Optical coherence tomography angiography findings of choroidal neovascularization in pseudoxanthoma elasticum

The role of multimodal imaging in characterization and monitoring of choroidal neovascularization secondary to angioid streaks

BACKGROUND

To characterize and monitor choroidal neovascularisation (CNV) secondary to angioid streaks (AS) using multimodal imaging and to compare the results with conventional fluorescein angiography (FA).

METHODS

A total of 11 eyes with CNV secondary to AS were included in this retrospective study. Multimodal morphological and functional assessment, including spectral-domain optical coherence tomography (SD-OCT), spectral-domain optical coherence tomography angiography (SD-OCTA), and fundus autofluorescence (FAF), were used to assess for evidence of CNV activity and compared with conventional FA. Morphological features of CNV were analyzed and treatment was continuously monitored using SD-OCT and SD-OCTA.

RESULTS

Our results showed that SD-OCTA provided reliable results for the detection of secondary CNV in AS that were comparable to conventional FA. With SD-OCTA, a total of 13 CNVs were detected in 11 eyes and analyzed by means of outer retinal choriocapillaris depth (ORCC) segmentation and the corresponding B-scans. Twelve of the 13 CNVs were classified as active and therefore required treatment. For treatment monitoring during intravitreal therapy (IVT), SD-OCTA was found to be a valuable diagnostic tool over a mean follow-up of 76 weeks.

CONCLUSIONS

Our study demonstrates that SD-OCTA can be routinely used to identify ill-defined CNV without dye-based angiography, especially in cases of CNV secondary to AS, where Bruch's membrane (BM) defects limit the diagnostic value of FA. Our results showed that non-invasive multimodal imaging facilitates sufficient CNV monitoring and treatment guidance. Further studies are warranted to provide more evidence in this rare retinal disease.

Clinical Use of Optical Coherence Tomography Angiography in Retinal Diseases

The advent of optical coherence tomography angiography (OCTA) is one of the cornerstones of fundus imaging. Essentially, its mechanism depends on the visualization of blood vessels by using the flow of erythrocytes as an intrinsic contrast agent. Although it has only recently come into clinical use, OCTA has become a non-invasive diagnostic tool for the diagnosis and follow-up of many retinal diseases, and the integration of OCTA in multimodal imaging has provided a better understanding of many retinal disorders. Here, we provide a detailed overview of the current applications of OCTA technology in the diagnosis and follow-up of various retinal disorders.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS IN A CASE OF CHOROIDAL NEOVASCULARIZATION SECONDARY TO TRAUMATIC CHOROIDAL RUPTURE

BACKGROUND/PURPOSE

To document by optical coherence tomography angiography, the onset of a choroidal neovascularization (CNV) secondary to traumatic choroidal rupture and describe its changes after an intravitreal injection of bevacizumab.

METHODS

Case report.

RESULTS

A 20-year-old woman presented referring vision loss after a blunt ocular trauma in her left eye. The patient underwent a complete ophthalmic examination. Best-corrected visual acuity was 20/200. Fundus examination, fluorescein angiography, indocyanine green angiography, and optical coherence tomography displayed a choroidal rupture with no evidence of CNV. Optical coherence tomography angiography showed the choroidal rupture as a line of choriocapillaris rarefaction because of the mechanical damage. Six months later, best-corrected visual acuity decreased to 20/300; optical coherence tomography angiography displayed the growth of a CNV, characterized by a tangled vascular network. After one intravitreal injection of bevacizumab, optical coherence tomography angiography documented a contraction of the CNV.

CONCLUSION

Optical coherence tomography angiography is a useful imaging technique for the diagnosis and follow-up of patients with choroidal ruptures. Anti-vascular endothelial growth factor agents represent an effective therapy for the treatment of CNVs secondary to this affection.

