This study aimed to explore differences in vascular and structural parameters using optical coherence tomography angiography in patients with type 1 diabetes (DM1) with mild signs of diabetic ...retinopathy (DR) over a two-year follow-up period. Parafoveal vessel density (PVD) and foveal avascular zone (FAZ) area were analyzed. The thickness of three predefined retinal slabs was measured, including the inner limiting membrane (ILM)-inner plexiform layer (IPL), IPL-inner nuclear layer (INL), and the IPL-outer nuclear layer (ONL). Twenty-two patients with DM1 and 21 controls were included. There was no significant difference in the FAZ area, perimeter and acircularity index between cohorts over time. Baseline superficial capillary plexus PVD was approximately 10% lower in patients with diabetes than in controls (p = 0.001), and was 12% lower at 2 years (p = 0.002). There was no difference in the annual linear trend between the groups (- 0.5% in diabetics vs. controls, p = 0.736). Baseline deep capillary plexus (DCP) PVD was slightly lower in diabetics than in controls (- 4.4%, p = 0.047) and the difference increased at 2 years (- 12.6%, p < 0.001). The annual linear trend was - 2.7% in diabetic patients compared to controls (p = 0.009)
In addition, the PVD of the DCP and the intermediate capillary plexus (ICP) were evaluated separately. Regarding the DCP PVD, no statistically significant difference at any time points in diabetic patients compared to controls and no statistically significant difference in the linear trend was found (p > 0.1). Conversely, no difference was recorded for parafoveal ICP density at individual time points (p > 0.1), but a statistically significant difference in the linear trend over time in diabetic patients compared to controls was recoded (- 3.2% per year, p = 0.001). Despite the apparent intergroup differences at baseline in structural OCT parameters, the differences including ILM-IPL (p = 0.273), IPL-INL (p = 0.708), and IPL-ONL (p = 0.054) were modest and not statistically significant with time. Therefore, the microvascular change of the deeper vessels might be a robust biomarker to evaluate the clinical progression of DR in DM1.
Aim
To investigate late changes in peripheral ischemia in patients affected by diabetic macular edema (DME) and treated with repeated dexamethasone (DEX) intravitreal implants over a 1-year period.
...Methods
In this retrospective cohort study, patients older than 18 years of age and with type 2 non-proliferative treatment-naïve diabetic retinopathy (DR) and DME at baseline were included. All patients were treated with two intravitreal DEX implants within 1 year of follow-up. A minimum of two annual ultra-widefield fluorescein angiography (UWF FA) were required to ensure that all cases had a baseline UWF FA (< 2 weeks before first treatment with dexamethasone) and a UWF FA performed at 12 months of follow-up. On baseline and 1-year UWFA images, peripheral retinal ischemia was quantified using the ischemic index (ISI).
Results
Six eyes of five patients (two males, three females) met the inclusion criteria and were enrolled in this study. Best-corrected visual acuity was 0.34 ± 0.22 LogMAR at baseline and improved to 0.21 ± 0.14 logMAR at the 1-year follow-up visit (
P
= 0.050). Mean ± SD central macular thickness was 467.6 ± 63.0 μm at baseline and 272.0 ± 14.7 μm at the 1-year follow-up visit (
P
= 0.043). Mean ± SD ISI was 26.7 ± 14.1% at baseline and reduced to 12.2 ± 5.0% at the 1-year follow-up visit (
P
= 0.012).
Conclusions
Improvement in retinal perfusion is still maintained 1 year after starting treatment with DEX implants. This improvement in retinal perfusion might be related to DEX implant-related positive effects on leukostasis.
This study evaluates if the addition of a curcumin formulation with a polyvinylpyrrolidone-hydrophilic carrier (CHC; Diabec
, Alfa Intes, Italy) to intravitreal injections of dexamethasone (DEX-IVT) ...can affect the morphological retinal characteristics, extending the steroid re-treatment period in patients with diabetic macular edema (DME).
A randomized controlled clinical trial was carried out in DME patients, randomly assigned to receive DEX-IVT or DEX-IVT and a CHC. The evaluation of the mean difference of central retinal thickness (CRT) was the primary aim. Secondary aims were the evaluations of best-corrected visual acuity, differences in the predetermined retinal layer thickness, the number/time of re-treatment, and the assessment of safety.
A total of 73 DME patients were included (35 in the control group and 38 in the combined therapy group). In both the control and combined therapy groups, the mean CRT change from T
to the 6 months' evaluation was significant (
= 0.00). The mean CRT result was significantly different at month 4 (
= 0.01) between the control and combined therapy groups, with a greater reduction in the combined therapy group, in particular, in patients with ≤10 years of diabetes. A trend of CRT reduction in the combined therapy group has been observed also considering patients with subfoveal neuroretinal detachment. In addition, we observed that the reduction of inner retinal layer thickness was greater in the combination group, in comparison with controls.
