Association between disorganization of retinal inner layers and visual acuity after proliferative diabetic retinopathy surgery

Assessment of area and structural irregularity of retinal layers in diabetic retinopathy using machine learning and image processing techniques

Diabetes retinopathy prevention necessitates early detection, monitoring, and treatment. Non-invasive optical coherence tomography (OCT) shows structural changes in the retinal layer. OCT image evaluation necessitates retinal layer segmentation. The ability of our automated retinal layer segmentation to distinguish between normal, non-proliferative (NPDR), and proliferative diabetic retinopathy (PDR) was investigated in this study using quantifiable biomarkers such as retina layer smoothness index (SI) and area (S) in horizontal and vertical OCT images for each zone (fovea, superior, inferior, nasal, and temporal). This research includes 84 eyes from 57 individuals. The study shows a significant difference in the Area (S) of inner nuclear layer (INL) and outer nuclear layer (ONL) in the horizontal foveal zone across the three groups (p < 0.001). In the horizontal scan, there is a significant difference in the smoothness index (SI) of the inner plexiform layer (IPL) and the upper border of the outer plexiform layer (OPL) among three groups (p < 0.05). There is also a significant difference in the area (S) of the OPL in the foveal zone among the three groups (p = 0.003). The area (S) of the INL in the foveal region of horizontal slabs performed best for distinguishing diabetic patients (NPDR and PDR) from normal individuals, with an accuracy of 87.6%. The smoothness index (SI) of IPL in the nasal zone of horizontal foveal slabs was the most accurate at 97.2% in distinguishing PDR from NPDR. The smoothness index of the top border of the OPL in the nasal zone of horizontal slabs was 84.1% accurate in distinguishing NPDR from PDR. Smoothness index of IPL in the temporal zone of horizontal slabs was 89.8% accurate in identifying NPDR from PDR patients. In conclusion, optical coherence tomography can assess the smoothness index and irregularity of the inner and outer plexiform layers, particularly in the nasal and temporal regions of horizontal foveal slabs, to distinguish non-proliferative from proliferative diabetic retinopathy. The evolution of diabetic retinopathy throughout severity levels and its effects on retinal layer irregularity need more study.

Changes in optical coherence tomography biomarkers in eyes with advanced idiopathic epiretinal membrane treated with dexamethasone implantation

PURPOSE

To investigate the effects of vitrectomy and intravitreal dexamethasone (DEX) implantation on retinal biomarkers in patients with advanced idiopathic epiretinal membrane (IERM) and to evaluate this treatment's anatomical and functional outcomes.

METHODS

This retrospective study included 41 patients with advanced IERM who underwent vitrectomy and were divided into a pars plana vitrectomy (PPV) group (20 eyes) and a dexamethasone (DEX) group (21 eyes) based on intravitreal DEX implantation. We collected data on best-corrected visual acuity (BCVA), central macular thickness (CMT), disorganization of the retinal inner layers (DRIL), subretinal fluid, intraretinal cystoid changes (IRC), integrity of the inner-outer segment layer, and intraocular pressure.

RESULTS

BCVA improved significantly in both groups; the DEX group had a higher visual acuity gain at 1 and 6 months (P = 0.002 and 0.023, respectively). Postoperative CMT gradually decreased in both groups, with the DEX group showing a greater decrease at 1 and 6 months (P = 0.009 and 0.033, respectively). Six months after surgery, the DRIL and IRC grades in the DEX group were significantly improved compared to those in the PPV group (P = 0.037 and 0.038, respectively). Multivariate regression analyses revealed that patients with intraoperative DEX implants were more likely to have a significant CMT reduction (≥ 100 μm) from baseline (odds ratio (OR), 9.44; 95% confidence intervals (CI), 1.58-56.56; P = 0.014) at 6 months and less likely to exhibit DRIL at 6 months postoperatively (OR, 0.08; 95% CI, 0.01-0.68; P = 0.021).

CONCLUSION

Vitrectomy combined with intravitreal DEX implantation facilitates the recovery of postoperative visual acuity and improvement of anatomical outcomes in patients with advanced IERM, effectively reducing CMT and improving DRIL.