Angioid Streaks in Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum, or Gronblad-Strandberg syndrome, is an inherited disorder that involves multiple organ systems. The characteristic degeneration and calcification of the elastic fibers caused by this disease were first observed by Ferdinand Jean Darrier in 1896. We report a case of a 27-year-old female who was diagnosed with pseudoxanthoma elasticum based on a skin biopsy prior to her presentation to our ophthalmology outpatient clinic. The past ocular history of the patient was unremarkable for any previous eye complaint or surgery. Her ocular and fundus examination showed pigmented grayish irregular post choroidal crack-like linear dehiscence, forming a network-like pattern, originating at the optic disc and extending radially involving the macular area and the posterior pole in both eyes, representing bilateral angioid streaks. There were no clinical or optical coherent tomographic signs of choroidal neovascularization. Periodic follow up for patients with pseudoxanthoma elasticum is recommended to detect choroidal neovascularization which is a sight-threatening complication. Ophthalmologists should be aware of this association as early recognition and treatment are vital to prevent irreversible visual loss.

Ocular manifestations of dermatological diseases part II: genodermatoses

Skin and eyes share a common embryological origin from the embryonic surface ectoderm. Ocular manifestations in dermatological diseases are common and have diagnostic value. At present, there are a limited number of comprehensive reviews emphasizing the ocular manifestations of dermatological diseases. More than 40 published articles about ocular findings in dermatology were reviewed. The search included Pubmed, Google Scholar, and Cochrane databases from 2014 to 2019. This review was divided into three parts including: I. infectious and inflammatory disorders; II. genodermatoses; III. connective tissue, autoimmune, neoplasms, and drug-related disorders. We excluded metabolic, endocrine, and nutrition-related dermatological diseases. In this part, we summarized the most common and important ocular findings in dermatology-related genetic disorders with appropriate referral recommendations to ophthalmology.

Long-term follow-up of management of choroidal neovascularisation secondary to angioid streaks with intravitreal anti-vascular endothelial growth factor

PURPOSE

To assess the short-term and long-term visual outcomes in patients with choroidal neovascularisation (CNV) secondary to angioid streaks treated with intravitreal anti-vascular endothelial growth factor (VEGF).

METHODS

Retrospective, single-centre study.

RESULTS

Overall 66 eyes of 52 patients were analysed. Follow-up ranged from 1 to 10 years. BCVA was 62 ETDRS letters at baseline, 68 letters at 1 year, 60 ETDRS letters at 5 years and 58 letters at 7 years. At 2 years patients gained 5.7 ETDRS letters from baseline but this gain was lost at 5 years. At 5 years there was an average loss of ETDRS letters from baseline of 3.3 letters. Sub-group analysis of subfoveal CNV showed worse outcome compared with eyes with extrafoveal and juxtafoveal CNV. In subfoveal CNV, BCVA was 53 ETDRS letters at 1 year (p < 0.0001) and 39 ETDRS at 5 years (p = 0.0005).

CONCLUSION

Anti-VEGF therapy is effective at stabilising visual acuity in patients with choroidal neovascularisation secondary to angiod streaks, however there is a gradual decline in visual acuity observed with 5-10 years of follow-up. Furthermore, subfoveal CNV have worse visual outcome compared with extrafoveal and juxtafoveal CNV.

Retinal imaging including optical coherence tomography angiography for detecting active choroidal neovascularization in pseudoxanthoma elasticum

IMPORTANCE

The diagnostic accuracy of different retinal imaging modalities to detect active choroidal neovascularization (CNV) in pseudoxanthoma elasticum (PXE) is essential to enable a correct diagnosis but is currently poorly understood.

BACKGROUND

Optical coherence tomography (OCT), fluorescein angiography (FA) and OCT angiography (OCT-A) are employed in daily practice, but a systematic comparison of these imaging techniques is lacking.

DESIGN

Retrospective, observational study.

PARTICIPANTS

Twenty patients (31 eyes) with PXE.

METHODS

OCT, FA and OCT-A imaging was performed in each eye and graded separately by independent readers.

MAIN OUTCOME MEASURES

Diagnostic accuracy, sensitivity and specificity to detect CNV-activity of each modality and longitudinal change of CNV size measured by OCT-A.

