Cup-to-disc Ratio Research Articles

Prevalence of glaucoma in Canada: results from the 2016–2019 Canadian Health Measures Survey

ObjectiveTo estimate the prevalence of glaucoma in Canada based on self-reports and test data, including Frequency Doubling Technology Perimetry (FDT), optic nerve vertical cup-to-disc ratio (CDR), intraocular pressure (IOP), and use of glaucoma medications. DesignCross-sectional survey. Participants2,600–4,100 participants aged 40–79 in the Canadian Health Measures Survey 2016–2019 with available information from self-report, CDR, FDT, and IOP. MethodsGlaucoma was defined by self-reports, CDR ≥ 0.7 only, or failed FDT only. Incorporating results of CDR, FDT, IOP, and use of glaucoma medications, participants were further classified as definite glaucoma (failed FDT and CDR ≥ 0.7) or glaucoma suspects (CDR ≥ 0.7 only, failed FDT only, or IOP > 21 mmHg only, or “normal” values of FDT, CDR, and IOP but used glaucoma medications). Survey weights were used in analyses. ResultsThe glaucoma prevalence was 2.5% (95% confidence interval [CI] 1.7%–3.3%) utilizing self-reports, 3.0% (95% CI 2.1%–3.9%) by CDR ≥ 0.7 only and 10.3% (7.8%–12.8%) with failed FDT only. Merging test data, the prevalence of definite glaucoma was 0.7% (95% CI 0.3%–1.1%) and the prevalence of suspected glaucoma was 16.3% (95% CI 13.2%–19.4%). Among the patients suspected of having glaucoma, 44.4% had ocular hypertension (OHT, mean IOP 22.8 mmHg) and 6.8% used glaucoma medications. IOP ≥28 mmHg was found in 2.4% of OHT individuals, and none used glaucoma medications.37.5% of Canadians with definite glaucoma were unaware they had glaucoma. ConclusionsGlaucoma prevalence in Canadians aged 40–79 varied between 0.7% and 10.3% depending on definition used. 16.3% of Canadians were labeled “glaucoma suspects”. Nearly 40% of Canadians with definite glaucoma were unaware of having glaucoma.

Does Inter-Eye Asymmetry of Disc Area Explain Differences in Onset of Nonarteritic Anterior Ischemic Optic Neuropathy?

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in individuals over the age of 50 years. It is associated with conventional vascular risk factors and structural vulnerabilities including "disc-at-risk." We aim to ascertain if a correlation exists between optic nerve head size and the onset of NAION. We performed a retrospective chart review of patients with an ICD-10 diagnosis of unilateral or bilateral NAION who underwent optical coherence tomography (OCT) and visual field testing. The primary outcome measure was the disc area as measured on OCT at a follow-up (minimum 6 months after acute vision loss) of the involved (or first involved for bilateral cases) vs fellow eye. The secondary outcome was the cup-to-disc ratio (CDR) of the first vs fellow eye. Seventy-three patients were included, of which 58 (79%) had unilateral and 15 (21%) had bilateral NAION, with a median follow-up of 23 months. Between the first eye involved and the fellow eye, there were no statistically significant differences in the mean disc area (1.69 ± 0.29 vs 1.71 ± 0.29, P = 0.7). However, average CDR (0.41 ± 0.20 vs 0.28 ± 0.18, P < 0.001) and vertical CDR (0.42 ± 0.20 vs 0.28 ± 0.19, P < 0.0001) were significantly larger in the involved eye. Despite no statistically significant differences in the disc area between the affected eye and the fellow eye, CDR was larger in eyes with a history of NAION compared with fellow eyes. Further research is required to elucidate local factors that may increase the risk of NAION in one eye relative to the other.

Two-Year Results of Gonioscopy-Assisted Transluminal Trabeculotomy in Primary Congenital Glaucoma.

