Short-Term Choriocapillaris Changes in Patients with Central Serous Chorioretinopathy after Half-Dose Photodynamic Therapy

Laser Treatment of Central Serous Chorioretinopathy - An Update

Laser treatment has been a mainstay for management of central serous chorioretinopathy for a few decades. Different types of lasers have been used and non-damaging retinal laser is the most recent option. The aim of this review is to provide an update on this form of treatment, based on the research published during last 5 years, in comparison with earlier studies published. A MEDLINE database search was performed with a combination of the following terms: central serous chorioretinopathy and laser photocoagulation or subthreshold laser or subthreshold micropulse laser or nanosecond laser or microsecond laser or end-point management or photodynamic therapy. Results were analyzed separately for each modality of laser treatment. Reports published in recent years confirm findings of previous research and do not distinguish treatments of this clinical entity. Among all analyzed laser options, photodynamic therapy provides the fastest and most prominent morphological improvements, including subretinal fluid resorption and reduction of choroidal thickness. This modality is also associated with fewer recurrences than with other treatments. Subthreshold micropulse laser allows the physician to maintain and, in selected cases, improve the patient's vision. Conventional photocoagulation is still effective, especially with the introduction of navigated laser systems. Despite the availability of variable laser treatment options, long-term functional improvements in chronic cases are minor for each modality. Long-lasting central serous chorioretinopathy cases with significantly altered retinal morphology do not usually present with functional improvement, despite satisfactory morphological outcomes. Early initiation of treatment has the potential to prevent visual loss and to improve the patient's quality of life.

Macular atrophy at 5 years after photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To investigate predictors for macular atrophy (MA) involving the fovea after photodynamic therapy (PDT) followed by pro re nata (PRN) treatment for polypoidal choroidal vasculopathy (PCV).

METHODS

This prospective observational study analysed treatment-naïve eyes with symptomatic PCV without MA at baseline which were followed up for 5 years. All eyes were initially treated with PDT, followed by a PRN regimen of anti-vascular endothelial growth factor (VEGF) therapy and/or PDT. We assigned eyes with and eyes without development of MA involving the fovea 5 years after the initial treatment into MA and non-MA groups, respectively. Baseline parameters and the number of treatments were compared between the two groups.

RESULTS

Seventy-two eyes of 69 consecutive patients were included, and 29 eyes of 29 patients were analysed. Twelve (41%) and 17 (59%) eyes were assigned into the MA and non-MA groups, respectively. There were significant differences in subfoveal choroidal thickness (226.2 ± 47.8 μm vs. 278.8 ± 68.1 μm, P = 0.03) and number of anti-VEGF injections (13.7 ± 9.6 vs. 5.4 ± 5.6, P = 0.007) between the MA and non-MA groups, but not in the number of PDT sessions (P = 0.71). Best-corrected visual acuity at 5 years in the MA group was lower than in the non-MA group (P = 0.048).

CONCLUSION

Our long-term observation suggests that a thin subfoveal choroid at baseline and many followed anti-VEGF injections in a PRN regimen increase the risk for development of MA involving the fovea 5 years after PDT.

INCREASING EVIDENCE FOR THE SAFETY OF FOVEA-INVOLVING HALF-DOSE PHOTODYNAMIC THERAPY FOR CHRONIC CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

A retrospective study was performed with data from the prospective randomized controlled trials, PLACE and SPECTRA, assessing the risk of foveal atrophy and the likelihood of structural and functional improvement on optical coherence tomography, after foveal half-dose photodynamic therapy in chronic central serous chorioretinopathy.

METHODS

A total of 57 chronic central serous chorioretinopathy patients received a single half-dose photodynamic therapy with a treatment spot that included the fovea. Optical coherence tomography scans and fundus autofluorescence images were analyzed for structural improvement and possible atrophy development, at baseline and at several visits after treatment. Main outcome measures were integrity of the external limiting membrane and ellipsoid zone on optical coherence tomography and hypoautofluorescence on fundus autofluorescence.

RESULTS

The subfoveal external limiting membrane was graded as continuous in 21 of 57 of patients (36.8%) at baseline, and the subfoveal ellipsoid zone was graded as continuous in 5 of 57 patients (8.8%) at first visit, which improved to 50 of 51 (98.0%) and 32 out of 51 (62.7%) at the final visit at 2 years, respectively (both P < 0.001). Hypoautofluorescent changes on fundus autofluorescence were present in 25 of 55 patients (45.5%) at baseline and in 23 of 51 patients (45.1%) at the final visit ( P = 0.480).

CONCLUSION

In patients with chronic central serous chorioretinopathy who received a single, foveal, half-dose photodynamic therapy, a significant improvement in structure and function was seen at the final follow-up. None of the patients developed foveal atrophy.

Superficial Retinal Microvasculature and Choriocapillaris Alterations after Photodynamic Therapy in Chronic Central Serous Chorioretinopathy

Purpose

To compare superficial retinal vascular, choriocapillaris (CC), and choroidal thickness changes in chronic central serous chorioretinopathy (CSCR) patients after half-dose photodynamic therapy (PDT).