RESULTS

OCT showed the highest diagnostic accuracy (kappa = 0.57) in comparison to OCT-A or FA (kappa = 0.39 and 0.37, respectively). OCT-A, OCT and FA showed a diagnostic sensitivity of 0.9, 0.85 and 0.6, and a diagnostic specificity of 0.45, 0.72 and 0.82, respectively. Evaluation of longitudinal OCT recordings (24 eyes) resulted in optimal sensitivity and specificity (kappa = 1.0). Although median CNV size assessed using OCT-A remained stable on longitudinal measures of seven eyes, two eyes showed a distinct increase over time despite anti-vascular endothelial growth factor treatment.

CONCLUSIONS AND RELEVANCE

The systematic use of OCT, FA and OCT-A imaging can facilitate the diagnostic accuracy for detection and follow-up of CNV activity in PXE. While structural OCT is of high value, especially when longitudinal follow-up images are available, FA and OCT-A data might contribute to diagnostic accuracy in more complex cases.

Multimodal imaging characteristics of quiescent type 1 neovascularization in an eye with angioid streaks

Purpose

To present the multimodal imaging characteristics including optical coherence tomography angiography (OCTA) as well as indocyanine green angiography (ICGA) of quiescent type 1 neovascularization (NV) in an asymptomatic eye with angioid streaks (AS).

Observations

A 67-year-old male patient was admitted to our clinic for routine eye examination. The presence of a quiescent type 1 NV was detected on both ICGA and OCTA in juxtafoveal localization under the retinal pigment epitheliumin the right eye. At the end of the one year of follow-up, the patient was asymptomatic and the type 1 NV was still quiescent.

Conclusions and Importance

In comparison to ICGA, OCTA seems to be an easily repeatable non-invasive imaging tool which enables us early detection and monitoring of type 1 NV lesions even in asymptomatic patients with AS.

LOCATING AND CHARACTERIZING ANGIOID STREAKS WITH EN FACE OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

To characterize angioid streaks (AS) with en face optical coherence tomography (OCT).

METHODS

Case report of a patient with myopia presenting with choroidal neovascularization secondary to AS. Swept-source en face OCT ability to image the streaks was compared with spectral-domain and swept-source B-scans as well as color and red-free pictures. A 48-year-old man with myopia presented with sudden central visual loss. Choroidal neovascularization secondary to AS was diagnosed and intraocular anti-vascular endothelial growth factor given with clinical and OCT features improvement.

RESULTS

Angioid streaks were visualized as less dark than the overlying retinal and the underlying choroidal vasculature. En face OCT located the changes at the level of Bruch membrane. An AS was found to be interrupted by the choroidal neovascularization, what was not captured by other modalities.

CONCLUSION

En face OCT allows to assess the extent of changes in Bruch membrane and their spatial relationship to choroidal neovascularization.

Optical coherence tomography angiography

Optical coherence tomography (OCT) was one of the biggest advances in ophthalmic imaging. Building on that platform, OCT angiography (OCTA) provides depth resolved images of blood flow in the retina and choroid with levels of detail far exceeding that obtained with older forms of imaging. This new modality is challenging because of the need for new equipment and processing techniques, current limitations of imaging capability, and rapid advancements in both imaging and in our understanding of the imaging and applicable pathophysiology of the retina and choroid. These factors lead to a steep learning curve, even for those with a working understanding dye-based ocular angiography. All for a method of imaging that is a little more than 10 years old. This review begins with a historical account of the development of OCTA, and the methods used in OCTA, including signal processing, image generation, and display techniques. This forms the basis to understand what OCTA images show as well as how image artifacts arise. The anatomy and imaging of specific vascular layers of the eye are reviewed. The integration of OCTA in multimodal imaging in the evaluation of retinal vascular occlusive diseases, diabetic retinopathy, uveitis, inherited diseases, age-related macular degeneration, and disorders of the optic nerve is presented. OCTA is an exciting, disruptive technology. Its use is rapidly expanding in clinical practice as well as for research into the pathophysiology of diseases of the posterior pole.