Gonioscopy-assisted transluminal trabeculotomy yielded a 45% reduction in intraocular pressure in primary congenital glaucoma, with a success rate of 86.6%. Hyphema was the most common complication. We did not encounter any vision-threatening complications. To assess the outcome of gonioscopy-assisted transluminal trabeculotomy (GATT) in primary congenital glaucoma (PCG) and identify the potential prognostic factors for adverse outcomes. This prospective study included patients aged <14 years, presenting with PCG from November 2019 till November 2021. We excluded eyes with hazy cornea, secondary glaucoma, peripheral anterior synechiae ≥90 degrees, and eyes in which the extent of GATT was <270 degrees. Success was defined as a final intraocular pressure (IOP) <18mmHg with IOP reduction >20%. Primary outcomes were reduction in IOP and medications, secondary outcomes were complications and correlation of IOP reduction and surgical success with possible risk factors. We included 60 eyes of 50 patients aged 1-156 months (mean: 25.5±36.5). A 353±21 degrees incision was created, with 85% achieving a 360-degree incision. There was a significant reduction in IOP and medications at all follow-up intervals up to 2 years, with a mean of 45% IOP reduction. The final success rate was 86.6%, with 76.7% being controlled without medications. There was a significant positive correlation between the preoperative cup-to-disc ratio (CDR) and failure rates ( P =0.03) and between the incision extent and the IOP reduction (r=0.4, P =0.001). Hyphema was the most common complication, affecting 33%, and resolved spontaneously in all cases. No vision-threatening complications occurred. GATT is a safe and effective procedure in eyes with PCG and clear cornea, including eyes that had previous failed glaucoma surgery. Circumferential GATT is associated with more favorable outcomes, while eyes with a larger CDR are at a higher risk for failure.

Effective low-cost pediatric vision screening by naive nonophthalmic examiners using the 'Arclight' device.

To explore whether a low-cost ophthalmoscope (Arclight) can be used by naive nonophthalmic examiners to effectively screen for pediatric eye disease. Fifty-four children (108 eyes) were examined by five medical students using an Arclight. Gold standard examination was performed by an ophthalmologist using a slit lamp and indirect ophthalmoscope. Examinations performed included ophthalmoscopy of the optic disc, estimation of the cup-to-disc ratio (CDR), corneal light reflex test (CRT), Bruckner's reflex test (BRT), and evaluation of refractive error. We determined the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the nonophthalmologist's Arclight exam compared to the gold standard findings of comprehensive evaluation by pediatric ophthalmologists. Using the Arclight, the optic nerve exam was successfully completed in 65% of patients. CDRs above and below 0.5 could be determined with 66.7% sensitivity and 84.4% specificity. Arclight CRT measurements were significant (P < .00001) predictors of strabismus, with 80% sensitivity, 95.1%, specificity, 80% PPV, and 95.1% NPV. BRT was not a significant predictor of amblyopia, with a 34.6% sensitivity, 85.7% specificity, 69.2% PPV, and 58.5% NPV. Refractive error was estimated with a success rate of 81% for emmetropia, 38% for myopia, and 21% for hyperopia. The Arclight ease-of-use was rated on average as 4.4 (SD = 0.9) on a scale of 1 to 5, with 1 being the hardest and 5 being the easiest. Our study shows the Arclight as an affordable and effective alternative to the traditional ophthalmoscope for assessing eye disease in children. This device can improve eye health services in under-resourced regions.

Optimizing open-angle glaucoma risk assessment in patients with retinal vein occlusions.

To evaluate factors associated with the diagnosis of open-angle glaucoma (OAG) after a retinal vein occlusion (RVO). Retrospective, cross-sectional study. Patients diagnosed with OAG after RVO were matched 2:1 with RVO patients without prior glaucoma. Logistic regression identified factors linked to OAG diagnosis. Of 1178 RVO patients without initial OAG, 51 (4.5%) were later diagnosed with OAG after an average of 5.5 ± 6.1 years. Screening tests for OAG were performed at a higher frequency in patients diagnosed with OAG compared with patients who never received this diagnosis (visual field [VF] testing 21.6% versus 10.8% (P = 0.073) and retinal nerve fiber layer [RNFL] imaging 52.9% versus 27.4% (P = 0.002), respectively). At the time of the first VF obtained after RVO, mean deviation averaged -10.3 dB in the affected eyes, compared with -5.0 dB in the fellow eyes (P < 0.001); in contrast, RNFL thickness was similar between eyes at the time of OAG diagnosis (72 µm versus 74 µm, P = 0.290). Predictive factors for OAG diagnosis included higher intraocular pressure (IOP) and cup-to-disc ratio (CDR) in the unaffected eye, and the absence of macular edema in the RVO-affected eye (R2 = 0.375, P < 0.001). OAG is a significant risk factor for RVO. Our study reveals a reciprocal relationship between RVO and the development of OAG, highlighting the need for glaucoma risk assessment in all patients with RVOs to avoid delays in diagnosis and vision loss from glaucoma.

