To compare fundus fluorescein angiography (FFA) and swept-source optical coherence tomography angiography (SS-OCTA) in the evaluation of macular perfusion in diabetic patients.
Forty-one eyes (21 ...diabetic patients) seen at Moorfields Eye Hospital (London) over a 1-month interval underwent color fundus photography, FFA, and SS-OCTA imaging of the capillary superficial plexus using 2 different protocols: 3 × 3 mm and 4.5 × 4.5 mm. Quantitative assessment (foveal avascular zone diameters and area), qualitative analysis (macroscopic and microscopic levels) and Early Treatment Diabetic Retinopathy Study diabetic macular ischemia grading were performed. Artifacts were recorded. Intraclass correlation coefficients and weighted kappa values were calculated.
Mean (SD) foveal avascular zone area was 0.695 (0.52) mm on FFA, 0.627 (0.54) mm on SS-OCTA 3 × 3 and 0.701 (0.54) mm on SS-OCTA 4.5 × 4.5 protocol. Intraclass correlation coefficients showed good agreement between FFA and SS-OCTA for both vertical diameter and foveal avascular zone area measurements. The agreement between SS-OCTA 3 × 3 and 4.5 × 4.5 was good for all quantitative measurements. Weighted kappa for diabetic macular ischemia grading showed low to fair agreement between FFA and SS-OCTA, whereas the agreement was good between two different SS-OCTA protocols.
Swept-source OCTA is a reproducible technique in the assessment of macular perfusion in diabetic patients with special regards to foveal avascular zone analysis. The agreement with FFA is limited especially for diabetic macular ischemia grading. Fundus fluorescein angiography is more sensitive in identifying microaneurysms.
To determine the test-retest variability of the retinal sensitivity of the Nidek MP1 microperimeter in patients with macular disease.
In this prospective study, 50 patients were enrolled with a range ...of macular diseases. One examiner performed two consecutive microperimetry tests for all patients using the same test strategy. Test-retest variability for mean sensitivity (MS), mean deviation (MD), point-wise sensitivity (PWS), local defect classification (LDC), average sensitivity for the central macula (CMS, 16 loci inside 10 degrees ), paracentral macular sensitivity (PMS, 52 loci in the 10 to 20 degrees ring), and dense scotoma size (DSS) were analyzed by calculating the 95% coefficients of repeatability or percentage agreement.
Mean (SD) age and visual acuity were 61 (15) years and 0.34 (0.32) logMAR, respectively. The mean difference in MS between tests 1 and 2 was +0.2 dB (SD, 0.9 dB; P = 0.127). The coefficients of repeatability for MS, MD, CMS, and PMS were 1.81, 2.56, 2.13, and 1.93 dB, respectively. The mean (SD) of coefficients of repeatability for PWS across all 68 loci was 5.56 (0.86) dB. Of all test loci in all patients 76% had perfect agreement in LDC, and 94% of patients had a change in DSS of four or fewer test loci.
Test-retest variability was lowest for MS and highest for PWS. However, MS does not provide spatial information. The authors recommend the use of CMS and PMS for monitoring macular function and consider a change of greater than 2.56 and 2.31 dB (the upper limit of the 95% confidence interval of their coefficients of repeatability), respectively, to exceed test-retest variability.
To perform qualitative and quantitative analyses of retinal and choroidal morphology in patients with punctate inner choroidopathy (PIC) using enhanced depth imaging optical coherence tomography ...(EDI-OCT).
Cross-sectional, consecutive series.
A total of 2242 patients attending 2 tertiary referral uveitis clinics at Moorfields Eye Hospital were screened; 46 patients with PIC diagnosis were identified, and 35 eyes (35 patients) had clinically inactive PIC had EDI-OCT images that met the inclusion criteria.
Punctate inner choroidopathy lesions were qualitatively assessed for retinal features, such as (1) focal elevation of the retinal pigment epithelium (RPE), (2) focal atrophy of the outer retina/RPE, and (3) presence of sub-RPE hyperreflective deposits and choroidal features: (a) presence of focal hyperreflective dots in the inner choroid and (b) focal thinning of the choroid adjacent to PIC lesions. Quantitative analyses of the retina, choroid, and choroidal sublayers were performed, and associations with clinical and demographic data were examined.
Prevalence of each lesion pattern and thickness of retinal and choroidal layers.
A total of 90 discrete PIC lesions were captured; 46.6% of PIC lesions consisted of focal atrophy of the outer retina and RPE; 34.4% consisted of sub-RPE hyperreflective deposits; and 18.8% consisted of localized RPE elevation with underlying hyporeflective space. Focal hyperreflective dots were seen in the inner choroid of 68.5% of patients, with 17.1% of eyes presenting focal choroidal thinning underlying PIC lesions. By excluding high myopes, patients with "atypical" PIC had reduced retinal thickness compared with patients with "typical" PIC (246.65±30.2 vs. 270.05±24.6 μm; P = 0.04), and greater disease duration was associated with decreases in retinal thickness (r = -0.53; P = 0.01). A significant correlation was observed between best-corrected visual acuity and foveal retinal thickness (r = -0.40; P = 0.03).
