Avascular Zone Research Articles

Retinal microvascular phenotypes can track small vessel disease burden and CPAP treatment effectiveness in obstructive sleep apnoea.

Optical coherence tomography angiography (OCT-A) retinal imaging enables in vivo visualization of the retinal microvasculature that is developmentally related to the brain and can offer insight on cerebrovascular health. We investigated retinal phenotypes and neuroimaging markers of small vessel disease (SVD) in individuals with obstructive sleep apnoea (OSA). We enrolled 44 participants (mean age 50.1 ± SD 9.1 years) and performed OCT-A imaging before and after continuous positive airway pressure (CPAP) therapy. Pre-treatment analyses using a generalized estimating equations model adjusted for relevant covariates, revealed perivascular spaces (PVS) volume in basal ganglia associated with greater foveal vessel density (fVD) (p-value < 0.001), and smaller foveal avascular zone area (p-value = 0.01), whereas PVS count in centrum semiovale associated with lower retinal vessel radius (p-value = 0.02) and higher vessel tortuosity (p-value = 0.01). A reduction in retinal vessel radius was also observed with increased OSA severity (p-value = 0.05). Post-treatment analyses showed greater CPAP usage was associated with a decrease in fVD (p-value = 0.02), and increased retinal vessel radius (p-value = 0.01). The findings demonstrate for the first time the potential use of OCT-A to monitor CPAP treatment and its possible impact on both retinal and brain vascular health.

The effects of topical latanoprost 0.005% treatment on microvascular changes in the optic nerve head and macula.

This prospective study aimed to assess the impact of topical latanoprost 0.005% treatment on the microvasculature of the macula and optic nerve head (ONH) in primary open-angle glaucoma (POAG). Fifty-seven eyes of 31 subjects were enrolled. ONH whole-image (wiVD), peripapillary (ppVD), and macular vascular density (VD) parameters were measured using optical coherence tomography angiography before treatment, at the 1st month, and at the 3rd month of treatment. There was a significant reduction in IOP post treatment, with a decrease of 17.0 ± 2.3 mmHg in the 1st month and 16.3 ± 2.5 mmHg in the 3rd month (P < 0.001 for both). ONH wiVD and ppVD significantly increased at the post-treatment 1st month (P = 0.001 for both) but decreased by the 3rd month, returning to baseline levels (P < 0.001 for both), indicating a return to pre-treatment levels (P > 0.05 for both). Similarly, macular wiVD and perifoveolar VD (pefVD) increased significantly at the 1st month (P = 0.013 and P < 0.001, respectively) but returned to baseline by the 3rd month (P < 0.001 for both). No significant difference was observed between before-treatment and post-treatment 3rd month regarding the macular wiVD and pefVD (P > 0.05 for both). Deep capillary plexus and foveal avascular zone parameters did not change during follow-up (P > 0.05 for both). The initial increase in ONH and peripapillary VD, as well as macular VD, is attributed to the acute reduction in IOP from topical latanoprost 0.005%. However, the diminishment of sustained differences by the 3rd month indicates adaptation of the ONH and retinal microvasculature to decreased IOP through compensatory mechanisms.

Quantitative detection of macular microvascular abnormalities identified by optical coherence tomography angiography in different hematological diseases

It is now understood that hematological diseases can have detrimental effects on the retina, reducing retinal capillaries, compromising visual function, and potentially causing irreversible visual impairment. Over the years, there has been limited research on macular microvascular abnormalities, such as changes in vessel density and the foveal avascular zone (FAZ) and variations in the severity of these effects across different types of blood disorders. This study aims to quantitatively assess the impact of various hematological disorders on the retina using optical coherence tomography angiography (OCTA). Compared with healthy eyes, patients with different blood diseases exhibited reductions in linear vessel density (LVD), perfusion vessel density (PVD), FAZ area, and FAZ perimeter. Notably, patients with erythrocyte diseases showed more significant abnormalities in LVD and PVD, while patients with lymphocytic diseases demonstrated more pronounced abnormalities in the FAZ area and perimeter. OCTA imaging could potentially reflect changes of the retinal microvascular of patients with hematological diseases and may serve as a valuable tool for distinguishing abnormalities affecting different blood cell lines. This approach offers a novel avenue for assessing, treating, and monitoring blood disorders.

