Non-mydriatic ultrawide field scanning laser ophthalmoscopy compared with dilated fundal examination for assessment of diabetic retinopathy and diabetic macular oedema in Chinese individuals with diabetes mellitus

Iris Cerclage To Treat Persistent Mydriasis Following Acute Angle Closure Glaucoma Improves Visual Quality

PRCIS

We developed a modified iris cerclage technique that improves best corrected visual acuity, pupillary parameters, self-assessed photophobia, and visual function index-14 questionnaire scores in patients with acute primary angle closure and permanent mydriasis after cataract surgery.

PURPOSE

To evaluate the efficacy of a modified iris cerclage technique in patients with acute primary angle closure (PAC) and permanent mydriasis after cataract surgery.

PATIENTS AND METHODS

Twelve eyes of 12 patients with acute PAC and permanent mydriasis at more than 3 months after phacoemulsification combined with intraocular lens (IOL) implantation underwent modified iris cerclage. Best corrected visual acuity (BCVA), intraocular pressure (IOP), pupil diameter, and visual function index-14 (VF-14) questionnaire and self-assessed photophobia scores before surgery and at 1 week, 1 month, and 3 months postoperatively were compared. Further, the postoperative pupil position morphology and complications were evaluated.

RESULTS

BCVA improved from 0.48±0.23 preoperatively to 0.28±0.15, 0.27±0.15, and 0.26±0.14 at 1 week, 1 month, and 3 months postoperatively, respectively ( P =0.008). No significant difference was observed between the preoperative and postoperative IOP ( P =0.974). Pupil diameter improved from 6.34±0.51 mm preoperatively to 3.59±0.33, 3.59±0.34, and 3.58±0.32 mm at 1 week, 1 month, and 3 months postoperatively, respectively ( P <0.001). Self-assessed photophobia scores improved from 3.33±0.78 preoperatively to 0.83±0.72, 0.51±0.15, and 0.45±0.14 at 1 week, 1 month, and 3 months postoperatively, respectively ( P <0.001). VF-14 scores improved from 47.6±6.1 points preoperatively to 67.9±6.2, 72.1±6.1, and 73.5±6.0 points at 1 week, 1 month, and 3 months postoperatively, respectively ( P< 0.001). Postoperatively, all pupils were centered and round. No postoperative complications, such as iris-suture slippage, iridodialysis, or exposure of the IOL's optical zone edge, were observed.

CONCLUSION

Modified iris cerclage creates a centered, precisely sized, round pupil. It improves visual quality in patients with acute PAC and permanent mydriasis after cataract surgery.

COMBINED APPLICATION OF B-SCAN ULTRASONOGRAPHY AND EYE-STEERING ULTRAWIDE FIELD IMAGING TO IMPROVE THE DETECTION OF RETINAL TEARS BEFORE CATARACT SURGERY

PURPOSE

To investigate the efficacy of combined application of B-scan ultrasonography (US) and ultrawide field imaging (UWFI) in detecting retinal tears before cataract surgery.

METHODS

Of 1,277 cataract patients, 2,552 eyes were enrolled and received both B-scan US and UWFI examinations preoperatively. Three types of combination were applied: type 1 (union, B-scan US or centered UWFI), type 2 (intersection, B-scan US and centered UWFI), and type 3 (B-scan US and eye-steering UWFI). Sensitivity and specificity of detecting retinal tears by different methods were assessed.

RESULTS

Totally 4.55% (116/2,552) of eyes were presented with retinal tears. The sensitivity of B-scan US and UWFI was 87.93% and 84.48%, and specificity was 95.16% and 99.79%, respectively. By applying type 1 and type 2 combination, the sensitivity was 98.28% and 74.14%, and specificity was 95.03% and 99.92%, respectively. By type 3 combination, the sensitivity increased to 95.69% and specificity to 99.88%, both of which were comparable to indirect ophthalmoscopy regardless of the number, type, and location of tears ( P > 0.05). In eyes with any cataract type or axial length, type 3 combination also gained comparable performance to indirect ophthalmoscopy.

