A New Approach to Staging Diabetic Eye Disease: Staging of Diabetic Retinal Neurodegeneration and Diabetic Macular Edema

Topic

The goal of this review was to summarize the current level of evidence on biomarkers to quantify diabetic retinal neurodegeneration (DRN) and diabetic macular edema (DME).

Clinical relevance

With advances in retinal diagnostics, we have more data on patients with diabetes than ever before. However, the staging system for diabetic retinal disease is still based only on color fundus photographs and we do not have clear guidelines on how to incorporate data from the relatively newer modalities into clinical practice.

Methods

In this review, we use a Delphi process with experts to identify the most promising modalities to identify DRN and DME. These included microperimetry, full-field flash electroretinogram, spectral-domain OCT, adaptive optics, and OCT angiography. We then used a previously published method of determining the evidence level to complete detailed evidence grids for each modality.

Results

Our results showed that among the modalities evaluated, the level of evidence to quantify DRN and DME was highest for OCT (level 1) and lowest for adaptive optics (level 4).

Conclusion

For most of the modalities evaluated, prospective studies are needed to elucidate their role in the management and outcomes of diabetic retinal diseases.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

INTERNATIONAL IMPACT OF THE COVID-19 PANDEMIC LOCKDOWN ON INTRAVITREAL THERAPY OUTCOMES: Fight Retinal Blindness Registry

PURPOSE

To evaluate the impact of the COVID-19 pandemic lockdowns on the outcomes of eyes treated for neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusion in eight countries.

METHODS

A multicenter international database study of 5,782 eyes (4,708 patients) receiving intravitreal antivascular endothelial growth factor injections before, during, and after national lockdowns. The baseline visit was defined as the last visit within 3 months before lockdown, and prelockdown and postlockdown periods were defined as 6 months before and after the lockdown date.

RESULTS

Eyes with neovascular age-related macular degeneration (n = 4,649) lost vision in all countries in proportion to the reduced number of injections. The mean visual acuity change postlockdown ranged from -0.4 to -3.8 logarithm of the minimum angle of resolution letters, and the median number of injections/visits decreased from 4-5/4-7 to 2-4/2-4 postlockdown. The diabetic macular edema (n = 654) and retinal vein occlusion (n = 479) eyes' mean visual acuity change ranged from -2.8 to +1.7 letters and -1.6 to +0.1 letters, and the median number of injections/visits decreased from 2.5-5/4-6 to 1-3/2-4 and from 3-5.5/4-5 to 1-3.5/2-3.5, respectively. The 6-month dropout rates postlockdown were 20% for neovascular age-related macular degeneration, 27% for diabetic macular edema, and 28% for retinal vein occlusion.

CONCLUSION

This international study provides estimates of the impact of COVID-19 pandemic lockdown on intravitreal therapy and suggests that prioritizing neovascular age-related macular degeneration eyes seems appropriate.

Validation of Automated Screening for Referable Diabetic Retinopathy With an Autonomous Diagnostic Artificial Intelligence System in a Spanish Population

PURPOSE

The purpose of this study is to compare the diagnostic performance of an autonomous artificial intelligence (AI) system for the diagnosis of referable diabetic retinopathy (RDR) to manual grading by Spanish ophthalmologists.

METHODS

Subjects with type 1 and 2 diabetes participated in a diabetic retinopathy (DR) screening program in 2011 to 2012 in Valencia (Spain), and two images per eye were collected according to their standard protocol. Mydriatic drops were used in all patients. Retinal images-one disc and one fovea centered-were obtained under the Medical Research Ethics Committee approval and de-identified. Exams were graded by the autonomous AI system (IDx-DR, Coralville, Iowa, United States), and manually by masked ophthalmologists using adjudication. The outputs of the AI system and manual adjudicated grading were compared using sensitivity and specificity for diagnosis of both RDR and vision-threatening diabetic retinopathy (VTDR).

RESULTS

A total of 2680 subjects were included in the study. According to manual grading, prevalence of RDR was 111/2680 (4.14%) and of VTDR was 69/2680 (2.57%). Against manual grading, the AI system had a 100% (95% confidence interval [CI]: 97%-100%) sensitivity and 81.82% (95% CI: 80%-83%) specificity for RDR, and a 100% (95% CI: 95%-100%) sensitivity and 94.64% (95% CI: 94%-95%) specificity for VTDR.