Impact of retinal traction induced by epiretinal membrane on aniseikonia

We investigated the effect of retinal traction caused by epiretinal membranes (ERMs) on aniseikonia and retinal microstructures in 81 unilateral ERMs. Retinal traction was quantified by measuring the maximum depth of the retinal fold (MDRF) using en face optical coherence tomography (OCT) images. Measurements included the mean inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), central retinal thickness (CRT), and interocular ratios of the foveal avascular zone (FAZ) area (FAZ ratio). Significant correlations were found between the preoperative MDRF and preoperative aniseikonia (P < 0.001), INL thickness (P < 0.001), CRT (P < 0.001), and FAZ ratio (P = 0.003). Preoperative aniseikonia was significantly correlated with preoperative INL and OPL-ONL thicknesses (P < 0.001 and P = 0.020, respectively) and CRT (P = 0.003). Multiple regression analysis revealed that preoperative aniseikonia was significantly associated with preoperative MDRF, INL, and OPL-ONL thicknesses (P = 0.029, 0.006, and 0.006, respectively). Twenty-nine eyes underwent membrane peeling, resolving all retinal folds 6 months postoperatively. A significant correlation was observed between preoperative MDRF and postoperative aniseikonia (P = 0.011). Our findings suggest that retinal traction by ERM is significantly associated with aniseikonia both pre- and postoperatively, alongside other OCT parameters.

Macular Changes in Adults with History of Premature Birth.

To characterize changes in macular structure and vascularity seen in premature-birth adults. Retrospective review of adult patients seen in our clinic from July 2018 to November 2020 with history of premature birth not requiring treatment for retinopathy of prematurity (ROP), as well as healthy controls. Swept-source OCT-angiography (OCT-A) scans were analyzed for various parameters related to macular structure and vascularity. Statistical analysis was performed using univariate linear regression. Thirty-four eyes were included (17 eyes from 10 premature-birth adults, 17 eyes from 11 control patients). Prematurity was associated with vascular changes on OCT-A: decreased foveal avascular zone (FAZ) area (p=0.001), decreased FAZ circularity index (p<0.001), decreased superficial capillary plexus vessel (CPV) density (p=0.02), and decreased deep CPV density (p<0.001). Prematurity was also associated with structural changes: shallower foveal pit depth (p<0.001), decreased cube average thickness (CAT) (p=0.005), and increased central subfield thickness-to-CAT ratio (p=0.002). This is the largest published series of OCT-A data for premature-birth adults. Even without a history of ROP treatment, premature birth is associated with multiple changes to macular structure and vascularity that persist into adulthood. These include a smaller, more irregularly shaped FAZ, decreased juxtafoveal vascular density, and a shallower foveal pit.

The relationship between ON-OFF function and OCT structural and angiographic parameters in early diabetic retinal disease.

This study measured associations between ON and OFF functional indicators and structural optical coherence tomography (OCT) and OCT angiography (OCTA) markers in diabetic retinal disease. Fifty-four participants with type 1 or type 2 diabetes (mean age = 34.1 years; range 18-60) and 48 age-matched controls (mean age = 35.4 years, range 18-59) underwent visual psychophysical testing, OCT and OCTA retinal imaging. Psychophysical tasks measuring (A) contrast increment and decrement sensitivity and (B) response times to increment and decrement targets were assessed as surrogate measures of ON and OFF retinal ganglion cell function. The group with diabetes had worse foveal contrast increment and decrement thresholds (p = 0.04) and were slower to search for increment and decrement targets relative to controls (p = 0.009). Individuals with diabetes had a less circular foveal avascular zone (FAZ) (p < 0.001) but did not differ from controls in foveal vessel density and FAZ area. Functional and structural outcome measures related to the peripheral retina were also comparable between those with and without diabetes. Functional responses to increments and decrements were not significantly correlated with FAZ circularity or vessel density in individuals with diabetes. Diabetic retinal disease results in impaired performance on measures of inferred ON and OFF pathway function in addition to vascular deficits measurable with OCTA. Future longitudinal studies may determine the temporal relationship between these deficits, and whether they predict future diabetic retinopathy.

