FROM DRUSEN TO TYPE 3 MACULAR NEOVASCULARIZATION.

PURPOSE: To investigate the imaging features preceding the occurrence of type 3 (T3) macular neovascularization (MNV) using tracked spectral-domain optical coherence tomography. METHOD: From a cohort of eyes with T3 MNV and ≥ 12 months of previously tracked spectral-domain optical coherence tomography, T3 lesions that developed above soft drusen were selected for optical coherence tomography analysis. Retinal imaging findings at the location where type T3 MNV occurred were analyzed at each follow-up until the onset of T3 MNV. The following optical coherence tomography parameters were assessed: drusen size (height and width), outer nuclear layer/Henle fiber layer thickness at the drusen apex, and the presence of intraretinal hyperreflective foci, retinal pigment epithelium disruption, incomplete retinal pigment epithelium and outer retina atrophy, and complete retinal pigment epithelium and outer retina atrophy. RESULTS: From a cohort of 31 eyes with T3 MNV, T3 lesions developed above soft drusen in 20 eyes (64.5%). Drusen showed progressive growth ( P < 0.001) associated with outer nuclear layer/Henle fiber ( P < 0.001) thinning before T3 MNV. The following optical coherence tomography features were identified preceding the occurrence of T3 MNV, typically at the apex of the drusenoid lesion: disruption of the external limiting membrane/ellipsoid zone and/or the retinal pigment epithelium, hyperreflective foci, and incomplete retinal pigment epithelium and outer retina atrophy/complete retinal pigment epithelium and outer retina atrophy. CONCLUSION: The results demonstrate specific anatomic alterations preceding the occurrence of T3 MNV that most commonly originates above soft drusen. Drusen growth, reduced outer nuclear layer/Henle fiber thickness, and retinal pigment epithelium atrophy at the drusen apex precede the development of T3 MNV. Identifying these optical coherence tomography features should warrant close monitoring for identification of T3 MNV, which can benefit from prompt intravitreal anti-vascular endothelial growth factor therapy.

ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY AND PLACOID VARIANT DISEASES MASQUERADING AS AGE-RELATED MACULAR DEGENERATION IN THE ELDERLY: A Case Series.

PURPOSE: To report eight cases of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) or persistent placoid maculopathy (PPM) initially masquerading as age-related macular degeneration in elderly individuals. METHODS: APMPPE or PPM eyes in patients above age 55 years with macular retinal pigment epithelium disruption including drusenoid lesions on macular examination and/or with multimodal imaging were included. At least one method of multimodal imaging including fluorescein angiography (FA), indocyanine green angiography, optical coherence tomography (OCT), and OCT angiography (OCTA) was performed in all eyes for diagnosis and to monitor for macular neovascularization. RESULTS: Eight elderly male patients presented with vision loss and were all initially diagnosed with non-neovascular or neovascular age-related macular degeneration. With the aid of multimodal retinal imaging, a final diagnosis of either APMPPE or PPM was rendered. With FA and indocyanine green angiography, choroidal hypoperfusion was detected in all but one eye. With OCT, the angular sign of Henle fiber layer hyperreflectivity was identified in >50% of eyes. With OCTA, inner choroidal flow deficits were detected in all eyes. Macular neovascularization requiring anti-vascular endothelial growth factor injection therapy complicated three of eight cases. CONCLUSION: Both APMPPE and PPM may develop in elderly individuals and may masquerade as age-related macular degeneration on presentation. Multimodal imaging including FA, indocyanine green angiography, and OCTA are important diagnostic modalities to assess for inner choroidal hypoperfusion to arrive at an accurate diagnosis and to detect macular neovascularization, which frequently complicates APMPPE and PPM. In these patients, serial anti-vascular endothelial growth factor intravitreal injections are essential in treating macular neovascularization and in preventing significant vision loss.

Sub retinal pigment epithelium hyporeflective spaces preceding large drusen collapse.