Clinical Utility of Spectral-Domain Optical Coherence Tomography Marker Disorganization of Retinal Inner Layers in Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

Disorganization of retinal inner layers (DRIL) is a potential spectral-domain optical coherence tomography (SD-OCT) imaging biomarker with clinical utility in diabetic retinopathy (DR).

PATIENTS AND METHODS

A cross-sectional study was conducted at a large academic center. The cohort was composed of 1,175 patients with type 2 diabetes with and without retinopathy on initial examination between September 2009 and January 2019 (n = 2,083 eyes). DR risk and progression factors were obtained from the medical record. Trained graders masked to patients' clinical histories evaluated SD-OCT scans for DRIL.

RESULTS

Of 2,083 eyes, 28.1% (n = 585) demonstrated presence of DRIL with high interrater reliability (K = 0.88, 95% CI 0.86-0.90). DRIL was associated with worse visual acuity (VA) (P < 0.001) and DR severity (P < 0.0001). Insulin users had more severe DR (P < 0.0001). DR-related factors, race (Black, White) and sex (male) were significantly associated with DRIL (P < 0.05).

CONCLUSIONS

DRIL was strongly associated with DR severity and worse VA, supporting its utility as an unfavorable prognostic indicator. [Ophthalmic Surg Lasers Imaging Retina 2023;54:692-700.].

Characterization of peripheral blood inflammatory indicators and OCT imaging biological markers in diabetic retinopathy with or without nephropathy

Objective

To observe the distribution characteristics of peripheral blood inflammatory indexes and retinal macular area optical coherence tomography (OCT) imaging biomarkers in patients with diabetic retinopathy (DR) with or without diabetic nephropathy (DN), in order to seek clinical biomarkers that can predict the development of DR and DN.

Methods

A total of 169 inpatients with DR who visited the ophthalmology department of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from October 2020 to June 2022 and had complete clinical data were collected, and the patients with DR were divided into two major groups, DR and DR/DN, according to whether they had DN, and then further divided into four subgroups, Non-proliferative DR(NPDR), proliferative DR(PDR), NPDR/DN and PDR/DN, according to the stage of DR. The distribution characteristics of peripheral blood inflammatory indexes [Neutrophil to lymphocyte ratio(NLR) and Platelet to neutrophil ratio(PLR)], renal function indexes [Cystatin-C(CYS-C), Creatinine(Crea), Uric acid(UA)and Urinary albumin to creatinine ratio(UACR)] and OCT imaging indexes [Hyperreflective foci(HRF), Disorgnization of retinal inner layers(DRIL), Outer retinal tubulations(ORTs), Central retinal thickness(CRT), Retinal nerve fiber layer(RNFL) and Ganglion cell layer(GCL)] were analyzed between the above subgroups.

Results

There was no difference between DR and DR/DN groups in terms of gender, family history of diabetes, duration of diabetes and Body mass index(BMI) (P>0.05), the mean age of the DR/DN group was significantly lower than that of the DR group (P<0.05), and the proportion of the DR/DN group with a history of hypertension was significantly higher than that of the DR group (P<0.05); there was no significant difference in hemoglobin A1C(HbA1c) between DR and DR/DN groups (P>0.05). (P>0.05), Hemoglobin(HGB) was significantly higher in the DR group than in the DR/DN group (P <0.05), NLR, PLR, Crea, UA and CYS-C were significantly higher in the DR/DN group than in the DR group (P<0.05); there was no significant difference in the comparison of HRF, DRIL, ORTs positive rate and CRT between the DR and DR/DN groups (P>0.05). RNFL and GCL thickness were significantly lower in the DR/DN group than in the DR group (P<0.05); history of hypertension (OR=2.759), NLR (OR=1.316), PLR (OR=1.009), Crea (OR=1.018), UA (OR=1.004), CYS-C (OR=3.742) were the independent (OR=0.951), age (OR=0.951), HGB (OR=0.976), RNFL (OR=0.909) and GCL (OR=0.945) were independent protective factors for DR/DN; RNFL (OR=0.899) and GCL (OR=0.935) were independent protective factors for NPDR/DN, RNFL (OR=0.852) and GCL (OR=0.928) were independent protective factors for PDR/DN. ROC curve analysis showed that the area under the curve (AUC) for CYS-C, PLR, Crea, UA and the combination of the four indicators to predict DR/DN were 0.717, 0.625, 0.647, 0.616 and 0.717, respectively.