Alterations in optical coherence tomography angiography parameters after cataract surgery in patients with diabetes

This prospective study aimed to investigate microvascular changes in diabetic patients undergoing cataract surgery. Foveal avascular zone (FAZ) area, as well as vessel density (VD) in the macula and radial peripapillary capillary plexus (RPC), were compared before and after surgery. Sixty eyes (72.3%) had no diabetic retinopathy (no DR group) and 23 eyes (27.7%) had non-proliferative diabetic retinopathy (DR group). In the no DR group, the FAZ area in the superficial capillary plexus (SCP) decreased from 0.41 ± 0.13 to 0.38 ± 0.11 mm2 (P = 0.036), while no significant change was observed in the DR group (0.33 ± 0.12 to 0.30 ± 0.12 mm2, P = 0.091) at 6 months postoperatively. VD in the RPC increased from 34.4 ± 2.3% to 35.6 ± 2.3% in the no DR group (P = 0.009), but there was no significant change in the DR group (33.0 ± 3.5% vs. 34.0 ± 2.3%, P = 0.051) after 6 months. VD in the macula did not change in either group. Phacoemulsification reduced the FAZ area in the SCP and increased the VD in the RPC in diabetic patients without diabetic retinopathy at six months postoperatively.

Severity Stratification of Coronary Artery Disease Using Novel Inner Ellipse-Based Foveal Avascular Zone Biomarkers.

Given the similarities between the retinal and coronary microvasculature, the retina holds promising potential to serve as a non-invasive screening tool for coronary artery disease (CAD). We aimed to develop novel inner ellipse-based metrics and discern whether foveal avascular zone (FAZ) alterations can serve as indicators for CAD presence and severity. Patients admitted to the Department of Cardiology who underwent coronary angiography were included. This resulted in an inclusion of 212 patients, of which 73 had no CAD. During the same visit, 6 × 6-mm (nominal size) fovea-centered optical coherence tomography angiography images of both eyes were acquired. The Gensini score (GS) was utilized to quantify CAD severity. Six known FAZ shape metrics were assessed and three novel biomarkers based on the inner ellipse were defined: absolute inner ellipse difference, Hausdorff distance, and Chamfer distance. Eight out of nine metrics showed significant associations with the GS in the left eye. However, significant differences across three CAD severity groups were only demonstrated by the novel metrics. Utilizing the Chamfer distance, age, and sex, patients with and without CAD could be distinguished with an average area under the curve (AUC) of 0.89 (95% confidence interval [CI], 0.84-0.95). Moreover, three CAD severity groups could be discerned with a macro average AUC of 0.77 (95% CI, 0.72-0.84). A comprehensive assessment of FAZ shape descriptors was performed, and a strong association with CAD was found. The inner ellipse-based biomarkers especially demonstrated high predictive abilities for CAD presence and severity.

Evaluation of the early effects of the first-dose administration of the Sinovac vaccine on the retina, choroid, and optic disc using optical coherence tomography (OCT) and OCT-angiography

