Search

Progressive optic neuropathies such as glaucoma are major causes of blindness globally. Multiple sources of subjectivity and analytical challenges are often encountered by clinicians in the process of early diagnosis and clinical management of these diseases. In glaucoma, the structural damage is often characterized by neuroretinal rim (NRR) thinning of the optic nerve head, and other clinical parameters. Baseline structural heterogeneity in the eyes can play a key role in the progression of optic neuropathies, and present challenges to clinical decision-making. We generated a dataset of Optical Coherence Tomography (OCT) based high-resolution circular measurements on NRR phenotypes, along with other clinical covariates, of 3973 healthy eyes as part of an established clinical cohort of Asian Indian participants. We introduced CIFU, a new computational pipeline for CIrcular FUnctional data modeling and analysis. We demonstrated CIFU by unsupervised circular functional clustering of the OCT NRR data, followed by meta-clustering to characterize the clusters using clinical covariates, and presented a circular visualization of the results. Upon stratification by age, we identified a healthy NRR phenotype cluster in the age group 40-49 years with predictive potential for glaucoma. Our dataset also addresses the disparity of representation of this particular population in normative OCT databases.

Computer-aided diagnosis of ocular disorders like glaucoma can be effectively performed with retinal fundus images. Since the advent of machine learning and later deep learning techniques in medical image analysis, research focusing on automated and early detection of glaucoma has gained prominence. In this paper, we show how a deep Convolutional Neural Network model can be used in visualising the features related to Glaucoma that are consistent with (a subset of) those used by ophthalmologists for diagnosis. However, since the doctors do not necessarily depend entirely on these features but back them up with other important measurements such as visual field testing (HVF), any deep neural network such as CNN may not necessarily be expected to yield 100% accuracy. Further, other important parameters such as Intraocular Pressure (IOP), which may be built into a deep learning model, may not necessarily correlate well with the presence of Glaucoma. In this work, a deep CNN model has been trained and tested on a large number of high-quality fundus images, both normal and glaucomatous. We compare the results with transfer learning models such as VGG16, ResNet50, and MobileNetV2. On an average, we obtained an accuracy of 93.75% in identifying glaucoma, focusing only on the features of the fundus image. [ABSTRACT FROM AUTHOR]

PurposeMethodsResultsConclusionsThe anti-inflammatory effect of therapeutic pars plana vitrectomy (PPV) in the management of posterior segment uveitis is incompletely quantified. In this study, we evaluated the change in total immunosuppression load (TIL) following PPV for the eyes of patients with non-infectious uveitis.Retrospective chart review of patients with non-infectious posterior segment uveitis on continuous anti-inflammatory therapy (systemic corticosteroids ± immunomodulatory therapy [IMT]) ±3 months, who received therapeutic PPV for non-resolving inflammation. The TIL scores were calculated by adding the total daily dose of prednisolone graded on a scale of 0–9, and of the IMT graded between 0 and 3, and calculating the mean values for the pre-operative and post-operative visits, respectively.Sixty-five eyes of 65 patients were included. Mean follow-up was 19.1 ± 14.6 months pre-operatively and 9.4 ± 7.1 months post-operatively. Mean TIL scores for the post-operative visits (2.6 ± 1.9) were significantly lower than the pre-operative (4.4 ± 1.7) visits (p < 0.001). Mean logMAR BCVA was four lines better 1 month post-operatively (0.5 ± 0.4) than the immediate pre-operative vision (0.9 ± 0.6, p < 0.001). On multivariate regression analyses, the reduction in mean TIL scores post-operatively was more with longer durations of pre-operative treatment (adjusted risk ratio [aRR] = -0.04, p = 0.04), while the improvement in one-month post-operative BCVA was more if pre-operative vitreous haze was ≥2+ (aRR = −0.25, p = 0.02). Post-operative adverse outcomes included new-onset cystoid macular edema (n = 6), raised intraocular pressure (n = 5), and intra-operative retinal break (n = 1). Eleven (16.9%) patients were off all immunosuppression during the final follow-up.Therapeutic PPV allowed control of intraocular inflammation on less intensive systemic anti-inflammatory therapy. Post-operative adverse outcomes observed were manageable. [ABSTRACT FROM AUTHOR]