LC-MANet: Location-constrained joint optic disc and cup segmentation via multiplex aggregation network

Many early ophthalmology-related diseases can be detected through fundus images. The cup-to-disc ratio (CDR) is an important criterion for the early screening and diagnosis of glaucoma. However, accurately calculating it is a challenging task primarily due to blurred boundaries and the physiological structure of the fundus. To alleviate these issues, this paper designs a location-constrained joint optic disc (OD) and optic cup (OC) segmentation method using the multiplex aggregation network (LC-MANet). This method incorporates independent segmentation and joint segmentation within a coarse-to-fine framework. In the independent segmentation stage, this paper utilizes the initial OD and OC as prior location auto-context information to constrain the joint segmentation of OD and OC. The proposed multiplex aggregation network combines features from the corresponding layer and across layers to capture global and local information. This paper employs a multi-channel fusion strategy in image preprocessing to suppress vascular interference in OD independent segmentation. To emphasize the superiority of our method, it is important to highlight the significant number of test images used in the evaluation. Our experiments are conducted on three public datasets, namely RIM-ONE (60 images), Drishti-GS (51 images), and REFUGE (400 images). Experimental results demonstrate that our method outperforms most others in terms of Dice Coefficient and absolute error. The accuracy of glaucoma screening achieved by our proposed method for the Drishti-GS, REFUGE, and RIM-ONE-r3 datasets is 0.9216, 0.9600, and 0.9000, respectively. The proposed framework successfully designs a multiplex aggregation network for a coarse-to-fine joint segmentation model and achieves state-of-the-art performance in OD and OC segmentation. Furthermore, it can be applied to other medical image segmentation tasks.

Optic nerve head and retinal nerve fiber layer changes by spectral domain optical coherence tomography in glaucoma suspects at tertiary care hospital

Introduction: Glaucoma is a progressive optic neuropathy characterized by functional loss or optic nerve dysfunction which is one of the leading causes of irreversible but preventable blindness. The aim of the study was to determine which of the retinal nerve fiber layer and optic nerve head parameters are reliable markers of optic nerve damage in glaucoma suspects. Methods: Observational cross-sectional study of 250 patient’s including147 glaucoma suspect eyes, 103 normal eyes. All subjects underwent complete eye examination and imaging with the spectral domain optical coherence tomography (SD-OCT) cirrus-TM OCT (Carl Zeiss Meditec, Dublin, CA). Retinal nerve fiber layer (RNFL) and optic nerve head (ONH) OCT protocols were used to evaluate all study participants. The main outcome measures were the difference in OCT parameters among groups. Results: Study shows statistically significant difference in the average RNFL thickness, superior, nasal, inferior, temporal quadrants, rim area, cup volume, average cup to disc ratio (CDR), vertical CDR with P value &lt;0.001 between the two groups. Average CDR, vertical CDR and cup volume had significantly greater AROC values (ROC: 0.99, 0.98, 0.95) than RNFL parameters for discriminating glaucoma suspects from normal eyes. Conclusion: Assessment of RNFL, macular and ONH damage with SD-OCT has been proven useful for diagnosing the disease at different levels of severity, as well as for quantifying risk in glaucoma suspects. In our study ONH measurements, as provided by the SD OCT, have more diagnostic value than RNFL parameters in the diagnosis of glaucoma suspects from normal. Keywords: glaucoma suspects; optic nerve head; retinal nerve fiber layer; optical coherence tomography

Optic cup morphology associated with glaucomatous damage: Findings from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study

