Associations of quantitative contrast sensitivity with vascular metrics on widefield swept-source OCT angiography across stages of diabetic retinopathy.

PURPOSE: To investigate structure-function associations between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics across stages of non-proliferative (NPDR) and proliferative diabetic retinopathy (PDR), without diabetic macular oedema. METHODS: Prospective cross-sectional study in 140 eyes of 99 patients: 33 mild NPDR, 24 moderate/severe NPDR, 15 PDR, 33 diabetic without DR (DMnoDR) and 46 control eyes. Mixed-effects multivariable regression models to evaluate associations between quantitative contrast sensitivity function (Adaptive Sensory Technology) and vessel density (VD) and vessel skeletonised density (VSD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) on same-day imaging with WF SS-OCTA (Plex Elite 9000, Carl Zeiss Meditec). RESULTS: Standardised ß coefficients for area under the logarithm of contrast sensitivity function curve (AULCSF) versus visual acuity (VA) at 3×3 mm scans: SCP VSD (ß=0.32, p<0.001 vs -0.18, p=0.044), DCP VSD (ß=0.30, p<0.001 vs -0.21, p=0.02), SCP VD (ß=0.25, p=0.004 vs -0.13, p=0.129), DCP VD (ß=0.26, p=0.003 vs -0.19, p=0.034). AULCSF was significantly reduced in mild NPDR (ß=-0.28, p<0.001) and DMnoDR (ß=-0.19, p=0.005) versus controls, while VA was not significantly different. AULCSF performed better than VA in differentiating between controls and DMnoDR (0.69 vs 0.50), controls and mild NPDR (0.76 vs 0.61) and controls and moderate/severe NPDR (0.89 vs 0.73). CONCLUSIONS: DR-induced microvascular changes on OCTA are associated with larger changes on CS than in VA. CS is affected earlier than VA in the course of DR and performed better in discriminating between controls, DMnoDR and across DR stages.

Widefield, Swept-Source Optical Coherence Tomography Angiography Metrics as Predictors of Anti-VEGF Treatment in Retinal Vein Occlusions.

BACKGROUND AND OBJECTIVE: Our objective was to assess baseline widefield swept-source optical coherence tomography angiography (WF SSOCTA) microvascular metrics as predictors for the number of anti-vascular endothelial growth factor (VEGF) injections and visual acuity (VA) at 12-months follow-up in patients with retinal vein occlusion (RVO). PATIENTS AND METHODS: This was a prospective study including 49 RVO eyes from 49 patients who had not received an anti-VEGF injection for at least 3 months prior to imaging. Microvascular metrics from 6×6-mm and 12×12-mm angiograms were assessed using linear regression models, adjusting for age. RESULTS: Reductions in the vessel density (VD) and vessel skeletonized density (VSD) vascular metrics were associated both with a higher number of anti-VEGF injections at all follow-up time points and reduced VA 12 months after imaging in all RVO eyes. CONCLUSIONS: WF SS-OCTA VD and VSD micro-vascular metrics at baseline can prognosticate VA and number of anti-VEGF injections required at 3, 6, and 12 months in RVO eyes. [Ophthalmic Surg Lasers Imaging Retina 2024;55:xx-xx.].

Early recurrence of macular schisis in X-linked retinoschisis treated with vitrectomy for rhegmatogenous retinal detachment under silicone oil: case report and brief literature review.

X-linked retinoschisis (XLRS) is an inherited retinal degeneration affecting males, characterized by splitting of the retinal layers. We herein present the outcomes of surgical treatment in a case of XLRS complicated by rhegmatogenous retinal detachment (RRD). A 22-year-old male presented to the emergency department due to decreased visual acuity and visual field defect in his left eye Oculus Sinister (OS) of 1 week duration. The patient reported an early onset retinal degeneration and decreased visual acuity in both eyes since childhood in his past ocular history. Upon presentation, best corrected visual acuity (BCVA) was 6/30 on the right eye Oculus Dexter (OD) and 6/120 OS. Fundus examination revealed areas of peripheral retinal schisis, and the characteristic spoke wheel pattern on the macula of both eyes. In OS, a temporal RRD involving the macula was identified. The patient underwent surgical treatment with pars plana vitrectomy with internal limiting membrane (ILM) peeling, endolaser, and silicone oil (SO) tamponade. BCVA in OS improved to 6/60 and schistic cavities resolution was observed in the immediate postoperative period. The patient's BCVA further improved to 6/19 at 1 month, as foveal anatomy showed relative improvement. However, there was a rapid reappearance of schisis spaces in the macular area at this point, which was also followed by progressive deterioration of foveal schisis by 3 months post-operatively. The resorption and recurrence of lamellar macular schisis changes after ILM peel and presence of SO, highlights that although XLRS findings can temporarily improve upon surgical intervention, the pathogenetic mechanisms contributing to disease phenotype remain to be elucidated.