Aim To determine the effects of the first-dose administration of the Sinovac vaccine on the retina, choroid, and optic disc in healthy participants. Methods This prospective design study was conducted with 27 healthy healthcare workers who received the first dose of Sinovac vaccine and 25 healthy controls who were not vaccinated. In the vaccinated group, ophthalmological examinations and measurements were performed before vaccination and one week and one month after vaccination. Subfoveal, nasal, and temporal choroidal thicknesses (CTs), retinal nerve fiber layer (RNFL) thickness, and macular thickness (MT) were determined using spectral domain-optical coherence tomography at all visits. Superficial, deep, and peripapillary radial capillary plexus (superficial capillary plexus, deep capillary plexus (DCP), and radial peripapillary capillary, respectively), choriocapillaris vascular density, and foveal avascular zone parameters were measured on optical coherence tomography-angiography (OCT-A). Results No significant difference was detected between the two groups in terms of the parameters measured by OCT and OCT-A (p > 0.05 for all). The CT values measured in all quadrants were significantly higher at the first week after vaccination (p < 0.05 for all), and they returned to their pre-vaccination values at the first month post-vaccination measurement (p > 0.05 for all). Concerning the RNFL and MT values, there was no significant difference between the pre-vaccination and post-vaccination first-week measurements (p > 0.05 for all), but a statistically significant increase was detected in the post-vaccination first-month MT and RNFL measurements (p < 0.05 for all). Only the decreases in the foveal DCP and choriocapillaris vascular density values were significant at the first week after vaccination (p < 0.05 for all). Conclusion The early changes detected after vaccination in this study suggest the possibility that autoimmune, vascular, and inflammatory diseases may simultaneously emerge in the early post-vaccination period or may be triggered after vaccination, or that the vaccine may unmask these diseases.

Subtyping stage 3 epiretinal membrane: a comprehensive study of ectopic inner foveal layers architecture and its clinical implications

AimsTo evaluate the visual function and foveal architecture in patients with stage 3 idiopathic epiretinal membrane (iERM).MethodsA cross-sectional observational study included 56 eyes of 52 patients with stage 3 iERM....

Predictive value of optical coherence tomography angiography in management of diabetic macular edema

BackgroundOptical coherence tomography angiography (OCTA) is a relatively new extension of Optical coherence tomography (OCT) that generates non-invasive, depth-resolved images of the retinal microvasculature which allows for the detection of various features of diabetic retinopathy.ObjectivesThis study aimed to detect biomarkers that may predict an early anatomical response to the treatment of diabetic macular edema (DME) with intravitreal ranibizumab (IVR) by means of OCTA.Patients and methodsThis prospective interventional study was undertaken on 111 eyes of 102 naïve participants who had diabetic macular edema; enrolled patients were evaluated by taking a complete ophthalmologic history, examination and investigations by use of a pre-designed checklist involving Optical Coherence Tomography Angiography.ResultsRegarding the best corrected visual acuity (BCVA) the Mean ± SD was 0.704 ± 0.158 preoperatively and 0.305 ± 0.131 postoperatively in good responder patients; and was 0.661 ± 0.164 preoperatively and 0.54 ± 0.178 postoperatively in poor responders. The central macular thickness (CMT) was 436.22 ± 54.66 μm preoperatively and 308.12 ± 33.09 μm postoperatively in good responder patients; and was 387.74 ± 44.05 μm preoperatively and 372.09 ± 52.86 μm postoperatively in poor responders. By comparing the pre injection size of the foveal avascular zone area (FAZ-A) in both groups, it found that the mean ± SD of FAZ-A was 0.297 ± 0.038 mm in good responder patients compared to 0.407 ± 0.05 mm in non-responder patients. The preoperative superficial capillary plexus (SCP) foveal vascular density (VD) was 24.02 ± 3.01% in good responder patients versus 17.89 ± 3.19% um in poor responders. The preoperative SCP parafoveal VD was 43.06 ± 2.67% in good responder patients versus 37.96 ± 1.82% um in poor responders. The preoperative deep capillary plexus (DCP) foveal VD was 30.58 ± 2.89% in good responder patients versus 25.45 ± 3.14% in poor responders. The preoperative DCP parafoveal VD was 45.66 ± 2.21% in good responder patients versus 43.26 ± 2.35% um in poor responders, this was statistically significant.ConclusionOCTA offers an accurate measurement for VD in the macula as well as the FAZ-A which could be used to predict an early anatomical response of anti-VEGF treatment in DME.

