Morphologic Predictors and Temporal Characteristics of Conversion from Nonexudative to Exudative Age-Related Macular Degeneration in the Fellow Eye

Optical Coherence Tomography Angiography: A 2023 Focused Update on Age-Related Macular Degeneration

Optical coherence tomography angiography (OCTA) has extensively enhanced our comprehension of eye microcirculation and of its associated diseases. In this narrative review, we explored the key concepts behind OCTA, as well as the most recent evidence in the pathophysiology of age-related macular degeneration (AMD) made possible by OCTA. These recommendations were updated since the publication in 2020, and are targeted for 2023. Importantly, as a future perspective in OCTA technology, we will discuss how artificial intelligence has been applied to OCTA, with a particular emphasis on its application to AMD study.

Exudative Progression of Treatment-Naïve Nonexudative Macular Neovascularization in Age-Related Macular Degeneration: A Systematic Review With Meta-Analyses

PURPOSE

To systematically review and report the rate of exudative progression over time in patients with nonexudative macular neovascularization (MNV) in age-related macular degeneration (AMD).

DESIGN

Systematic review with prevalence meta-analyses and individual participant meta-analysis.

METHODS

We searched 10 literature databases on March 26, 2023, for studies of consecutive patients with treatment-naïve nonexudative MNV in AMD. The primary outcome of interest was time from diagnosis to exudative progression. We conducted meta-analyses on the prevalence of exudative progression at 1 and 2 years. Where possible, we extracted individual participant data from studies and conducted an individual participant meta-analysis and explored the exudative progression using a time-to-event curve.

RESULTS

We identified 16 eligible studies with a total of 384 eyes with nonexudative MNV. Exudative progression had occurred in 20.9% (95% CI 13.1%-29.8%) of eyes at 1 year and in 30.7% (95% CI 21.8%-40.4%) at 2 years. Similar results were observed in the individual participant meta-analysis, showing exudative progression in 18.9% (95% CI 13.5%-26.3%) of eyes at 1 year and 31.3% (95% CI 24.2%-40.0%) at 2 years. Risk factors for a fast exudative progression were the presence of subretinal lipid globules, large MNV areas, rapid MNV growth, growth in pigment epithelium detachment height and width, appearance of a branching pattern, and development of a hyporeflective halo around the MNV.

CONCLUSIONS

Nonexudative MNVs in AMD are at high risk of exudative progression. Recognition of these lesions may allow for better individualized follow-up regimens in which closer monitoring may facilitate earlier diagnosis of exudative progression.

Second eyes to develop neovascular age-related macular degeneration have fewer symptoms and better one-year visual outcomes

BACKGROUND

This study compares the visual and anatomical outcomes for the eyes of patients who developed sequential neovascular age-related macular degeneration (nAMD), both at the time of diagnosis and at one year after treatment.

METHODS

The study comprised a retrospective case series of 52 patients whose eyes were diagnosed sequentially with nAMD. All eyes were treated with three monthly loading doses of anti-vascular endothelial growth factor agents, followed by further intravitreal injections, as required. Baseline characteristics and outcomes at one year after diagnosis and initial treatment were compared between first and second eyes and included visual acuity (VA), central macular thickness (CMT), and pigment epithelial detachment (PED) height on optical coherence tomography (OCT) imaging.

RESULTS

VA at diagnosis was better for second eyes compared with first eyes to develop nAMD (logMAR 0.68 ± 0.51 versus logMAR 0.41 ± 0.34, P = 0.002) and remained so at one year (logMAR 0.61 ± 0.60 versus logMAR 0.42 ± 0.37, P = 0.041). Similarly, PED height at diagnosis was higher in first eyes (225 ± 176 μm versus 155 ± 144 μm, P = 0.003) and also at one year (188 ± 137 μm versus 140 ± 112 μm, P = 0.019). Whereas most patients reported symptoms at first eye diagnosis (71.2%), half as many second eyes were symptomatic (28.8%, P < 0.001). Significantly more symptomatic first eyes experienced visual distortions (32.4% versus 13.3%) or scotomas (29.4% versus 6.7%), compared with a less specific visual complaint of blurry vision (38.2% versus 80.0%, P = 0.006).

CONCLUSIONS

Compared with first eyes to develop nAMD, second eyes tended to have better vision, smaller PED heights, and fewer symptoms likely because monitoring permitted earlier diagnosis.