CONCLUSION

Combined application of B-scan US and eye-steering UWFI presented satisfactory performance in detecting retinal tears before cataract surgery.

Comparison of Standard 7-Field, Clarus, and Optos Ultrawidefield Imaging Systems for Diabetic Retinopathy (COCO Study)

Purpose

The purpose of this study was to compare diabetic retinopathy (DR) severity levels assessed from 7 standard-field stereoscopic color photographs on a 35° fundus camera to both Clarus and Optos ultrawidefield color images.

Design

Cross-sectional, comparative imaging study.

Participants

Participants with DR imaged at a single-center retina practice.

Methods

Participants were imaged on 3 cameras at a single visit with the Topcon 35° fundus camera, Clarus, and Optos. The DR Severity Scale (DRSS) level was determined within the 7-field (7F) area of each image set using the ETDRS scale. An additional global DRSS was assigned for both Clarus and Optos images using the entire visible retina. Weighted kappa (wκ) measured the agreement between cameras.

Main Outcome Measures

The primary outcome was a 3-way comparison of DRSS level within the 7F area imaged on the 3 cameras. Secondary outcomes included a comparison of the DRSS obtained with standard 7F imaging to the global DRSS of Clarus and Optos and a comparison of the global DRSS between Clarus and Optos only.

Results

Ninety-seven eyes (50 participants) were evaluated. Agreement within 1-step of ETDRS levels between standard 7F imaging and Clarus 7F was 90.1% (wκ = 0.65), and with Optos 7F in 85.9%, (wκ = 0.58). Agreement within 1-step between standard 7F imaging and Clarus global was 88.9% of eyes (wκ = 0.63), and Optos global was 85.7%, (wκ = 0.54). Agreement between Clarus and Optos global DR level within 1-step was 89.1% (wκ = 0.68). Intergrader agreement for the 7F ETDRS level was 96% for standard 7F imaging, 98% for Clarus, and 95.5% for Optos.

Conclusions

These findings suggest that when evaluating the 7F area on Clarus and Optos, DR severity grades are comparable to standard 7F imaging. However, it is important to understand the unique attributes and differences of each fundus camera when changing the type of system used in a clinical setting due to upgrading equipment. Additionally, if the facility has access to > 1 device, there should not be an exchange between cameras for the same patient.

Financial Disclosures

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

Comparison of quantitative assessment and efficiency of diabetic retinopathy diagnosis using ETDRS seven-field imaging and two ultra-widefield imaging

PURPOSE

This study compared the efficiency of diabetic retinopathy (DR) diagnosis and differences in the relative visible retinal area among the Early Treatment Diabetic Retinopathy Study (ETDRS) seven-field, ultra-widefield (UWF)-Optos, and UWF-Clarus fundus imaging methods.

METHODS

This was a prospective and clinic-based comparative study. All patients underwent three fundus examinations, and all images were graded using the ETDRS severity scale. We compared and analysed the agreement of DR severity and the relative visible retinal area among the three fundus examination methods, and the number and type of lesions outside the ETDRS seven-field (peripheral lesions) between the two UWF imaging methods.

RESULTS

A total of 202 patients (386 eyes) were included. Weighted kappa for the agreement between ETDRS seven-field and blinded Optos images was 0.485; between ETDRS seven-field and blinded Clarus images, 0.924; and between blinded Optos and Clarus images, 0.461. Blinded Clarus showed excellent performance when a ETDRS scale was used for grading the images. The relative visible retinal area for ETDRS seven-field images was 195 ± 28 disc area (DA); single Optos images, 371 ± 69 DA; single Clarus images, 261 ± 65 DA; two-montage Clarus images, 462 ± 112 DA; and four-montage Clarus images, 598 ± 139 DA. The relative visible retinal area was statistically significant between any two of the imaging systems used. In total, 2015 and 4200 peripheral lesions were detected in single Optos and Clarus images, respectively (P < 0.001). These peripheral lesions on two UWF images suggested a more severe DR level in approximately 10% and 12% of eyes, respectively.