PurposeWhile it has been well established that advanced glaucoma is associated with a large cup-to-disc ratio (CDR), it is not known if the shape of the cup, particularly excavated cups with expanded lower portions (bean-pot cups), play any additional role in glaucomatous damage. We investigated this among individuals of African ancestry, a population that is more vulnerable to glaucoma than any other ethnic group. DesignCase-control study Methods SettingInstitutional (University of Pennsylvania) Subjects3,255 eyes from 1,734 glaucoma cases from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. ProcedureTwo graders independently assessed quantitative and qualitative aspects of the optic cup, with any discrepancies adjudicated by an ophthalmologist. The predominant cup shape (>50 %) was chosen in cases in which features of two or more cup shapes were present in the same eye. Comparisons of demographic and ocular characteristics among three cup shape groups (conical, cylindrical, and bean-pot) performed using generalized linear models, and generalized estimated equations applied to account for inter-eye correlation. Main Outcome MeasuresQualitative features of cup shape and phenotypic traits, in conjunction with demographic and genetic information. ResultsOf 3,255 eyes, a total of 1,339 (41.1 %) exhibit a conical cup shape, 1,470 (45.2 %) have a cylindrical cup shape, and 446 (13.7 %) display a bean-pot cup shape. Compared to other cup morphology, bean-pot cups are significantly associated with lower MD, larger CDR, higher IOP, thinner RNFL, and worse VA in logMAR (all p < 0.001). Genetic analysis does not show any association between various genetic variants and cup shape. Factors independently predictive of bean-pot cupping include younger age at diagnosis (aOR 0.96 per 1 year increase in age of enrollment, p < 0.0001), CDR (adjusted odds ratio (aOR) 1.87, p < 0.0001), and the presence of certain optic disc features, including visible pores in the LC (aOR 2.76, p < 0.0001), nasalization of vessels (aOR 2.64, p < 0.0001), and vessel bayonetting (aOR 2.94, p < 0.0001). ConclusionThis study shows the clinical significance of different cup shapes in glaucoma in an African ancestry population and suggests that bean-pot cups are associated with the most severe glaucomatous damage, independent of cup-disc ratio. This association should be considered when determining prognosis following glaucoma interventions.

Correlative Study of Central Corneal Thickness and Intraocular Pressure with Optic Disc Changes in Primary Open-Angle Glaucoma

Abstract Background: Primary open-angle glaucoma (POAG) is characterised by open angles, raised intraocular pressure (IOP) and optic disc changes. Undetected glaucoma is the third leading cause of blindness. The study aims to correlate central corneal thickness and IOP with optic disc changes in POAG and to aid in the early detection and timely management of glaucoma to prevent advanced damage and vision loss. Methods: In this hospital-based prospective observational study, 50 cases (100 eyes) of POAG were selected after applying the inclusion and exclusion criteria. Detailed history, ocular examination, visual acuity testing, slit-lamp examination, gonioscopy, ultrasound pachymetry for central corneal thickness (CCT), IOP with Goldmann Applanation Tonometry (GAT), fundus examination with +90D lens and visual fields on Humphrey’s automated field analyser were performed for all patients. Results: There was a statistically highly significant positive correlation between IOP and CCT in the right and left eyes (P &lt; 0.01). There was a statistically very highly significant difference between mean IOP and mean corrected IOP in the right eye and left eye also (P &lt; 0.001). There was a statistically very highly significant difference in IOP, CCT and fundus cup-to-disc ratio (CDR) with HAP staging (P &lt; 0.001). Conclusions: IOP was positively related to CCT. Thinner CCT &lt;510μm eyes are at greater risk for more advanced disc cupping. Disc cupping increased proportionately with the rise in IOP. Thinner corneal readings should alarm the ophthalmologist to evaluate the patient thoroughly for glaucoma and monitor follow-up to keep a check on possible progression.

MA‐ResUNet: Multi‐attention optic cup and optic disc segmentation based on improved U‐Net

AbstractGlaucoma poses a significant threat to vision, capable of causing irreversible damage and, in severe instances, leading to permanent blindness. Accurate optic cup (OC) and optic disc (OD) segmentation are essential in glaucoma screening. In this study, a novel OC and OD segmentation approach is proposed. Based on U‐Net, it is optimized by introducing cardinality dimensions. Moreover, attention gates are implemented to reinforce salient features while suppressing irrelevant information. Additionally, a convolutional block attention module (CBAM) is integrated into the decoder segment. This fusion hones in on effective information in both channel and spatial dimensions. Meanwhile, an image processing procedure is proposed for image normalization and enhancement. All of these increase the accuracy of the model. This model is evaluated on the ORIGA and REFUGE datasets, demonstrating the model's superiority in OC and OD segmentation compared to the state‐of‐the‐art methods. Additionally, after the proposed image processing, cup‐to‐disc ratio (CDR) prediction on a batch of 155 in‐house fundus images yields an absolute CDR error of 0.099, which is reduced by 0.04 compared to the case where only conventional processing was performed.