Quantitative Contrast Sensitivity Function and the Effect of Aging in Healthy Adult Eyes: A Normative Database.

BACKGROUND AND OBJECTIVE: We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF. PATIENTS AND METHODS: Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated. RESULTS: A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1.18; contrast acuity: 1.32; contrast sensitivity (CS) at 1 cycle per degree (cpd): 1.32; CS at 1.5 cpd: 1.37; CS at 3 cpd: 1.38; CS at 6 cpd: 1.20; CS at 12 cpd: 0.69; CS at 18 cpd: 0.22. Linear reductions in qCSF values per decade of age ranged from -0.02 to -0.07 vs 0.01 for visual acuity (VA). Age had a greater effect on the majority of qCSF values than VA (beta standardized regression coefficient ranged from -0.309 to -0.141 for qCSF values vs 0.177 for VA). CONCLUSIONS: We herein establish a normative database for qCSF and quantify the effect of age on qCSF values, adding evidence towards the validation of qCSF as a clinical endpoint. [Ophthalmic Surg Lasers Imaging Retina 2024;55:212-219.].

Feasibility demonstration of a device for vitreous liquid biopsy incidental to intravitreal injection.

PURPOSE: VitreoDx is an experimental device enabling push-button collection of a neat vitreous liquid biopsy incidental to an intravitreal injection. We explored the ability of the device to collect a sample usable for proteomic biomarker discovery and testing. DESIGN: Pilot study using ex vivo human eyes. METHODS: Non-vitrectomized, human eyes from nine donors 75-91 years of age were refrigerated in BSS and used within 5 days of death. Four VitreoDx devices fitted with 25G needles, and four staked needle insulin syringes with 30G needles, were inserted at equal intervals through the pars plana of each eye and held in place by a fixture. The sampling mode of each VitreoDx device was triggered to attempt to acquire a liquid biopsy up to 70 µL. The plunger of each insulin syringe was retracted to attempt to obtain a liquid biopsy with a maximum volume of 50 µL. Samples acquired with the VitreoDx were extracted to polypropylene cryovials, refrigerated to -80 ºC, and sent for offsite proteomic analysis by proximity extension assay with a focus on panels containing approved and pipelined drug targets for neovascular disease and inflammatory factors. RESULTS: Of the attempted liquid biopsies with the novel 25G VitreoDx, 92% (66 of 72) resulted in successful acquisition (>25 µL) while 89% (64 of 72) attempted by a traditional 30G needle resulted in a successful acquisition. Sample volume sufficient for proteomics array analysis was acquired by the VitreoDx for every eye. Detectable protein was found for 151 of 166 unique proteins assayed in at least 25% of eyes sampled by VitreoDx. CONCLUSIONS: The high acquisition rate achieved by the prototype was similar to that achieved in previous clinical studies where a standard syringe was used with a 25G needle to biopsy vitreous fluid directly prior to standard intravitreal injection. Successful aspiration rates were likewise high for 30G needles. Together, these suggest that it is possible to routinely acquire liquid vitreous biopsies from patients who typically receive intravitreal injections with an injection device using a standard size needle without a vitreous cutter. Protein analysis shows that proteins of interest survive the sampling mechanism and may have potential to direct care in the future.

Effects of newer-generation anti-diabetics on diabetic retinopathy: a critical review.

