Development and validation of an offline deep learning algorithm to detect vitreoretinal abnormalities on ocular ultrasound

Purpose: We describe our offline deep learning algorithm (DLA) and validation of its diagnostic ability to identify vitreoretinal abnormalities (VRA) on ocular ultrasound (OUS). Methods: Enrolled participants underwent OUS. All images were classified as normal or abnormal by two masked vitreoretinal specialists (AS, AM). A data set of 4902 OUS images was collected, and 4740 images of satisfactory quality were used. Of this, 4319 were processed for further training and development of DLA, and 421 images were graded by vitreoretinal specialists (AS and AM) to obtain ground truth. The main outcome measures were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under receiver operating characteristic (AUROC). Results: Our algorithm demonstrated high sensitivity and specificity in identifying VRA on OUS ([90.8%; 95% confidence interval (CI): 86.1�.3%] and [97.1% (95% CI: 93.7�.9%], respectively). PPV and NPV of the algorithm were also high ([97.0%; 95% CI: 93.7�.9%] and [90.8%; 95% CI: 86.2�.3%], respectively). The AUROC was high at 0.939, and the intergrader agreement was nearly perfect with Cohen抯 kappa of 0.938. The model demonstrated high sensitivity in predicting vitreous hemorrhage (100%), retinal detachment (97.4%), and choroidal detachment (100%). Conclusion: Our offline DLA software demonstrated reliable performance (high sensitivity, specificity, AUROC, PPV, NPV, and intergrader agreement) for predicting VRA on OUS. This might serve as an important tool for the ophthalmic technicians who are involved in community eye screening at rural settings where trained ophthalmologists are not available

Utilidad de la tomografía de coherencia óptica para la caracterización y clasificación del edema macular diabético / Utility of the optical coherence tomography for characterization and classification of diabetic macular edema

Introducción: El edema macular es la causa más frecuente de deterioro visual en pacientes con retinopatía diabética no proliferativa, la separación de los fotorreceptores, inducida por permeabilidad vascular anormal, reduce el poder de resolución del ojo y la capacidad visual, lo que lleva al paciente a la baja visión. Objetivo: Caracterizar el comportamiento del edema macular diabético y su clasificación según la tomografía de coherencia óptica. Material y métodos: Se realizó un estudio descriptivo, prospectivo, de corte transversal no controlado, en 40 diabéticos (80 ojos) con diagnóstico clínico de edema macular diabético, quienes acudieron a la consulta de Retina del Hospital Docente Dr. Salvador Allende y el Centro de Atención al Diabético entre enero 2014 y diciembre 2016. La evaluación única fue realizada mediante la biomicroscopía posterior y la tomografía de coherencia óptica (OCT Stratus 3000), basada en la clasificación propuesta por Panozzo y colaboradores. Resultados: Se constataron variaciones del grosor macular por encima de las 250 micras, predominó el engrosamiento cistoide y según la clasificación aplicada y el grado de tracción epirretiniana, se incluyeron más pacientes en los grupos T1 y T2. Finalmente, se clasificó el edema en no traccional (T0 y T1, 69 por ciento) y en traccional (T2yT3, 31 por ciento). Conclusiones: La tomografía de coherencia óptica y la clasificación de Panozzo son de gran utilidad para caracterizar el tipo de edema macular traccional o no traccional y orienta sobre el adecuado tratamiento a seguir en cada paciente. El edema macular diabético no traccional sobresalió en la muestra estudiada(AU)

Introduction: Macular edema is the most frequent cause of visual loss in patients suffering from non-proliferative diabetic retinopathy. In this condition, the detachment of photoreceptors induced by an abnormal vascular permeability reduces the resolving power of the eye and visual capacity, causing low vision in the patient. Objective: To characterize the behavior of diabetic macular edema and its classification according to the main changes in the optical coherence tomography. Material and methods: A descriptive, prospective, cross-sectional and non-controlled study was carried out in 40 diabetic patients, (80 eyes), with the clinical diagnosis of diabetic macular edema in the Department of Retina of Salvador Allende University Hospital and the Diabetes Care Center from January 2014 to December 2016. A single evaluation was carried out with a subsequent biomicroscopy and optical coherence tomography (Stratus OCT; model 3000), based on the classification suggested by Panozzo and collaborators. Results: Variations in retinal volume over 250 microns were found in the tomography. The cystoid thickening predominated; and according to the classification used and the degree of epiretinal traction, more patients were included in T1 and T2 groups. Finally, edema was classified as non-tractional (T0 and T1, 69 percent), and tractional (T2 and T3, 31 percent). Conclusions: Optical coherence tomography and the classification suggested by Panozzo are highly useful to characterize the type of the macular edema into tractional or non-tractional, and allows to follow the adequate treatment in each patient. Non-tractional diabetic macular edema was highly noticeable in the sample studied(AU)

Effect of IGF-1 on expressions of VEGF under suppression of HIF-1α by shRNA in cultured human RPE cells / 中华实验眼科杂志