CORRELATION OF VISUAL FIELD CHANGES WITH OPTICAL COHERENCE TOMOGRAPHY IN PRIMARY OPEN ANGLE GLAUCOMA

PURPOSE: To detect morphological changes in Optic Nerve Head (ONH), macula and Retinal nerve fibre layer (RNFL) using spectral domain optical coherence tomography (SDOCT) and to correlate them with functional loss (Visual field changes) using 24-2 and 10-2 standard automated perimetry in Primary open angle glaucoma patients. RESULTS: Mean value of 90D cup to disc ratio (CDR) of study subjects was 0.64 ± 0.13 with median (25th-75th percentile) of 0.7(0.6-0.7). Mean value of average RNFL thickness(microns), superior quadrant thickness (micron), inferior quadrant thickness (micron), nasal quadrant thickness (micron) and temporal quadrant thickness (micron) of study subjects was 62.35 ± 14.43, 77.96 ± 14.29, 81.41 ± 22.84, 51.33 ± 21.14 and 50.71 ± 17.71 with median(25th-75th percentile) of 63(52-75), 78(66.25-89), 81.5(64.25-93.75), 54(46-63) and 50.5(39-57.75) respectively. Mean value of average macular thickness (micron), macular GCL-IPL thickness -Superior quadrant (micron) and macular GCL-IPL thickness -Inferior quadrant (micron) of study subjects was 65.6 ± 11.7, 76.49 ± 11.63 and 76.76 ± 16.86 with median (25th-75th percentile) of 64(56-75), 75(67-87.75) and 75.5(65.25-93) respectively. Mean value of MD and PSD of study subjects was -7.34 ± 4.47 and 6.8 ± 3.11 with median (25th-75th percentile) of -7.65(-11--3.1) and 6.9(3.9-9.1) respectively. 57(41.3%) eyes had early glaucoma, 51(37%) eyes had moderate glaucoma and 30(21.7%) eyes had advanced glaucoma. CONCLUSION: In present study, ONH parameters (rim area), RNFL parameter (inferior quadrant thickness) and macula parameters (average macular GCLIPL thickness) showed statistically significant correlation with VF MD. Correlation between VF parameters i.e. MD and PSD with OCT parameters shown that there was a relation between Macular GCLIPL thickness ,RNFL thickness and ONH with the changes in the results of VF.

DEC-DRR: deep ensemble of classification model for diabetic retinopathy recognition.

Most diabetes patients are liable to have diabetic retinopathy (DR); however, the majority of them might not be even aware of the ailment. Therefore, early detection and treatment of DR are necessary to prevent vision loss. But, avoiding DR is not a simple process. An ophthalmologist can typically identify DR through an optical evaluation of the fundus and through the evaluation of color pictures. However, due to the increased count of DR patients, this could not be possible as it consumes more time. To rectify this problem, a novel deep ensemble-based DR classification technique is developed in this work. Initially, a Wiener filter (WF) is applied for preprocessing the image. Then, the enhanced U-Net-based segmentation process is done. Subsequent to the segmentation process, features are extracted that include statistical features, inferior superior nasal temporal (ISNT), cup to disc ratio (CDR), and improved LGBP as well. Further, deep ensemble classifiers (DEC) like CNN, Bi-GRU, and DMN are used to recognize the disease. The outcomes from DMN, CNN, and Bi-GRU are then subjected to improved SLF. Additionally, the weights of DMN, CNN, and Bi-GRU are adjusted via pelican updated Tasmanian devil optimization (PU-TDO). Finally, outputs on DR (microaneurysms, hemorrhages, hard exudates, and soft exudates) are obtained. The performance of DEC + PU-TDO for diabetic retinopathy is computed over extant models with regard to different measures for four datasets. The results on accuracy using the DEC + PU-TDO scheme for the IDRID dataset is maximum around 0.975 at 90th LP while other models have less accuracy. The FPR of DEC + PU-TDO is less around 0.039 at the 90th LP for the SUSTech-SYSU dataset, while other extant models have maximum FPR.

Highly Accurate and Precise Automated Cup-to-Disc Ratio Quantification for Glaucoma Screening