Evaluation of foveal avascular zone changes in patients with type 1 diabetes using optical coherence topography angiography

Aim To evaluate vascular changes in the foveal avascular zone in pediatric patients with type 1 diabetes by using optical coherence tomography angiography (OCTA). Patients and methods This cross-sectional study was performed in Benha University Hospital at Department of Ophthalmology. The patients were obtained from the Pediatric Endocrinology Clinic in Benha University Hospital. The study was conducted on 48 patients (96 eyes) divided into two groups: group A, 24 diabetic children with type 1 diabetes, group B, 24 healthy children of the same age and sex who met the inclusion criteria. The patients were collected from April 2022 to April 2023. The patients were photographed using the Optovue AngioVue OCTA System. Results Our results show that according to the foveal avascular zone it was slightly wider in type 1 diabetic cases with no clinically evident diabetes retinopathy (DR) than control. There were insignificant differences between the two groups as regards foveal density, but as regards foveal thickness, it was significantly lower in diabetic cases than in the control group. Conclusion We discovered that OCTA could consistently identify microvascular changes in the Deep and Superficial Capillary Plexus prior to the clinical indications’ onset of DR. In order to assess the OCTA potential for the screening of DR in children with T1DM, it is necessary to conduct numerous prospective studies.

Quantitative analysis of three-dimensional choroidal changes in coronary artery disease patients with swept-source optical coherence tomography angiography

PurposeTo quantitatively analyze three-dimensional (3D) choroidal changes in coronary artery disease (CAD) patients with swept-source optical coherence tomography angiography (SS-OCTA) based on a scan area of 12×12mm. Methods236 CAD patients and 78 controls were included after coronary angiography (CAG) evaluation in this prospective cross-sectional study. Choroidal and foveal avascular zone (FAZ) parameters were compared between the two groups. Choroidal morphological characteristics were also evaluated based on ETDRS quadrants. Receiver operating characteristics (ROC) curves were generated to determine the discriminative power of choroidal and FAZ parameters. Linear regression analysis was used to determine the relationships between Gensini score and choroidal parameters. ResultsChoroidal thickness (CT), choroidal vascular volume/ area (CVV/a), and choroidal stromal volume/ area (CSV/a) were significantly reduced in CAD patients, while 2D vascular density decreased only in 1-6mm, and no statistical difference in choroidal vascularity index (CVI) values was detected. The AUC values of choroidal parameters were greater in the inner-6mm area than the outer-6mm area, and good performance was found with a combination with FAZ parameters (AUC=0.77, P<0.001). For morphological analysis, both groups showed the greatest values in superior quadrant and the lowest in nasal quadrant. After controlling for confounding factors, Gensini score was negatively associated with CT (β=-0.35, P=0.003), CVV/a (β=-0.17, P=0.004), and CSV/a (β=-0.18, P=0.005). ConclusionThe SS-OCTA provided excellent visualization and quantification of the choroid and showed decreased choroidal thickness and volume in CAD patients, but the morphological features were unchanged. The severity of coronary artery stenosis was independently associated with choroidal changes.

Optical coherence tomography (OCT) and OCT Angiography in Stages 3 and 4 proliferative sickle cell retinopathy

