The Cilioretinal Artery is Protective Against Choroidal Neovascularization in Age-Related Macular Degeneration

Importance: A hemodynamic role in the pathogenesis of age-related macular degeneration (AMD) has been proposed, but a relationship between retinal vasculature and late AMD has not been investigated. Objective: To determine if the presence and location of a cilioretinal artery may affect the risk of developing late AMD in the age-related eye disease study (AREDS). Design, Setting, and Participants: Retrospective analysis of prospective, randomized, clinical trial data from 3647 AREDS participants. Fundus photographs of AREDS participants were reviewed by two masked graders for the presence or absence of a cilioretinal artery, and if any branch extend within 500µm of the center of the macula. Multivariate regressions were used to determine the association of the cilioretinal artery and vessel location, adjusted for age, sex, and smoking status, with the prevalence of choroidal neovascularization (CNV) or central geographic atrophy (CGA), as well as AMD severity score, for eyes at randomization and progression at 5 years. Main Outcomes and Measures: Association of cilioretinal artery with prevalence of and progression to CNV or CGA. Results: Among AREDS participants, 26.9% of subjects had a cilioretinal artery in one eye, and 8.4% had the vessel bilaterally. At randomization, eyes with a cilioretinal artery had a lower prevalence of CNV (5.0% vs. 7.6%, OR 0.66, P=0.001), but no difference in CGA (1.1% vs 0.8%, OR 1.33, P=0.310). In eyes without late AMD, those with a cilioretinal artery also had a lower AMD severity score (3.00 ± 2.35 vs. 3.19 ± 2.40, P=0.019). At 5 years, eyes at risk with a cilioretinal artery had lower rates of progression to CNV (4.1% vs 5.5%, OR 0.75, P=0.050), but no difference in developing CGA (2.2% vs. 2.7%, OR 0.83, P=0.354) or change in AMD severity score (+0.65 ± 1.55 vs. +0.73 ± 1.70, P=0.112). In subjects with a unilateral cilioretinal artery, eyes with the vessel showed a lower prevalence of CNV than the fellow eyes (4.7% vs. 7.2%, P=0.012). Conclusions and Relevance: The presence of a cilioretinal artery may be protective against the development of CNV, but not CGA. This finding suggests a hemodynamic contribution to neovascular AMD pathogenesis

Analysis of the retinal capillary plexus layers in a murine model with diabetic retinopathy: effect of intravitreal injection of human CD34+ bone marrow stem cells.

BackgroundDiabetic retinopathy is a retinal vasculopathy involving all three retinal capillary plexus layers. Since human CD34+ bone marrow stem cells (BMSCs) have the potential to promote revascularization of ischemic tissue, this study tests the hypothesis that intravitreal injection of human CD34+ BMSCs can have protective effects on all layers of the retinal vasculature in eyes with diabetic retinopathy.MethodsStreptozotocin (STZ)-induced diabetic mice were injected intravitreally with 50,000 human CD34+ BMSCs or phosphate-buffered saline (PBS) into the right eye. Systemic immunosuppression with rapamycin and tacrolimus was started 5 days before the injection and maintained for study duration to prevent rejection of human cells. All mice were euthanized 4 weeks after intravitreal injection; both eyes were enucleated for retinal flat mount immunohistochemistry. The retinal vasculature was stained with Isolectin-GS-IB4. Confocal microscopy was used to image four circular areas of interest of retina, 1-mm diameter around the optic disc. Images of superficial, intermediate, and deep retinal capillary plexus layers within the areas of interest were obtained and analyzed using ImageJ software with the Vessel Analysis plugin to quantitate the retinal vascular density and vascular length density in the three plexus layers.ResultsThree distinct retinal capillary plexus layers were visualized and imaged using confocal microscopy. Eyes that received intravitreal injection of CD34+ BMSCs (N=9) had significantly higher vascular density and vascular length density in the superficial retinal capillary plexus when compared to the untreated contralateral eyes (N=9) or PBS treated control eyes (N=12; P values <0.05 using ANOVA followed by post-hoc tests). For the intermediate and deep plexus layers, the difference was not statistically significant.ConclusionsThe protective effect of intravitreal injection of the human CD34+ BMSCs on the superficial retinal capillary plexus layers is demonstrated using confocal microscopy in this murine model of diabetic retinopathy

Effects of intravitreal injection of human CD34+ bone marrow stem cells in a murine model of diabetic retinopathy.