Detection of Nonexudative Choroidal Neovascularization Secondary to Angioid Streaks Using Optical Coherence Tomography Angiography

Purpose

To present a case of nonexudative choroidal neovascularization secondary to angioid streaks in a patient with pseudoxanthoma elasticum. The lesion was monitored over an 8-month period with the use of optical coherence tomography angiography.

Methods

Case report.

Results

The neovascular tissue area increased by 0.160 mm2 over a period of 8 months without any sign of exudation seen on optical coherence tomography or fluorescein angiography.

Conclusions

To our knowledge, this is the first report of a nonexudative choroidal neovascularization secondary to angioid streaks. Given that once a patient with angioid streaks develops choroidal neovascularization in one eye there is a high risk of bilateral involvement within a short amount of time, optical coherence tomography angiography can prove a useful tool for monitoring such lesions over time.

Ranibizumab for choroidal neovascularization secondary to pseudoxanthoma elasticum: 4-year results from the PIXEL study in France

PURPOSE

To evaluate the long-term effectiveness and safety of ranibizumab 0.5 mg in patients with choroidal neovascularization (CNV) secondary to pseudoxanthoma elasticum (PXE) in a real-world setting.

METHODS

A descriptive, observational, multicenter study in a retrospective and prospective cohort was conducted in France that included patients who had received at least one injection of ranibizumab 0.5 mg during the period October 2011 to October 2014, for CNV secondary to PXE. Eligible patients were identified by review of medical records or during routine consultations. The main objectives were to describe patient characteristics, assess changes in best-corrected visual acuity [VA, Early Treatment Diabetic Retinopathy Study (ETDRS) letters] over time, the number and reasons for ranibizumab treatment and overall safety.

RESULTS

Of the 72 enrolled patients (98 eyes) from 23 centers, 39 (54.2%) were male and mean [±standard deviation (SD)] age was 59.6 (±8.3) years. The mean VA was 64.6 letters at the first ranibizumab injection, which was maintained at the 1-year follow-up (64.7 letters). Thereafter, the mean VA was stable until the 4-year follow-up. At 4 years, the proportion of eyes with VA gain of ≥15 letters was 3/19 (15.8%) and stable VA (change between -15 and +15 letters) was 10/19 (52.6%). Mean (±SD) annual number of ranibizumab injections was 4.1 (±4.0), lower in the second versus first year. The most common reason for ranibizumab treatment was progression of neovascular activity (42.9%). No deaths or new safety findings were reported.

CONCLUSIONS

In patients with CNV secondary to PXE, ranibizumab 0.5 mg resulted in stable VA over 4 years with a limited number of injections. Safety findings were consistent with the established safety profile of ranibizumab.

Optical coherence angiography: A review

BACKGROUND

Retinal vascular diseases are one of the most common causes of blindness in the developed world. Optical Coherence Tomography Angiography (OCT-A) is a new noninvasive method that uses several algorithms to detect blood movement. This enables the creation of high-resolution vascular images with contrast depicting motionless tissue.

METHODS

This review presents the results of articles relevant to age-related macular degeneration (AMD), diabetic retinopathy (DR), and OCT-A. The OCT-A technique can successfully be used in the diagnosis of neovascularization, retinal vein occlusion (RVO) and retinal artery occlusion (RAO), vessel abnormalities and even anterior segment neovascularization. OCT-A can also be applied to compute data such as vessel density, and flow index in both superficial and deep plexuses.

RESULTS

Many studies have compared fluorescein angiography with OCT-A. Other studies have reported differences in vascular density in AMD patients and have compared them with people having healthy eyes. Although OCT-A offers rapid picture acquisition, high repeatability and resolution, it also has many drawbacks. The most common are: motion artifacts, projections from overlying vessels and limited field of view.An interesting new application is the possibility to assess changes during antivascular endothelial growth factor (anti-VEGF) therapy. Another function of OCT-A is the possible application in the study of choriocapillaries in many fields of ocular pathology.

CONCLUSION

OCT-A is a new promising method that allows the visualization of the retinal vascular network and the counting of blood flow parameters. This technique provides reliable images useful in clinical routines.