Sensitivity of fluorescein angiography alone or with SD-OCT for the diagnosis of myopic choroidal neovascularization

Algorithm of the major and minor diagnostic criteria for active myopic choroidal neovascularization

PURPOSE

To propose an algorithm of the major and minor diagnostic criteria for macular myopic choroidal neovascularization (mCNV).

METHODS

This single-center, retrospective, cross-sectional study was based in Istituto Auxologico Italiano, Milan, Italy. Two authors evaluated the clinical and imaging parameters of eyes with high myopia (spherical equivalent of -6D or less) and suspected to have naïve, recurrent, or inactive mCNV. Recordings of the eyes that met the inclusion criteria were then independently evaluated by two other senior retinal specialists. Fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), and OCT angiography were used for multimodal imaging.

RESULTS

One-hundred and twenty-two eyes (n = 107; 39 men, 68 women) were included in the study. The mean patient age was 66 years (range, 22-89 years). There were 83 and 39 eyes in the active mCNV and control groups, respectively. The best diagnostic algorithm had positive- and negative-predictive values of 89% and 85%, respectively, and was based on four criteria: leakage/staining on FA, retinal thickening, fuzzy area on SD-OCT, and recent metamorphopsia. When excluding FA-derived findings, retinal pigment epithelium (RPE) features played a diagnostic role in 33 eyes (27%). Twenty-seven eyes with active mCNV (32%) did not have the fuzzy area. Taken singularly, no clinical or imaging parameter had both sensitivity and specificity greater than 78%. Matching of 2 or 3 biomarkers did not yield a sensitivity or specificity greater than 79%. Sensitivities and specificities ≥ 90% were found in ten criteria combinations that included four to five biomarkers. The most frequent were metamorphopsia, fuzzy area, retinal thickening, and leakage. Less frequently, they included hemorrhage, staining, and RPE features such as elevation, flattening, and focal interruption. For all the parameters, the agreement between the investigators was good (Cohen k ≥ 0.66), being the lowest when detecting the ELM interruption within the lesion.

CONCLUSIONS

A combination of at least four clinical and biological markers yielded the highest positive- and negative-predictive values. More ("major") and less ("minor") frequent diagnostic criteria are proposed.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Structural and optical coherence tomography angiography in myopic choroidal neovascularization: Agreement with conventional fluorescein angiography

PURPOSE

To evaluate the agreement between fluorescein angiography and structural optical coherence tomography in diagnosing and monitoring the activity of myopic choroidal neovascularization and to provide a comparative analysis with optical coherence tomography angiography.

METHODS

Thirteen patients with active myopic choroidal neovascularization were prospectively enrolled. At the baseline, 2-month, and 6-month visits, each patient underwent a complete ophthalmological examination, including best-corrected visual acuity assessment, fundus examination, fluorescein angiography, and optical coherence tomography with structural and angiographic assessment. Sensitivity and specificity for all optical coherence tomography parameters were evaluated taking fluorescein angiography as the reference examination.

RESULTS

At the baseline, fluorescein angiography confirmed myopic choroidal neovascularization leakage in all patients. Structural optical coherence tomography demonstrated intraretinal or subretinal fluid in 61% of cases, fuzzy borders and absence of external limiting membrane visibility in 84% of cases, and subretinal hyperreflective exudation in 53% of cases. Sensitivity to the presence of retinal fluid and subretinal hyperreflective exudation was lower than sensitivity to fuzzy borders and external limiting membrane visibility, which reached 84%. During ranibizumab therapy, external limiting membrane visibility showed a higher sensitivity (100%) compared with fuzzy borders and subretinal hyperreflective exudation (66.6%) while displaying an equal specificity of 100%. At baseline and final visit, sensitivity increased to 100% when all structural optical coherence tomography parameters were pooled. Optical coherence tomography angiography detected myopic choroidal neovascularization at baseline, 2-month, and 6-month visits in 92%, 76%, and 76% of cases, respectively.

CONCLUSION

The study confirms that the new indicators of myopic choroidal neovascularization activity are more reliable than the presence or absence of retinal fluid. Optical coherence tomography angiography identified myopic choroidal neovascularization in most patients in the diagnostic phase and during treatment monitoring and could be considered as an alternative to fluorescein angiography in selected patients.

Fluorescein Leakage and Optical Coherence Tomography Features of Choroidal Neovascularization Secondary to Pathologic Myopia

Purpose

We compare the fluorescein angiography (FA) patterns with morphologic alterations detectable on spectral-domain OCT (SD-OCT) in myopic choroidal neovascularization (mCNV) and evaluate whether they influence the effects of intravitreal ranibizumab (IVRI) in an as-needed (PRN) regimen.

Methods

The 49 patients enrolled in this prospective case series underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA), FA, and SD-OCT assessment. The main outcome measure was correlation between FA patterns and SD-OCT features. Secondary outcomes were changes in BCVA and central macular thickness (CMT), and characterization of subretinal hyperreflective exudation (SHE).