Diabetic retinopathy (DR) is the leading etiology of blindness in the working population of the USA. Its long-term management relies on effective glycemic control. Seven anti-diabetic classes have been introduced for patients with type 2 diabetes (T2D) in the past two decades, with different glucose-lowering and cardiovascular benefits. Yet, their effects specifically on DR have not been studied in detail. A systematic review of the literature was conducted to investigate this topic, focusing on the available clinical data for T2D. Published studies were evaluated based on their level of statistical evidence, as long as they incorporated at least one endpoint or adverse event pertaining to retinal health. Fifty nine articles met our inclusion criteria and were grouped per anti-diabetic class as follows: alpha-glucosidase inhibitors (1), peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists (8), amylin analogs (1), glucagon-like peptide-1 (GLP-1) receptor agonists (28), dipeptidyl peptidase 4 (DPP-4) inhibitors (9), and sodium glucose co-transporter-2 (SGLT-2) inhibitors (9), plus one retrospective study and two meta-analyses evaluating more than one of the aforementioned anti-diabetic categories. We also reviewed publicly-announced results of trials for the recently-introduced class of twincretins. The available data indicates that most drugs in the newer anti-diabetic classes are neutral to DR progression; however, there are subclasses differences in specific drugs and T2D populations. In particular, there is evidence suggesting there may be worse diabetic macular edema with PPAR-gamma agonists, potential slight DR worsening with semaglutide (GLP-1 receptor agonist), and potential slight increase in the incidence of retinal vein occlusion in elderly and patients with advanced kidney disease receiving SGLT-2 inhibitors. All these warrant further investigation. Longer follow-up and systematic assessment of at least one DR-related endpoint are highly recommended for all future trials in the T2D field, to ultimately address this topic.

Associations of quantitative contrast sensitivity with wide-field swept-source optical coherence tomography angiography in retinal vein occlusion.

PURPOSE: To investigate associations between contrast sensitivity (CS) and vascular metrics on wide-field swept-source optical coherence tomography angiography (WF-SS-OCTA) in patients with retinal vein occlusion (RVO). METHODS: This prospectively recruited, cross-sectional observational study included RVO patients who underwent quantitative CS function (qCSF) testing and WF-SS-OCTA using 3 × 3, 6 × 6, and 12 × 12 mm angiograms on the same day. The study measured several qCSF outcomes and WF-SS-OCTA vascular metrics, including vessel density (VD), vessel skeletonized density (VSD), and foveal avascular zone (FAZ). The data were analyzed using multivariable regression analysis controlling for age and central subfield thickness (CST). RESULTS: A total of 43 RVO eyes of 43 patients and 30 fellow eyes were included. In RVO eyes, multiple vascular metrics were associated with CS outcomes but not visual acuity (VA). On 12 × 12 images, CS thresholds at 1 cpd, 1.5 cpd, and 3 cpd were significantly associated with VD and VSD, but VA was not. When comparing standardized regression coefficients, we found that vascular metrics had a larger effect size on CS than on VA. For instance, the standardized beta coefficient for FAZ area and CS at 6 cpd (ß* = - 0.46, p = 0.007) was larger than logMAR VA (ß* = 0.40, p = 0.011). CONCLUSION: Microvascular changes on WF-SS-OCTA in RVO had a larger effect size on CS than VA. This suggests CS may better reflect the microvascular changes of RVO compared to VA. qCSF-measured CS might be a valuable adjunct functional metric in evaluating RVO patients.

Peripheral monocytes and neutrophils promote photoreceptor cell death in an experimental retinal detachment model.

Photoreceptor cell death and immune cell infiltration are two major events that contribute to retinal degeneration. However, the relationship between these two events has not been well delineated, primarily because of an inadequate understanding of the immunological processes involved in photoreceptor degeneration, especially that of peripheral leukocytes that infiltrate the subretinal space and retinal tissues. In this work, we characterized the role of leukocyte infiltration within the detached retina. We observed that CD45+ CD11b+ Ly6G+ neutrophils and CD45+ CD11b+ Ly6G- Ly6C+ monocytes are the predominant peripheral immune cell populations that infiltrate the retinal and subretinal space after detachment. Selective depletion of monocytes or neutrophils using cell-specific targeting is neuroprotective for photoreceptors. These results indicate that peripheral innate immune cells contribute to photoreceptor degeneration, and targeting these immune cell populations could be therapeutic during retinal detachment.