Conclusions

(1) Low age combined with hypertension HGB, NLR, PLR, CYS-C, Crea and UA may be serum biological markers for predicting DN in DR; meanwhile, PLR, CYS-C, Crea, UA and the combination of the four indicators can be used for risk assessment and adjunctive diagnosis of DN in DR combined with hypertension. (2) The RNFL and GCL thickness in the temporal aspect of the central macular sulcus may be imaging biological markers for predicting DN in DR; meanwhile, GCL thickness may have important value for risk prediction and diagnosis of DN in combination with DR.

Automated assessment of the smoothness of retinal layers in optical coherence tomography images using a machine learning algorithm

Quantifying the smoothness of different layers of the retina can potentially be an important and practical biomarker in various pathologic conditions like diabetic retinopathy. The purpose of this study is to develop an automated machine learning algorithm which uses support vector regression method with wavelet kernel and automatically segments two hyperreflective retinal layers (inner plexiform layer (IPL) and outer plexiform layer (OPL)) in 50 optical coherence tomography (OCT) slabs and calculates the smoothness index (SI). The Bland-Altman plots, mean absolute error, root mean square error and signed error calculations revealed a modest discrepancy between the manual approach, used as the ground truth, and the corresponding automated segmentation of IPL/ OPL, as well as SI measurements in OCT slabs. It was concluded that the constructed algorithm may be employed as a reliable, rapid and convenient approach for segmenting IPL/OPL and calculating SI in the appropriate layers.

Disorganization of retinal inner layers: diagnostic and clinical characteristics

This review describes the current state of knowledge oт the phenomenon of disorganization of retinal inner layers. DRIL is characterized by alteration of microcirculation in retinal capillary plexuses detected with optical coherence tomography angiography, alteration of several inner layers of the retina with the inability to differentiate them on optical coherence tomography, and by an impact on the quality of vision. Disorganization of retinal inner layers occurs in a number of different vascular retinal disorders, which indicates its importance as a clinical biomarker and clinical significance. However, the literature data on disorganization of retinal inner layers are still limited, and questions about the pathogenesis of this disease warrant further investigations.

LONGITUDINAL ELLIPSOID ZONE AND OUTER RETINAL INTEGRITY DYNAMICS AFTER EPIRETINAL MEMBRANE SURGERY

PURPOSE

To quantify ellipsoid zone (EZ) changes in integrity after epiretinal membrane (ERM) surgery, correlate findings to visual acuity, and determine predictors for prognosis.

METHODS

A post hoc analysis of eyes undergoing ERM surgery pooled from the prospective DISCOVER intraoperative optical coherence tomography study and eyes undergoing conventional ERM surgery without intraoperative optical coherence tomography. Quantitative EZ features were extracted using a multilayer machine learning enabled automated segmentation platform after image analyst review/correction for segmentation accuracy. Visual acuity and EZ integrity were quantitatively assessed and correlated before and after ERM surgery. Multiple linear regression was performed to assess preoperative visual acuity and EZ features as predictors for improvement in visual acuity or EZ integrity.

RESULTS

There were 177 eyes from 177 subjects that underwent ERM surgery from the DISCOVER and conventional arms. Improvement in visual acuity and multiple EZ integrity features was noted after ERM surgery, including EZ partial attenuation and EZ-retinal pigment epithelium (RPE) volume (P < 0.05). A reduction in EZ partial attenuation and increase in EZ-RPE central subfield thickness (EZ-RPE CST) was significantly correlated with improved visual acuity after ERM surgery (P < 0.05). More robust EZ-RPE CST at baseline predicted visual acuity improvement after ERM peel in regression modeling (β = 0.005, P < 0.05).