Results

Three main patterns were identified on the FA: no (5%), minimal (35%), and profuse (59%) leakage CNV. Comparison between minimal versus profuse leakage CNV subtypes revealed no difference regarding baseline and final BCVA, CNV area, choroidal thickness, final CMT, and proportion of intraretinal cysts, subretinal fluid, and external limiting membrane (ELM) interruption; however, the minimal leakage CNV subgroup revealed a lower percentage of SHE (P = 0.0039), required fewer IVRI (P = 0.003), and showed a baseline smaller CMT (P = 0.004). Patients presenting with SHE showed a similar baseline BCVA to those without exudation, but displayed greater final BCVA improvement. CMT was greater at the baseline and the reduction also was more marked. CNV area achieved a significant reduction only in eyes with SHE. ELM interruption was present in all cases compared to 86.3% of eyes without SHE. Lastly, the eyes with SHE required more injections (P = 0.04).

Conclusions

Different patterns of mCNV may be identified in FA and they correlate with specific SD-OCT alterations. Moreover, the type of FA leakage may assist in identifying more active mCNV.

Diagnostic algorithm utilising multimodal imaging including optical coherence tomography angiography for the detection of myopic choroidal neovascularisation

PURPOSE

To develop a diagnostic algorithm in patients with pathologic myopia who present with typical symptoms or signs of myopic choroidal neovascularisation (mCNV).

METHODS

Retrospective study. Patients with high myopia and suspected mCNV underwent fluorescein angiography (FFA), structural spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Active mCNV on one imaging modality plus clinical features were considered as the benchmark reference for the other two tests. Sensitivity was calculated for each modality individually and in combination. Morphological features were noted on SD-OCT and OCTA.

RESULTS

Twenty-seven eyes of 26 patients were analysed. Sensitivity of SD-OCT or FFA alone was 85.19% (23/27 eyes). Sensitivity of OCTA was 74.07% (20/27 eyes). The sensitivity for SD-OCT combined with OCTA was 96.16% and combined with FFA was 97.80%. On OCTA, a "tight net" appearance was seen in 16 eyes (80%); a core vessel was visible in seven eyes (35%), all with active lesions. A "perilesional halo" was visible in 11 eyes (55%) of which 10 had active lesions.

CONCLUSION

When combined, OCTA and SD-OCT or SD-OCT and FFA showed similar higher sensitivities than each modality alone. A tight vascular net and the combination of a perilesional halo and a visible core on OCTA may serve as biomarkers of mCNV activity.

NEOVASCULARIZATION SECONDARY TO HIGH MYOPIA IMAGED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To describe the optical coherence tomography angiography (OCTA) characteristics of active myopic choroidal neovascularization (CNV) and to compare its sensitivity versus fluorescein angiography and spectral-domain optical coherence tomography.

METHODS

Consecutive highly myopic patients complicated with active myopic CNV were prospectively included. The OCTA features were analyzed and correlated with the findings of conventional imaging (spectral-domain optical coherence tomography and fluorescein angiography).

RESULTS

Twenty eyes of 19 patients (mean age: 59.6 ± 12.1 years, mean spherical equivalent: -13.5 ± 3.6 diopters) presenting with both treatment-naive CNV and recurrent CNV were included in the analysis. The OCTA showed a 90% sensitivity for myopic CNV detection in 18 of 20 eyes, revealing a high-flow neovascular network accurately visible using a 30-μm manual segmentation underneath Bruch membrane. Mean selected area of myopic CNV on OCTA images was 0.34 ± 0.45 mm, whereas the mean vessel area was 0.22 ± 0.27 mm. Two neovascular phenotypes prevailed in our series: disorganized vascular loops and organized interlacing patterns.

CONCLUSION

The OCTA seems to be a valuable tool in detecting myopic CNV with a high sensitivity. However, its specificity needs to be investigated in further studies.

Features of optical coherence tomography predictive of choroidal neovascularisation treatment response in pathological myopia in association with fluorescein angiography

BACKGROUND/AIMS

The aim of this study was to evaluate the usefulness of several optical coherence tomography (OCT) findings to estimate choroidal neovascularisation (CNV) activity in pathological myopia using fluorescein angiography (FA) as a reference.

METHODS

This was a single-centre, retrospective study. The medical records of patients with active myopic CNV who received intravitreal bevacizumab treatment were reviewed. Parameters to monitor CNV activity were morphological features of CNV on OCT, such as CNV height, central foveal thickness, intraretinal cysts, subretinal fluid, fuzziness of the CNV border, CNV network area on FA, and haemorrhage or exudation on fundus photo.

RESULTS

There were 46 patients with active CNV enrolled in this study. After intravitreal bevacizumab treatment, all the previously mentioned parameters of CNV were significantly improved. Using logistic regression analyses with backward elimination, the fuzzy border seen on OCT showed the most significant correlation with improvement of leakage on FA, when compared with other variables such as intraretinal cysts, subretinal fluid or central foveal thickness (R²=0.324, p=0.009).