An enlarged cup-to-disc ratio (CDR) is a hallmark of glaucomatous optic neuropathy. Manual assessment of the CDR may be less accurate and more time-consuming than automated methods. Here, we sought to develop and validate a deep learning-based algorithm to automatically determine the CDR from fundus images. Algorithm development for estimating CDR using fundus data from a population-based observational study. A total of 181768 fundus images from the United Kingdom Biobank (UKBB), Drishti_GS, and EyePACS. FastAI and PyTorch libraries were used to train a convolutional neural network-based model on fundus images from the UKBB. Models were constructed to determine image gradability (classification analysis) as well as to estimate CDR (regression analysis). The best-performing model was then validated for use in glaucoma screening using a multiethnic dataset from EyePACS and Drishti_GS. The area under the receiver operating characteristic curve and coefficient of determination. Our gradability model vgg19_batch normalization (bn) achieved an accuracy of 97.13% on a validation set of 16045 images, with 99.26% precision and area under the receiver operating characteristic curve of 96.56%. Using regression analysis, our best-performing model (trained on the vgg19_bn architecture) attained a coefficient of determination of 0.8514 (95% confidence interval [CI]: 0.8459-0.8568), while the mean squared error was 0.0050 (95% CI: 0.0048-0.0051) and mean absolute error was 0.0551 (95% CI: 0.0543-0.0559) on a validation set of 12183 images for determining CDR. The regression point was converted into classification metrics using a tolerance of 0.2 for 20 classes; the classification metrics achieved an accuracy of 99.20%. The EyePACS dataset (98172 healthy, 3270 glaucoma) was then used to externally validate the model for glaucoma classification, with an accuracy, sensitivity, and specificity of 82.49%, 72.02%, and 82.83%, respectively. Our models were precise in determining image gradability and estimating CDR. Although our artificial intelligence-derived CDR estimates achieve high accuracy, the CDR threshold for glaucoma screening will vary depending on other clinical parameters. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Features Associated with Visible Lamina Cribrosa Pores in Individuals of African Ancestry with Glaucoma: Primary Open-Angle African Ancestry Glaucoma Genetics (POAAGG) Study.

There are scarce data regarding the rate of the occurrence of primary open-angle glaucoma (POAG) and visible lamina cribrosa pores (LCPs) in the eyes of individuals with African ancestry; the potential impact of these features on disease burden remains unknown. We recruited subjects with POAG to the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. Through regression models, we evaluated the association between the presence of LCPs and various phenotypic features. In a multivariable analysis of 1187 glaucomatous eyes, LCPs were found to be more likely to be present in eyes with cup-to-disc ratios (CDR) of ≥0.9 (adjusted risk ratio (aRR) 1.11, 95%CI: 1.04-1.19, p = 0.005), eyes with cylindrical-shaped (aRR 1.22, 95%CI: 1.11-1.33) and bean pot (aRR 1.24, 95%CI: 1.13-1.36) cups versus conical cups (p < 0.0001), moderate cup depth (aRR 1.24, 95%CI: 1.06-1.46) and deep cups (aRR 1.27, 95%CI: 1.07-1.50) compared to shallow cups (p = 0.01), and the nasalization of central retinal vessels (aRR 1.33, 95%CI: 1.23-1.44), p < 0.0001). Eyes with LCPs were more likely to have a higher degree of African ancestry (q0), determined by means of SNP analysis (aRR 0.96, 95%CI: 0.93-0.99, p = 0.005 for per 0.1 increase in q0). Our large cohort of POAG cases of people with African ancestry showed that LCPs may be an important risk factor in identifying severe disease, potentially warranting closer monitoring by physicians.

Design of an Iterative Method for Enhanced Retinal Image Analysis Using Stacked Deep Learning Operations

The necessity for advanced diagnostic techniques in ophthalmology has become increasingly evident, particularly for conditions such as glaucoma and diabetic retinopathy, which necessitate precise retinal image analysis. Current methodologies, while effective to a degree, fall short in terms of accuracy, efficiency, and adaptability, especially in semantic segmentation and disease classification tasks. These limitations underscore the need for more sophisticated and reliable approaches to retinal image analysis. In response, this work introduces a comprehensive framework leveraging Fully Convolutional Neural Networks (FCNNs) for optic disc segmentation and Cup-to-Disc Ratio (CDR) estimation. The selection of FCNNs is predicated on their demonstrated proficiency in semantic segmentation, ability to discern spatial dependencies, and capacity to learn intricate structures within fundus images without relying on manually engineered features. This approach aims to surpass existing segmentation accuracy benchmarks, targeting over 95% Intersection over Union (IoU) while reducing the mean absolute error in CDR estimation to below 10%. To address the challenges of data variability and quality, the framework incorporates Contrast Limited Adaptive Histogram Equalization (CLAHE) for synthetic data generation, enhancing local contrast while preserving image integrity levels. This method is expected to improve contrast in augmented images by 30%, simultaneously enhancing image quality metrics. Furthermore, the introduction of an overlapping sliding window technique with adaptive patch sizes ensures meticulous coverage and analysis of fundus images, significantly elevating lesion detection sensitivity and reducing false positives. Lastly, the framework employs an innovative multi-disease classification strategy utilizing ensemble learning and stacking of CNN architectures. This synergistic approach amalgamates multiple base models to diminish overfitting risks and enhance generalization capabilities, aiming for a classification accuracy surpassing 95% in binary assessments and 85% for specific retinal diseases. The proposed model not only addresses the current gaps in retinal image analysis but also sets a new standard for precision, reliability, and efficiency in diagnosing and managing ocular diseases, marking a significant step forward in the application of artificial intelligence in ophthalmology.