PurposeTo investigate macular findings in Goldberg stages 3 and 4 proliferative sickle cell retinopathy (PSCR) using optical coherence tomography (OCT) and OCT Angiography MethodsA case-control study using retrospective OCT and OCTA data from PSCR eyes (cases) and prospective data from age and sex-matched normal (controls). OCTA data included vessel density (VD) in the superficial capillary vascular plexus (SCP) and deep capillary vascular plexus (DCP), foveal avascular zone (FAZ) characterization, including the shape (in the SCP & DCP), size (area covered), and perimeter. OCT data were whole, superior, and inferior hemi-retina thickness for the superficial and deep retina. ResultsThere were 38 OCT / OCTA scans of PSCR eyes of 21 SCD patients; ten eyes were excluded for not meeting inclusion criteria. We analyzed nineteen (19) patients (ten unilateral and 9 bilateral), 28 eyes, nine SS eyes (32%), and nineteen SC eyes (68%). The controls consisted of 29 eyes of 16 normal subjects (three unilateral and 13 bilateral). The commonest FAZ shape in PSCR was “irregular” in 14 eyes (50%), followed by “round” in 11 eyes (39.3%) versus controls, the commonest shape “round” in 18 eyes (62%), followed by “irregular” 9 eyes (31%) (p = 0.165). FAZ area and perimeter were larger in PSCR (p > 0.05). The deep and superficial VD was reduced in PSCR. The mean whole deep VD for cases was 48.9 ± 6.1 versus 52.9 ± 6.4 for controls (p = 0.019). Mean whole superficial VD for cases was 47.4 ± 5.5 versus 49.8 ± 3.4 for controls (p = 0.058).Retina thickness in the whole, superior and inferior hemi-retina, for superficial and deep retina, was higher in PSCR compared to controls (p < 0.05). Superficial whole thickness for cases and controls were 287.0 µm [IQR 35.3 µm] versus 273.0 µm [IQR 18 µm] respectively (p = 0.008). Deep whole thickness for cases and controls was 287.0 µm [IQR 35.25 µm] versus 273.0 µm [IQR 18 µm] (p = 0.008).VD was reduced in SS compared to SC eyes (deep whole VD: 50.28 ± 6.01 vs 46.78 ± 5.80) (p = 0.139). Retina thickness in SS was reduced relative to SC. Peripheral retinal laser photocoagulation did not affect VD, though it was associated with a thinner macula. ConclusionOCT/OCTA of stage 3 and 4 PSCR revealed reduced VD in the DCP and SCP. Despite the thin temporal retina in SCD, there is a thicker whole, superior, and inferior hemiretina in both the superficial and deep retina. An irregularly shaped FAZ is common, a reflection of abnormal microcapillary loss in the perifoveal area.

Longitudinal Assessment of Retinal Microvasculature in Preclinical Alzheimer's Disease.

To investigate if changes in vessel density (VD) and the foveal avascular zone (FAZ) occur in the preclinical phase of Alzheimer's disease (pAD) over time. Optical coherence tomography angiography (OCTA) was used to image VD and FAZ at baseline and for a follow-up period of 2years. Positron emission tomography (PET) was used to determine the amyloid beta (Aβ) status of participants. The VD and FAZ of 148 participants (54% female) were analyzed at baseline and follow-up (mean time between measurements, 2.24 ± 0.35years). The mean age of the participants was 68.3 ± 6.0years at baseline and 70.3 ± 5.9years at follow-up. Participants were divided into three groups: control group, participants who had negative Aβ status at both measurements (Aβ-, n = 116); converter group, participants who transitioned from negative to positive between baseline and follow-up (Aβ-+, n = 18); and participants who were consistently positive at both visits (Aβ++, n = 14). The VD of both Aβ+ groups demonstrated non-significant increases over time in both macula and optic nerve head (ONH) regions. The Aβ- group was found to be significantly higher in both ONH and macular regions. The VD of the Aβ++ group was significantly higher in the macula inner and outer rings compared to the Aβ-+ and Aβ- groups. No significant change was found in FAZ values over time. Alterations in VD seem to manifest already in pAD, exhibiting distinct variations between the ONH and macula. Further longitudinal studies with a longer follow-up design and known amyloid pathology should be undertaken to validate these observations.

Optical Coherence Tomography Angiography of Macular Microangiopathy in Children With Sickle Cell Disease.

In this study, we identified the presence of sickle cell maculopathy and determined correlations between hemolysis indicators and systemic and ocular manifestations in children with sickle cell disease (SCD). Thirty-three patients with SCD 5 to 18 years of age underwent optical coherence tomography angiography (OCTA) as part of a thorough eye examination. The hematological indices and clinical data (hemoglobin, fetal hemoglobin, mean corpuscular volume, and frequency of sickle cell-associated complications and therapy) were collected. The SCD group contained 33 patients (66 eyes), and the control group contained 36 healthy participants (72 eyes). The SCD group had significantly thinner parafoveal thickness ( P =0.041) and significantly smaller parafoveal volume ( P =0.041) than the controls. The SCD group had lower deep capillary plexus density than the controls ( P =0.029). The SCD group had significantly smaller flow areas than the controls ( P <0.001). The foveal avascular zone (FAZ) perimeter, foveal density, and FAZ area in the entire retina did not differ significantly between the groups ( P >0.05). The platelet level was negatively correlated with parafoveal and perifoveal thickness and density. OCTA detected early macular microvascular changes in children and adolescents with asymptomatic SCD.