Characterizing Macular Neovascularization in Myopic Macular Degeneration and Age-Related Macular Degeneration Using Swept Source OCTA.

Purpose: Visual prognosis and treatment burden for macular neovascularization (MNV) can differ between myopic macular degeneration (MMD) and age-related macular degeneration (AMD). We describe and compare MNV associated with MMD and AMD using swept-source (SS)-OCTA. Patients and Methods: Adult patients with documented MNV associated with MMD or AMD were consecutively recruited. Qualitative and quantitative features were assessed from 6x6mm angiograms, including the MNV area and vessel density (VD). Descriptive statistics and linear regression analyses were carried out. Results: Out of 75 enrolled eyes with diagnosed MNV (30 MMD-MNV and 45 AMD-MNV; mean age 55±19 and 75±8 years, respectively), 44 eyes had discernible MNV (11 MMD-MNV and 33 AMD-MNV) on SS-OCTA at the time of the study and were included in the analysis. The MMD-MNV group exhibited a three-fold smaller sized MNV (p=0.001), lower greatest linear dimension (p=0.009) and greatest vascular caliber (p<0.001) compared to AMD-MNVs, and had a higher prevalence of tree-in-bud pattern. Eyes with AMD showed a higher prevalence of type 1 MNVs with medusa pattern. There was no difference in the location of the MNV, shape's regularity, margins, presence of core vessel, capillary fringe, peripheral loops, or perilesional dark halo (p>0.05) between both conditions. After adjustment, decreased MNV area and increased VD were associated with the tree-in-bud pattern, whereas the diagnosis did not significantly influence those parameters. Conclusion: While larger studies are warranted, this study is the first to describe and compare MMD-MNV and AMD-MNV using SS-OCTA, providing relevant clinical insight on MNV secondary to MMD and AMD. These findings also further validate OCTA as a powerful tool to detect and characterize MNV non-invasively.

Comparative study of widefield swept-source optical coherence tomography angiography in eyes with concomitant age-related macular degeneration and diabetic retinopathy.

BACKGROUND/AIMS: We sought to evaluate widefield swept-source optical coherence tomography angiography (WF SS-OCTA) among eyes with concomitant age-related macular degeneration (AMD) and diabetes mellitus or diabetic retinopathy (DM/DR). METHODS: This cross-sectional, comparative study consisted of three study groups: eyes with (1) AMD and DM/DR, (2) AMD alone and (3) DM/DR alone. WF SS-OCTA (3×3, 6×6 and 12×12 mm) images were captured. Vascular metrics included foveal avascular zone (FAZ), vessel density (VD) and vessel skeletonised density (VSD). Mixed-effects multivariable regression models adjusted for age were performed by cohort and subgroup based on AMD and DR stages. RESULTS: Our cohort included 287 eyes from 186 patients with an average age of 64±14.0 years old. Results revealed significantly reduced vascular metrics in concomitant AMD and DM/DR eyes (N=68) compared with AMD-only eyes (N=71) on all angiograms but not compared with DM/DR-only eyes (N=148). For example, when compared with AMD-only eyes, AMD and DM/DR eyes had significantly reduced VD (ß=-0.03, p=0.016) and VSD (ß=-1.09, p=0.022) on 12×12 mm angiograms, increased FAZ perimeter (ß=0.51, p=0.025) and FAZ area (ß=0.11, p=0.015) on 6×6 mm angiogram, and reductions in all VD and VSD metrics on 3×3 and 6×6 mm angiograms. However, only 3×3 mm angiogram FAZ metrics were significantly different when comparing DM/DR eyes with concomitant AMD and DM/DR eyes. CONCLUSION: WF SS-OCTA revealed significant reductions in retinal microvasculature metrics in AMD and DM/DR eyes compared with AMD-only eyes but not compared with DM/DR-only eyes.

CSF1R inhibition is not specific to innate immune cells but also affects T-helper cell differentiation independently of microglia depletion.