PURPOSE: To describe and study hyporeflective sub retinal pigment epithelium (RPE) spaces in large drusen and drusenoid pigment epithelial detachment prior to collapse. METHOD: Retrospective longitudinal study which enrolled patients with large and very large drusen due to intermediate age-related macular degeneration (AMD). The following optical coherence tomography (OCT) parameters were assessed: Drusen size (maximum width and height), OCT biomarkers of RPE atrophy, presence of intraretinal and subretinal fluid (IRF, SRF), acquired vitelliform lesion and sub RPE regions of hyporeflectivity within the PED compartment. RESULTS: Of the 50 eyes from 41 patients (mean age of 77.1 ± 9 years, 78% women) with large and very large drusen, 16 eyes progressed to collapse. Eyes with sub RPE hyporeflective spaces (n=8 eyes, 50%) were associated with greater drusen width and height than eyes without sub RPE hyporeflective spaces. At the collapse visit, eyes with sub RPE hyporeflective spaces displayed poorer visual acuity and greater iRORA (incomplete RPE outer retinal atrophy) and cRORA (complete RORA) length than eyes without sub RPE hyporeflective spaces (p=0.004 and p=0.04, respectively). CONCLUSION: Sub RPE hyporeflective spaces are a novel OCT finding of large and very large drusen that collapse to atrophy. Progressive RPE dysfunction and failure may lead to reduced drusenoid material formation and progressive degenerative hydration of the large drusen prior to collapse, but this awaits confirmation with histopathological analysis.

INDOCYANINE GREEN ANGIOGRAPHY OF TYPE 1 MACULAR NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION AND CENTRAL SEROUS CHORIORETINOPATHY REVEALS DIFFERENT DISEASE MECHANISMS.

PURPOSE: To assess the rate of late phase hyperfluorescent plaque (LPHP) in Type 1 macular neovascularization (MNV) in central serous chorioretinopathy (CSCR) and age-related macular degeneration (AMD) and to evaluate its prognostic value. METHODS: Retrospective study including Type 1 MNV in AMD and CSCR, from 2012 to 2020. Eyes with a late indocyanine green angiography image (>20 minutes) and clear visualization of MNV on optical coherence tomography angiography (OCTA) were included. Quantitative and qualitative parameters on optical coherence tomography and best-corrected visual acuity were recorded at baseline and after three monthly antivascular endothelial growth factor injections. RESULTS: Eighty-three eyes were included, 35 with CSCR and 48 with AMD. Patients in the CSCR group were significantly younger than in the AMD group (61.3 ± 10.4 vs. 80.2 ± 6.8 years, respectively, P < 0.001), predominantly male (68.6% CSCR vs. 35.4% AMD; P = 0.003), and with a thicker choroid (379 ± 93.3 µ m vs. 204.2 ± 93.2 µ m; P < 0.001). Type 1 MNV in CSCR showed fewer LPHP compared with AMD (31.4% vs. 77.1%; P < 0.001). The baseline visual acuity was lower in patients with LPHP (0.37 ± 0.22 vs. 0.27 ± 0.28 logarithm of the minimum angle of resolution, P = 0.03). On multivariate analysis, AMD was associated with the presence of LPHP ( P < 0.001). No significant difference in the response to antivascular endothelial growth factor was observed. CONCLUSION: Leakage of macromolecules from MNV and accumulation in the retinal pigment epithelium and/or in the stroma imaged by the LPHP is less common in eyes with Type 1 MNV in CSCR than in AMD. Late phase indocyanine green angiography imaging offers an insight into the metabolism of the dye and the environment surrounding the neovascular membrane.