In a large series of patients with clinically inactive PIC, one fifth of the lesions analyzed revealed RPE elevation with underlying hyporeflective space, described before as a sign of activity and suggesting subclinical inflammation. Retinal thickness seems to be associated with disease type and duration of disease in non-highly myopic eyes. Improved visualization of the inner choroid using EDI-OCT may allow noninvasive assessment of inflammatory status.
To obtain measurements of vitreous signal intensity from optical coherence tomography (OCT) image sets in patients with uveitis, with the aim of developing an objective, quantitative marker of ...inflammatory activity in patients with this disease.
Retrospective, observational case-control series.
Thirty patients (30 eyes) with vitreous haze secondary to intermediate, posterior, or panuveitis; 12 patients (12 eyes) with uveitis but without evidence of vitreous haze; and 18 patients (18 eyes) without intraocular inflammation or vitreoretinal disease.
Clinical and demographic characteristics were recorded, including visual acuity (VA), diagnosis, and anatomic type of uveitis. In each eye, the anterior chamber (AC) was graded for cellular activity and flare according to standardized protocols. The presence and severity of vitreous haze were classified according to the National Eye Institute system. Spectral-domain OCT images were analyzed using custom software. This software provided an "absolute" measurement of vitreous signal intensity, which was then compared with that of the retinal pigment epithelium (RPE), generating an optical density ratio with arbitrary units ("VIT/RPE-Relative Intensity").
Correlation between clinical vitreous haze scores and OCT-derived measurements of vitreous signal intensity.
The VIT/RPE-Relative Intensity was significantly higher in uveitic eyes with known vitreous haze (0.150) than in uveitic eyes without haze or in healthy controls (0.0767, P = 0.0001). The VIT/RPE-Relative Intensity showed a significant, positive correlation with clinical vitreous haze scores (r = 0.566, P = 0.0001). Other ocular characteristics significantly associated with VIT/RPE-Relative Intensity included VA (r = 0.573, P = 0.0001), AC cells (r = 0.613, P = 0.0001), and AC flare (r = 0.385, P = 0.003). Measurement of VIT/RPE-Relative Intensity showed a good degree of intergrader reproducibility (95% limits of agreement, -0.019 to 0.016).
These results provide preliminary evidence that OCT-derived measurements of vitreous signal intensity may be useful as an outcome measure in patients with uveitis. If validated in future studies, such measures may serve as an objective, quantitative disease activity end point, with the potential to improve the "signal:noise" ratio of clinical trials in this area, thus enabling smaller studies for the same power. The incorporation of automated vitreous analysis in commercial OCT systems may, in turn, facilitate monitoring and re-treatment of patients with uveitis in clinical practice.
To compare the effectiveness of continuous aflibercept versus pro re nata (PRN) ranibizumab therapy for neovascular age-related macular degeneration (nAMD).
Multicentre, national electronic medical ...record (EMR) study on treatment naive nAMD eyes undergoing PRN ranibizumab or continuous (fixed or treat and extend (F/TE)) aflibercept from 21 UK hospitals. Anonymised data were extracted, and eyes were matched on age, gender, starting visual acuity (VA) and year of starting treatment. Primary outcome was change in vision at 1 year.
1884 eyes (942 eyes in each group) were included. At year 1, patients on PRN ranibizumab gained 1.6 ETDRS (Early Treatment Diabetic Retinopathy Study) letters (95% CI 0.5 to 2.7, p=0.004), while patients on F/TE aflibercept gained 6.1 letters (95% CI 5.1 to 7.1, p=2.2e-16). Change in vision at 1 year of the F/TE aflibercept group was 4.1 letters higher (95% CI 2.5 to 5.8, p=1.3e-06) compared with the PRN ranibizumab group after adjusting for age, starting VA, gender and year of starting therapy. The F/TE aflibercept group had significantly more injections compared with the PRN ranibizumab group (7.0 vs 5.8, p<2.2e-16), but required less clinic visits than the PRN ranibizumab group (10.8 vs 9.0, p<2.2e-16). Cost-effectiveness analysis showed an incremental cost-effectiveness ratio of 58 047.14 GBP/quality-adjusted life year for continuous aflibercept over PRN ranibizumab.
Aflibercept achieved greater VA gains at 1 year than ranibizumab. The observed VA differences are small and likely to be related to more frequent treatment with aflibercept, suggesting that ranibizumab should also be delivered by F/TE posology.