CONCLUSION

UWF-Clarus fundus imaging offers a suitable assessment approach for DR severity; it could improve DR diagnosis and has the potential to replace ETDRS seven-field imaging after additional clinical trials.

Assessment of early diabetic retinopathy severity using ultra-widefield Clarus versus conventional five-field and ultra-widefield Optos fundus imaging

To compare early diabetic retinopathy (DR) severity level and the abilities in detecting early DR lesions among conventional five-field, ultrawide-field (UWF) Optos, and UWF Clarus fundus imaging methods. This was a single-center, prospective, clinic-based, and comparative study. In total, 157 consecutive patients with diabetes mellitus were enrolled in this study. All patients underwent comprehensive ophthalmological examinations. Following mydriasis, each eye was examined with conventional five-field, UWF Optos, and UWF Clarus fundus imaging methods. The initial UWF images were overlaid with a template mask that obscured the retina, which created a five-field view from UWF images (covered UWF images). The covered UWF images were then graded, after which the template mask was removed, and the original UWF images were also evaluated. All images were graded using the International Clinical DR severity scale. DR grades were compared and analyzed by weighted kappa statistics among the three fundus imaging methods. In total, 157 consecutive patients with diabetes (302 eyes) were enrolled in this study. Weighted kappa statistics for agreement were 0.471 (five-field vs. covered Optos), 0.809 (five-field vs. covered Clarus), 0.396 (covered Optos vs. covered Clarus), 0.463 (five-field vs. Optos), 0.521 (five-field vs. Clarus 133°), 0.500 (five-field vs. Clarus 200°), 0.323 (Optos vs. Clarus 133°), and 0.349 (Optos vs. Clarus 200°). The area under curve of covered Clarus images was higher than that of conventional five-field images at three different thresholds. Compared with conventional five-field and Optos fundus imaging methods, Clarus fundus imaging methods exhibited excellent performance in assessing early DR severity. Thus, Clarus fundus imaging methods were superior for early detection of DR.

Recent Advances in Clinical Applications of Imaging in Retinal Diseases

Many diseases that cause visual impairment, as well as systemic conditions, manifest in the posterior segment of the eye. With the advent of high-speed, high-resolution, reliable, and noninvasive imaging techniques, ophthalmologists are becoming more dependent on ocular imaging for disease diagnosis, classification, and management in clinical practice. There are rapid advances on the indications of multimodal retinal imaging techniques, including the application of ultra-widefield fundus angiography, fundus autofluorescence, optical coherence tomography, as well as optical coherence tomography angiography. This review summarizes and highlights the clinical applications, latest indications, and interpretations of multimodal imaging in age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic macular edema, central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, and uveitis.

Prediction of Refractive Error Based on Ultrawide Field Images With Deep Learning Models in Myopia Patients

Summary

Ultrawide field fundus images could be applied in deep learning models to predict the refractive error of myopic patients. The predicted error was related to the older age and greater spherical power.

Purpose

To explore the possibility of predicting the refractive error of myopic patients by applying deep learning models trained with ultrawide field (UWF) images.

Methods

UWF fundus images were collected from left eyes of 987 myopia patients of Eye and ENT Hospital, Fudan University between November 2015 and January 2019. The fundus images were all captured with Optomap Daytona, a 200° UWF imaging device. Three deep learning models (ResNet-50, Inception-v3, Inception-ResNet-v2) were trained with the UWF images for predicting refractive error. 133 UWF fundus images were also collected after January 2021 as an the external validation data set. The predicted refractive error was compared with the “true value” measured by subjective refraction. Mean absolute error (MAE), mean absolute percentage error (MAPE) and coefficient (R²) value were calculated in the test set. The Spearman rank correlation test was applied for univariate analysis and multivariate linear regression analysis on variables affecting MAE. The weighted heat map was generated by averaging the predicted weight of each pixel.