EVALUATION OF PARAVASCULAR INNER RETINAL DEFECTS USING EN FACE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To evaluate the prevalence and risk factors for development of paravascular inner retinal defects (PIRDs) using en face optical coherence tomography. METHODS: This is a retrospective cross-sectional study. En face and cross-sectional optical coherence tomography images were reviewed (9 × 9 mm or 12 × 12 mm). Paravascular inner retinal defects were classified as either Grade 1 (i.e., paravascular inner retinal cysts) when the lesion was confined within the nerve fiber layer without any communication to the vitreous cavity or Grade 2 (i.e., paravascular lamellar hole) when the defects communicated to the vitreous. Paravascular inner retinal defect grading was correlated with presence of high myopia, stage of posterior vitreous detachment, and presence of epiretinal membrane and retinoschisis. RESULTS: Of 1,074 patients (2,148 eyes), PIRDs were detected in 261 eyes with a prevalence of 261 per 2,148 eyes (12.2%) and 176 per 1,074 patients (16.4%). A total of 116 eyes (44.4%) displayed Grade 2 PIRDs while 145 eyes (55.6%) were Grade 1. In the multivariate logistic regression model, the presence of partial/complete posterior vitreous detachment, retinoschisis, and epiretinal membrane was significantly correlated with PIRDs (OR = 2.78 [1.7-4.4], P < 0.001; OR = 2.93 [1.7-5], P < 0.001; and OR = 25.9 [2.8-242.5], P < 0.001, respectively). The presence of partial/complete posterior vitreous detachment and epiretinal membrane was also significantly associated with Grade 2 PIRDs versus Grade 1 PIRDs ( P = 0.03 and P < 0.001). CONCLUSION: Our results indicate that wide-field en face optical coherence tomography facilitates the identification of PIRDs over a large area of retina with a single capture. The presence of PIRDs was significantly associated with posterior vitreous detachment, epiretinal membrane, and retinoschisis, confirming the role of vitreoretinal traction in the pathogenesis of PIRDs.

CENTRAL SEROUS CHORIORETINOPATHY: High-Resolution Imaging of Asymptomatic Fellow Eyes Using Adaptive Optics Scanning Laser Ophthalmoscopy.

PURPOSE: To investigate cone density in the asymptomatic fellow eye of patients with unilateral central serous chorioretinopathy (CSCR). METHODS: Seventeen asymptomatic fellow eyes of patients with unilateral CSCR and 17 eyes of aged-matched and gender-matched healthy controls underwent adaptive optics ophthalmoscopy. Cone density and spacing were assessed at the fovea. Clinical and multimodal imaging findings were also recorded. RESULTS: In the CSCR group, the patient mean age was 48.9 ± 9.8 years. The mean (±SD) subfoveal choroidal thickness was 417.8 ± 125.2 µm. The foveal external limiting membrane and ellipsoid zone were intact in all patients. Adaptive optics fundus imaging showed a significant decrease in cone density at 2° of eccentricity nasal and temporal to the fovea in asymptomatic fellow eyes of patients with unilateral CSCR compared with controls (P = 0.001 and P = 0.027, respectively). No statistically significant difference in cone density was found at 4° of eccentricity nasal and temporal to the fovea between both groups. CONCLUSION: Asymptomatic fellow eyes of patients with unilateral CSCR showed a reduced density of foveal cones in the absence of a decreased visual acuity and photoreceptor line disruption on optical coherence tomography. These results suggest that the photoreceptors could be damaged independently of the occurrence of a serous retinal detachment.

Preoperative Optical Coherence Tomography Findings of Foveal-Splitting Rhegmatogenous Retinal Detachment.

PURPOSE: To assess preoperative optical coherence tomography (OCT) findings of foveal-splitting retinal detachment (RD) and determine postoperative outcomes. METHODS: Consecutive patients who underwent RD surgery over a 1-year period were included. Patients diagnosed with a detachment extending to the edge of the fovea on fundus examination (i.e., macula-On/Off) underwent macular OCT scanning. Visual acuity (VA) after 1 year of macula-On/Off, macula-On, and macula-Off eyes was compared. RESULTS: A total of 85 eyes were included, 8 of which had a macula-On/Off RD. On preoperative OCT, all macula-On/Off RD eyes had foveal detachment extending beyond the foveal center over a median distance of 632 µm. Mean VA of the macula-On/Off eyes had improved from 20/160 to 20/40 at 1 year postoperatively (p = 0.035). The preoperative VA of macula-On/Off eyes was significantly better than macula-Off eyes (p = 0.032) and lower than macula-On eyes (p = 0.004). At 1 year, the VA of macula-On/Off eyes was no different from that of the macula-On eyes (p = 0.320), and tended to be better than that of the macula-Off eyes (p = 0.062). CONCLUSION: Preoperative OCT revealed a shallow RD extending beyond the foveal center in eyes with clinical foveal-splitting RD. These eyes, termed macula-On/Off RD eyes, had a preoperative VA between macula-On and macula-Off eyes, while their final VA was close to those with macula-On RD.

