Fluorescein angiography key in diagnosing retinal diseases

March 26, 2020

 Despite being an older procedure, fluorescein angiography (FA) is proving to be an effective tool for ophthalmologists. 

This article was reviewed by Steven Yeh, MD

Imaging modalities have been continuously evolving over the years and becoming more powerful. Fluorescein angiography (FA) is one of the oldest procedures used by ophthalmologists, but its age does not decrease its value.

Steven Yeh, MD, described the patterns of various diseases and how FA adds to the clinical evaluations of these patients. Dr. Yeh is the M. Louise Simpson Associate Professor of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta.

Related: Coming to terms with 'ultra-widefield' and 'widefield' imaging 

Birdshot Retinochoroidopathy (BRC)
Dr. Yeh described a 40-year-old man who complained of floaters and debris in the visual field for two years. He underwent laser retinoplexy for suspicious lesions. An examination showed 1+ anterior vitreous cells bilaterally, trace vitreous haze, and mild disc edema. The optic disc had some hyperfluorescence with leakage and the vessels had characteristic segmental periphlebitis. 

No lesions characteristic of birdshot retinochoroidopathy (BRC) were apparent in the left eye, and the segmental periphlebitis was even more prominent with leakage from the optic disc in the late frames and a retinal pigment epithelial (RPE) blush.

Indocyanine green angiography (ICGA) images showed multiple hyposinus lesions that define the BRC phenotype but no cystoid macular edema (CME). 

“There was a paucity of lesions on FA images, but ICGA showed more lesions,” Dr. Yeh said. “It is important to pair the two technologies when this disease is suspected.”

Related: Prevention of CME, infection in lens-based surgery: Evidence-based approaches

BRC can lead to severe CME and resultant changes in visual acuity. In another patient in whom BRC developed, optical coherence tomography (OCT) showed the diffuse RPE blush bilaterally that developed because of the chronic nature of the disease. OCT also showed intraretinal and subretinal fluid and an epiretinal membrane. Local and systemic treatments resulted in improved vision.

BRC can also result in choroidal neovascularization (CNV). A 53-year-old woman with HLA-A29+ BRC had accompanying bilateral distorted vision of 20/40 in the right eye. OCT showed the presence of subretinal hyperreflective material over a pigment epithelial detachment (PED). 

Dr. Yeh explained that fluorescein still has a role in patients such as this. 

“It showed hyperfluorescence in an early angiogram with leakage within the choroidal neovascular membrane and the optic disc,” he said. “This suggests that the disease has both inflammatory and neovascular components. The patient was treated with adalimumab (Humira, AbbVie) and serial anti-vascular endothelial growth factor (VEGF) injections and had a good outcome as seen on FA and OCT.

According to Dr. Yeh, CNV can occur in about 5% to 10% of BRC cases. 

“The risk of CNV in these cases is not surprising because the macula is involved,” he said. “In this context, combination therapy is important.”

Related: Quest for data increases debate for anti-VEGF therapy approach 

Acute posterior multifocal placoid pigment epitheliopathy
A 24-year-old woman presented to Dr. Yeh with vision loss to 20/100. Placoid lesions were seen on fundus photographs. FA showed characteristic early hypofluorescence with a late hyperfluorescent signal throughout the posterior pole. Previously oral prednisone (60 mg/day) was started at another institution, the patient discontinued treatment, and the vision decreased to 20/100.

Imaging of the left eye showed lesions encroaching on the fovea. Early hypofluorescence was seen with late diffuse and subtle hyperfluorescence over the lesions. Laboratory workup was negative for infectious diseases. Intravenous solumedrol was administered for 3 days; oral prednisone taper was administered.

One month after treatment, the vision improved from 20/100 to 20/40 and ultimately to 20/25.

Related: The emergence of multimodal imaging in ophthalmology 
 

Serpiginous choroidopathy
A 40-year-old patient with inactive serpiginous choroidopathy presented with the complaint of a new scotoma in his right eye. The patient had been treated with cyclosporine and azathioprine. An early-phase angiogram showed some hypofluorescence and the late-phase angiogram some staining.

Fundus autofluorescence-a key imaging modality for this disease-showed a large area of hypoautofluorescence that corresponded precisely to the fundus photograph. New imaging showed a new area of hypofluorescence and possibly some late hyperfluorescence at the lesion border. It had to be determined if this new finding needed additional treatment. 

In this patient the fundus autofluorescence highlights the lesion in conjunction with FA findings. 

“We found this to be a marker of disease activity,” Dr. Yeh said. “In this context FA should be used with fundus autofluorescence.”

Related: Connecting the dots: Diagnosing, managing multifocal choroiditides

Punctate inner choroidopathy (PIC)
A 27-year-old woman with myopia had a history of punctate inner choroidopathy (PIC) and a scotoma in the left eye. She presented with new visual distortion in the right eye. Evaluation of a subtle yellow blush was done to determine if this represented CNV or inflammation. “This is a case in which FA comes in handy,” Dr. Yeh noted.

The venous-phase angiogram was unremarkable, but the late-phase images showed diffuse punctate hyperfluorescence with leakage. 

“We interpreted this as an active inflammatory lesion that was treated with prednisone (1 mg/kg) tapered over the course,” he said.

The patient was followed with fundus photography and OCT. FA showed lesion resolution.

Related: UBM, AS-OCT viable for use with anterior segment lesions 

CNV associated with PIC is a high-risk complication that is thought to occur in from 69% to 77% of patients with PIC. “CNV is a key distinguishing feature of this disease. In these patients, FA shows early hyperfluorescence in an area of subretinal blood and late leakage from the CNV that requires anti-VEGF treatment,” he said.

In another PIC case, FA highlights the CNV well-demarcated lesion early and the PED extent in the disease.
 

Multiple evanescent white dot syndrome
This disease process is seen predominantly in women and is unilateral in 80% of cases. One-third of patients report a viral prodrome. The disease falls into an acute idiopathic large blind spot syndrome spectrum of disorders, Dr. Yeh explained.

FA shows early and late hyperfluorescence in areas of focal granularity and some areas of hyposinus lesions on ICGA images.

Dr. Yeh said FA remains a key imaging modality that shows subtle and highly characteristic patterns for BRC, acute posterior multifocal placoid pigment epitheliopathy, serpiginous choroidopathy, PIC, and multiple evanescent white dot syndrome that can help distinguish these disease diagnoses. 

Related: Casting a net to diagnose, treat cancerous lesions

“We use FA during initial evaluations and think it is extremely valuable for diagnosing and recognizing structural complications,” he said. 

In many cases, monitoring can be performed using other imaging modalities depending on the diagnosis and the secondary manifestations, according to Dr. Yeh. 

“Disease recurrences and complication are also highlighted by FA findings,” he concluded. “FA remains a valuable tool for the white dot syndromes.” 

Read more by Lynda Charters 

Steven Yeh, MD
E: steven.yeh@emory.edu
Dr. Yeh has no financial interest in the subject matter of this report.