Method

In this prospective interventional case series study, fifteen eyes of 14 patients with chronic CSCR undergoing half-dose PDT treatment were enrolled. All patients underwent enhanced depth imaging optical coherence tomography angiography (EDI-OCT) and optical coherence tomography angiography (OCTA) at baseline and 3 months after treatment. Best-corrected visual acuity (BCVA), superficial retinal vascular density, CC vessel density, foveal avascular zone (FAZ), central macular thickness (CMT), and choroidal thickness were compared.

Results

Mean BCVA before and after PDT was 0.34 ± 0.26 and 0.19 ± 0.25 logMAR, respectively (p=0.011). Mean FAZ before treatment was 410.21 ± 117.00 μm², which increased to 433.50 ± 116.76 μm² (P=0.253). Mean vessel density at superficial capillary plexus (SCP) was 38.93 ± 11.12 at baseline, which increased to 39.04 ± 11.43 (P=0.886). Mean CC vessel density was 53.21 ± 4.14 at baseline, which significantly decreased to 51.85 ± 4.21 (P=<0.001). BCVA has no significant correlation with FAZ (P=0.282) and vessel density (P=0.0.241) at SCP. CMT significantly decreased from 380.87 ± 41.66 μ at baseline to 268.20 ± 28.07 μ at 3 months (P=0.132). We did not find any correlation between CMT and FAZ (P=0.040) and vessel density (P=0.686) at SCP. Mean subfoveal choroidal thickness reduced from 411 ± 171 μm before treatment to 372 ± 117 μm (P=0.106).

Conclusion

PDT treatment can affect retinal and choroidal structural parameters, but we could not find any significant influence on retinal vascular parameters, including FAZ area and vessel densityonly mean CC vessel density and subfoveal choroidal thickness decreased.

Evaluation of the choriocapillaris after photodynamic therapy for chronic central serous chorioretinopathy. A review of optical coherence tomography angiography (OCT-A) studies

PURPOSE

Emerging evidence suggests that choroidal microcirculation and microstructural changes after verteporfin photodynamic therapy (vPDT) for chronic central serous chorioretinopathy (CSC) can be shown in detail using OCT-Angiography (OCT-A). The use of OCT-A for the examination of choriocapillaris (CC) has attracted significant attention as the technique offers potential explanations for the effects of vPDT on choroidal tissue.

METHODS

A meticulous literature search was performed in the PubMed database without restriction on year of publication until June 2021. The reference list of all electronically retrieved articles was carefully reviewed for potentially relevant articles that had not been identified.

RESULTS

We identified and reviewed 11 studies reporting a comprehensive update on microvasculature and morphologic changes of the CC layer as seen on OCT-A in chronic CSC. The reviewed articles extensively analyze both the qualitative and quantitative characteristics of the CC flow pattern after applying vPDT safety-enhanced protocols. The changes in the CC plexus indicate the potential of beneficial or deleterious treatment effect on choroidal tissue remodeling. The reviewed series have revealed variability of flow pattern, vessel density, and perfusion of the CC over time.

CONCLUSION

The CC plexus alterations during the post-vPDT period in chronic CSC may imply the treatment effect on choroidal tissue, indicating the potential of anatomical or functional recovery over time. The reviewed literature may confirm the diagnostic value of OCT-A in the assessment of the pathophysiology of eyes with CSC.

Geographic Atrophy Progression Is Associated With Choriocapillaris Flow Deficits Measured With Optical Coherence Tomographic Angiography

Purpose

The purpose of this study was to assess the associations between baseline choriocapillaris (CC) flow deficits and geographic atrophy (GA) progression.

Methods

In this prospective cohort study, patients with GA underwent 3 × 3-mm macular spectral-domain optical coherence tomographic angiography (OCTA) at baseline and follow-up visits. Annual GA enlargement rate was defined as change of square root of GA area in 12 months. Shadow areas due to iris, media opacity, retinal vessels, and drusen were excluded. CC vessel density (CC-VD) in non-GA areas was measured using a validated machine-learning-based algorithm. Low perfusion area (LPA) was defined as capillary density below the 0.1 percentile threshold of the same location of 40 normal healthy control eye. Focal perfusion loss (FPL) was defined as percentage of CC loss within LPA compared with normal controls.

Results

Ten patients with GA were enrolled and followed for 26 months on average. At baseline, the mean GA area was 0.84 ± 0.70 mm2. The mean CC-VD was 44.5 ± 15.2%, the mean LPA was 4.29 ± 2.6 mm2, and the mean FPL was 50.4 ± 28.2%. The annual GA enlargement rate was significantly associated with baseline CC-VD (r = -0.816, P = 0.004), LPA (r = 0.809, P = 0.005), and FPL (r = 0.800, P = 0.005), but not with age (r = 0.008, P = 0.98) and GA area (r = -0.362, P = 0.30).

Conclusions

Baseline CC flow deficits were significantly associated with a faster GA enlargement over the course of 1 year, suggesting the choriocapillaris perfusion outside of a GA area may play a role in GA progression.