Colony-stimulating factor 1 receptor (CSF1R) inhibition has been proposed as a specific method for microglia depletion. However, recent work revealed that in addition to microglia, CSF1R inhibition also affects other innate immune cells, such as peripheral monocytes and tissue-resident macrophages of the lung, liver, spleen, and peritoneum. Here, we show that this effect is not restricted to innate immune cells only but extends to the adaptive immune compartment. CSF1R inhibition alters the transcriptional profile of bone marrow cells that control T helper cell activation. In vivo or ex vivo inhibition of CSF1R profoundly changes the transcriptional profile of CD4+ cells and suppresses Th1 and Th2 differentiation in directionally stimulated and unstimulated cells and independently of microglia depletion. Given that T cells also contribute in CNS pathology, these effects may have practical implications in the interpretation of relevant experimental data.

Impact of phacoemulsification on posterior vitreous detachment formation in eyes with vitreomacular traction.

Purpose: To investigate the impact of phacoemulsification on posterior vitreous detachment formation in eyes with vitreomacular traction (VMT) with or without macular holes. Methods: A retrospective search of the medical records was conducted to identify patients with VMT who underwent cataract surgery at Mass Eye and Ear from 2016 to 2021. Patient demographics, ocular comorbidities, and clinical characteristics were extracted from the record, and optical coherence tomography images were assessed to confirm VMT and the presence of a lamellar or full-thickness macular hole (FMTH). Patients who underwent vitrectomy prior to cataract surgery were excluded. Results: A total of 22 patients (15 women [68%]) met inclusion criteria (average age, 71 years). Fifteen eyes had an associated epiretinal membrane (63%), 7 had a lamellar hole (29%), and 8 had an FTMH (33%). Epiretinal membrane was present in 3 of 7 eyes with lamellar holes (43%) and 4 of 8 with a FTMH (50%). No eyes developed a complete posterior vitreous detachment following phacoemulsification. In 2 cases, there was progression of the macular hole stage following phacoemulsification. Ten eyes underwent subsequent pars plana vitrectomy (PPV). There was no statistically significant difference in visual acuity between eyes pre- and post-phacoemulsification; however, there was a statistically significant improvement in visual acuity pre- and post-PPV. Conclusions: Unlike other studies, in this case series of 24 eyes with VMT or VMT with holes, no cases of full posterior vitreous detachment occurred following unremarkable phacoemulsification or YAG capsulotomy.

Evolution of macular atrophy in eyes with neovascular age-related macular degeneration compared to fellow non-neovascular eyes.

PURPOSE: Τo evaluate the evolution of macular atrophy (MA) in patients with neovascular AMD (nAMD), compared with their fellow eyes exhibiting dry AMD (dAMD). METHODS: This retrospective study included 124 patients from three centers treated with anti-VEGF in their nAMD eye and having dAMD in the fellow eye. Patients without MA at baseline were analyzed to study the time to first MA development. Synchronous and unsynchronous time course of MA was also studied. MA was evaluated using near-infrared images, while all available optical coherence tomography (OCT) images were used to confirm the criteria proposed by the Classification of Atrophy Meetings group for complete MA. RESULTS: MA first detection in nAMD eyes increased significantly from year 2 to 6 compared to dAMD eyes. Over the study's follow-up, 45.1% of nAMD-E developed MA, compared to 16.5% of fellow eyes (p < 0.001). When MA in the two eyes was compared in a synchronous paired manner over 4 years, nAMD eyes had an average MA progression rate of 0.275 mm/year versus 0.110 mm/year in their fellow dAMD eyes. Multivariate ANOVA revealed significant time (p < 0.001), eye (p = 0.003), and time-eye interaction (p < 0.001) effects. However, when MA did develop in dAMD eyes and was compared in an asynchronous manner to MA of nAMD eyes, it was found to progress faster in dAMD eyes (dAMD: 0.295 mm/year vs. nAMD: 0.176 mm/year) with a significant time-eye interaction (p = 0.015). CONCLUSIONS: In this study, a significant difference in MA incidence and progression was documented in eyes with nAMD under treatment, compared to fellow eye exhibiting dAMD. Eyes with nAMD tended to develop more MA compared to fellow dAMD eyes. However, when atrophy did develop in the fellow dAMD eyes, it progressed faster over time compared to MA in nAMD eyes.