The combination of a CHC to DEX-IVT is a promising therapeutic option in case of DME, in particular, for patients with early-stage diabetes and with an inflammatory phenotype. Further studies will be necessary to confirm these findings.
The aim of this study was to evaluate and compare the effects of photodynamic therapy (PDT) in eyes with subfoveal and juxtafoveal choroidal neovascularization (CNV) secondary to pathological myopia. ...The study was a single-center, 10-year analysis on 19 eyes. Patients underwent best-corrected visual acuity (BCVA) measurement, slit-lamp examination, ophthalmoscopy and fluorescein angiography. Eyes with subfoveal CNV (7 eyes, 37%) progressively worsened during the 10-year follow-up from 0.68 ± 0.26 to 0.80 ± 0.47 logMAR, while in the eyes with juxtafoveal CNV (12 eyes, 63%) BCVA improved from 0.59 ± 0.42 to 0.33 ± 0.27 logMAR. Prevalence and extension of chorioretinal atrophy (CRA) were greater in eyes with subfoveal compared with juxtafoveal CNV (84 vs. 66%, respectively) and enlargement (10.05 ± 6.7 vs. 3.53 ± 4.7 mm(2), respectively). Our results confirm the limited long-term effectiveness of PDT in myopic subfoveal CNV. Satisfactory results can be achieved in juxtafoveal CNV with a better visual outcome and a minor CRA extension.
To explore the retinal and choroidal thicknesses (RT, CT), as measured using enhanced depth imaging (EDI) optical coherence tomography (OCT, Spectralis) in highly myopic eyes and its relationship ...with visual function.
Prospective, case-control, noninterventional clinical study. CT was measured by EDI-OCT in highly myopic eyes (≥6 dpt) without any macular diseases and age-matched control eyes. A complete ophthalmological examination, visual acuity assessment and MP1 microperimetry were obtained.
38 myopic (15 M/23 F, mean age 51 ± 8.9 years) and 21 control eyes (5 M/16 F, mean age 50 ± 5.4 years) were included. The myopic mean refractive error was -13.3 ± 4.9 dpt and axial length 29.2 ± 2.2 mm. The mean best-corrected visual acuity (BCVA) was lower in highly myopic than in control eyes (77.3 ± 9.25 vs. 84.8 ± 0.6 letters, p = 0.0001, respectively) as was the mean retinal sensitivity (MRS; 16.32 ± 2.6 vs. 19.9 ± 0.2 dB, p < 0.0001). While RT was similar between groups (291.5 ± 24.2 vs. 283.6 ± 13.9 µm, p = 0.06, respectively), subfoveal CT was thinner in highly myopic compared to control eyes (114.3 ± 78.5 vs. 272.6 ± 110.2 µm, p < 0.0001). A significant relationship was found between subfoveal CT and MRS (R(2) = 0.22; p = 0.003) and BCVA (R(2) = 0.13; p = 0.027).
Macular function is reduced in highly myopic eyes without any visible macular diseases compared to controls, and a significant proportion of the macular function variability seems to be related to a reduced CT.
Purpose
Diabetic retinopathy (DR) can lead to significant vision loss and blindness and has a particularly high prevalence in patients with type 1 diabetes (DM1). In this study, we investigate ...quantitative differences in optical coherence tomography angiography (OCTA) data between DM1 patients with no or mild signs of retinopathy and non‐diabetic subjects.
Methods
Optical coherence tomography angiography (OCTA) imaging was performed on DM1 patients with no or mild nonproliferative diabetic retinopathy and healthy, age‐matched controls. Parafoveal vessel density and foveal avascular zone (FAZ) area in the deep capillary plexus (DCP) and superficial capillary plexus (SCP) were calculated with automated quantification software and compared between patient cohorts.
Results
A significant decrease in parafoveal vessel density was seen in the DCP of DM1 patients compared to non‐diabetic controls (57.0 ± 3.3% versus 60.7 ± 2.4%, p < 0.001). There was no significant difference in SCP parafoveal vessel density, DCP FAZ area, or SCP FAZ area between cohorts.
Conclusion
M1 patients with no or mild signs of retinopathy have reduced parafoveal vessel density in the DCP on OCTA when compared to non‐diabetic controls. These OCTA findings suggest that parafoveal capillary nonperfusion is an early process in DM1‐related retinal changes and occurs initially at the level of the DCP. Further investigation is needed to understand the prognostic role of these vascular changes.
To assess demographic, metabolic, and imaging predictors influencing microvasculature and photoreceptors changes over a 4-year follow-up in type 1 diabetes mellitus (DM1).