Long-Term Visual Outcome in Inferior Posterior Staphyloma and Efficacy of Treatment for Complicated Choroidal Neovascularization

PURPOSE

To investigate long-term visual outcome in inferior posterior staphyloma (IPS) in each group classified based on macular complications and to examine the treatment effect for eyes with IPS with choroidal neovascularization (CNV).

DESIGN

Prospective clinical cohort study.

PARTICIPANTS

We analyzed 56 eyes of 43 consecutive patients with IPS who were followed for 4 years.

METHODS

We classified eligible eyes into 3 groups based on baseline findings: eyes without CNV or retinal exudate (no-exudate group), eyes without CNV and with retinal exudate (exudate group), and eyes with CNV (CNV group). We investigated the best-corrected visual acuity (BCVA) and associated parameters for 4 years.

RESULTS

BCVA declined during 4 years only in the exudate group (P = .002), whereas it was maintained for 4 years in the no-exudate and CNV groups (P = .53 and .20, respectively). Baseline BCVA was lower in the CNV group than in the exudate group (P = .004); however, the 4-year BCVA was not (P = .84). The 4-year BCVA was associated with baseline BCVA in all groups. Eyes in the CNV group required 9.0 ± 8.7 anti-vascular endothelial growth factor therapy in 4 years.

CONCLUSIONS

Better baseline BCVA in eyes with exudative IPS without CNV spontaneously declined in 4 years, whereas worse baseline BCVA in eyes with IPS with CNV did not, probably because of treatment for retinal exudate from CNV. Anti-vascular endothelial growth factor therapy would be effective for long-term maintenance of BCVA in eyes with IPS with CNV, similar to other diseases with CNV.

Quantitative evaluation of damage to retinal capillaries caused by half-dose and half-time photodynamic therapy with optical coherent tomographic angiography

PURPOSE

To determine and compare retinal capillaries damage in patients with chronic central serous chorioretinopathy (CSC) after half-dose and half-time photodynamic therapy (PDT) based on optical coherence tomographic angiography (OCTA).

METHODS

Thirty-three eyes of 33 patients and 32 eyes of 32 patients with active CSC were treated with half-dose PDT and half-time PDT respectively and followed up for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best corrected visual acuity (BCVA) and OCTA were performed at baseline, 3-day, 7-day, 14-day, 1-month, and 3-month follow-up visits.

RESULTS

Twenty-eight patients in half-dose group and 27 patients in the half-time group finished the 3-month follow-up visits. BCVA was significantly improved at post-PDT 1 month and 3 months (both P < 0.05) and central macula thickness (CMT) was significantly decreased at all post-PDT time points (all P < 0.05) in both groups. 22 patients (78.57%) in the half-dose group and 21 patients (77.78%) in the half-time group had complete absorption of subretinal fluid (SRF) at post-PDT 3 months. There was no significant difference in the above-mentioned prognostic measurements between two groups. The mean vessel densities of superficial retina (VDSR) and inner retina (VDIR) layers were decreased at all post-PDT time points in both groups. However, the decrease of VDIR and VDSR at post-PDT 3 days and 3 months in the half-dose group was much severe than those in the half-time group (P < 0.05).

CONCLUSIONS

Both half-dose and half-time modifications of PDT were similarly effective in improving the BCVA and decreasing the SRF for chronic CSC. However, the retinal capillaries damage in the half-time group was less severe than that in the half-dose group, so the half-time modification may be a more appropriate parameter for patients with chronic CSC.

Choriocapillaris: Fundamentals and advancements

The choriocapillaris is the innermost structure of the choroid that directly nourishes the retinal pigment epithelium and photoreceptors. This article provides an overview of its hemovasculogenesis development to achieve its final architecture as a lobular vasculature, and also summarizes the current histological and molecular knowledge about choriocapillaris and its dysfunction. After describing the existing state-of-the-art tools to image the choriocapillaris, we report the findings in the choriocapillaris encountered in the most frequent retinochoroidal diseases including vascular diseases, inflammatory diseases, myopia, pachychoroid disease spectrum disorders, and glaucoma. The final section focuses on the development of imaging technology to optimize visualization of the choriocapillaris as well as current treatments of retinochoroidal disorders that specifically target the choriocapillaris. We conclude the article with pertinent unanswered questions and future directions in research for the choriocapillaris.

Optical coherence tomography angiography in central serous chorioretinopathy: The current clinical role and future perspectives

Optical coherence tomography angiography (OCTA) images the layers of retinal and choroidal vasculature in the absence of an injectable dye. Since its introduction, OCTA has been utilized in various posterior segment diseases, including central serous chorioretinopathy. We provide a comprehensive review of OCTA's application to central serous chorioretinopathy published between 2014 and 2020.

Quantitative Evaluation of Retinal Vessel Density in Central Serous Chorioretinopathy after Half-dose Photodynamic Therapy

PURPOSE

To determine vessel changes in retinochoroid with optical coherence tomographic angiography (OCT angiography) and spectral-domain OCT (SD-OCT) of patients with central serous chorioretinopathy (CSC) after half-dose photodynamic therapy (hd-PDT).

