OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FEATURES OF SUBRETINAL FIBROSIS AFTER MYOPIC NEOVASCULARIZATION

VIDEO COLOR OCT ANGIOGRAPHY FOR MYOPIC CHOROIDAL NEOVASCULARIZATION

PURPOSE

To investigate the myopic macular neovascularization (mMNV) features on dynamic video-color optical coherence tomography (OCT) angiography (OCTA) and the diagnostic rate versus the static, four-segmentations visualization mode.

DESIGN

Retrospective cohort study PARTICIPANTS: Fifty-four patients with mMNV METHODS: Sixty-two eyes with high myopia complicated by mMNV were included. Clinical charts, fluorescein angiography and structural OCT were used as standard reference to assess lesion activity. Static and video-color OCTA were then analysed and compared by two independent reviewers.

MAIN OUTCOME MEASURES

Morphology description of mMNV on video-color OCTA and differences in the proportion of diagnosis between video-colour and static OCTA.

RESULTS

62 eyes from 54 patients (mean age 63,22 years) were enrolled. Thirty-four (55%) mMNV were active and 28 (45%) inactive. Twenty-two (65%) active mMNV presented on video-color OCTA as an interlacing vascular network in the outer retina and the choriocapillaris. A tapered form was the prevalent size (72,7%). In 3 eyes (9%) an abnormal and irregular vascular network (AVN) was disclosed and in 5 (15%) only some blood flow alteration. All the lesions extended both in the outer retinal and the choriocapillaris. Eleven (39%) inactive mMNV presented on video-color OCTA as an interlacing vascular network too, in the outer retina and the choriocapillaris. Eight (29%) had some AVN and 6 (21%) only some blood flow alteration. The diagnostic rate of video-color vs static OCTA was 95% (IC 95% 86% to 99%) vs 77% (IC 95% 86% to 99%, p= 0.0009), and shows an advantage in favour of video-colour OCTA of 15% (CI 95%, 3%-27%) and 22% (CI 95%, 7%-38%) in active and inactive lesions, respectively (p<0.026). Lesion extension within both the outer retina and the choriocapillaris was present in 90% and 69% of cases on dynamic OCTA and static OCTA, respectively, with a proportion difference of 20% (CI 95%, 10%-31%, p= 0.0005). Concordance between the two examiners was high: 0.95 (95%, CI 0.88 to 1.00) and 0.96 (0.91 to 1.00) for active and inactive lesions, respectively.

CONCLUSIONS

Video color-enhanced OCTA may help in diagnosing mMNV and should be considered by clinicians in addition to structural OCT and static OCTA.

Morphological parameters of myopic choroidal neovascularization as predictive factors of anti-VEGF treatment response

The objective of this prospective study was to investigate the morphological changes of myopic choroidal neovascularization (mCNV) after treatment with anti-vascular endothelial growth factor and to identify potential features predictive of the final BCVA. OCT and OCTA features were evaluated at baseline and at 1, 6 and 12 months. Parameters investigated were the maturity pattern, presence of mCNV OCT activity signs, subretinal fibrosis and mCNV area. Forty patients (41 eyes) were included in the study. At the final visit, after a mean of 3.1 ± 1.4 injections, BCVA had improved significantly (p = 0.009) and subretinal hyperreflective exudation, subretinal fluid and intraretinal cysts nearly disappeared at 12 months. At baseline, 20 eyes had an immature CNV that were smaller, required less injections (2.5 ± 1.2 vs 3.8 ± 1.4, p = 0.002), they completely regressed in seven eyes and achieved a better BCVA (0.14 ± 0.15 vs 0.40 ± 0.26 logMAR, p < 0.001) when compared to mature CNV. Subretinal fibrosis developed in 19 eyes (46.3%) with lower final BCVA than eyes without fibrosis (0.19 ± 0.24 vs 0.38 ± 0.22 logMAR, p = 0.012). Baseline immature pattern (p = 0.005) and baseline BCVA (p < 0.001) were predictive of final BCVA. Multimodal imaging is useful to define mCNV changes during treatment. OCTA provides prognostic information which cannot achieved by other imaging techniques.

Anti-VEGF Therapy in Myopic CNV

In this narrative-review, we report the most recent data from the literature of anti-vascular endothelial growth factor treatment for myopic choroidal neovascularization (mCNV). Myopic CNV is the most frequent sight-threatening complication of pathologic myopia. The natural course of mCNV can result in expanding macular atrophy and /or fibrosis, leading to irreversible visual loss after 5 years. Retinal multimodal imaging is mandatory for early diagnosis and monitoring of the disease during treatment. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is recommended as the first-line treatment option for mCNV. Prompt treatment of active mCNV with intravitreal anti-VEGF therapy has been demonstrated to be effective in terms of visual outcome improvements reducing the occurrence of late-stage complications.

Flow pattern and perforating vessels in three different phases of myopic choroidal neovascularization seen by swept-source optical coherence tomography angiography

PURPOSE

To compare the choroidal neovascularization (CNV) flow patterns and the relationship between perforating vessels (PVs) and CNV in the three different stages of networks in myopic CNV (mCNV) using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

This retrospective study included 28 eyes with mCNV that was divided into three phases (active, scar, and atrophic) and observed by SS-OCTA. SS-OCTA findings, with special focus on the relationship between the PVs and CNV, were compared among the three phases.

RESULTS

Overall, the CNV signal was detected in 31 of the 34 areas of CNV (91%); in the active, scar, and atrophic phases, respectively, CNV signals were detected in eight of eight areas of CNV (100%), 10 of 11 areas of CNV (91%), and 13 of 15 areas of CNV (86%). Two signal patterns were observed in each phase, i.e., dense and loop; in the atrophic phase, seven eyes were unclassifiable. The ratio between the dense and loop patterns did not differ significantly among the phases. In 30 of 34 areas of CNV for which clear images were obtained, the PVs and CNV were connected directly or indirectly in 19 area of CNV, and in five areas of CNV, trunk-like vessels were connected to the PVs within the CNV. The numbers of foveal or parafoveal CNVs accompanied by PVs were significantly (p=0.0048) greater than those of the extrafoveal CNV.

CONCLUSIONS

OCTA provides detailed observation of mCNV and the relationship between CNV and PVs. Although the CNV signal pattern does not differ depending on the degree of atrophy, there are cases in which only the trunk-like vessels connect to the PVs within the CNV in the atrophic phase without CNV flow signal.