Risk factors for hydroxychloroquine retinopathy in systemic lupus erythematosus: a case-control study with hydroxychloroquine blood-level analysis.

OBJECTIVE: HCQ is an essential medication in SLE, proven to lengthen survival and reduce flares. Its use, however, is limited by its rare but severe ophthalmological complications. Here, we aimed to analyse factors associated with HCQ retinopathy including HCQ blood levels. METHODS: This case-control study compared SLE patients with and without HCQ retinopathy, defined by abnormal results for at least two of the following ophthalmological tests: automated visual fields, spectral-domain optical coherence tomography (SD-OCT), multifocal electroretinogram (mfERG) and fundus autofluorescence. We compared clinical and laboratory findings to assess risk factors for HCQ retinopathy. RESULTS: The study included 23 patients with confirmed retinopathy (cases) and 547 controls. In the univariate analysis, age (P < 0.001), height (P = 0.045), creatinine clearance (P < 0.001), haemoglobin concentration (P = 0.01), duration of HCQ intake, (P < 0.001), higher cumulative HCQ dose (P < 0.001) and geographical origin (West Indies and sub-Saharan Africa) (P = 0.007) were associated with the risk of retinopathy, while HCQ blood levels were not. In the multivariate analysis, only cumulative dose (P = 0.016), duration of intake (P = 0.039), creatinine clearance (P = 0.002) and geographical origin (P < 0.0001, odds ratio 8.7) remained significantly associated with retinopathy. CONCLUSION: SLE patients on HCQ should be closely monitored for retinopathy, especially those from the West Indies or sub-Saharan Africa, or with renal insufficiency, longer HCQ intake or a high cumulative dose. Although reducing the daily dose of HCQ in patients with persistently high HCQ blood levels seems logical, these concentrations were not associated with retinopathy in this study with controls adherent to treatment.

Mineralocorticoid antagonists in the treatment of central serous chorioetinopathy: Review of the pre-clinical and clinical evidence.

Central serous chorioretinopathy (CSCR) is part of the pachychoroid spectrum disorders, characterized by serous retinal detachments, retinal pigment epithelium alterations and dilation of choroidal vessels. No consensus exists regarding the clinical classification and the physiopathogenic mechanisms of the disease, delaying the comprehension of the most optimal treatment options. An overactivation of the mineralocorticoid receptor (MR) pathway in the choroid/retina has been suggested in CSCR. Since, MR antagonists could target the affected RPE/choroid in CSCR and have shown to act as disease modifier drugs inducing tissue remodeling in other organs (heart, kidney, vessels), we summarize here the pre-clinical and clinical evidence for using oral mineralocorticoid receptor antagonist in the treatment of CSCR.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF FLAT IRREGULAR PIGMENT EPITHELIUM DETACHMENT IN CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To assess the rate of choroidal neovascularization (CNV) detected by optical coherence tomography angiography (OCTA) in flat irregular pigment epithelium detachment (PED) in chronic central serous chorioretinopathy. METHODS: Data on all consecutive patients with chronic central serous chorioretinopathy who underwent OCTA over a 1-year period were reviewed. The presence of flat irregular PED, which was defined as an irregular elevation of the retinal pigment epithelium allowing the visualization of a distinct Bruch's membrane was assessed on high-resolution OCT B-scan. Clinical, multimodal imaging, and OCTA data were reviewed by two graders for the detection of CNV. RESULTS: Eighty-eight eyes of 61 patients with chronic central serous chorioretinopathy were included. Patient mean age (±SD) was 54.5 ± 12.2 years, and 78.7% were males. Mean subfoveal choroidal thickness (±SD) was 452.6 ± 145.6 µm. Flat irregular PEDs were detected in 59 eyes of 51 patients. OCTA detected the presence of CNV in flat irregular PEDs in 35.6% of cases. Conversely, using the combination of spectral domain optical coherence tomography angiography, fluorescein and indocyanine green angiography, CNV was detected in only 25% of flat irregular PEDs. All hyporeflective flat irregular PEDs on OCT were avascular on OCTA while they were at least partially hyperreflective when associated with CNV. CONCLUSION: One-third of flat irregular PEDs in chronic central serous chorioretinopathy contained CNV. OCTA detected CNV more frequently than the other imaging modalities. Further longitudinal studies are needed to assess the indication of antivascular endothelial growth factor treatments in such cases.