METHODS

A prospective observational study of 62 eyes of 58 patients undergoing hd-PDT was followed for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best-corrected visual acuity (BCVA), fundus photography, OCT angiography and SD-OCT were performed at baseline, 1-month, and 3-month follow-up visits.

RESULTS

The mean vessel density of inner retina (VDIR) layer was 50.72 ± 3.17 at baseline, then decreased to 48.97 ± 4.34 at 1-month follow-up (p < .001), and partially recovered to 49.00 ± 4.28 at 3-month follow-up (p < .001); the mean area of foveal avascular zone (FAZ) was 0.303 ± 0.107 mm² at baseline, and then increased to 0.339 ± 0.121 mm² and 0.342 ± 0.125 mm² at 1-month and 3-month follow-up after hd-PDT (p < .001, p < .001). The mean diameters of choroidal big vessels (DCV) were 309.66 ± 72.24 microns at baseline, then decreased to 300.13 ± 69.38 microns at 1-month and 293.39 ± 69.92 microns at 3-month after treatment (p < .001, p < .001).

CONCLUSIONS

Currently common applied hd-PDT for patients with CSC has significantly impact on both retinal and choroidal vessels. The retinal capillary flow decreased, therefore optimizing PDT parameters for treating CSC may still be necessary in the future.

Assessment of choriocapillary blood flow changes in response to half-dose photodynamic therapy in chronic central serous chorioretinopathy using optical coherence tomography angiography

Background

Optical coherence tomography angiography (OCTA) is a newly developed imaging quantitative technique for analysis of choriocapillaris (CC) flow changes, thereby exploring the pathological mechanism of chronic central serous chorioretinopathy (CCSC) and the therapeutic effects of photodynamic therapy (PDT). In this study, we sought to quantify the blood flow changes in CC of CCSC patients receiving half-dose PDT using OCTA.

Methods

A total of 28 affected eyes and 24 unaffected eyes of 26 CCSC patients receiving half-dose PDT, and 40 eyes of 20 healthy gender- and age-matched subjects were retrospectively enrolled in this study. The proportion of total areas of flow signal voids (FSV, %) in CC level of OCTA was assessed in both eyes of the CCSC patients at baseline and repeated in multiple sections at 1-week, 1-month, 3-month and 6-month intervals after PDT. In addition, the CC patterns in response to PDT at early stage and the subsequent morphologic changes were qualitatively documented using OCTA.

Results

For affected eyes, FSV at 6-m follow-up was significantly lower than that at 1-m follow-up (p = 0.036). When compared to normal control eyes, FSV in affected eyes was significantly higher at 1-m, 3-m and 6-m follow-up (p < 0.05 for all), and FSV in unaffected eyes was significantly higher at baseline, 1-w, 1-m and 3-m follow-up (p < 0.05 for all). Three CC patterns of early response to PDT were identified, including signs of recovery with more even flow signals, transient appearance of worse ischemia and secondary neovascularization within CC level.

Conclusion

Abnormal CC flow attenuation remains in completely resolved eyes of CCSC patients treated with half-dose PDT.

Evaluation of the different thresholding strategies for quantifying choriocapillaris using optical coherence tomography angiography

BACKGROUND

In this paper, we evaluate the different thresholding strategies that have been used for the quantification of the choriocapillaris (CC) and explore their repeatability and the interchangeability of the measurements resulting from its application.

METHODS

Observational study. Eighteen eyes from nine healthy volunteers aged >18 years were imaged four consecutive times with a SD-OCTA system (Heidelberg Engineering, Germany) using a 10°×10° high-resolution protocol centered on the fovea. Projection artifacts were removed, and the CC was bracketed between 10 and 30 µm below Bruch's membrane. For the quantification of CC, we used four flow deficits (FD) parameters: FD number, mean FD size, total FD area and FD density. We performed a systematic review of literature to collect the thresholding methods that have been used for the quantification of CC. The CC quantification parameters were then evaluated after applying each of the thresholding strategies. Intraclass correlation coefficient (ICC) and Pearson's correlation analysis were used to compare the repeatability and interchangeability among the different thresholding strategies for quantifying the CC.

RESULTS

A total of 72 optical coherence tomography angiography (OCTA) examinations were considered. The systematic review allowed us to conclude that three local thresholding strategies (Phansalkar, mean and Niblack) and three global thresholding strategies (mean, default, Otsu) have been used for CC quantification. These strategies were evaluated in our observational study. We found a high agreement within the same method in the quantification of FD number, mean FD size, total FD area and FD density but a poor agreement with different strategies. Local strategies achieved a significantly superior ICC than global ones in CC quantification.

CONCLUSIONS

In conclusion, the interchangeability of the CC quantification using different thresholding strategies is low, and direct comparisons should not be performed. Local thresholding strategies are significantly superior to global ones for quantifying CC and should be preferred. There is an unmet need for a uniform strategy to quantify CC in future studies.

Choroidal Anatomic Alterations After Photodynamic Therapy for Chronic Central Serous Chorioretinopathy: A Multicenter Study

PURPOSE

To study the early anatomic choroidal alterations in eyes with chronic central serous chorioretinopathy (CSCR) undergoing photodynamic therapy (PDT).

