Understanding the Mechanisms of Fluid Development in Age-Related Macular Degeneration

Quantitative Multimodal Imaging Characterization of Intraretinal Cysts versus Degenerative Pseudocysts in Neovascular Age-Related Macular Degeneration

OBJECTIVE

To differentiate intraretinal fluid (IRF) cysts from degenerative pseudocysts in neovascular age-related macular degeneration (AMD) by quantitative multimodal imaging.

DESIGN

Observational, cross-sectional.

PARTICIPANTS

Patients affected by macular neovascularization secondary to AMD.

METHODS

All patients were analyzed by OCT, OCT angiography (OCTA), and dense automatic real-time (ART) OCTA. New-onset cysts were considered IRF, whereas those cysts that were found to be persistent for at least 3 months were categorized as degenerative pseudocysts. Intraretinal cysts were automatically segmented to calculate cyst circularity. Peri-cyst space was quantitatively analyzed to assess the presence of perfusion signal and hyperreflective foci (HF).

MAIN OUTCOME MEASURES

Best-corrected visual acuity, cyst circularity, peri-cyst perfusion, peri-cyst HF, fibrosis, and outer retinal atrophy.

RESULTS

We analyzed 387 cysts collected from 35 eyes of 35 patients with neovascular AMD (14 men; mean age, 80 ± 5 years). We classified 302 IRF cysts and 85 degenerative pseudocysts. Intraretinal fluid cysts were characterized by significantly higher circularity (0.86; range, 0.81-0.91), perfusion signal in the peri-cyst space, and peri-cyst HF in 89% of cases (all P < 0.05). Degenerative pseudocysts showed significantly lower circularity (0.68; range, 0.64-0.76), no perfusion signal in the peri-cyst space, and peri-cyst HF in only 29% of cases (all P < 0.05). The adopted quantitative metrics significantly correlated with disease duration, number of injections, fibrosis, and outer retinal atrophy.

CONCLUSIONS

Intraretinal fluid cysts can be discriminated from degenerative pseudocysts using a quantitative multimodal imaging approach. These findings are clinically relevant and should be included in future training models for artificial intelligence algorithms to improve the diagnostic power and fluid monitoring in neovascular AMD.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Non-neovascular fluid in age-related macular degeneration: observe-and-extend regimen in a case-series study

OBJECTIVE

To describe the course of non-neovascular fluid in age-related macular degeneration (AMD) after anti-vascular endothelial growth factor (anti-VEGF) therapy or after observation without injections.

DESIGN

Retrospective case series.

METHODS

AMD eyes with macular drusen and (or) drusenoid pigment epithelial detachment associated with non-neovascular fluid were included. Optical coherence tomography (OCT) angiography was performed in all eyes to exclude the presence of macular neovascularization. Subretinal fluid (SRF) was measured to determine the response after anti-VEGF therapy and after observation without injections.

RESULTS

Ten eyes of 9 patients with intermediate AMD and SRF were studied over a median period of 59.5 months (range, 7-128 months). Six patients (6 eyes) had a history of anti-VEGF therapy. Median follow-up off injections was 13.5 months (range, 4-44 months). SRF thickness remained stable and unchanged during the follow-up off injections in all eyes (n = 6) with prior injection and in all eyes (n = 4) that had never been injected. Six eyes developed complete retinal pigment epithelial (RPE) and outer retinal atrophy, and 1 eye developed incomplete RPE and outer retinal atrophy. All eyes exhibited at least 2 OCT biomarkers associated with a high risk for progression to atrophy.

CONCLUSION

This study provides preliminary data regarding the progression of non-neovascular fluid in AMD with or without anti-VEGF injections. A possible mechanism for fluid development may be related to RPE pump impairment. Distinguishing neovascular versus non-neovascular fluid using multimodal imaging, including OCT angiography, is essential to avoid unnecessary anti-VEGF therapy. An observe-and-extend regimen may be considered in AMD eyes with non-neovascular fluid.

SUBRETINAL FLUID ASSOCIATED WITH DRUSENOID PIGMENT EPITHELIAL DETACHMENT

PURPOSE

To analyze the clinical characteristics of drusenoid pigment epithelial detachment (PED) with subretinal fluid (SRF) and to evaluate the impact of SRF on the long-term visual and anatomical outcomes.

METHODS

Forty-seven eyes with drusenoid PED (47 patients) who completed >24 months of follow-up were retrospectively analyzed. Intergroup comparisons of the visual and anatomical outcomes with and without SRF were made.

RESULTS

The mean duration of follow-up was 32.9 ± 18.7 months. The group with drusenoid PED with SRF (14 eyes) showed significantly higher PED height (468 ± 130 µ m vs. 313 ± 88 µ m, P < 0.001), larger PED diameter (2,328 ± 953 µ m vs. 1,227 ± 882 µ m, P < 0.001), and larger PED volume (1.88 ± 1.73 mm 3 vs. 1.12 ± 1.35 mm 3 , P = 0.021) than that in the group with drusenoid PED without SRF (33 eyes) at baseline. No significant intergroup difference was found regarding the best-corrected visual acuity at the final visit. In addition, the incidence of complete retinal pigment epithelial and outer retinal atrophy (cRORA; 21.4%) and the development of macular neovascularization (MNV; 7.1%) for the group with drusenoid PED with SRF showed no difference compared with those (39.4% for cRORA development and 9.1% for MNV development) with drusenoid PED without SRF.