CONCLUSION

Our study showed that the fuzziness of the hyper-reflective CNV margin showed the most significant improvement and the strongest correlation with the improvement of CNV leakage on FA after intravitreal bevacizumab injections, suggesting its important role as an OCT parameter for the assessment of myopic CNV activity.

Selective and complementary use of Optical Coherence Tomography and Fluorescein Angiography in retinal practice

The current field of posterior pole and retinal imaging of the human eye has expanded into detailed analyses of the macula, retinal periphery, individual retinal layers, vitreoretinal interface, imaging of the choroid and the optic nerve head. The challenge in retinal imaging is the enduring pursuit of deeper penetration into tissues, increased resolution to the cellular level, and interpretation of observations. How much deeper can we go and with what resolution and reproducibility? These are fundamental questions for experts in search of novel imaging modalities. New discoveries may resolve existing controversies, but inevitably stimulate new questions. Emerging technologies in retinal imaging include adaptive optics retinal imaging and optical coherence tomography-based retinal angiography.

In this review, the focus of our discussion will be the discrepancy between the findings (interpretation) of one imaging technology that do not agree or are not even found with a complementary technology. If a clearly seen abnormality is present with one technology but absent in another, what are the possible explanations? Following is a summary of key concepts of retinal and optic nerve imaging modalities and current controversies regarding their interpretation and/or limitations.

Multimodal imaging and diagnosis of myopic choroidal neovascularization in Caucasians

Purpose

To investigate myopic choroidal neovascularization (mCNV) by fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) reflectance, and autofluorescence (AF).

Methods

This retrospective study included 65 eyes of 62 Caucasian patients with a mean age of 66.72 years (95% confidence interval [CI] 63–70 years) and a mean refraction of −9.72 diopters (95% CI −8.74 to −10.70 diopters).

Results

Most of the mCNV cases were foveal-juxtafoveal (60/65, 92.3%), with thickening of the corresponding retina (62/65, 95.3%) and leakage on FA (44/65, 67.6%). No retinal fluid was detectable in 32 (49.2%) eyes and there was no hemorrhage in 25 (38.4%) eyes. Papillary chorioretinal atrophy was evident in 58 (89.2%), a shadowing effect in 48 (73.8%), and an epiretinal membrane in 38 (58.4%) eyes. If an area of macular chorioretinal atrophy was present, mCNV frequently developed adjacent to it and was hyperfluorescent rather than with leakage (P⩽0.001). In eyes with edema or hemorrhage, hyper-reflective foci were more frequent (P⩽0.005). NIR and AF features were indeterminable in 19 (29.2%) and 27 (41.5%) eyes, respectively. The predominant feature was black or grayish on NIR (34/65, 52.3%) and patchy (hypo- and hyperfluorescence was observed) on AF (25/65, 38.4%). FA and SD-OCT correctly detected mCNV in 49 (75.3%) and 48 (73.8%) eyes, respectively, whereas NIR and AF exhibited limited diagnostic sensitivity. Doubtful diagnosis was associated with hyperfluorescent mCNV (P⩽0.001), absence of retinal fluid and epiretinal membrane (P⩽0.05), and presence of macular chorioretinal atrophy (P⩽0.01).

Conclusion

Tomographic, angiographic, AF, and NIR features of mCNV are described in this study. Combination of SD-OCT and FA is recommendable for diagnosis.

Fluorescein angiography and optical coherence tomography in myopic choroidal neovascularization

PURPOSE

To assess intra/inter-observer agreement, and diagnostic capabilities of a color fundus photograph, fundus fluorescein angiography (FFA), and spectral domain optical coherence tomography (SD-OCT) in making a diagnosis of myopic choroidal neovascularization (CNV).

PATIENTS AND METHODS

Two masked observers evaluated FFA and SD-OCT images to identify the presence of myopic CNV in 80 high-myopic eyes of 57 patients. A third masked observer identified CNV on a color fundus photo. Presence of myopic CNV on a fundus photo was defined as presence of subretinal hemorrhage, thickening of the retina and/or visible membrane at the macula. Presence of myopic CNV on FFA was defined as hyperfluorescence in the early phase with increase in intensity and size in the late phase; presence of a large irregular lesion; and hypofluorsescence due to subretinal hemorrhage. Myopic CNV on SD-OCT was defined as the hyper-reflective lesion with or without intraretinal fluid or subretinal fluid with retinal thickening.

RESULTS

Intraobserver repeatability on FFA and SD-OCT was 0.54 and 0.44, respectively. Agreement (kappa) between FFA and SD-OCT was 0.38 and 0.3, respectively. Among 34 eyes, which had the presence of CNV on a color fundus photo, CNV was diagnosed in 18 (53%) eyes on FFA and in 20 (58.8%) eyes on SD-OCT. Sensitivity and specificity of FFA was 47 and 80.4%, respectively, and that of SD-OCT was 58.8 and 86.9%, respectively.

CONCLUSION

Repeatability and reproducibility for diagnosis of myopic CNV was better with FFA compared with SD-OCT; however, agreement is very poor between FFA and SD-OCT. SD-OCT is comparatively a better tool to rule out presence of myopic CNV.