DESIGN

Multicenter retrospective cohort study.

METHODS

A total of 77 patients and 81 eyes with chronic CSCR treated with PDT and 64 untreated fellow eyes were evaluated. Central macular thickness (CMT) and choroidal features including subfoveal choroidal thickness (SFCT), total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were analyzed. Choroidal vascularity index (CVI) was calculated in all study eyes at baseline and at 1- and 3-months post-PDT.

RESULTS

In eyes receiving PDT, Snellen visual acuity (VA) significantly improved at months 1 and 3 (P < .001). CMT and SFCT showed a significant reduction from baseline at months 1 and 3 (P < .001), whereas TCA and LCA showed a significant decrease only at the 1-month follow-up visit. Baseline mean TCA and LCA were 2.30 ± 1.41 mm² and 1.23 ± 0.73 mm², respectively, and decreased to 2.07 ± 1.21 mm² and 1.08 ± 0.63 mm² at the 1-month follow-up visit, respectively (P = .01). No significant changes were recorded for SCA and CVI. In the fellow eye group, VA, CMT, and all choroidal parameters showed no differences between baseline and any follow-up visits (all P > .05).

CONCLUSIONS

After PDT for chronic CSCR we observed sustained reductions in CMT and SFCT, while reductions in TCA and LCA were only noted at the 1-month follow-up interval. These choroidal parameters may provide additional quantitative biomarkers to evaluate the anatomic response to therapy but await further prospective validation.

Choroidal Structure after Half-Dose Photodynamic Therapy in Chronic Central Serous Chorioretinopathy

The study aims to analyze the changes produced by half-dose photodynamic therapy (HD-PDT) in the choroid of eyes with chronic central serous chorioretinopathy (CSC) applying the binarization method to spectral domain optical coherence tomography (SDOCT) and OCT Angiography (OCTA) images. SDOCT and OCTA were performed before, one hour, one week, and one month after HD-PDT. Binarization with a modified Niblack method and analysis by ImageJ were applied. An average ratio between luminal part and total structure was calculated. Twenty-two eyes of 21 patients (20 male and 1 female; mean age 54.8 years) were enrolled. A statistically significant reduction of the central choroidal thickness was observed one week (from 407 µm to 362 µm, p = 0.034) and one month (from 407 µm to 341.5 µm, p = 0.0004) after HD-PDT. The baseline average ratio between luminal part and total structure was 33.4% in SDOCT, and 61.1% in OCTA. These values were 35.3% and 61% one hour, 33.9% and 60.4% one week, and 34.5% and 60.6% one month after HD-PDT, respectively. Overall, PDT seems to produce short-term changes on the luminal component of both choriocapillaris and choroid, which return to baseline status after one month from treatment. However, choroid stays significantly thinner after one month, with both luminal and interstitial components significantly reduced.

Relationship between vascular densities of choriocapillaris and the whole choroid using OCTA

PURPOSE

To study the vascular density (VD) of choriocapillaris and the whole choroid using optical coherence tomography-angiography (OCTA).

METHODS

Cross-sectional study enrolling healthy individuals between 18 and 35 years old and with an axial length (AL) lower than 26 mm, who were examined with swept-source OCTA Triton DRI (Topcon). Color pictures of both VD were obtained from a fovea-centered 6 × 6 mm macular exam, which were divided into 900 squares and codified into numbers.

RESULTS

A total of 50 patients (100 eyes) with a mean age of 27.29 ± 3.90 years and a mean AL of 23.67 ± 0.74 mm were analyzed. The highest choroidal VD was found in juxtapapillary macula, being followed by the most temporal macula and fovea. The lowest was found in superior and inferior perifoveal areas. The highest VD in choriocapillaris was in the fovea. VD in this layer was uniform, with a decrease from temporal toward nasal. Both VD differed and but correlated, especially in the fovea and in inferior-temporal macula.

CONCLUSION

VD of choriocapillaris and the whole choroid are not similar. The former is maximal in the fovea, and the latter is maximal in the juxtapapillary macula. In general lines, choroidal VD is higher than that of choriocapillaris. Both VD are directly correlated.

Analysis of choriocapillaris perfusion and choroidal layer changes in patients with chronic central serous chorioretinopathy randomised to micropulse laser or photodynamic therapy

PURPOSE

The purpose of this study was to investigate the signal changes in choriocapillaris flow deficits and choroidal thickness changes using swept-source optical coherence tomography angiography (OCTA) following different treatments.

DESIGN

A double-blind, randomised controlled trial.

METHODS

Patients with unilateral chronic central serous chorioretinopathy (CSC) were randomised to receive subthreshold micropulse laser therapy (MLT) or half-dose photodynamic therapy (PDT). Choroidal thickness and choriocapillaris flow deficit signals were investigated.