CONCLUSION

Compared to manual grading by ophthalmologists, the autonomous diagnostic AI system had high sensitivity (100%) and specificity (82%) for diagnosing RDR and macular edema in people with diabetes in a screening program. Because of its immediate, point of care diagnosis, autonomous diagnostic AI has the potential to increase the accessibility of RDR screening in primary care settings.

Use in clinical practice of an automated screening method of diabetic retinopathy that can be derived using a diagnostic artificial intelligence system

BACKGROUND AND OBJECTIVE

To compare the diagnostic performance of an autonomous diagnostic artificial intelligence (AI) system for the diagnosis of derivable diabetic retinopathy (RDR) with manual classification.

MATERIALS AND METHODS

Patients with type 1 and type 2 diabetes participated in a diabetic retinopathy (DR) screening program between 2011-2012. 2 images of each eye were collected. Unidentifiable retinal images were obtained, one centered on the disc and one on the fovea. The exams were classified with the autonomous AI system and manually by anonymous ophthalmologists. The results of the AI system and manual classification were compared in terms of sensitivity and specificity for the diagnosis of both (RDR) and diabetic retinopathy with decreased vision (VTDR).

RESULTS

10,257 retinal inages of 5,630 eyes of 2,680 subjects were included. According to the manual classification, the prevalence of RDR was 4.14% and that of VTDR 2.57%. The AI system recorded 100% (95% CI: 97-100%) sensitivity and 81.82% (95% CI: 80 -83%) specificity for RDR, and 100% (95% CI: 95-100%) of sensitivity and 94.64% (95% CI: 94-95%) of specificity for VTDR.

CONCLUSIONS

Compared to the manual classification, the autonomous diagnostic AI system registered a high sensitivity (100%) and specificity (82%) in the diagnosis of RDR and macular edema in people with diabetes. Due to its immediate diagnosis, the autonomous diagnostic AI system can increase the accessibility of RDR screening in primary care settings.

THU0379 REDUCTION OF ANTERIOR UVEITIS FLARES IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS FOLLOWING ONE YEAR OF TREATMENT WITH CERTOLIZUMAB PEGOL: 48-WEEK INTERIM RESULTS FROM A 96-WEEK OPEN-LABEL STUDY

Background:

Acute anterior uveitis (AAU), inflammation of the anterior uveal tract, is reported in up to 40% of patients (pts) with axial spondyloarthritis (axSpA).1AAU is associated with significant clinical burden; symptoms include blurred vision, photophobia and pain.2Previous studies have shown that TNF inhibitors (TNFi) can reduce AAU flare incidence in pts with radiographic axSpA,3-5but few have focused on pts across the full axSpA spectrum.

Objectives:

To analyse the impact of certolizumab pegol (CZP) treatment on AAU in pts with active radiographic and non-radiographic axSpA and a recent history of AAU.

Methods:

C-VIEW (NCT03020992) is an ongoing multicentre, open-label, phase 4 study. Pts had active axSpA according to the ASAS classification, a history of recurrent AAU (≥2 AAU flares in total and ≥1 AAU flare in the year prior to study entry), were HLA-B27 positive, and were eligible for TNFi treatment (previous failure of ≥2 NSAIDs, biologic naïve or had failed ≤1 TNFi). Pts received CZP 400 mg at Weeks (Wks) 0/2/4, then 200 mg every two wks (Q2W) to Wk 96. The primary variable was incidence of AAU flares compared to historic rates. A pre-specified interim analysis compared AAU incidence in the 48 wks prior to CZP treatment with the 48 wks of treatment, using Poisson regression adjusted for possible within-pt correlations, with period (pre- and post-baseline) and axSpA disease duration as covariates. Incidence rates (IR) were calculated based on the number of cases/pts at risk over 48 wks. Observed data are reported.

Results:

Of 115 enrolled pts, 89 initiated CZP treatment; 85 completed Wk 48. Baseline characteristics are shown in the Table. The 48-wk interim analysis revealed significantly fewer AAU flares/pt during CZP treatment vs before treatment (Figure; Poisson-adjusted IR: 0.2 vs 1.5, p<0.001). The number of pts experiencing 1 and ≥2 AAU flares (64.0% and 31.5% respectively) substantially reduced during CZP treatment (12.4% and 2.2%). After 48 wks CZP treatment, disease activity improved substantially (mean ± SD Ankylosing Spondylitis Disease Activity Score [ASDAS]: 2.0 ± 0.9; Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]: 3.3 ± 2.1), with 31.4% pts achieving ASAS partial remission and 29.1% ASDAS major improvement. No new safety signals were identified.

Table.