PurposeMethodsResultsConclusion\nSUMMARYWhat was known beforeWhat this study addsTo assess the tear film parameters associated with photophobia in dry eye disease (DED).Three hundred seventy-four patients with DED (mean age, 42.2 ± 12.8 years) had their tear film and OSDI scores evaluated using Oculus keratograph 5 M (TMH, NIBUT, Meibography), Lipiview interferometer (LLT), and TearLab osmolarity system. Photophobia scoring from OSDI sheets was used to calculate the odds ratio via multivariate logistic regression analysis. Data from the eye with severely affected NIBUT was used.Of 374, 127 had aqueous deficient dry eye disease (ADDE), and 247 had evaporative DED. The mean age, female sex, Schirmer I, TMH, NIBUT, LLT, and tear osmolarity values in patients with photophobia versus no or mild photophobia were 42.2. vs. 40.9 years, 42% vs. 40%, 11.6 vs. 10.5 mm, 0.27 vs. 0.29 mm, 4.6 vs. 4.7s, 60.3 vs. 60.9 nm and 305 vs. 307 mOsm/L, respectively. Multivariate analysis revealed no tear film parameters predictive of photophobia in evaporative DED, whereas tear osmolarity had a weak negative association with photophobia (odds ratio of 0.96, 95% C.I, 0.92–1, p = .04) in ADDE patients.Tear film parameters do not predict the presence or absence of photophobia in DED except for a weak inverse association with tear osmolarity in ADDE. This suggests the role of central sensitization in regulating photophobia in DED patients.Photophobia is a common dry eye symptom. The severity of photophobia correlates with dry eye severity and improves with treatment.1. Tear film parameters, such as tear break-up time, tear volume, meibomian gland loss and lipid layer thickness do not predict photophobia risk in dry eye disease.2. This study provides the basis for future research in understanding the central neural sensitization in DED patients with photophobia. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to analyze the yield of retinal images obtained in a rural diabetes eye care model.Methods: An analysis of a sample of nonmydriatic fundus photography (NMFP) of posterior segment ophthalmic images, obtained by an indigenous equipment (3 nethra-Forus Royal), was done in a district-wide rural diabetic retinopathy (DR) screening program; a trained optometrist did the initial image grading. DR and diabetic macular edema (DME) were classified based on international DR and DME severity scale. The agreement between the optometrist and retina specialist was very good (κ = 0.932; standard error = 0.030; 95% confidence interval = 0.874-0.991).Results: Posterior segment images of 2000 eyes of 1000 people with diabetes mellitus (DM) were graded. The mean age of the participants was 55.7 ± 11.5 standard deviation years. Nearly 42% of the screened participants (n = 420/1000) needed referral. The most common referable posterior segment abnormality was DR (8.2%). The proportion of people with any form of DR was seen in 110/1225 eyes, and sight-threatening DR was seen in 35/1225 eyes. About 62% of posterior segment images were gradable. The reasons for ungradable posterior segment images (34%) were small pupil, unfocused/partially available field of images, and cataract.Conclusion: A NMFP model was able to detect referable posterior segment abnormalities in a rural diabetes eye care program. Reasons found for ungradability of images in the present study can be addressed while designing future DR screening programs in the rural areas. [ABSTRACT FROM AUTHOR]

Purpose: Extracellular vesicles (EVs) are messenger pigeons of the cells that communicate about cellular microenvironment. In this study, we evaluated the expression of C8α and calpain-2 in EVs from vitreous of patients with bacterial endophthalmitis to assess its utility as a diagnostic marker., Methods: EVs were isolated from vitreous of patients with bacterial endophthalmitis (culture positive and culture negative) and noninfectious control by exosome isolation reagent and characterized, and the levels of C8α and calpain-2 was assessed by enzyme-linked immunosorbent assay in isolated EVs and direct vitreous. The receiver operating characteristic curve was generated to assess the diagnostic performance., Results: Scanning electron microscopy (SEM) and dynamic light scattering (DLS) confirmed the presence of EVs having a diameter (nm) of 275.2 ± 93, 92 ± 22, and 77.28 ± 12 in culture-positive (CP), culture-negative (CN), and control respectively. The expression level (ng/mL) of C8α in the EVs obtained from CP was 144 ± 22 and CN was 31.2 ± 9.8, which was significantly higher (P < 0.01) than control 3.7 ± 2.4. Interestingly, C8α is not expressed directly in the vitreous of CN and controls. Calpain-2 was significantly downregulated (P ≤ 0.0001) in CP (0.94 ± 0.16) and CN (0.70 ± 0.14) than control. The sensitivity and specificity of 1 for C8α and calpain-2 in the EVs implied that its diagnostic accuracy was significant., Conclusions: This study showed that the EV proteins C8α and calpain-2 could be suitable diagnostic markers for endophthalmitis. However, the presence of C8α in the EVs of CN samples but not in direct vitreous promises EVs as the future of diagnostics., Translational Relevance: Expression levels of EV-calpain-2 and EV-C8α could diagnose CN bacterial endophthalmitis.