RESULTS

Eighteen patients were randomised into the MLT group and 15 patients into the PDT group. Areas with flow deficit signals were identified in all baseline OCTA images of the choriocapillaris, with mean areas of 0.420 and 0.465 mm² in the MLT and PDT groups, respectively. These flow deficit signal areas were significantly reduced at 6 months (p=0.011) in the MLT group and at 3 months (p=0.008) in the PDT group. Patients from the PDT group were shown to have smaller flow deficit areas than patients from the MLT group at all time points after treatment (p=0.001, analyses of variance). The mean choroidal volume of the fovea showed a significant reduction at 1 month (p=0.003), 3 months (p=0.199) and 6 months (p=0.006) in the PDT group.

CONCLUSION

The flow deficit areas identified in the choriocapillaris layer may suggest possible relative choroidal ischaemia. With measurement of choroidal volume reduction and faster rates of flow deficit area change, PDT has a stronger effect than MLT in promoting choriocapillaris recovery.

Study of vessel density by optical coherence tomography angiography in patients with central serous chorioretinopathy after low-fluence photodynamic therapy

BACKGROUND

To perform a quantitative analysis of retinal and choriocapillaris vessel density (VD) in patients with central serous chorioretinopathy (CSC) after low-fluence verteporfin photodynamic therapy (vPDT), using Optical Coherence Tomography Angiography (OCTA).

METHODS

A total of 28 eyes of 27 patients with CSC (21 females, 6 males, mean age 47 ± 11 years) were included in this retrospective study. At baseline and after 6 months after vPDT, we evaluated VD of the superficial capillary plexus (SCP), the deep capillary plexus (DCP) and the choriocapillaris (CC) in different macular areas (whole image, parafovea and fovea). We also analyzed the central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) with Enhanced Depth Imaging-Optical Coherence Tomography (EDI-OCT).

RESULTS

Eighteen eyes and ten eyes were responders and non responders to low-fluence vPDT, respectively. The responders group showed a significant increase in VD in DCP and CC after treatment (p < 0.05). In the non responders group the VD in SCP, DCP and CC did not differ before and after treatment. We also found a significant correlation in responders group between Best-Corrected Visual Acuity (BCVA) and CFT (r = 0.566; p = 0.014) and between BCVA and the increased VD of CC (r= -0.559; p = 0.016). In non responders group, the correlation between OCT, OCTA parameters and BCVA was not statistically significant.

CONCLUSIONS

OCTA allowed us to enhance our knowledge regarding the pathophysiology of vascular changes in retinal and CC networks after low-fluence vPDT. OCTA may represent a new biomarker to evaluate the efficacy of low-fluence vPDT in the treatment of CSC.

Assessment of the Dynamic Alteration of Choriocapillaris Vessel Density after Focal Laser Photocoagulation with OCT Angiography

PURPOSE

To evaluate the changes of choriocapillaris blood flow beneath laser lesions in noncenter-involved diabetic macular edema patients using optical coherence tomography angiography (OCTA).

METHODS

This was a retrospective case-series study. We used OCTA to analyze the characteristics of the choriocapillaris blood flow beneath laser lesions before laser treatment and at several intervals after treatment. The choriocapillaris vessel density (CCVD) beneath the laser lesions was based on the OCTA images and was defined as the proportion of flow pixels in the selected area calculated using FIJI software through automatic binarization processing based on threshold methods.

RESULTS

A total of 63 laser lesions in 8 eyes of 5 patients were included in this study. There was a significant decrease in the CCVD at 1 hour and 1 day following laser treatment (24.25% ± 5.04% and 22.00% ± 4.71%, respectively) when compared with the baseline value (39.09% ± 3.71%, all p < 0.001). The CCVD was 31.82% ± 4.53% in 1 week after laser treatment, which was significantly higher than that in 1 day after treatment (p < 0.001). The CCVD was 31.82% ± 4.53% in 1 week after laser treatment, which was significantly higher than that in 1 day after treatment (p < 0.001). The CCVD was 31.82% ± 4.53% in 1 week after laser treatment, which was significantly higher than that in 1 day after treatment (.

CONCLUSIONS

OCTA image analysis can reflect changes in the choriocapillaris blood flow beneath laser lesions at different times following laser treatment in vivo. Spot size and laser energy may affect blood flow recovery.

CHANGES IN CHORIOCAPILLARIS, SATTLER, AND HALLER LAYER THICKNESSES IN CENTRAL SEROUS CHORIORETINOPATHY AFTER HALF-FLUENCE PHOTODYNAMIC THERAPY

PURPOSE

To determinate the variation in thickness of the individual choroidal layers in patients with central serous chorioretinopathy treated with half-fluence photodynamic therapy.

METHODS

Twenty-two eyes were evaluated with spectral-domain optical coherence tomography. The images were taken before photodynamic therapy, 3 months, and 6 months after the treatment. Two investigators performed these measurements: 1) choroidal thickness (CT), 2) Haller layer thickness, defined as the most external layer containing a 100-μm vessel, and 3) choriocapillaris + Sattler layer (C&S). Nine measurements were taken in the macular region.