Human CD34 + stem cells are mobilized from bone marrow to sites of tissue ischemia and play an important role in tissue revascularization. This study used a murine model to test the hypothesis that intravitreal injection of human CD34 + stem cells harvested from bone marrow (BMSCs) can have protective effects in eyes with diabetic retinopathy. Streptozotocin-induced diabetic mice (C57BL/6J) were used as a model for diabetic retinopathy. Subcutaneous implantation of Alzet pump, loaded with Tacrolimus and Rapamycin, 5 days prior to intravitreal injection provided continuous systemic immunosuppression for the study duration to avoid rejection of human cells. Human CD34 + BMSCs were harvested from the mononuclear cell fraction of bone marrow from a healthy donor using magnetic beads. The CD34 + cells were labeled with enhanced green fluorescent protein (EGFP) using a lentiviral vector. The right eye of each mouse received an intravitreal injection of 50,000 EGFP-labeled CD34 + BMSCs or phosphate buffered saline (PBS). Simultaneous multimodal in vivo retinal imaging system consisting of fluorescent scanning laser ophthalmoscopy (enabling fluorescein angiography), optical coherence tomography (OCT) and OCT angiography was used to confirm the development of diabetic retinopathy and study the in vivo migration of the EGFP-labeled CD34 + BMSCs in the vitreous and retina following intravitreal injection. After imaging, the mice were euthanized, and the eyes were removed for immunohistochemistry. In addition, microarray analysis of the retina and retinal flat mount analysis of retinal vasculature were performed. The development of retinal microvascular changes consistent with diabetic retinopathy was visualized using fluorescein angiography and OCT angiography between 5 and 6 months after induction of diabetes in all diabetic mice. These retinal microvascular changes include areas of capillary nonperfusion and late leakage of fluorescein dye. Multimodal in vivo imaging and immunohistochemistry identified EGFP-labeled cells in the superficial retina and along retinal vasculature at 1 and 4 weeks following intravitreal cell injection. Microarray analysis showed changes in expression of 162 murine retinal genes following intravitreal CD34 + BMSC injection when compared to PBS-injected control. The major molecular pathways affected by intravitreal CD34 + BMSC injection in the murine retina included pathways implicated in the pathogenesis of diabetic retinopathy including Toll-like receptor, MAP kinase, oxidative stress, cellular development, assembly and organization pathways. At 4 weeks following intravitreal injection, retinal flat mount analysis showed preservation of the retinal vasculature in eyes injected with CD34 + BMSCs when compared to PBS-injected control. The study findings support the hypothesis that intravitreal injection of human CD34 + BMSCs results in retinal homing and integration of these human cells with preservation of the retinal vasculature in murine eyes with diabetic retinopathy

Long-term natural history of idiopathic epiretinal membranes with good visual acuity.

Background/objectivesTo evaluate the long-term progression of idiopathic epiretinal membranes (iERMs) with good baseline visual acuity, and to identify predictors of visual decline.DesignRetrospective case series SUBJECTS METHODS: We reviewed records of 145 eyes with iERM and best-corrected visual acuity (BCVA) of 20/40 or greater at presentation, including BCVA, lens status, and central macular thickness (CMT) at yearly visits; as well as anatomic biomarkers including vitreomacular adhesion, pseudohole, lamellar hole, intraretinal cysts, disorganization of the inner retinal layers (DRIL), and disruption of outer retinal layers. Linear mixed effects and mixed-effects Cox proportional hazards models were used to identify clinical and anatomic predictors of vision change and time to surgery.ResultsAt presentation, mean BCVA was 0.17 ± 0.10 logMAR units (Snellen 20/30) and mean CMT was 353.3 ± 75.4 μm. After a median follow-up of 3.7 years (range 1-7 years), BCVA declined slowly at 0.012 ± 0.003 logMAR units/year, with phakic eyes declining more rapidly than pseudophakic eyes (0.019 ± 0.003 vs. 0.010 ± 0.004 logMAR units/year). Metamorphopsia, phakic lens status, lamellar hole, and inner nuclear layer cysts were associated with faster visual decline. Cumulative rates of progression to surgery were 2.9, 5.6, 12.2, and 21.1% at years 1-4. Visual symptoms, metamorphopsia, greater CMT, and disruption of outer retinal layers were associated with greater hazard for surgery.ConclusionEyes with iERM and visual acuity ≥ 20/40 experience slow visual decline, with 21% of eyes requiring surgery after 4 years. Clinical and anatomic predictors of vision loss may be distinct from factors associated with earlier surgical intervention

Intraoperative Retinal Changes May Predict Surgical Outcomes After Epiretinal Membrane Peeling.

PurposeTo investigate whether intraoperative retinal changes during epiretinal membrane (ERM) peeling affect anatomic or functional outcomes after surgery.MethodsWe measured retinal thickness using an intraoperative optical coherence tomography (iOCT) device in patients undergoing pars plana vitrectomy with membrane peeling for idiopathic ERM. Changes in intraoperative central macular thickness (iCMT) were compared with postoperative improvements in CMT and best-corrected visual acuity (VA).ResultsTwenty-seven eyes from 27 patients (mean age 68 years) underwent iOCT-assisted ERM peeling surgery. Before surgery, mean VA was logMAR 0.50 ± 0.36 (Snellen 20/63), and mean baseline CMT was 489 ± 82 µm. Mean iCMT before peeling was 477 ± 87 µm, which correlated well with preoperative CMT (P < 0.001). Mean change in iCMT was -39.6 ± 37 µm (range -116 to +77 µm). After surgery, VA improved to logMAR 0.40 ± 0.38 (Snellen 20/50) at month 1 and logMAR 0.27 ± 0.23 (Snellen 20/37) at month 3, whereas CMT decreased to 397 ± 44 µm and 396 ± 51 µm at months 1 and 3. Eyes that underwent greater amount of iCMT change (absolute value of iCMT change) were associated with greater CMT reduction at month 1 (P < 0.001) and month 3 (P = 0.010), whereas those with greater intraoperative thinning (actual iCMT change) showed a trend toward better VA outcomes at months 1 (P = 0.054) and 3 (P = 0.036).ConclusionsIntraoperative changes in retinal thickness may predict anatomic and visual outcomes after idiopathic ERM peeling surgery.Translational relevanceOur study suggests that intraoperative retinal tissue response to ERM peeling surgery measured by iOCT may be a prognostic indicator for restoration of retinal architecture and for visual acuity outcomes