Baseline characteristics

CZP 200 mg Q2W (N=89)Age (years), mean ± SD46.5 ± 11.2Male, n (%)56 (62.9)Racial group, n (%) Caucasian87 (97.8) Other2 (2.2)Diagnosis, n (%) Radiographic axSpA76 (85.4) Non-radiographic axSpA13 (14.6)Duration of axSpA (years), mean ± SD8.6 ± 8.4Time since onset of first uveitis flare (years), mean ± SD9.9 ± 9.0ASDAS, mean ± SD3.5 ± 0.9BASDAI, mean ± SD6.5 ± 1.5

Conclusion:

In this open-label study, AAU flare rate significantly reduced in axSpA pts with a history of recurrent AAU during the first 48 wks of CZP. Pts also experienced substantial improvements in axSpA disease activity.

References:

[1]Martin TM. Curr Opin Rheumatol 2002;14:337–41

[2]Bacchiega ABS. Rheumatology (Oxford) 2017;56:2060–7

[3]van der Heijde D. Rheumatology (Oxford) 2017;56:1498–509

[4]van Bentum RE. J Rheumatol 2019;46:153–9

[5]van Denderen JC. J Rheumatol 2014;41:1843–8

Acknowledgments:

This study was funded by UCB Pharma. Editorial services were provided by Costello Medical.

Disclosure of Interests:

Irene van der Horst-Bruinsma Grant/research support from: AbbVie, Novartis, Eli Lilly, Bristol-Myers Squibb, MSD, Pfizer, UCB Pharma, Consultant of: AbbVie, Novartis, Eli Lilly, Bristol-Myers Squibb, MSD, Pfizer, UCB Pharma, Rianne van Bentum: None declared, Frank Verbraak Grant/research support from: Bayer, Novartis, IDxDR, UCB Pharma, Consultant of: Bayer, Novartis, IDxDR, UCB Pharma, Thomas Rath Grant/research support from: AbbVie, Bristol-Myers Squibb, Chugai, Eli Lilly, MSD, Novartis, Pfizer, Roche, UCB Pharma, James Rosenbaum Consultant of: AbbVie, Corvus, Eyevensys, Gilead, Novartis, Janssen, Roche, UCB Pharma; royalties from UpToDate, Maria Misterska-Skora: None declared, Bengt Hoepken Employee of: UCB Pharma, Oscar Irvin-Sellers Employee of: UCB Pharma, Brenda VanLunen Employee of: UCB Pharma, Lars Bauer Employee of: UCB Pharma, Martin Rudwaleit Consultant of: AbbVie, BMS, Celgene, Janssen, Eli Lilly, MSD, Novartis, Pfizer, Roche, UCB Pharma

Optical coherence tomography angiography in preclinical Alzheimer's disease

BACKGROUND/AIMS

As a protrusion from the brain, the retina might reflect the status of the brain. Previous studies showed a decrease in vessel density and foveal avascular zone (FAZ) enlargement on optical coherence tomography angiography (OCTA) in individuals suffering from Alzheimer's disease (AD). This study aims to assess whether such changes are already present in preclinical stages of AD, in a population of monozygotic (MZ) twins.

METHODS

124 cognitively healthy individuals (MZ twins, ages 60-93 years) underwent [18F]flutemetamol amyloid positron emission tomography (PET) scanning and OCTA. PET scans were visually rated for cortical amyloid-beta (Aβ) positivity. Parametric global cortical non-displaceable binding potential (BPND) was used as a continuous measure for Aβ aggregation. FAZ size and vessel densities for the inner and outer ring of the macular ETDRS grid and in a 3-6 mm ring around the optic nerve head (ONH) were measured.OCTA measures were associated with visual Aβ score, BPND and amyloid load estimated by twin concordance on visual Aβ score. Twin correlations were estimated as a measure of maximum heritability of OCTA measures.

RESULTS

13 of 124 participants were Aβ+. Aβ+ individuals had significantly higher vessel density than Aβ- individuals in all regions but did not differ in FAZ size. Twin analyses showed a positive association between and vessel densities in all regions. BPND tended to be associated with higher vessel density in the inner ring. Twin correlations were moderate/high for all OCTA parameters except vessel density around the ONH, which correlated weakly.

CONCLUSION

Retinal vessel density was higher in individuals with preclinical AD.