Results

ResNet-50, Inception-v3 and Inception-ResNet-v2 models were trained with the UWF images for refractive error prediction with R² of 0.9562, 0.9555, 0.9563 and MAE of 1.72(95%CI: 1.62–1.82), 1.75(95%CI: 1.65–1.86) and 1.76(95%CI: 1.66–1.86), respectively. 29.95%, 31.47% and 29.44% of the test set were within the predictive error of 0.75D in the three models. 64.97%, 64.97%, and 64.47% was within 2.00D predictive error. The predicted MAE was related to older age (P < 0.01) and greater spherical power(P < 0.01). The optic papilla and macular region had significant predictive power in the weighted heat map.

Conclusions

It was feasible to predict refractive error in myopic patients with deep learning models trained by UWF images with the accuracy to be improved.

Application of mydriasis and eye steering in ultrawide field imaging for detecting peripheral retinal lesions in myopic patients

PURPOSE

To compare mydriatic and eye-steering ultrawide field imaging (UWFI) with standard non-mydriatic UWFI examination in detecting peripheral retinal lesions in myopic patients.

METHODS

Cross-sectional, observational study. 220 eyes of 110 myopic patients with known peripheral retinal lesions in at least one eye under Goldmann three mirror contact lens examination were recruited. Non-mydriatic standard and eye-steering UWFI images were taken centrally and with eye-steering technique in upper, lower, nasal and temporal gazes under Optomap UWFI (Daytona, Optos, UK). Mydriatic standard and eye-steering UWFI was captured in central gaze and four different peripheral gazes. Sensitivity of detecting peripheral retinal lesions under different UWFI settings was compared.

RESULTS

141 (64.09%) eyes were with peripheral retinal lesions. The sensitivity for detecting peripheral lesions from low to high was 41.84% (95% CI 33.62% to 50.54%) under non-mydriatic standard UWFI setting, 52.48% (95% CI 44.08% to 60.75%) under mydriatic standard setting, 75.18% (95% CI 67.21% to 82.06%) under non-mydriatic eye-steering setting and 86.52% (95% CI 79.76% to 91.69%) under mydriatic eye-steering setting. Both mydriasis and eye-steering technique increased sensitivity of detecting peripheral lesions with statistical significance (p<0.001). By applying eye-steering technique, sensitivity of detecting lesions located in superior and inferior quadrants witnessed a greater increase compared with other two quadrants (p<0.05). Neither spherical equivalence (p>0.05) nor axial length (p>0.05) was an independent influence factor for detecting peripheral lesions.

CONCLUSIONS

Eye-steering technique and mydriasis could both efficiently improve the sensitivity of detecting peripheral retinal lesions in myopic patients. Lesions of superior and inferior quadrants benefited more from eye-steering technique.

Optical coherence tomography angiography characteristics and correlated factors with visual acuity in retinal arterial occlusion

PURPOSE

To reveal the characteristics of vascular changes in retinal arterial occlusion (RAO) using optical coherence tomography angiography (OCTA) and determine the correlated factors with best-corrected visual acuity (BCVA).

METHODS

This retrospective study recruited 54 RAO patients and 27 healthy individuals. Ophthalmic examinations including BCVA and OCTA were performed in all the patients and individuals. The OCTA outcomes were analyzed using SPSS software, and the characteristics of vascular changes and BCVA-related factors were summarized.