CONCLUSION

The size, height, and volume of drusenoid PED were associated with the development of SRF. The SRF in drusenoid PED did not affect the visual prognosis or the development of macular atrophy during long-term follow-up.

Pathways of Fluid Leakage in Age-Related Macular Degeneration

Age related macular degeneration is the most common cause of blindness in the western world and the development of intravitreal pharmacotherapies for the treatment of the neovascular complications of this disorder is considered a revolution in the care of this devastating disease. Anti-vascular endothelial growth factor (VEGF) agents such as ranibizumab and aflibercept can prevent blindness by reducing or resolving fluid in AMD and therefore the detection of these biomarkers (e.g. intraretinal and subretinal fluid) with high resolution, depth resolved tools such as optical coherence tomography (OCT) is a critical process in the successful management of this condition. However, there is growing evidence to indicate that fluid is not always the result of neovascular pathways and therefore the obligatory administration of anti-VEGF therapy in response to the observation of fluid on OCT may be flawed. Non-neovascular mechanisms of fluid leakage (e.g. retinal pigment epithelium pump impairment) should also be considered and in these circumstances anti-VEGF injection should be deferred. This editorial will review the neovascular and non-neovascular pathways of fluid leakage in AMD and will provide more informed guidance for the overall evaluation and management of exudation in AMD, including an observe and extend regimen in the context of non-neovascular fluid.

Prognostic Optical Coherence Tomography Biomarkers in Neovascular Age-Related Macular Degeneration

Optical coherence tomography has revolutionized the diagnosis and management of neovascular age-related macular degeneration. OCT-derived biomarkers have the potential to further guide therapeutic advancements with anti-vascular endothelial growth factor; however, the clinical convergence between these two tools remains suboptimal. Therefore, the aim of this review of literature was to examine the current data on OCT biomarkers and their prognostic value. Thirteen biomarkers were analyzed, and retinal fluid had the strongest-reported impact on clinical outcomes, including visual acuity, clinic visits, and anti-VEGF treatment regimens. In particular, intra-retinal fluid was shown to be associated with poor visual outcomes. Consistencies in the literature with regard to these OCT prognostic biomarkers can lead to patient-specific clinical decision making, such as early-initiated treatment and proactive monitoring. An integrated analysis of all OCT components in combination with new efforts toward automated analysis with artificial intelligence has the potential to further improve the role of OCT in nAMD therapy.

Advanced OCT Analysis of Biopsy-proven Vitreoretinal Lymphoma

PURPOSE

Although diagnosing vitreoretinal lymphoma (VRL) can be challenging, early detection is critical for visual prognosis. We analyzed the spectrum of optical coherence tomography (OCT) findings in patients with biopsy-proven VRL and correlate these features with clinical parameters.

DESIGN

This retrospective cross-sectional study was a multicenter chart review from 13 retina, uveitis, and ocular oncology clinics worldwide from 2008 to 2019. We included patients with a diagnosis of biopsy-proven VRL imaged with OCT at presentation. Ocular information, systemic information, and multimodal retinal imaging findings were collected and studied. The main outcome measure was the characteristics of VRL on OCT.

RESULTS

A total of 182 eyes of 115 patients (63 women, mean age 65 years) were included in this study. The disease was bilateral in 81 patients (70%), and mean baseline visual acuity was 0.2 ± 0.89 logMAR (Snellen equivalent, 20/32). At baseline, 38 patients (33%) presented with isolated ocular involvement, 54 (45%) with associated central nervous system involvement, and 11 (10%) with other systemic lymphomatous involvement; an additional 12 patients (10%) presented with central nervous system and other systemic involvement. On OCT, tumor infiltration was identified in various retinal layers, including lesions in the subretinal pigment epithelium compartment (91% of eyes), the subretinal compartment (43% of eyes), and the intraretinal compartment (7% of eyes). OCT analysis of eyes with VRL identified 3 main regions of retinal infiltration. Subretinal pigment epithelium location, with or without subretinal infiltration, was the most common pattern of involvement and isolated intraretinal infiltration was the least.

Difference Between the Incidence of Retinal Fluid Subtypes and Their Association with Visual Outcomes According to the Types of Macular Neovascularization in a Korean Population

Purpose: To investigate differences in the incidence of retinal fluid subtypes among different subtypes of macular neovascularization (MNV) and evaluate the influence of the presence of retinal fluid subtypes on visual outcome in each subtype of MNV. Methods: This retrospective study included 248 patients (248 eyes) diagnosed with treatment-naive neovascular age-related macular degeneration and polypoidal choroidal vasculopathy (PCV). The incidence of retinal fluid subtypes at diagnosis and during the 24-month follow-up was compared among the different subtypes of MNV. In addition, visual acuity was compared between patients with and without the retinal fluid subtypes. Results: At diagnosis, there was a significant difference in the incidence of subretinal fluid (SRF), intraretinal fluid (IRF), and subretinal pigment epithelial fluid among type 1 MNV, type 2 MNV, type 3 MNV, and PCV (P < 0.001). The incidence of SRF (P < 0.001) during follow-up also differed among the 4 groups. In patients with type 1 MNV and IRF, the visual acuity at diagnosis (P = 0.004) and at 24 months (P < 0.001) were significantly worse. However, the presence of SRF was not associated with poor visual acuity. In type 3 MNV, there was no significant difference in visual acuity between patients with and without SRF/IRF. Conclusion: The results of this study indicate that the clinical significance of retinal fluid subtypes may differ in different subtypes of MNV, suggesting the need for analysis in isolation of each MNV subtype in fluid-based prognostication.