Polarization-sensitive optical coherence tomography as a tool to visualize the fiber direction of retinal nerves and peripapillary sclera

Polarization sensitive optical coherence tomography (PS-OCT) has been used to visualize the orientation of the nerves in the retinal nerve fiber layer (RNFL) and to visualize the orientation of the collagen fibers in peripapillary sclera in retinas of healthy volunteers. Optic axis orientation images clearly visualize the nerve fibers leaving the optic nerve head (ONH) in all radial directions. Sclera orientation images show that the sclera consist of two layers, an inner layer with an orientation parallel to the RNFL orientation, and a deeper layer where the collagen is circularly oriented.

Resilience to cognitive impairment in the oldest-old: design of the EMIF-AD 90+ study

BACKGROUND

The oldest-old (subjects aged 90 years and older) population represents the fastest growing segment of society and shows a high dementia prevalence rate of up to 40%. Only a few studies have investigated protective factors for cognitive impairment in the oldest-old. The EMIF-AD 90+ Study aims to identify factors associated with resilience to cognitive impairment in the oldest-old. In this paper we reviewed previous studies on cognitive resilience in the oldest-old and described the design of the EMIF-AD 90+ Study.

METHODS

The EMIF-AD 90+ Study aimed to enroll 80 cognitively normal subjects and 40 subjects with cognitive impairment aged 90 years or older. Cognitive impairment was operationalized as amnestic mild cognitive impairment (aMCI), or possible or probable Alzheimer's Disease (AD). The study was part of the European Medical Information Framework for AD (EMIF-AD) and was conducted at the Amsterdam University Medical Centers (UMC) and at the University of Manchester. We will test whether cognitive resilience is associated with cognitive reserve, vascular comorbidities, mood, sleep, sensory system capacity, physical performance and capacity, genetic risk factors, hallmarks of ageing, and markers of neurodegeneration. Markers of neurodegeneration included an amyloid positron emission tomography, amyloid β and tau in cerebrospinal fluid/blood and neurophysiological measures.

DISCUSSION

The EMIF-AD 90+ Study will extend our knowledge on resilience to cognitive impairment in the oldest-old by extensive phenotyping of the subjects and the measurement of a wide range of potential protective factors, hallmarks of aging and markers of neurodegeneration.

TRIAL REGISTRATION

Nederlands Trial Register NTR5867 . Registered 20 May 2016.

Validation of automated screening for referable diabetic retinopathy with the IDx-DR device in the Hoorn Diabetes Care System

Purpose

To increase the efficiency of retinal image grading, algorithms for automated grading have been developed, such as the IDx‐DR 2.0 device. We aimed to determine the ability of this device, incorporated in clinical work flow, to detect retinopathy in persons with type 2 diabetes.

Methods

Retinal images of persons treated by the Hoorn Diabetes Care System (DCS) were graded by the IDx‐DR device and independently by three retinal specialists using the International Clinical Diabetic Retinopathy severity scale (ICDR) and EURODIAB criteria. Agreement between specialists was calculated. Results of the IDx‐DR device and experts were compared using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), distinguishing between referable diabetic retinopathy (RDR) and vision‐threatening retinopathy (VTDR). Area under the receiver operating characteristic curve (AUC) was calculated.

Results

Of the included 1415 persons, 898 (63.5%) had images of sufficient quality according to the experts and the IDx‐DR device. Referable diabetic retinopathy (RDR) was diagnosed in 22 persons (2.4%) using EURODIAB and 73 persons (8.1%) using ICDR classification. Specific intergrader agreement ranged from 40% to 61%. Sensitivity, specificity, PPV and NPV of IDx‐DR to detect RDR were 91% (95% CI: 0.69–0.98), 84% (95% CI: 0.81–0.86), 12% (95% CI: 0.08–0.18) and 100% (95% CI: 0.99–1.00; EURODIAB) and 68% (95% CI: 0.56–0.79), 86% (95% CI: 0.84–0.88), 30% (95% CI: 0.24–0.38) and 97% (95% CI: 0.95–0.98; ICDR). The AUC was 0.94 (95% CI: 0.88–1.00; EURODIAB) and 0.87 (95% CI: 0.83–0.92; ICDR). For detection of VTDR, sensitivity was lower and specificity was higher compared to RDR. AUC's were comparable.

Conclusion

Automated grading using the IDx‐DR device for RDR detection is a valid method and can be used in primary care, decreasing the demand on ophthalmologists.

Use of a new intra-ocular spectral domain optical coherence tomography in vitreoretinal surgery

PURPOSE

To describe the use of a novel intra-ocular side-scanning probe enabling the acquisition of spectral-domain optical coherence tomography (SD-OCT) images during surgery in a series of patients with complex forms of retinal detachment.