RESULTS

The vessel density in all areas except fovea of both superficial capillary plexus (SCP) and deep capillary plexus (DCP) was significantly reduced in RAO eyes compared with the fellow eyes and normal control eyes (P < 0.05). The vessel density of DCP in all areas except fovea was significantly reduced in the fellow eyes compared with that in the normal control eyes as well (P < 0.05). The retinal thickness in fovea was significantly increased in RAO eyes compared with that in the fellow eyes and normal control eyes (P < 0.05), without any differences in other areas between the RAO eyes and the other two groups (P > 0.05). The retinal thickness in whole area and retinal thickness in fovea were correlated with BCVA, respectively (whole area: r = 0.295, P = 0.030; fovea: r = 0.322, P = 0.018).

CONCLUSIONS

OCTA is a fast, noninvasive, and effective examination means for RAO that can display the vascular density and retinal thickness quantitatively and distinctly. RAO patients had reduced vascular density in both eyes and increased foveal retinal thickness in RAO eyes, showing a correlation with BCVA.

Imaging Modalities Employed in Diabetic Retinopathy Screening: A Review and Meta-Analysis

INTRODUCTION

Urbanization has caused dramatic changes in lifestyle, and these rapid transitions have led to an increased risk of noncommunicable diseases, such as type 2 diabetes. In terms of cost-effectiveness, screening for diabetic retinopathy is a critical aspect in diabetes management. The aim of this study was to review the imaging modalities employed for retinal examination in diabetic retinopathy screening.

METHODS

The PubMed and Web of Science databases were the main sources used to investigate the medical literature. An extensive search was performed to identify relevant articles concerning "imaging", "diabetic retinopathy" and "screening" up to 1 June 2021. Imaging techniques were divided into the following: (i) mydriatic fundus photography, (ii) non-mydriatic fundus photography, (iii) smartphone-based imaging, and (iv) ultrawide-field imaging. A meta-analysis was performed to analyze the performance and technical failure rate of each method.

RESULTS

The technical failure rates for mydriatic and non-mydriatic digital fundus photography, smartphone-based and ultrawide-field imaging were 3.4% (95% CI: 2.3-4.6%), 12.1% (95% CI: 5.4-18.7%), 5.3% (95% CI: 1.5-9.0%) and 2.2% (95% CI: 0.3-4.0%), respectively. The rate was significantly different between all analyzed techniques (p < 0.001), and the overall failure rate was 6.6% (4.9-8.3%; I2 = 97.2%). The publication bias factor for smartphone-based imaging was significantly higher than for mydriatic digital fundus photography and non-mydriatic digital fundus photography (b = -8.61, b = -2.59 and b = -7.03, respectively; p < 0.001). Ultrawide-field imaging studies were excluded from the final sensitivity/specificity analysis, as the total number of patients included was too small.

CONCLUSIONS

Regardless of the type of the device used, retinal photographs should be taken on eyes with dilated pupils, unless contraindicated, as this setting decreases the rate of ungradable images. Smartphone-based and ultrawide-field imaging may become potential alternative methods for optimized DR screening; however, there is not yet enough evidence for these techniques to displace mydriatic fundus photography.

The foveal avascular zone area in healthy eyes measured by ocular coherence tomography angiography using a full spectrum probabilistic algorithm

PURPOSE

Report the foveal avascular zone (FAZ) area imaged by OCT angiography (OCTA) using a full spectrum probabilistic algorithm in eyes of healthy individuals from Costa Rica without any ocular or systemic pathology.

METHODS

Retrospective chart review of consecutive healthy patients that were evaluated from January 2018 to October 2018 that underwent OCTA of the macular area. The OCTA consisted of a 10° × 10° cube of 512 A scans separated by 6 µm each with an automated real time mode of 5. The FAZ area of the superficial vascular complex (SVC), the deep vascular complex (DVC), superficial vascular plexus (SVP), intermediate vascular plexus (IVP) and the deep vascular plexus (DVP) were measured manually by 2 different observers at 3 different times.