Purpose: To determine macular pigment (MP) density scores in healthy Indians and examine correlations with demographic and lifestyle variables., Methods: We observed 484 Indians without an ocular pathology. Body mass index (BMI) and self-reported lifestyle factors (sunglasses usage, physical activity, and smoking) were noted. MP density was assessed as the threshold of perception of the shadow of their macular pigments on their retina using a new MP assessment tool (MP-eye). Lutein and zeaxanthin intake was assessed using a prevalidated questionnaire regionally designed for the Indian diet. Clusters of participants were created for statistical analysis based on MP-eye scores secondarily to detect any relevant effects in very low, low, medium, and high ranges of MPs., Results: Data analyzed included 235 males and 249 females with mean age of 36.1 ± 12.9 years (range, 14-72). The median MP-eye score was 6 (range, 0-10, with 10 being high). Most were non-smokers (413, 85.3%) and did not use sunglasses (438, 90.5%), and 314 (64.9%) had low physical activity. Diabetes was present in 62 participants (12.8%) and hypertension in 53 (10.9%). Advancing age (r = -0.209; P < 0.000) and BMI (r = -0.094; P = 0.038) had weak negative correlation with MP-eye scores. Hypertension was less prevalent (7/88) in the cluster with the highest median MP-eye score (P = 0.033). Dietary intake of MPs and other lifestyle factors did not correlate significantly with MP-eye score overall or when analyzed in clusters., Conclusions: MP-eye scores of an Indian population were normally distributed. Higher age, high BMI, and presence of hypertension were weakly associated with lower MP-eye scores. The impact of diet on MPs requires further evaluation., Translational Relevance: This normative regional database enables risk stratification of macular degeneration.

Purpose: To describe the clinical significance of in vivo corneal findings in eyes with acute corneal hydrops., Methods: Medical records and anterior segment optical coherence tomography (ASOCT) images of 24 patients with keratoconus and unilateral acute corneal hydrops were reviewed. Clinical findings and position, integrity, and orientation of the Descemet membrane (DM) on ASOCT were noted. Size of the DM break, depth of the DM detachment, and corneal thickness were measured by ASOCT and correlated with the duration of corneal edema, assessed clinically. Outcomes of intracameral perfluoropropane (C(3)F(8)) gas in 13 eyes and histopathological findings after penetrating keratoplasty in 2 eyes were also correlated with serial ASOCT findings., Results: Duration of corneal edema was 9.3 ± 4.4 weeks. On ASOCT, DM showed 3 patterns: detachment with break and rolled ends (n = 13), detachment with break and flat ends (n = 10), and detachment with no break (n = 1). Initial corneal thickness was 1.3 ± 0.25 mm, size of the DM break was 1.1 ± 0.8 mm, and depth of the DM detachment was 0.9 ± 0.6 mm. On multiple regression analysis, duration of corneal edema showed significant positive association with the depth of DM detachment (P = 0.0002) and size of DM break (P = 0.002) and negative association with intracameral C3F8 (P < 0.0001). Correlation of ASOCT with histopathological findings revealed 2 stages of resolution of hydrops: reattachment of DM and endothelial migration., Conclusions: Eyes with deeper DM detachments and larger DM breaks required more time for resolution of corneal edema despite intracameral C(3)F(8). This association needs to be validated by a prospective study.