Opposing Roles of Blood-Borne Monocytes and Tissue-Resident Macrophages in Limbal Stem Cell Damage after Ocular Injury.

Limbal stem cell (LSC) deficiency is a frequent and severe complication after chemical injury to the eye. Previous studies have assumed this is mediated directly by the caustic agent. Here we show that LSC damage occurs through immune cell mediators, even without direct injury to LSCs. In particular, pH elevation in the anterior chamber (AC) causes acute uveal stress, the release of inflammatory cytokines at the basal limbal tissue, and subsequent LSC damage and death. Peripheral C-C chemokine receptor type 2 positive/CX3C motif chemokine receptor 1 negative (CCR2+ CX3CR1-) monocytes are the key mediators of LSC damage through the upregulation of tumor necrosis factor-alpha (TNF-α) at the limbus. In contrast to peripherally derived monocytes, CX3CR1+ CCR2- tissue-resident macrophages have a protective role, and their depletion prior to injury exacerbates LSC loss and increases LSC vulnerability to TNF-α-mediated apoptosis independently of CCR2+ cell infiltration into the tissue. Consistently, repopulation of the tissue by new resident macrophages not only restores the protective M2-like phenotype of macrophages but also suppresses LSC loss after exposure to inflammatory signals. These findings may have clinical implications in patients with LSC loss after chemical burns or due to other inflammatory conditions.

Sustained Inhibition of VEGF and TNF-α Achieves Multi-Ocular Protection and Prevents Formation of Blood Vessels after Severe Ocular Trauma.

PURPOSE: This study aimed to develop a clinically feasible and practical therapy for multi-ocular protection following ocular injury by using a thermosensitive drug delivery system (DDS) for sustained delivery of TNF-α and VEGF inhibitors to the eye. METHODS: A thermosensitive, biodegradable hydrogel DDS (PLGA-PEG-PLGA triblock polymer) loaded with 0.7 mg of adalimumab and 1.4 mg of aflibercept was injected subconjunctivally into Dutch-belted pigmented rabbits after corneal alkali injury. Control rabbits received 2 mg of IgG-loaded DDS or 1.4 mg of aflibercept-loaded DDS. Animals were followed for 3 months and assessed for tolerability and prevention of corneal neovascularization (NV), improvement of corneal re-epithelialization, inhibition of retinal ganglion cell (RGC) and optic nerve axon loss, and inhibition of immune cell infiltration into the cornea. Drug-release kinetics was assessed in vivo using an aqueous humor protein analysis. RESULTS: A single subconjunctival administration of dual anti-TNF-α/anti-VEGF DDS achieved a sustained 3-month delivery of antibodies to the anterior chamber, iris, ciliary body, and retina. Administration after corneal alkali burn suppressed CD45+ immune cell infiltration into the cornea, completely inhibited cornea NV for 3 months, accelerated corneal re-epithelialization and wound healing, and prevented RGC and optic nerve axon loss at 3 months. In contrast, anti-VEGF alone or IgG DDS treatment led to persistent corneal epithelial defect (combined: <1%; anti-VEGF: 15%; IgG: 10%, of cornea area), increased infiltration of CD45+ immune cells into the cornea (combined: 28 ± 20; anti-VEGF: 730 ± 178; anti-IgG: 360 ± 186, cells/section), and significant loss of RGCs (combined: 2.7%; anti-VEGF: 63%; IgG: 45%) and optic nerve axons at 3 months. The aqueous humor protein analysis showed first-order release kinetics without adverse effects at the injection site. CONCLUSIONS: Concomitant inhibition of TNF-α and VEGF prevents corneal neovascularization and ameliorates subsequent irreversible damage to the retina and optic nerve after severe ocular injury. A single subconjunctival administration of this therapy, using a biodegradable, slow-release thermosensitive DDS, achieved the sustained elution of therapeutic levels of antibodies to all ocular tissues for 3 months. This therapeutic approach has the potential to dramatically improve the outcomes of severe ocular injuries in patients and improve the therapeutic outcomes in patients with retinal vascular diseases.