Racial Disparities in Glaucoma Vision Outcomes and Eye Care Utilization: An IRIS Registry Analysis

PurposeTo evaluate racial disparities in vision outcomes and eye care utilization among glaucoma patients. DesignRetrospective cohort study. SettingPopulation-based IRIS Registry (Intelligent Research in Sight) study. ParticipantsPatients with minimum one diagnosis code for glaucoma at least 6 months prior to Jan 1st, 2015 and at least one eye exam, visual field (VF), optical coherence tomography (OCT), or eye-related inpatient or emergency department (ED) code in 2015. Main Outcomes and MeasuresMultivariable logistic and negative binomial regression models were used to assess vision and utilization outcomes, respectively, across race and ethnicity from Jan 1st 2015 – Jan 1st 2020. Vision outcomes included cup-to-disc ratio (CDR) progression > 0.80, poor vision (visual acuity 20/200 or worse), low vision codes, and need for glaucoma filtering surgery. Utilization outcomes included outpatient eye exams, OCTs, VFs, inpatient/ED encounters, and lasers/surgeries. ResultsAmong 996,297 patients, 73% were non-Hispanic White, 15% non-Hispanic Black, 9% Hispanic, 3% Asian/Pacific Islander, and 0.3% Native American/Alaska Native. Compared to White eyes, Black and Hispanic eyes had higher adjusted odds of CDR progression (odds ratio (OR)=1.12, 95%CI=1.08-1.17; OR=1.28, 95%CI=1.22-1.34), poor vision (OR=1.26, 95%CI=1.22-1.29; OR=1.26, 95%CI=1.22-1.31), glaucoma filtering surgery (rate ratio (RR)=1.47, 95%CI=1.42-1.51; RR=1.13, 95%CI=1.09-1.18). Hispanic eyes also had increased odds of low vision diagnoses (Hispanic OR=1.18, 95%CI=1.07-1.30). Black and Hispanic patients were less likely to have eye exams (RR=0.94, 95%CI=0.94-0.95; RR=0.99, 95%CI=0.99-0.99) and OCTs (RR=0.86, 95%CI=0.85-0.86; RR=0.97, 95%CI=0.96-0.98), yet Black patients had higher odds of inpatient/ED encounters (RR=1.64, 95%CI=1.37-1.96) compared to White patients. Native American patients were more likely to have poor vision (OR=1.17, 95%CI=1.01-1.36) and less likely to have outpatient visits (RR=0.89, 95%CI=0.86-0.91), OCTs (RR=0.85, 95%CI=0.82-0.89), visual fields (RR=0.91, 95%CI=0.88-0.94) or lasers/surgeries (RR=0.87, 95%CI=0.79-0.96) compared to White patients. ConclusionsWe found that significant disparities in US eye care exist with Black, Hispanic, and Native American patients having worse vision outcomes and less disease monitoring. Glaucoma may be undertreated in these racial and ethnic minority groups, increasing risk for glaucoma-related vision loss.

Structure-function relationship of reading performance in patients with early to moderate glaucoma.

To assess reading performance in patients with mild to moderate primary open-angle glaucoma (POAG), and to determine the relationship between reading ability and visual field (VF), microperimetry, and optical coherence tomography (OCT) parameters. Reading performance of 30 POAG patients examined by the Minnesota Reading Acuity Chart (MNREAD) was compared to that of 21 age-matched controls collected from Ankara University in Turkey. Humphrey Field Analyzer (HFA) 24-2 SITA Standard and 10-2 patterns, and microperimetry were used for VF measurements. All subjects underwent OCT analysis for retinal nerve fiber layer thickness (RNFLT), optic nerve head (ONH) measurements, and ganglion cell inner plexiform layer thickness (GCIPLT). The linear relationship between reading parameters and VF, microperimetry, and OCT parameters was investigated. Univariate and multiple logistic regression models were used to identify the risk factors for glaucoma. In POAG patients, maximum reading speed (MRS) had a significant association with average rim area, mean cup-to-disc ratio (CDR), and cup volume (p < 0.05, for all). Decreased MRS was associated with thinner average GCIPLT and inferotemporal, superior, and inferior GCIPLT quadrants (p < 0.05, for all). Global index values for the HFA 24-2/10-2 tests, microperimetry, and ONH/RNFLT parameters had no correlation with reading performance. After accounting for the better and worse eyes, gender, education, age, and visual acuity of the glaucoma patients, MRS score was 23 units lower in the worse eye (p = 0.009), critical print size (CPS) was 0.21 units larger in the better eye (p = 0.03) and 0.25 units larger in the worse eye (p < 0.001), reading accesibility index (ACC) was 0.11 units lower in the better eye (p = 0.02) and 0.13 units lower in the worse eye (p = 0.002), and RA was 0.13 units higher in the worse eye (p = 0.003) of POAG patients. POAG had significantly lower reading performance when compared to healthy subjects. Reading speed was associated with decreased macular GCIPLT indicating that reading performance may be affected in the earlier stages of the disease.