Growth of nonexudative macular neovascularization in age-related macular degeneration: an indicator of biological lesion activity

PURPOSE

To investigate the growth of nonexudative macular neovascularization (MNV) in age-related macular degeneration (AMD) using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

Patients with treatment-naïve nonexudative AMD in one eye and exudative AMD in the fellow eye who underwent SS-OCTA imaging for at least 12 months were retrospectively reviewed. The MNV area measurement was quantified in eyes with treatment-naïve nonexudative MNV using ImageJ for analysing the correlation between MNV growth and the onset of exudation, as well as evaluating the consistency of the MNV growth rate during the subclinical and exudative stages. Kaplan-Meier survival analysis and logistic regression analyses were used.

RESULTS

In total, 45 eyes with treatment-naïve nonexudative AMD from 45 patients were enrolled. Treatment-naïve nonexudative MNV was identified in 21 eyes (46.67%) at baseline. The development of exudative findings was noted in eight eyes (17.78%), including six eyes with previously noted nonexudative MNV. Eyes with growing MNV (increase in area ≥50% within 12 months) had an increased risk of exudation and developed exudation earlier than eyes with stable MNV (13.60 [6.43-20.77] months versus 31.11 [26.61-35.62] months, P < 0.0001, Log-rank test). Consistent growth pattern of MNV lesions was further identified in eyes with growing MNV during anti-VEGF treatment.

CONCLUSION

SS-OCTA allows to qualitatively and quantitatively evaluate nonexudative MNV in AMD patients. Growing MNV involved higher probabilities and a faster onset of exudation compared to stable MNV. Identifying the growth of MNV on OCTA might be helpful for establishing treatment strategies and follow-up planning.

FIVE-YEAR INCIDENCE OF FELLOW EYE NEOVASCULAR INVOLVEMENT IN AGE-RELATED MACULAR DEGENERATION AND POLYPOIDAL CHOROIDAL VASCULOPATHY IN AN ASIAN POPULATION

PURPOSE

To assess 5-year cumulative incidence and risk factors of fellow eye involvement in Asian neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy.

METHODS

In a prospective cohort study of Asian nAMD and polypoidal choroidal vasculopathy, the fellow eyes were evaluated for exudation. The 5-year incidence of exudation was compared between nAMD and polypoidal choroidal vasculopathy.

RESULTS

A total of 488 patients were studied. The 5-year incidence of exudation in fellow eyes was 16.2% (95% confidence interval: 12.0-20.2). Polypoidal choroidal vasculopathy compared with nAMD in the first eye was associated with lower fellow eye progression (9.8% [95% confidence interval: 5.1-14.3]) vs. 22.9% [95% confidence interval: 15.8-29.3], P < 0.01). Drusen (hazards ratio 2.11 [95% confidence interval: 1.10-4.06]), shallow irregular retinal pigment epithelium elevation (2.86 [1.58-5.18]), and pigment epithelial detachment (3.01 [1.27-7.17]) were associated with greater progression. A combination of soft drusens and subretinal drusenoid deposits, and specific pigment epithelial detachment subtypes (multilobular, and sharp peaked) were associated with progression. Pigment epithelial detachment, shallow irregular retinal pigment epithelium elevation, and new subretinal hyperreflective material occurred at 10.4 ± 4.2 months, 11.1 ± 6.0 months, and 6.9 ± 4.3 months, respectively, before exudation.

CONCLUSION

The 5-year incidence of fellow eye involvement in Asian nAMD is lower than among Caucasians because of a higher polypoidal choroidal vasculopathy prevalence. Drusens, shallow irregular retinal pigment epithelium elevation, and pigment epithelial detachment are risk factors for fellow eye progression.

Consequences of Real-World Surveillance of Fellow Eyes in Neovascular Age-Related Macular Degeneration

This study investigated whether the interval of monitoring at-risk, fellow eyes of patients with unilateral neovascular age-related macular degeneration (nAMD) has any bearing on the severity of the disease at the time of diagnosis. The study comprised a retrospective, cross-sectional comparative case series of treatment-naïve eyes in patients who were diagnosed sequentially with nAMD. We compared the visual acuity (VA) and central macular thickness (CMT) of patients who were actively receiving intravitreal injections (IVIs) of anti-vascular endothelial growth factor (anti-VEGF) agents at the time of second eye diagnosis with the VA and CMT of patients who had ceased treatment in their first eye because of reaching end-stages of disease. Intervals of visits and frequency of monitoring the macula of fellow eyes by means of optical coherence tomography (OCT) were abstracted from the medical record. We found that the at-risk fellow eyes of patients who had stopped treatment for nAMD in their first eye prior to fellow eye conversion were monitored significantly less frequently than the fellow eyes of patients who continued to receive treatment at the time of second eye diagnosis. Despite less frequent monitoring, VA and CMT were similar at the time of fellow eye diagnosis for both groups.

