Cost-Effectiveness of Screening for Open Angle Glaucoma Compared With Opportunistic Case Finding.

PRCIS: The manuscript evaluates cost-effectiveness of glaucoma screening with imaging devices and telemedicine based on a screening campaign performed in Spain. The screening strategy implemented in our analysis was cost-effective compared with opportunistic case finding. INTRODUCTION: Open angle glaucoma is an asymptomatic ocular disease that represents one of the first causes of blindness. Diagnosis is currently made by opportunistic case finding, usually by community optometrists or general ophthalmologists. The aim of this study was to assess the cost-effectiveness of a screening strategy based on optical coherence tomography and fundus photographs in glaucoma detection. MATERIALS AND METHODS: A cost-effectiveness analysis was carried out to compare 2 alternative strategies: opportunistic finding versus screening. A Markov tree model was carried out with 10 health states according to disease progression. Quality-adjusted life years (QALYs) were used as a measure of effectiveness. We included short-term and long-term direct health costs and a discount rate of 3%. We performed a probabilistic sensitivity analysis and several 1-way sensitivity analyses. RESULTS: The cohort in the screening program entailed an increase in 0.097 QALYs and additional costs of €1187 versus opportunistic finding, with an incremental cost-effectiveness ratio of about €12.214/QALY. The 1-way sensitivity analysis showed that inputs related to age and screening program (cost and detection rate) were those most strongly influencing the results of the analysis. Probabilistic sensitivity analyses showed that the model was robust to significant changes in the main variables of the analysis. CONCLUSIONS: The screening strategy implemented in our analysis was cost-effective compared with opportunistic finding in patients with glaucoma in this Spanish setting.

Interobserver and Intertest Agreement in Telemedicine Glaucoma Screening with Optic Disk Photos and Optical Coherence Tomography.

Purpose: To evaluate interobserver and intertest agreement between optical coherence tomography (OCT) and retinography in the detection of glaucoma through a telemedicine program. Methods: A stratified sample of 4113 individuals was randomly selected, and those who accepted underwent examination including visual acuity, intraocular pressure (IOP), non-mydriatic retinography, and imaging using a portable OCT device. Participants' data and images were uploaded and assessed by 16 ophthalmologists on a deferred basis. Two independent evaluations were performed for all participants. Agreement between methods was assessed using the kappa coefficient and the prevalence-adjusted bias-adjusted kappa (PABAK). We analyzed potential factors possibly influencing the level of agreement. Results: The final sample comprised 1006 participants. Of all suspected glaucoma cases (n = 201), 20.4% were identified in retinographs only, 11.9% in OCT images only, 46.3% in both, and 21.4% were diagnosed based on other data. Overall interobserver agreement outcomes were moderate to good with a kappa coefficient of 0.37 and a PABAK index of 0.58. Higher values were obtained by experienced evaluators (kappa = 0.61; PABAK = 0.82). Kappa and PABAK values between OCT and photographs were 0.52 and 0.82 for the first evaluation. Conclusion: In a telemedicine screening setting, interobserver agreement on diagnosis was moderate but improved with greater evaluator expertise.

Diagnostic Accuracy and Detection Rate of Glaucoma Screening with Optic Disk Photos, Optical Coherence Tomography Images, and Telemedicine.

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of optical coherence tomography (OCT) and retinography in the detection of glaucoma through a telemedicine program. METHODS: A population-based sample of 4113 persons was randomly selected. The screening examination included a fundus photograph and OCT images. Images were evaluated on a deferred basis. All participants were then invited to a complete glaucoma examination, including gonioscopy, visual field, and dilated fundus examination. The detection rate, sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: We screened 1006 persons. Of these, 201 (19.9%) were classified as glaucoma suspects; 20.4% were identified only by retinographs, 11.9% only by OCT images, and 46.3% by both. On ophthalmic examination at the hospital (n = 481), confirmed glaucoma was found in 58 (12.1%), probable glaucoma in 76 (15.8%), and ocular hypertension in 10 (2.1%), and no evidence of glaucoma was found in 337 (70.0%). The detection rate for confirmed or probable glaucoma was 9.2%. Sensitivity ranged from 69.4% to 86.2% and specificity from 82.1% to 97.4%, depending on the definition applied. CONCLUSIONS: The combination of OCT images and fundus photographs yielded a detection rate of 9.2% in a population-based screening program with moderate sensitivity, high specificity, and predictive values of 84-96%.

Automatic glaucoma classification using color fundus images based on convolutional neural networks and transfer learning.