METHODS

A 23-gauge, side-scanning SD-OCT probe (C7 System; LightLab Imaging, Inc/St Jude Medical, St. Paul, MN, USA) in a 20-gauge catheter, was used to acquire the intra-operative OCT images in seven patients with vitreoretinal diseases. Twenty-five gauge pars plana vitrectomy (PPV) was performed in every patient in a standard fashion. After enlarging the temporal sclerotomy to a 20-gauge port, all the patients were scanned with intra-ocular side-scanning SD-OCT, during different steps of the surgery based on surgeon needs. Scans were recorded real time and directly evaluated on a screen during surgery. Optical coherence tomography (OCT) scans were judged beneficial when they would recognize structures otherwise not seen on biomicroscopy.

RESULTS

The intra-ocular SD-OCT has been helpful in acquiring extra information during vitreoretinal surgery such as the detection of the presence of otherwise invisible membranes (epiretinal membrane, subretinal membrane), the location of small tears and the identification of the retinal plane under suboptimal conditions for visualization.

CONCLUSION

The use of an intra-ocular SD-OCT can expand upon visual cues during surgery, helping in the decision-making process and allowing additional deliberate surgical manoeuvres aimed at improving surgical outcomes.

Müller cell-specific autoantibodies in a patient with progressive loss of vision

PURPOSE

To study the specificity of circulating retinal autoantibodies in a patient with progressive loss of vision resembling cancer-associated retinopathy in the absence of systemic malignancy.

METHODS

Patient's serum was tested for the presence of antiretinal antibodies by Western blot analysis, and immunohistochemical analysis was performed on cryosections of rat retina and on cultured rat retinal Müller cells.

RESULTS

Western blot analysis revealed that the serum contained a high titer of autoantibodies against a 35-kDa retinal antigen. A protein of similar molecular weight and antigenicity has been found to be present in protein extracts of bovine, rat, and fish retina. Immunohistochemical analysis suggested that the autoantibodies did not localize to retinal neural cells, as reported for several other putative autoimmune retinal disorders, but rather to the retinal Müller cells. This cell type-specificity could be confirmed using purified cultured retinal Müller cells.

CONCLUSIONS

These results suggest that an autoimmune response directed against the retinal Müller cells, in the absence of overt systemic malignancy, may lead to a slow-developing visual deterioration.

Cytomegalovirus glycoprotein B genotyping in ocular fluids and blood of AIDS patients with cytomegalovirus retinitis

PURPOSE

To determine the frequency of cytomegalovirus glycoprotein B (gB) genotypes in clinical samples of ocular fluids of patients with acquired immune deficiency syndrome (AIDS) who have cytomegalovirus retinitis and to compare these with the cytomegalovirus gB genotype in paired peripheral blood leukocytes.

METHODS

Glycoprotein B genotypes of cytomegalovirus genomic DNA were determined in 29 ocular and 9 paired blood samples of 27 patients, by polymerase chain reaction amplification followed by restriction fragment length polymorphism analysis.

RESULTS

In the 29 ocular samples, 30 gB genotypes were determined: Glycoprotein B1 was found in 8 samples (27%), gB2 in 9 samples (30%), gB3 in 6 samples (20%), and gB4 in 3 samples (10%). In one sample, a mixed genotype was observed. In addition to these previously characterized gB genotypes, a new gB variant was observed in the ocular fluid of four patients. Partial sequence analysis revealed that this new gB genotype is closely related to gB3, and it was therefore named gB3'. In the blood samples, only gB1, gB2, and gB3 genotypes were observed. In the nine paired samples of ocular fluid and blood, four showed a difference in gB genotype between these compartments.

CONCLUSIONS

The distribution of cytomegalovirus glycoprotein B genotypes gB1-gB4 in ocular fluids of patients with AIDS who have cytomegalovirus retinitis was determined in this study. The predominance of gB2, as described by others, was not confirmed. The glycoprotein B genotype in the eye can be different from the genotype found in the blood of the same patient. A new gB variant, gB3', was found in the ocular samples of 4 of 27 patients, but not in the blood samples tested.

Genetic heterogeneity in Rieger eye malformation

A three generation family with Rieger eye malformation sequence is described. No other abnormalities were present apart from the eye malformation. Linkage to EGF and D4S193 localised in 4q25 was excluded and this indicates that Rieger eye malformation is genetically different from typical Rieger syndrome with teeth and umbilical anomalies.