RESULTS

Choroidal thickness before photodynamic therapy was 471.8 µm ± 145.8. The Haller layer was 358.4 µm ± 122.6, and C&S was 114.3 µm ± 27.8. At 3-month follow-up, CT was 441.1 µm ± 150.7, Haller layer 348.8 µm ± 127.6, and C&S 92.4 µm ± 27.9. At 6-month follow-up, CT was 420.4 µm ± 118.4, Haller layer 331.8 µm ± 97.2, and C&S 89.5 µm ± 28.0. Using a multilevel mixed-effects linear regression, CT was found to be reduced at both 3 months (P < 0.03) and at 6 months (P < 0.001), Haller layer showed no significant reduction at 3 months (P = 0.483) or at 6 months (P = 0.055), and C&S showed reduction at 3 months (P < 0.001) and at 6 months (P < 0.001). Fellow nonaffected eyes showed no statistical variation at 3-month and 6-month follow-up.

CONCLUSION

Reduction in CT in patients affected by central serous chorioretinopathy after half-fluence photodynamic therapy occurs primarily in the choriocapillaris and medium diameter vessel layers of the choroid in a short- and medium-term follow-up.

Quantitative evaluation of choriocapillaris using optical coherence tomography and optical coherence tomography angiography in patients with central serous chorioretinopathy after half-dose photodynamic therapy

PURPOSE

To quantify the structural and perfusion changes in choriocapillaris in chronic central serous chorioretinopathy after half-dose photodynamic therapy by using spectral-domain optical coherence tomography and optical coherence tomography angiography.

METHODS

This retrospective interventional case series examined the eyes of patients with central serous chorioretinopathy. Patients underwent full ophthalmic examinations, including spectral-domain optical coherence tomography and angiography, prior to and 1, 3, and 6 months after the treatment. Clinical and tomographic features of the choriocapillaris and choroidal thickness and vascular changes were evaluated by assessing flow signal voids.

RESULTS

All 56 eyes of 56 patients showed complete resolution of subretinal fluid at 3 months after photodynamic therapy. The best-corrected visual acuity significantly improved at 6 months (p<0.001). The central subfield thickness, subfoveal choroidal thickness, subfoveal choroidal large vessel layer thickness, and mean total area of flow signal voids decreased significantly at 6 months (all p values < 0.001), but the subfoveal choriocapillaris layer thickness did not change significantly at 6 months (p≥0.16). Multivariate analysis revealed positive linear correlations of the central subfield thickness and subfoveal choroidal large vessel layer thickness with the mean total area of flow signal voids at 6 months (p<0.001). There was a negative linear correlation between the subfoveal choriocapillaris layer and the mean total area of flow signal voids at 6 months (p = 0.013).

CONCLUSION

Half-dose photodynamic therapy improved the anatomic and functional outcomes of central serous chorioretinopathy, induced subfoveal choroidal thickness thinning, and increased choriocapillaris perfusion. In addition, the recovery of the subfoveal choriocapillaris layer thickness and improved choriocapillaris perfusion were closely associated.

Detecting and measuring areas of choriocapillaris low perfusion in intermediate, non-neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is a vision-threatening disease that affects the outer retina and choroid of elderly adults. Because photoreceptors are found in the outer retina and rely primarily on the trophic support of the underlying choriocapillaris, imaging of flow or lack thereof in choriocapillaris by optical coherence tomography angiography (OCTA) has great clinical potential in AMD assessment. We introduce a metric using OCTA, named "focal perfusion loss" (FPL) to describe the effects of age and non-neovascular AMD on choriocapillaris flow. Because OCTA imaging of choriocapillaris is vulnerable to artifacts-namely motion, projections, segmentation errors, and shadows-they are removed by postprocessing software. The shadow detection software is a machine learning algorithm recently developed for the evaluation of the retinal circulation and here adapted for choriocapillaris analysis. It aims to exclude areas with unreliable flow signal due to blocking of the OCT beam by objects anterior to the choriocapillaris (e.g., drusen, retinal vessels, vitreous floaters, and iris). We found that both the FPL and the capillary density were able to detect changes in the choriocapillaris of AMD and healthy age-matched subjects with respect to young controls. The dominant cause of shadowing in AMD is drusen, and the shadow exclusion algorithm helps determine which areas under drusen retain sufficient signal for perfusion evaluation and which areas must be excluded. Such analysis allowed us to determine unambiguously that choriocapillaris density under drusen is indeed reduced.

Intravitreal bevacizumab administration for the treatment of chronic central serous chorioretinopathy

Purpose

To evaluate the effects of intravitreal bevacizumab (IVB) injection on chronic central serous chorioretinopathy (CSC).

Methods

In this prospective interventional case series, a total of 22 eyes of 22 patients, diagnosed with unresolved CSC for three months or longer, received 1.25 mg IVB injection. Also, in case of failure to achieve success parameters, double dose IVB injections continued in order to reach the complete subretinal fluid (SRF) absorption. A complete ophthalmic assessment was carried out one day, one week, and one-month post-injection, and then a monthly visit was performed, and re-injection was done if needed. Visual acuity, subretinal space volume (SSV), central macular thickness (CMT), and contrast sensitivity were measured and compared among baseline values and final post-treatment values.