Glaucoma detection in color fundus images is a challenging task that requires expertise and years of practice. In this study we exploited the application of different Convolutional Neural Networks (CNN) schemes to show the influence in the performance of relevant factors like the data set size, the architecture and the use of transfer learning vs newly defined architectures. We also compared the performance of the CNN based system with respect to human evaluators and explored the influence of the integration of images and data collected from the clinical history of the patients. We accomplished the best performance using a transfer learning scheme with VGG19 achieving an AUC of 0.94 with sensitivity and specificity ratios similar to the expert evaluators of the study. The experimental results using three different data sets with 2313 images indicate that this solution can be a valuable option for the design of a computer aid system for the detection of glaucoma in large-scale screening programs.

Diagnostic Accuracy of Spectralis SD OCT Automated Macular Layers Segmentation to Discriminate Normal from Early Glaucomatous Eyes.

PURPOSE: To evaluate the accuracy of the macular retinal layer segmentation software of the Spectralis spectral-domain (SD) optical coherence tomography (OCT) device (Heidelberg Engineering, Inc., Heidelberg, Germany) to discriminate between healthy and early glaucoma (EG) eyes. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Forty EG eyes and 40 healthy controls were included. METHODS: All participants were examined using the standard posterior pole and the peripapillary retinal nerve fiber layer (pRNFL) protocols of the Spectralis OCT device. Using an Early Treatment Diagnostic Retinopathy Study circle at the macular level, the automated retinal segmentation software was applied to determine thicknesses of the following parameters: total retinal thickness, inner retinal layer (IRL), macular retinal nerve fiber layer (mRNFL), macular ganglion cell layer (mGCL), macular inner plexiform layer (mIPL), macular inner nuclear layer (mINL), macular outer plexiform layer (mOPL), macular outer nuclear layer (mONL), photoreceptors (PR), and retinal pigmentary epithelium (RPE). The ganglion cell complex (GCC) was determined by adding the mRNFL, mGCL, and mIPL parameters and the ganglion cell layer-inner plexiform layer (mGCL-IPL) was determined by combining the mGCL and mIPL parameters. Thickness of each layer was compared between the groups, and the layer and sector with the best area under the receiver operating characteristic curve (AUC) were identified. MAIN OUTCOME MEASURES: Comparison of pRNFL, IRL, mRNFL, mGCL, mIPL, mGCC, mGCL-IPL, mINL, mOPL, mONL, PR, and RPE parameters and total retinal thicknesses between groups for the different areas and their corresponding AUCs. RESULTS: Peripapillary RNFL was significantly thinner in the EG group globally and in all 6 sectors assessed (P < 0.0005). For the macular variables, retinal thickness was significantly reduced in the EG group for total retinal thickness, mIRL, mRNFL, mGCL, and mIPL. The 2 best isolated parameters to discriminate between the 2 groups were pRNFL (AUC, 0.956) and mRNFL (AUC, 0.906). When mRNFL, mGCL, and mIPL measurements were combined (mGCC and mGCL plus mIPL), then its diagnostic performance improved (AUC, 0.940 and 0.952, respectively). CONCLUSIONS: Macular RNFL, mGCL-IPL, and mGCC measurements showed a high diagnostic capability to discriminate between healthy and EG participants. However, macular intraretinal measurements still have not overcome standard pRNFL parameters.

The changing scenario of hepatocellular carcinoma over the last two decades in Italy.

BACKGROUND & AIMS: This study investigates whether the aetiologic changes in liver disease and the improved management of hepatocellular carcinoma (HCC) have modified the clinical scenario of this tumour over the last 20 years in Italy. METHODS: Retrospective study based on the analysis of the ITA.LI.CA (Italian Liver Cancer) database including 3027 HCC patients managed in 11 centres. Patients were divided into 3 groups according to the period of HCC diagnosis: 1987-1996 (year of the "Milano criteria" publication), 1997-2001 (year of release of the EASL guidelines for HCC), and 2002-2008. RESULTS: The significant changes were: (1) progressive patient ageing; (2) increasing prevalence of HCV infection until 2001, with a subsequent decrease, when the alcoholic aetiology increased; (3) liver function improvement, until 2001; (4) increasing "incidental" at the expense of "symptomatic" diagnoses, until 2001; (5) unchanged prevalence of tumours diagnosed during surveillance (around 50%), with an increasing use of the 6-month schedule; (6) favourable HCC "stage migration", until 2001; (7) increasing use of percutaneous ablation; (8) improving survival, until 2001. CONCLUSIONS: Over the last 20 years, several aetiologic and clinical features regarding HCC have changed. The survival improvement observed until 2001 was due to an increasing number of tumours diagnosed in early stages and in a background of compensated cirrhosis, and a growing and better use of locoregional treatments. However, the prevalence of early cancers and survival did not increase further in the last years, a result inciting national policies aimed at implementing surveillance programmes for at risk patients.