Currently, most medical image data, such as optical coherence tomography (OCT) images, are displayed in two dimensions on a computer screen. Advances in computer information technology have ...contributed to the growing storage of these data in electronic form. However, the data are usually processed only locally on site. To overcome such hurdles, a cyberspace virtual reality (csVR) application was validated, in which interactive OCT data were presented simultaneously to geographically distant sites (Lucerne, London, and Barcelona) where three graders independently measured the ocular csVR OCT diameters. A total of 109 objects were measured, each three times, resulting in a total of 327 csVR measurements. A minor mean absolute difference of 5.3 µm was found among the 3 measurements of an object (standard deviation 4.2 µm, coefficient of variation 0.3% with respect to the mean object size). Despite the 5 h of online work, csVR was well tolerated and safe. Digital high-resolution OCT data can be remotely and collaboratively processed in csVR. With csVR, measurements and actions enhanced with spatial audio communication can be made consistently in near real time, even if the users are situated geographically far apart. The proposed visuo-auditory framework has the potential to further boost the convenience of digital medicine toward csVR precision and collaborative medicine.
Optical coherence tomography angiography (OCTA) enables three-dimensional reconstruction of the functional blood vessels in the retina. Therefore, it enables the quantification of 3D retinal vessel ...parameters such as surface area and vessel volume. In spite of the widespread use of OCTA, no representative volume-rendered vessel volume (VV) data are published to date. In this study, OCTA 3 × 3 mm macular cubes were processed with volume-rendering techniques to measure VV in 203 eyes from 107 healthy volunteers. Generalized linear models (GLM) were constructed to assess the impact of age, gender, visual acuity (VA), spherical equivalent (SE), and axial length (AL) on VV. Overall mean VV was 0.23 ± 0.05mm
. Age and axial length showed a negative correlation with VV. However, GLM model analysis found that AL exerted the most pronounced influence on VV. No statistically significant associations were identified between gender or between left and right eyes. This is the first study to assess 3D OCTA VV and its naturally occurring variations in a large series of healthy subjects. It offers novel insights into the characterization of normal retinal vascular anatomy in healthy individuals, contributing to a valuable reference for future research in this field.
We described the optical coherence tomography (OCT) features of diabetic macular ischemia (DMI), and correlate these findings with visual acuity (VA).
Clinical and imaging data were collected from ...100 patients with type 2 diabetes. Qualitative grading of DMI severity was determined according to criteria defined by the Early Treatment Diabetic Retinopathy Study. Quantitative analysis of foveal avascular zone (FAZ), and OCT images were performed using custom software.
In all eyes, the outer retina was thicker in eyes with DMI (167.4 ± 18.5 vs. 150.4 ± 31.4 μm, P = 0.04). However, subanalysis of eyes "without macular edema" revealed the converse; outer retinal thinning in eyes with DMI (223.1 ± 31.2 vs. 244.9 ± 37.2 μm, P = 0.007). A thinner retinal nerve fiber layer also was observed to correlate with increasing FAZ size (r = -0.231, P = 0.03), which strengthened in eyes "without macular edema" (r = -0.62, P = 0.001). In the choroid, quantification of its sublayers revealed a thicker Haller's large vessel layer in the presence of DMI (144.3 ± 51.0 vs. 103.5 ± 39.4 μm, P = 0.01). In eyes with DMI, a thicker retina was correlated with worsening VA (r = 0.52, P = 0.001). However, when eyes with macular edema were excluded, a thinner retina was associated with poor VA (r = -0.37, P = 0.004).
In eyes with DMI, we observed thinning of the retinal nerve fiber layer, outer retina, and thickening of Haller's large vessel layer of the choroid. These parameters showed good correlation with VA and may serve as a useful tool for monitoring DMI in clinical practice or future clinical trials.
To investigate if previous intravitreal therapy is a predictor of posterior capsule rupture (PCR) during cataract surgery.
Multicenter, national electronic medical record (EMR) database study with ...univariate and multivariate regression modeling.
A total of 65 836 eyes of 44 635 patients undergoing cataract surgery.
Anonymized data were extracted for eyes undergoing cataract surgery from 20 hospitals using the same EMR for cases performed between 2004 and 2014. Variables included as possible risk indicators for PCR were age, sex, number of previous intravitreal injections, indication for intravitreal therapy, grade of healthcare professional administering intravitreal therapy, advanced cataract, and cataract surgeon grade.
Presence or absence of posterior capsular rupture during cataract surgery.
Data were available on 65 836 cataract operations, of which 1935 had undergone previous intravitreal therapy (2.9%). In univariate regression analyses, patient age, advanced cataract, junior cataract surgeon grade, and number of previous intravitreal injections were significant predictors of PCR. By considering the number of previous intravitreal injections as a continuous variable, the odds ratio for PCR per intravitreal injection was 1.04 (P = 0.016) after adjusting for age, advanced cataract, and cataract surgeon grade. Repeat analysis considering intravitreal injections as a categoric variable showed 10 or more previous injections were associated with a 2.59 times higher likelihood of PCR (P = 0.003) after again adjusting for other significant independent predictors.
Previous intravitreal therapy is associated with a higher likelihood of PCR during cataract surgery. This study provides data to help inform surgeons and patients about the risk of complications when undergoing cataract surgery after multiple prior intravitreal injections. Further investigation is required to determine the cause behind the increased PCR risk.
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