CONCLUSIONS

Longitudinal assessment of EZ features demonstrates significant postoperative improvement in multiple EZ integrity metrics after ERM surgery. Improving EZ integrity was correlated to improving the visual acuity. Ellipsoid zone integrity and visual acuity were significant predictors in regression modeling and may have value in clinical prognostication.

Inner Retinal Morphology and Visual Outcomes in Idiopathic Epiretinal Membrane Surgery: A Retrospective Optical Coherence Tomography Study

Purpose:

Epiretinal membrane (ERM) is a common retinal finding for patients older than 50 years. Disorganization of the retinal inner layers (DRIL) has emerged as a novel predictor of poor visual acuity (VA) in eyes with inner retinal pathology. The aim of our study is to correlate preoperative DRIL with visual outcomes after ERM surgery.

Methods:

Medical records and optical coherence tomography (OCT) images of 81 pseudophakic patients who underwent treatment of idiopathic ERM were reviewed. Preoperative DRIL on OCT was correlated with VA at baseline and at 3 and 6 months after ERM surgery. DRIL was defined as the loss of distinction between the ganglion cell–inner plexiform layer complex, inner nuclear layer, and outer plexiform layer. DRIL severity was based on its extent within the central 2-mm region of a transfoveal B-scan (absent/mild: <one-third, severe: >one-third horizontal width).

Results:

Review of preoperative OCT showed severe DRIL in 41% and absent/mild DRIL in 59%. Severe DRIL was associated with worse baseline VA ( P < .001). Preoperative VA and DRIL status at baseline were both predictors of postoperative VA at follow-up time points ( P < .001). Severe DRIL was associated with significantly less improvement in VA at 6 months (–0.23 logMAR for absent/mild vs –0.14 for severe DRIL).

Conclusions:

Presence of severe preoperative DRIL correlates with worse baseline VA in patients with ERM and reduced VA improvement at 6 months. DRIL can be a strong predictor of long-term poor visual outcomes in ERM surgery.

Livelayer: a semi-automatic software program for segmentation of layers and diabetic macular edema in optical coherence tomography images

Given the capacity of Optical Coherence Tomography (OCT) imaging to display structural changes in a wide variety of eye diseases and neurological disorders, the need for OCT image segmentation and the corresponding data interpretation is latterly felt more than ever before. In this paper, we wish to address this need by designing a semi-automatic software program for applying reliable segmentation of 8 different macular layers as well as outlining retinal pathologies such as diabetic macular edema. The software accommodates a novel graph-based semi-automatic method, called "Livelayer" which is designed for straightforward segmentation of retinal layers and fluids. This method is chiefly based on Dijkstra's Shortest Path First (SPF) algorithm and the Live-wire function together with some preprocessing operations on the to-be-segmented images. The software is indeed suitable for obtaining detailed segmentation of layers, exact localization of clear or unclear fluid objects and the ground truth, demanding far less endeavor in comparison to a common manual segmentation method. It is also valuable as a tool for calculating the irregularity index in deformed OCT images. The amount of time (seconds) that Livelayer required for segmentation of Inner Limiting Membrane, Inner Plexiform Layer-Inner Nuclear Layer, Outer Plexiform Layer-Outer Nuclear Layer was much less than that for the manual segmentation, 5 s for the ILM (minimum) and 15.57 s for the OPL-ONL (maximum). The unsigned errors (pixels) between the semi-automatically labeled and gold standard data was on average 2.7, 1.9, 2.1 for ILM, IPL-INL, OPL-ONL, respectively. The Bland-Altman plots indicated perfect concordance between the Livelayer and the manual algorithm and that they could be used interchangeably. The repeatability error was around one pixel for the OPL-ONL and < 1 for the other two. The unsigned errors between the Livelayer and the manual algorithm was 1.33 for ILM and 1.53 for Nerve Fiber Layer-Ganglion Cell Layer in peripapillary B-Scans. The Dice scores for comparing the two algorithms and for obtaining the repeatability on segmentation of fluid objects were at acceptable levels.

