowness on B-scan found after up to 15 years of stability. The vast majority of choroidal nevi with initial atypical standardized A-scan features showed ultrasonographic hollowness.