Results

The mean best corrected visual acuity increased significantly from 0.70 ± 0.22 to 0.17 ± 0.15 logMAR (P <0.001), and the CMT showed a significant reduction from 557.36 ± 129.12 to 259.50 ± 116.73 μm (P <0.001 ). In addition, SSV decreased significantly from 10.53 ± 2.03 to 6.63 ± 1.80 (P = 0.001), and contrast sensitivity improved significantly from 13.8182 ± 2.64820 dB to 17.6818 ± 1.80967 dB (P <0.001).

Conclusion

In this series, SRF absorption occurred and visual acuity improved after IVB injections, however, further comparative studies are needed to show the effect of IVB in chronic CSC.

Time course of swept-source optical coherence tomography angiography findings after photodynamic therapy and aflibercept in eyes with age-related macular degeneration

Purpose

To report swept-source optical coherence tomography angiography (SS-OCTA) findings after full-fluence photodynamic therapy (PDT) and aflibercept intravitreal injection (IVA) for age-related macular degeneration (AMD).

Methods

Five eyes of five patients with AMD treated with PDT and IVA were include into the study. We retrospectively reviewed the data obtained from the five patients using SS-OCTA before and after treatment. Three eyes had type 1 choroidal neovascularization (CNV) and two eyes had polypoidal choroidal vasculopathy.

Results

Before treatment, the CNV signals detected in all cases, decreased in three eyes and were not detected completely in two eyes at 1 months after treatment. The areas indicating CNV increased over time, but they did not increase to the baseline level. No CNV signal was detected in one eye during follow-up. In all cases, the exudation unchanged or resolved without additional IVA; the exudation recurred in two cases. In one eye, the CNV signal and the exudation occurred simultaneously; however, there was no association in another eye. A feeder vessel, from which the CNV signal seemed to originate, was seen in one of the five eyes.

Conclusion and Importance

SS-OCTA is useful to monitor the morphology of CNV after PDT and IVA, indicating that the remodeling of the choroidal vasculature occurs gradually after treatment. The presence or absence of the CNV signal might indicate CNV activity.

Age-dependent Changes in the Macular Choriocapillaris of Normal Eyes Imaged With Swept-Source Optical Coherence Tomography Angiography

PURPOSE

Swept-source optical coherence tomography angiography (SS-OCTA) was used to measure the age-dependent changes in macular choriocapillaris (CC) flow deficits (FDs) in normal eyes.

DESIGN

A prospective, cross-sectional study.

METHODS

Subjects with normal eyes ranging in age from their 20s to their 80s were imaged using a 100-kHz SS-OCTA instrument (PLEX Elite 9000, Carl Zeiss Meditec, Dublin, California, USA). Both 3 × 3-mm and 6 × 6-mm scans were used to image the macular CC. Visualization of the CC and quantification of FDs were performed using a previously validated algorithm. The percentage of FDs (FD%) in the central 1-mm circle (C₁), 1.5-mm rim (R_1.5), and 2.5-mm circle (C_2.5) from the 3 × 3-mm and 6 × 6-mm scans and FD% in the 2.5-mm rim (R_2.5) and 5-mm circle (C₅) from the 6 × 6-mm scans were measured and correlated with age and axial length.

RESULTS

A total of 164 subjects were enrolled, with at least 10 subjects from each decade of life. No meaningful correlations were found between FD% and axial length (|r| < 0.30). FD% in all fields increased with increasing age (all r > 0.50; all P < .001); however, the greatest increases were found in the central macula C₁ regions and the smallest increases in the peripheral macula R_2.5 regions.

CONCLUSIONS

In normal aging, the FD% increased with age across the central 5 mm of the macula, but the greatest increase was found in the central 1-mm region of the macula.

Choriocapillaris impairment around the atrophic lesions in patients with geographic atrophy: a swept-source optical coherence tomography angiography study

AIMS

To evaluate the choriocapillaris (CC) flow alterations around geographic atrophy (GA) in eyes with dry age-related macular degeneration.

METHODS

Using a swept-source optical coherence tomography angiography (SS-OCTA) device, two volume 6×6 mm scans were acquired in patients with GA presenting between June and December 2017 at the Doheny-UCLA Eye Centers. The area of GA was delineated on the en face structural OCT fundus images. For each eye, the en face OCTA slabs at the level of the CC from the two acquisitions were averaged and compensated for signal loss using the corresponding structural en face images. The resulting images were binarised and analysed for the percentage of flow voids in the para-atrophy zone (a 500 µm wide ring around the immediate edge of the atrophy) and in the peri-atrophy zone (a 500 µm wide ring around the para-atrophy zone edge), the latter considered as a reference in the comparative analysis.

RESULTS

Thirty eyes of 20 patients were enrolled. The percentage of flow voids in the para-atrophy zone was 27.23%±6.29% and was significantly higher than in the surrounding peri-atrophy zone (23.4%±6.01%; p<0.001). There was no significant correlation between the flow void percentage in these regions and age, visual acuity, extent of the atrophic area or central choroidal thickness.

CONCLUSIONS

A significant impairment of the CC flow is present in the zone immediately surrounding the GA lesions strengthening the hypothesis that CC alterations may be relevant to the progression of GA.