Retinal vascular changes after Silicon Oil removal in the Eye with Rhegmatogenous Retinal detachment

BackgroundThis study aims to examine vessel density changes in the optic nerve and macula following silicone oil removal (SOR) surgery in eyes with rhegmatogenous retinal detachment (RRD) at different time points by Optical Coherence Tomography Angiography (OCTA) in compared to the contralateral eye.MethodsA total of 43 eyes from 43 patients with silicone oil in their eyes for 3–9 months underwent OCT-A using AngioVue and optic disc-associated vessel density (VD) and thickness, macular-associated VD and thickness, Foveal avascular zone (FAZ) area, FAZ perimeter (PERIM), Acircularity index (AI), vessel density within a 300 μm wide region of the FAZ were compared between eyes. OCTA scans were performed one week before SOR and one month and three months after SOR.ResultsThe mean age of participants was 52.8 years (SD = 15.85) and a median visual acuity was 0.8 (range: 0.5-1.0). Notably, male participants constituted 67.4% of the sample. The preoperative mean value BCVA (logMAR) of patients was 0.73, and 3 months post-oil removal was 0.7727. Regarding optic disc parameters, RNFL thickness and vessel density (VD) measurements Peripapillary, whole disc, inside disc, and Disc Angio (superior, Nasal, inferior, temporal) did not change.In analyzing macular thickness parameters, all of them (Whole and Fovea, parafoveal, and Perifovea) remained unchanged. Examining macular vessel density parameters revealed no significant changes across superficial and deep retinal layers. Finally, the comparison of the foveal avascular zone (FAZ) area and flow density (FD) parameters demonstrated consistent measurements with non-significant alterations observed in FAZ size (p = 0.6) and FD values (p = 0.49) over the monitored duration.ConclusionThere was no change in peripapillary VD and macular vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after silicone oil removal. FAZ and full retinal thickness remained stable 3 month after SOR. Clinical trial number: Not applicable.

Clinical Presentation and Treatment Outcomes of Adult-Onset Coats Disease

Purpose: To study the clinical profile, treatment, and outcomes of patients 35 years or older diagnosed with Coats disease. Methods: A cross-sectional observational hospital-based study was performed. Results: The study included 74 eyes diagnosed with adult-onset Coats disease. The mean age at presentation was 50 years (range, 35-75). Most patients were men (72.5%) and had a unilateral presentation (92.8%). The most common stage at presentation was 2A (extrafoveal exudation) (39.2%) followed by 2B (foveal exudation (33.7%). Optical coherence tomography was performed in 40 eyes; 32 eyes (80.0%) had intraretinal fluid (IRF), 31 eyes (77.5%) had hard exudates, and 22 eyes (55.0%) had a disorganized retinal inner layer. Fluorescein angiography was performed in 35 eyes and showed an irregular foveal avascular zone in 28 eyes (80.0%). Multiple leaking microaneurysms were seen in 32 eyes (91.4%), with extensive vascular abnormalities involving the macula (86%) and extramacular zones (91%). Treatment modalities comprised laser photoablation (43.4%), cryotherapy with or without laser application (5.7%), and intravitreal injections (49%), alone or in combination. At a mean follow-up of 28 months (range, 3-293), 23 eyes (39.6%) had anatomic resolution of subretinal fluid and/or IRF. No statistical improvement was found in the mean best-corrected visual acuity (VA) between preoperatively and postoperatively ( P &gt; .05). Conclusions: Patients with adult-onset Coats disease have a unilateral presentation with a less severe stage than patients with childhood-onset disease. Despite the good anatomic responses after treatment, the final VA remained unchanged.

Retinal microcirculation changes in prediabetic patients with short-term increased blood glucose using optical coherence tomography angiography.