Choroidal Imaging with Swept-Source Optical Coherence Tomography in Patients with Birdshot Chorioretinopathy: Choroidal Reflectivity and Thickness.

PURPOSE: To characterize choroidal thickness and choroidal reflectivity in the eyes of patients with birdshot chorioretinopathy (BSCR). DESIGN: Cross-sectional observational study. PARTICIPANTS: Two hundred twenty BSCR patients and 59 healthy controls. METHODS: Patients with BSCR and healthy controls underwent imaging of the macula in both eyes with a swept-source optical coherence tomography device (DRI-OCT1 Atlantis; Topcon). Images were exported from the device, and analysis was performed by 2 graders in the Doheny Image Reading Center using Image J software. The choroidal thickness at the foveal center was measured. In addition, the inner and outer boundaries of the choroid and retinal pigment epithelium (RPE) as well as the inner retinal surface all were segmented to allow the brightness and reflectivity of the pixels in the choroid, RPE band, and overlying vitreous to be quantified. An adjusted or normalized choroidal reflectivity, with the RPE as the bright reference standard and the vitreous as the dark reference standard, was computed using the formula: normalized choroidal reflectivity = (choroidal reflectivity-vitreous reflectivity)/RPE reflectivity. MAIN OUTCOME MEASURES: Choroidal reflectivity and choroidal thickness. RESULTS: Three hundred eighty-six eyes in the BSCR group and 59 eyes in the control group were included in this analysis. Higher choroidal reflectivity and lower choroidal thickness were documented in inactive BSCR patients compared with active BSCR and controls (P < 0.01). Active BSCR patients showed lower choroidal thickness compared with controls (P < 0.01). There was a negative correlation between choroidal reflectivity and choroidal thickness (r = -0.793; P < 0.001). On multiple regression analysis, choroidal thickness, age, and disease duration (all P < 0.01) all were significant predictors of choroidal reflectivity. CONCLUSIONS: Choroidal reflectivity and choroidal thickness changes are evident in active and inactive BSCR patients. Novel choroidal parameters such as choroidal reflectivity may warrant further study in the setting of BSCR.

Choroidal mast cells in retinal pathology: a potential target for intervention.

Mast cells are important in the initiation of ocular inflammation, but the consequences of mast cell degranulation on ocular pathology remain uncharacterized. We induced mast cell degranulation by local subconjunctival injection of compound 48/80. Initial degranulation of mast cells was observed in the choroid 15 minutes after the injection and increased up to 3 hours after injection. Clinical signs of anterior segment inflammation paralleled mast cell degranulation. With the use of optical coherence tomography, dilation of choroidal vessels and serous retinal detachments (SRDs) were observed and confirmed by histology. Subconjunctival injection of disodium cromoglycate significantly reduced the rate of SRDs, demonstrating the involvement of mast cell degranulation in posterior segment disorders. The infiltration of polymorphonuclear and macrophage cells was associated with increased ocular media concentrations of tumor necrosis factor-α, CXCL1, IL-6, IL-5, chemokine ligand 2, and IL-1ß. Analysis of the amounts of vascular endothelial growth factor and IL-18 showed an opposite evolution of vascular endothelial growth factor compared with IL-18 concentrations, suggesting that they regulate each other's production. These findings suggest that the local degranulation of ocular mast cells provoked acute ocular inflammation, dilation, increased vascular permeability of choroidal vessels, and SRDs. The involvement of mast cells in retinal diseases should be further investigated. The pharmacologic inhibition of mast cell degranulation may be a potential target for intervention.