BackgroundProliferative vitreo-retinal disease (PVD)is one group of ocular complications marked by the enhanced proliferation of various cells included retinal pigment epithelial (RPE) cells.Insulin-like growth factor-1 (IGF-1)and vascular endothelial growth factor(VEGF) are implicated in the aberrant cell proliferation and pathological neovascularization that characterizes PVD,but the signaling mechanism is unclear now. Objective This study was to explore the effect of IGF-1 on VEGF in cultured human RPE cells under the small hairpin loop RNA (shRNA) keeping hypoxia-inducible factor-1 α ( HIF-1 α) silencing. Methods Human retinas were isolated from 4 healthy male donors,and the RPE cells were harvested and cultured.The ceils were identified using anti-human keratin antibody.The third to fifth generation of human RPE cells were used in the experiment.One target site of HIF-1α mRNA was chosen by certain design principle,and shRNA was designed and synthesized by the target site and transferred into the cells in vitro,and then the cells were cultivated with 50 μg/L IGF-1 for 24 hours.The mRNA and protein expressions of HIF-1α and VEGF were detected by RT-PCR and Western blot respectively. Results Cultured human RPE cells showed the flat irregularly multangular shape,and 97％cells appeared the positive response for keratin.HIF-1α mRNA expression in human RPE cells was significantly lower in 50 μg/L IGF-1 group than the 0 pg/L IGF-1 group ( 1.49±0.18 vs 1.46±0.17 ) ( t =0.335,P =0.743 ),however,the expressing levels of HIF-1α protein( 1049.86±172.54 vs 0.00±0.00) and VEGF mRNA(0.95±0.15 vs 0.35±0.07) and VEGF protein (391.98±56.77 vs 214.36±37.15)were raised in the 50 μg/L IGF-I group compared with 0 μg/L IGF-1 group (t=16.098,9.935,6.928,P＜0.05).After the HIF-1α-specific shRNA was transferred into cultured RPE cells,the expressions of both HIF-1α mRNA and its protein significantly decreased in RPE cells under 50 μg/L IGF-1 concentration condition( F=68.679,89.904,P=0.000),moreover,the expression of VEGF mRNA and its protein were significantly lowed(F=21.770,6.205,P＜0.05). ConclusionsIGF-1 promotes the accumulation of HIF-1α protein and induce the expression of VEGF in human RPE cells,which probably play a pivotal role in the development of PVD.

Expression and significance of hypoxia-inducible factor 1α in vitreous body in eyes with proliferative vitreo-retinal diseases / 中华实验眼科杂志

Background Proliferative vitreo-retinal diseases include all the overly proliferative diseases of eyes.Many kinds of cytokines play important roles in their pathogenesis.Hypoxia-inducible factor 1α(HIF-1α)participates in the pathogenesis of a lot of ischemic diseases.HIF-1α may play an important role in the pathogenesis of proliferative vitreo-retinal diseases. Objective Present study was to observe the expression of HIF-1α in vitreous body in the eyes with proliferative vitreo-retinal diseases.The vitreous samples were collected during the vitrectomy from 71 eyes of 69 patients(experimental group)including 39 eyes with proliferative diabetic retinopathy(PDR)and 32 eyes with proliferative Vitreoretinopathy(PVR).Sixteen eyes of 16 patients as the cases control group,including 14 eyes with macular hole(MH)and 2 eyes with epiretinal macular membrane(ERM).What is more,there were 8 vitreous fluid samples of the normal control group.The concentrations of HIF-1α in vitreous body were detected by enzyme-linked immunosorbent assay(ELISA).The written informed consent was obtained from each patient before any medical procedure. Results The concentrations of HIF-1α in vitreous body in the eyes of experimental group,the cases control group and the normal control group were(294.08±2.97)、(260.41±8.29)、(16.38±3.56)mg/L respectively,showing a significant difference among the three groups(F=248.77,P=0.00).The concentrations of HIF-1α in vitreous body were obviously increased in the eyes of experimental group in comparison with the normal control group and the cases control group respectively(t=22.25,P=0.00;t=2.70,P=0.00 respectively).The concentrations of HIF-1α in vitreous body were increased in the eyes of the cases control group in comparison with the normal control group eyes(t=14.21,P=0.00).There was inferior correlation between the concentrations of HIF-1α in vitreous body in the eyes of experimental group and the course of ophthalmopathy. Conclusion Intravitreous HIF-1α level regulates in the eyes with proliferative vitreo-retinal diseases. Expression of HIF-1α in vitreous had inferior correlation with the course of ophthalmopathy. HIF-1α may play an important role in the pathogenesis of proliferative vitreo-retinal diseases.

Prevention of complications of vitreo-retinal surgery / 眼科

Vitreo-retinal surgery is one of the effective methods in treating severe vitreoretinopathy.However,there remains great variance in surgical quality,outcomes and success rates among hospitals of different areas in China.This article focuses on how to im- prove in surgical outcomes and success rate as well as to avoid complications of vitreo-retinal surgery.Specific issues are addressed on such as indications and timing of vitreo-retinal surgery,management of pre-operative patients,applications of new appliances and mate- rials,maneuver of surgical techniques and nurturing appropriate habits of surgery.