Towards a better understanding of non-exudative choroidal and macular neovascularization

Non-exudative macular and choroidal neovascularization (MNV and CNV) usually refers to the entity of treatment-naïve type 1 neovascularization in the absence of associated signs of exudation. Histopathological studies, dating back in the early 70s, identified the presence of non-exudative MNV, but the first clinical report of this finding was in the late 90s using indocyanine green angiography in eyes with age-related macular degeneration (AMD). With more advanced retinal imaging, there has been an ever increasing appreciation of non-exudative MNV associated with AMD and CNV with other macular disorders. However, consensus regarding the exact definition and the clinical management of this entity is lacking. Furthermore, there may be variation in the imaging features and clinical course suggesting that a spectrum of disease may exist. Herein, we review the large body of published work that has provided a better understanding of non-exudative MNV and CNV in the last decade. The prevalence, multimodal imaging features, clinical course, and response to treatment are discussed to elucidate further key insights about this entity. Based on these observations, this review also proposes a new theory about the origin and course of different sub-types of non-exudative MNV/CNV which can have different etiologies and pathways according to the clinical context of disease.

Outer Retinal Layer Thickening Predicts the Onset of Exudative Neovascular Age-Related Macular Degeneration

PURPOSE

To assess changes in outer retinal layer (ORL) thickness before the development of exudative macular neovascularization (MNV) in eyes with age-related macular degeneration.

DESIGN

Retrospective observational case series.

METHODS

Eyes with age-related macular degeneration that eventually developed exudative MNV followed with sequential optical coherence tomography for ≥2 years before the exudation occurred were enrolled. The ORL thickness was automatically calculated by the optical coherence tomography software for each sector of the early treatment diabetic retinopathy study map at each follow-up visit. The ORL thickness change from baseline to the day when the exudative MNV developed was compared between sectors that eventually developed exudative MNV and those that did not.

RESULTS

Forty-seven eyes (47 patients) were included. At baseline (24 ± 3 months before exudative MNV), mean (standard deviation) ORL thickness of sectors that eventually developed exudative MNV was similar to that of sectors that did not (85.2 [8.2] µm vs 86.8 [5.7] µm, P = .08). ORL thickness significantly increased in sectors that developed exudative MNV compared with those that did not (+5.8 [10.4] µm vs -2.8 [3.6] µm, P < .01). The regression model based on these data predicted an increase in ORL thickness from baseline of +4.2% 55 days and +11.1% 30 days before exudative MNV was detected. The ORL thickness of areas that did not develop exudative MNV did not change.

CONCLUSION

Thickening of the ORL begins in the area where exudative MNV will develop long before the exudation, accelerating significantly in the last 2 months. The occurrence of exudative MNV could be predicted by 2 months using this simple analysis.

Differential reperfusion patterns in retinal vascular plexuses following increase in intraocular pressure an OCT angiography study

To describe patterns of reperfusion in the superficial vascular plexus (SVP), deep capillary plexus (DCP) and choriocapillaris (CC) as detected on optical coherence tomography (OCTA) in cynomogulus macaque monkey model following increase in intraocular pressure by an intravitreal injection. Animal imaging study. Two cynomogulus macaque monkeys. A 100 µL intravitreal injection (IVI) of saline was given in one eye of each monkey. Serial OCTA using a Zeiss Plex Elite 9000 was used to evaluate reperfusion patterns within the SCP, DCP, and CC. OCTA evidence of perfusion. Pulsation of the central retinal artery was detected after the intraocular pressure was elevated to 98 and ≥ 99 mmHg from IVI. Episodic flow within the SVP arterioles and venules and poor visualization of flow in capillaries was noted during the initial phase of elevated pressure. As the pressure declined, the flow signal within the DCP appeared initially as dots, which progressed laterally to loops which form capillary vortex configuration. Recovery of flow within the SVP and CC appeared sooner than in the DCP. At 40 min after the injection, well after the intraocular pressure normalized, the retinal and choriocapillaris vascular perfusion showed focal defects in every layer. Compared with pre-injection images, vessel density in the DCP was 68.8% and 78.6% of baseline in monkey 1 and monkey 2, respectively. In contrast vessel density in the SVP recovered to 84.2% and 88.9% of baseline. Increases in intraocular pressure from IVI have the potential to affect every layer of blood flow in the fundus. After nominal return of intraocular pressure, focal defects in flow persisted, which may result in longer term damage to the retina.