Retinal microcirculation alterations are early indicators of diabetic microvascular complications. Optical coherence tomography angiography (OCTA) is a noninvasive method to assess these changes. This study analyzes changes in retinal microcirculation in prediabetic patients during short-term increases in blood glucose using OCTA. To investigate the changes in retinal microcirculation in prediabetic patients experiencing short-term increases in blood glucose levels using OCTA. Fifty volunteers were divided into three groups: Group 1 [impaired fasting glucose (IFG) or impaired glucose tolerance (IGT)], Group 2 (both IFG and IGT), and a control group. Retinal microcirculation parameters, including vessel density (VD), perfusion density (PD), and foveal avascular zone (FAZ) metrics, were measured using OCTA. Correlations between these parameters and blood glucose levels were analyzed in both the fasting and postprandial states. One hour after glucose intake, the central VD (P = 0.023), central PD (P = 0.026), and parafoveal PD (P < 0.001) were significantly greater in the control group than in the fasting group. In Group 1, parafoveal PD (P < 0.001) and FAZ circularity (P = 0.023) also increased one hour after glucose intake. However, no significant changes were observed in the retinal microcirculation parameters of Group 2 before or after glucose intake (P > 0.05). Compared with the control group, Group 1 had a larger FAZ area (P = 0.032) and perimeter (P = 0.018), whereas Group 2 had no significant differences in retinal microcirculation parameters compared with the control group (P > 0.05). Compared with Group 1, Group 2 had greater central VD (P = 0.013) and PD (P = 0.008) and a smaller FAZ area (P = 0.012) and perimeter (P = 0.010). One hour after glucose intake, Group 1 had a larger FAZ area (P = 0.044) and perimeter (P = 0.038) than did the control group, whereas Group 2 showed no significant differences in retinal microcirculation parameters compared with the control group (P > 0.05). Group 2 had greater central VD (P = 0.042) and PD (P = 0.022) and a smaller FAZ area (P = 0.015) and perimeter (P = 0.016) than Group 1. At fasting, central PD was significantly positively correlated with blood glucose levels (P = 0.044), whereas no significant correlations were found between blood glucose levels and OCTA parameters one hour after glucose intake. A short-term increase in blood glucose has a more pronounced effect on retinal microcirculation in prediabetic patients with either IFG or IGT.

Optical coherence tomography angiography analysis of the fellow eye in unilateral pseudoexfoliation syndrome

PurposeTo compare the macular and optic disc vascular parameters in the unaffected fellow eyes of subjects with unilateral pseudoexfoliation syndrome (PXS) and controls using optical coherence tomography angiography (OCTA).MethodsThe medical records of 61 eyes of 61 patients were analyzed in a retrospective study. Of these, 30 eyes were unaffected fellow eyes and 31 eyes were control eyes. The vessel density (VD), perfusion density (PD) and foveal avascular zone (FAZ)-related parameters of the superficial capillary plexus (SCP) in the circumpapillary and macular area and the VD and PD of the deep capillary plexus (DCP) in the macular area were measured using OCTA after dilatation and were compared between two groups after adjustment for age, sex and axial length.ResultsThere were no statistically significant differences in sex ratio or mean age, central corneal thickness measurements, refractive errors, intraocular pressures and axial length between both groups (all P > 0.05). In the circumpapillary area, inferior VD and PD in the inner zone, as well as average, temporal, inferior, and nasal VD and PD in the outer zone were significantly reduced in the unaffected fellow eyes with unilateral PXS, while the circumpapillary retinal nerve fiber layer (RNFL) thicknesses were similar between groups. In the macular SCP, VDs were significantly lower in all sectors in the inner area and in the outer zones (p < 0.05 for all), PDs were significantly lower in all sectors (p < 0.05 for all) except the nasal sector of the outer zone (p = 0.003 for average, p = 0.029 for superior sector, p = 0.004 for temporal sector, p < 0.001 for inferior sector), and the FAZ circularity (p = 0.037) were significantly lower in the unaffected fellow eyes with unilateral PXS, whereas macular ganglion cell inner plexiform layer (GCIPL) thickness was similar between the two groups.ConclusionsAlthough circumpapillary RNFL and GCIPL thicknesses were similar between the two groups, VDs and PDs in the circumpapillary and macular SCP and FAZ circularity were significantly lower in the fellow eye of subjects with unilateral PXS.