Crocin supplementation in primary open angle glaucoma: A randomized, triple-blind, placebo-controlled clinical trial

PurposeGlaucoma is the leading cause of irreversible visual loss in the world. The present study was designed to evaluate the beneficial effects of crocin, as a supplement, in the management of primary open-angle glaucoma (POAG). MethodsIn total, 50 POAG patients within the age range of 30–71 years with intraocular pressure (IOP) between 12 and 21 mmHg were entered into the study, and ultimately, 40 patients (49 eyes) finished the clinical trial. The participants were randomly divided into crocin and placebo groups. Patients in the crocin group received a 15 mg crocin tablet per day for four months while others, in the placebo group, received a placebo tablet per day for four months besides the main medications during the study. After four months, all patients underwent a two-month washout period. The IOP level and optical coherence tomography of the retinal nerve fiber layer (RNFL), cup-to-disc ratio (CDR), and the best-corrected visual acuity (BCVA), as the secondary outcomes, were measured at baseline, as well as four and six months later. ResultsThe IOP value decreased significantly in the crocin group after four (P = 0.0001) and six months (P = 0.003). The difference in CDR changes after four and six months was significant between the two groups (P = 0.00009). The crocin and placebo groups did not have a statistically significant difference regarding the changes in BCVA values and RNFL thickness (P = 0.092); however, the optical coherence tomography results showed stable conditions in the retinal nerve fiber layer. ConclusionThis study indicated that administration of crocin, as a potent neuroprotective and antioxidant ingredient of saffron, could be useful as a supplement for the prevention of the POAG progression.

Glaucoma after penetrating keratoplasty and keratoprosthesis

To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure. Retrospective interventional case series. Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included. Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures. Mean follow-up was 4.7years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045). A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

MRSNet: Joint consistent optic disc and cup segmentation based on large kernel residual convolutional attention and self-attention

Glaucoma is a prevalent eye disease that is responsible for causing blindness worldwide. To diagnose glaucoma, the cup-to-disc ratio (CDR) is an important factor. We introduce MRSNet, a novel segmentation network that incorporates encoding and decoding structures. The key innovation of this network is the application of convolutional block with large kernel convolutional attention to the task of medical image segmentation for optic cup and disc. By combining the benefits of residual and self-attention, our network achieves improved performance. The coding region of the network utilizes convolutional block with large kernel convolutional attention, enabling the extraction of multi-scale features with lower computational resources while also enhancing spatial attention. The self-attention layer acts as a transition between the encoding and decoding regions, capturing long connection information and providing additional image details. To further enhance segmentation performance, we employ a multi-resolution image combination approach and adaptively extract the input form using the compression and excitation module. Additionally, we propose a novel approach that combines the principle of consistency of deep supervision mechanisms with cross-entropy and Dice loss to guide the network towards accurate segmentation. In this study, we utilized a five-fold cross-validation method to train our network model. We then performed experimental validation and evaluation on three widely-used datasets, namely REFUGE, DRISHTI-GS, and RIM-ONE-r3. Our model achieved impressive results in the cup-to-disc ratio metric, which accurately reflects the segmentation effect. Specifically, we achieved scores of 0.0242, 0.0941, and 0.0158 for the aforementioned datasets, respectively. These scores outperformed some current classical algorithms. The experimental results demonstrate that the method proposed in this paper has the capability to extract more comprehensive information about the optic cup and disc, with the ability to generalize across different datasets. Furthermore, it shows that the convolutional block with large kernel convolutional attention module can be effectively utilized for the segmentation task of optic cup and disc. These findings provide a valuable research foundation for future researchers.