CORRELATION BETWEEN CYSTOID SPACES IN CHRONIC DIABETIC MACULAR EDEMA AND CAPILLARY NONPERFUSION DETECTED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To study the relationship between the location of cystoid spaces and retinal capillary nonperfusion areas in diabetic cystoid macular edema (DCME). METHODS: In this retrospective study, 24 eyes of 21 patients with chronic DCME were followed using optical coherence tomography angiography. The capillary density of the superficial capillary plexus and deep capillary plexus was measured using AngioAnalytics software in all DCME eyes and in 20 healthy controls. Diabetic cystoid macular edema improved spontaneously or after treatment in 11 eyes. RESULTS: The intraretinal cystoid spaces were surrounded by capillary-flow void areas in the superficial capillary plexus in 71% of cases and in the deep capillary plexus in 96% of cases. The deep capillary plexus had lost its regular pattern in all cases. The capillary density was decreased in both plexus (mean decrease of -23.0% in the superficial capillary plexus and -12.4% in the deep capillary plexus vs. normal). In the 11 cases with DCME resolution, the capillary did not reperfuse in areas of resolved cystoid spaces, and the capillary density did not change significantly. CONCLUSION: In chronic DCME, cystoid spaces were located within capillary dropout areas. No reperfusion occurred after DCME resolution. The impact of the severity of this nonperfusion on the risk of recurrence of DCME remains to be clarified.

PACHYCHOROID: an inherited condition?

PURPOSE: Thick choroid (pachychoroid) is associated with central serous chorioretinopathy (CSC), but whether pachychoroid is inherited is unknown. METHODS: In a prospective observational study, first- or second-degree relatives (16 individuals) of 5 patients with CSC had refraction and visual acuity measurement, fundus examination, nonmydriatic photography, and autofluorescence photography. Eyes were graded using the following criteria: 0: normal fundus and autofluorescence photography, 1: focal retinal pigment epithelium hyperfluorescence and/or hypofluorescence and/or retinal pigment epithelial detachment, 2: CSC or diffuse retinal epitheliopathy. Choroid thickness was measured by enhanced depth imaging mode on optical coherence tomography. RESULTS: Considering 395 µm as the threshold limit for normal subfoveal choroidal thickness, 50% of the eyes from relatives had a thick choroid. Nine eyes of Grade 0 (28%) with an isolated pachychoroid would thus have been considered normal, if choroidal thickness was not included as a screening sign predisposing for CSC. CONCLUSION: Our observation suggests that pachychoroid could be an inherited condition with potentially a dominant transmission mode. Its inclusion in the phenotype of CSC for genetic studies should be considered.

SPIRONOLACTONE FOR NONRESOLVING CENTRAL SEROUS CHORIORETINOPATHY: A RANDOMIZED CONTROLLED CROSSOVER STUDY.

PURPOSE: To evaluate the effect of spironolactone, a mineralocorticoid receptor antagonist, for nonresolving central serous chorioretinopathy. METHODS: This is a prospective, randomized, double-blinded, placebo-controlled crossover study. Sixteen eyes of 16 patients with central serous chorioretinopathy and persistent subretinal fluid (SRF) for at least 3 months were enrolled. Patients were randomized to receive either spironolactone 50 mg or placebo once a day for 30 days, followed by a washout period of 1 week and then crossed over to either placebo or spironolactone for another 30 days. The primary outcome measure was the changes from baseline in SRF thickness at the apex of the serous retinal detachment. Secondary outcomes included subfoveal choroidal thickness and the ETDRS best-corrected visual acuity. RESULTS: The mean duration of central serous chorioretinopathy before enrollment in study eyes was 10 ± 16.9 months. Crossover data analysis showed a statistically significant reduction in SRF in spironolactone treated eyes as compared with the same eyes under placebo (P = 0.04). Secondary analysis on the first period (Day 0-Day 30) showed a significant reduction in subfoveal choroidal thickness in treated eyes as compared with placebo (P = 0.02). No significant changes were observed in the best-corrected visual acuity. There were no complications related to treatment observed. CONCLUSION: In eyes with persistent SRF due to central serous chorioretinopathy, spironolactone significantly reduced both the SRF and the subfoveal choroidal thickness as compared with placebo.