RESULTS

A total of 234 eyes of 121 patients were included in this study. Mean age was 50 years (range, 15-89), 85 patients (70%) were female. Inter- and intra-observer agreements were excellent. The mean FAZ areas in the different layers were 0.258 ± 0.0035 mm² for the SVC, 0.205 ± 0.01 mm² for the DVC, 0.415 ± 0.01 mm² for the SVP, 0.305 ± 0.01 mm² for the ICP and 0.420 ± 0.01 mm² for the DCP. The mean FAZ areas in most of the measured layers increased with age and decreased with CMT. Gender and spherical equivalence were not correlated with FAZ area.

CONCLUSION

Manual measurements of the FAZ imaged by OCT-A using a full spectrum probabilistic algorithm are widely reproducible both by the same observer and between observers. The FAZ increases with age and decreases with CMT in normal individuals.

Impact of blood pressure control on retinal microvasculature in patients with chronic kidney disease

Chronic kidney disease (CKD) is an emerging disease worldwide. We investigated the relationship between blood pressure (BP) control and parafoveal retinal microvascular changes in patients with CKD. This case–control study enrolled 256 patients with CKD (stage 3–5) and 70 age‐matched healthy controls. Optical coherence tomography angiography showed lower superficial vascular plexus (SVP) vessel density, lower deep vascular plexus (DVP) vessel density, and larger SVP flow void area in the CKD group. The BP parameters at enrollment and during the year before enrollment were collected in patients with CKD. Partial correlation was used to determine the relationship between BP parameters and microvascular parameters after controlling for age, sex, diabetes mellitus, axial length, and intraocular pressure. The maximum systolic blood pressure (SBP) (p = 0.003) and within-patient standard deviation (SD) of SBP (p = 0.006) in 1 year were negatively correlated with SVP vessel density. The average SBP (p = 0.040), maximum SBP (p = 0.001), within-patient SD of SBP (p < 0.001) and proportion of high BP measurement (p = 0.011) in 1 year were positively correlated with the SVP flow void area. We concluded that long-term SBP was correlated with SVP microvascular injury in patients with CKD. Superficial retinal microvascular changes may be a potential biomarker for prior long-term BP control in these patients.

Screening for diabetic retinopathy in diabetic patients with a mydriasis-free, full-field flicker electroretinogram recording device

PURPOSE

To investigate the accuracy of the RETeval full-field flicker ERG in the screening of diabetic retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR) and to determine a suitable range of DR diagnostic reference for patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a cross-sectional study involving 172 subjects with T2DM, including 71 subjects without clinically detectable DR (NDR), 25 subjects with mild non-proliferative diabetic retinopathy (NPDR), 24 subjects with moderate NPDR, 27 subjects with severe NPDR and 25 subjects with proliferative diabetic retinopathy (PDR). All the subjects underwent a full-field flicker ERG using the RETeval device (DR assessment protocol), which is a mydriasis-free, full-field electroretinogram (ERG) recording system. The performance of the DR assessment protocol in detecting the DR (including mild NPDR, moderate NPDR, severe NPDR and PDR) and VTDR was analyzed with the receiver operating characteristic (ROC) curve.

RESULTS

For the detection of DR (mild NPDR, moderate NPDR, severe NPDR, PDR), the area under the ROC curve was 0.867 (p < 0.001, 95% CI 0.814-0.920), and the best cutoff value for DR was determined to be 20.75, with a sensitivity of 80.2% and specificity of 81.7%. Meanwhile, for the detection of VTDR, the area under the ROC curve was 0.965 (p < 0.001, 95% CI 0.941-0.989), and the best cutoff value was set to 23.05, with a sensitivity of 94.6% and a specificity of 88.8%.

CONCLUSION

The DR assessment protocol in RETeval device was effective in screening for DR (mild NPDR, moderate NPDR, severe NPDR, PDR) and VTDR in patients with diabetes. It could be helpful in referring and managing patients with T2DM in primary healthcare setting. However, caution should be taken that optimal cutoff value of DR assessment protocol may vary in different ethnic populations.