This prospective cohort ...study enrolled patients with DM1 with mild non-proliferative diabetic retinopathy. Complete medical records, glycosylated hemoglobin (HbA1c), optical coherence tomography angiography, and adaptive optics were collected for the 4 years of follow-up. The main outcome measures included perfusion density at the superficial capillary plexus (SCP) and deep capillary plexus (DCP), choriocapillaris (CC) flow deficits (FDs, %), cone density, linear dispersion index (LDi), and heterogeneity packing index (HPi).
The SCP presented a dichotomic perfusion trend, with increasing PD at 1 and 2 years and a subsequent decline (P < 0.001). DCP presented a similar trend in the first 2 years (P < 0.01) but not at the following time points, whereas CC FDs constantly increased over time (P < 0.01). The best-fitted model for the microvascular parameters demonstrated that the main factors affecting SCP included time (P < 0.001), duration of diabetes (P = 0.007), and HbA1c (P = 0.03), whereas the DCP was influenced by LDi modifications (P = 0.006). The LDi and HPi were mainly influenced by SCP and CC perfusion in the parafovea (P = 0.02).
This study demonstrated an initial vasodilatory phenomenon resulting from a compensatory mechanism from the superficial vasculature, followed by capillary dropout. Initially, it would seem that there was an adaptive response by the DCP to the needs of the photoreceptors. Although the SCP may initially support the DCP, when the microvascular damage becomes diffuse and involves the SCP and CC it directly affects photoreceptor integrity.
To assess the impact of histogram adjustments and binarization thresholding selection on quantitative measurements of diabetic macular ischemia using optical coherence tomography angiography (OCTA).
...Patients with diabetic retinopathy (DR) who had swept-source OCTA imaging obtained were enrolled. An additional group of 15 healthy control subjects was included for comparison. Previously used brightness/contrast changes and binarization thresholds were applied to original OCTA images to obtain and compare different binarized images. Qualitative and quantitative comparisons were performed.
Thirty patients with DR (30 eyes) were included in the analysis. Fifteen eyes displayed the presence of diabetic macular edema. Qualitative grading revealed that binarized images obtained using a global threshold had better quality compared with local or multistep thresholds. The "median" filter was most frequently graded as the histogram adjustment resulting in binarized images with best quality. In the quantitative analysis, local thresholds tended to generate higher values of measured metrics. Differences in OCTA metrics between global and local thresholds were associated with presence of diabetic macular edema and signal strength index value. In the comparison between healthy and DR eyes, differences in OCTA metrics were significantly affected by binarization threshold selection.
Quantitative OCTA parameters may be significantly influenced by strategies to quantify macular perfusion. Image quality and presence of macular edema can significantly impact OCTA-derived quantitative vascular measurements and differences between global and local binarization thresholds. These findings highlight the importance of consistent strategies to reliably generate quantitative OCTA metrics in patients with DR.
Purpose:
To evaluate the agreement between fluorescein angiography and structural optical coherence tomography in diagnosing and monitoring the activity of myopic choroidal neovascularization and to ...provide a comparative analysis with optical coherence tomography angiography.
Methods:
Thirteen patients with active myopic choroidal neovascularization were prospectively enrolled. At the baseline, 2-month, and 6-month visits, each patient underwent a complete ophthalmological examination, including best-corrected visual acuity assessment, fundus examination, fluorescein angiography, and optical coherence tomography with structural and angiographic assessment. Sensitivity and specificity for all optical coherence tomography parameters were evaluated taking fluorescein angiography as the reference examination.
Results:
At the baseline, fluorescein angiography confirmed myopic choroidal neovascularization leakage in all patients. Structural optical coherence tomography demonstrated intraretinal or subretinal fluid in 61% of cases, fuzzy borders and absence of external limiting membrane visibility in 84% of cases, and subretinal hyperreflective exudation in 53% of cases. Sensitivity to the presence of retinal fluid and subretinal hyperreflective exudation was lower than sensitivity to fuzzy borders and external limiting membrane visibility, which reached 84%. During ranibizumab therapy, external limiting membrane visibility showed a higher sensitivity (100%) compared with fuzzy borders and subretinal hyperreflective exudation (66.6%) while displaying an equal specificity of 100%. At baseline and final visit, sensitivity increased to 100% when all structural optical coherence tomography parameters were pooled. Optical coherence tomography angiography detected myopic choroidal neovascularization at baseline, 2-month, and 6-month visits in 92%, 76%, and 76% of cases, respectively.
Conclusion:
The study confirms that the new indicators of myopic choroidal neovascularization activity are more reliable than the presence or absence of retinal fluid. Optical coherence tomography angiography identified myopic choroidal neovascularization in most patients in the diagnostic phase and during treatment monitoring and could be considered as an alternative to fluorescein angiography in selected patients.
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