Anti-vascular endothelial growth factor acts on retinal microglia/macrophage activation in a rat model of ocular inflammation.

PURPOSE: To evaluate whether anti-vascular endothelial growth factor (VEGF) neutralizing antibodies injected in the vitreous of rat eyes influence retinal microglia and macrophage activation. To dissociate the effect of anti-VEGF on microglia and macrophages subsequent to its antiangiogenic effect, we chose a model of acute intraocular inflammation. METHODS: Lewis rats were challenged with systemic lipopolysaccharide (LPS) injection and concomitantly received 5 µl of rat anti-VEGF-neutralizing antibody (1.5 mg/ml) in the vitreous. Rat immunoglobulin G (IgG) isotype was used as the control. The effect of anti-VEGF was evaluated at 24 and 48 h clinically (uveitis scores), biologically (cytokine multiplex analysis in ocular media), and histologically (inflammatory cell counts on eye sections). Microglia and macrophages were immunodetected with ionized calcium-binding adaptor molecule 1 (IBA1) staining and counted based on their differential shapes (round amoeboid or ramified dendritiform) on sections and flatmounted retinas using confocal imaging and automatic quantification. Activation of microglia was also evaluated with inducible nitric oxide synthase (iNOS) and IBA1 coimmunostaining. Coimmunolocalization of VEGF receptor 1 and 2 (VEGF-R1 and R2) with IBA1 was performed on eye sections with or without anti-VEGF treatment. RESULTS: Neutralizing rat anti-VEGF antibodies significantly decreased ocular VEGF levels but did not decrease the endotoxin-induced uveitis (EIU) clinical score or the number of infiltrating cells and cytokines in ocular media (interleukin [IL]-1ß, IL-6, tumor necrosis factor [TNF]-α, and monocyte chemoattractant protein [MCP]-1). Eyes treated with anti-VEGF showed a significantly decreased number of activated microglia and macrophages in the retina and the choroid and decreased iNOS-positive microglia. IBA1-positive cells expressed VEGF-R1 and R2 in the inflamed retina. CONCLUSIONS: Microglia and macrophages expressed VEGF receptors, and intravitreous anti-VEGF influenced the microglia and macrophage activation state. Taking into account that anti-VEGF drugs are repeatedly injected in the vitreous of patients with retinal diseases, part of their effects could result from unsuspected modulation of the microglia activation state. This should be further studied in other ocular pathogenic conditions and human pathology.

Cystoid macular edema as a complication of central retinal artery occlusion.

Purpose: To describe the development of cystoid macular edema (CME) as a complication of central retinal artery occlusion (CRAO) in 2 cases. Observations: The first patient was a 51-year-old female who presented with acute loss of vision in the left eye. Multimodal retinal imaging revealed a CRAO with a perfused cilioretinal artery. CME acutely developed one week after presentation. Cystoid spaces predominantly involved the outer nuclear layer (ONL) on optical coherence tomography (OCT) and completely resolved in two weeks. The second case was a 50-year-old man who presented with acute vision loss in the right eye for 3 weeks. Multimodal retinal imaging illustrated an acute CRAO of the right eye. Four weeks later, visual acuity spontaneously improved to 20/20 and was maintained at 20/20 for more than 2 years. After 28 months, the patient returned with a recurrent drop of vision in the right eye. Cross sectional and en face OCT revealed CME in the right eye without leakage on FA. Cystoid spaces predominantly involved the inner nuclear layer (INL) and resolved with intravitreal anti-VEGF injection combined with carbonic anhydrase inhibitor (CAI) and steroid topical drop therapy. Conclusions and Importance: CME can rarely complicate both the acute and chronic phase of CRAO. In the acute phase, cystoid spaces were transient and confined to the ONL on OCT. While in the chronic phase, cystoid spaces were confined to the INL on OCT and angiographically silent on FA. Further studies are needed to identify the incidence, underlying pathophysiology and visual prognosis of CME in cases of CRAO.