Reliability of Subjective Assessment of Spectral-Domain OCT Pathologic Features by Multiple Raters in Retinal Vein Occlusion

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Disorganization of the retinal inner layers as a predictor of visual acuity in eyes with macular edema secondary to uveitis

AIM

To assess the correlation between disorganization of the retinal inner layers (DRIL) and best-corrected visual acuity (BCVA) in patients with uveitis and macular edema (UME) who underwent systemic treatment using optical coherence tomography (OCT).

METHODS

A retrospective clinical study of 23 patients (30 eyes) with DRIL and 23 patients (31 eyes) without DRIL secondary to UME were included. All patients underwent comprehensive ophthalmic examinations at baseline, 3, 6, and 12mo after local and systemic treatment. The OCT-based parameters included foveal center point thickness (FCPT), mean thickness (MT), and diameters of DRIL in horizontal and vertical directions. BCVA and OCT-based parameters were compared between the two groups. The relationship between each OCT parameter and BCVA was evaluated using linear correlation and regression analysis.

RESULTS

At the initial visit, the mean baseline FCPT was 441.03±128.68 µm in the eyes with DRIL and 337.26±99.31 µm in the eyes without DRIL (P=0.001). No significant differences were observed in MT (P=0.357). The mean size of transverse and vertical diameters of DRIL was 684.07±267.51 and 267.07±104.61 µm at baseline, respectively. There was significant improvement in BCVA and OCT-based parameters at 3, 6, and 12mo in all cases (P<0.001 for each timepoint). In addition, significant differences were detected in BCVA and OCT parameters between eyes with and without DRIL at each time point (P<0.01 for each timepoint). A greater DRIL range at baseline was associated with a worse baseline BCVA (transverse diameter of DRIL: r=0.875, P<0.001; vertical diameter of DRIL: r=0.622, P<0.001). The transverse diameter of baseline DRIL was found to be significantly correlated with the final BCVA (P=0.003).

CONCLUSION

The improvement in BCVA is associated with DRIL in patients with UME. DRIL is an easy-to-determine and robust imaging biomarker that could help predict BCVA prognosis in eyes with UME.

Association of disorganization of retinal inner layers with optical coherence tomography angiography features in branch retinal vein occlusion

PURPOSE

To examine the associations between the disorganization of the retinal inner layers (DRIL) and optical coherence tomography angiography characteristics and visual acuity (VA) outcomes in eyes with macular edema secondary to branch retinal vein occlusion (BRVO).

METHODS

In this single-center cross-sectional cohort study, the data of 43 patients with macular edema secondary to BRVO that received pro re nata anti-vascular endothelial growth factor therapy were analyzed. B-scan and en face angiographic images were obtained by swept-source-based wide-field optical coherence tomography angiography performed at a single visit 1 month after the anti-vascular endothelial growth factor therapy session and evaluated. Correlations between the vascular indices in macula-centered 3 × 3 and 12 × 12 mm² areas and B-scan parameters, such as DRIL length and VA, were examined.

RESULTS

The mean DRIL length (Rs = 0.588, p < 0.001) and the proportion of scans with DRIL out of five scans (Rs = 0.507, p = 0.001) were significantly correlated with the final best-corrected VA in patients with BRVO. DRIL length was associated with vascular density (VD) and vascular length in the macula (Rs =  - 0.425, p = 0.006 and Rs =  - 0.382, p = 0.013, respectively), but not with VD and vascular length in the larger areas (12 × 12 mm²). Multilinear regression analysis revealed that the extent of macular edema (p = 0.0016) and VD in the 3 × 3 mm² area (p = 0.004) was significantly associated with the DRIL development.

CONCLUSION

DRIL severity was correlated with VA and associated with the peri-macular perfusion status in eyes with BRVO. Macular edema and macular perfusion affected DRIL severity. These findings would help understand the pathogenesis of DRIL in eyes with BRVO.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.