Purpose To evaluate the predictors for subretinal fluid resorption in patients with chronic central serous retinopathy (cCSR) submitted to half-dose photodynamic therapy (HD-PDT). Methods Observational, longitudinal, and retrospective study of patients with cCSR submitted to HD-PDT in a tertiary ophthalmology department in Portugal between January 2015 and February 2018. Best-corrected visual acuity (BCVA) and SD-OCT at baseline and 12 ± 3 months after treatment were performed. The central macular thickness (CMT), outer nuclear layer (ONL) thickness, integrity of the external limiting membrane (ELM), ellipsoid (EZ) and interdigitation zone (IZ), subretinal fluid (SFR) height, and choroidal thickness (CT) were evaluated. Patients were classified into responders and nonresponders based on SRF resorption. Results Sixty-one eyes of 42 patients were included; 75.4% were classified as responders. Final BCVA was significantly better in responders (p=0.002). The baseline ONL was thicker (p < 0.01) and intact ELM (67.2% vs. 16.4%), EZ (49.2% vs. 8.2%), and IZ (31.2% vs. 1.6%) were more prevalent in responders than in nonresponders. Anatomic response was correlated with a thicker ONL (rs (59) = 0.416, p=0.001∗), intact ELM (rs (59) = 0.261, p=0.04∗), EZ (rs (59) = 0.278, p=0.03∗), and IZ (rs (59) = 0.318, p=0.01∗). Binary logistic regression showed that a thicker ONL thickness increased the chance of an anatomic response to HD-PDT. The other evaluated retinal layers did not have statistical significance in the binary regression model. Conclusions cCSR responders to HD-PDT have a better final BCVA, a thicker baseline ONL, and an intact baseline ELM, EZ, and IZ. However, ONL was the only predictor in a logistic regression model for SRF resorption.

This study applies random field theory to simulate the spatial variability of the ground where a tunnel was excavated in a granitic soil mass, in the city of Porto (Portugal). Numerical analyses are performed using finite element method combined with random field theory to simulate tunnel excavation. A parametric study to analyse the influence of the correlation coefficient is performed. The results are compared with the measured values and the values obtained with the deterministic computation. The performance of the models is evaluated using two measures of error: root mean squared error (RMSE) and mean absolute deviation (MAD). With the random fields approach (correlation length equal to 0.5) values of MAD equal to 2.18 and RMSE equal to 4.16 were obtained, whereas with the deterministic approach values of MAD equal to 2.29 and RMSE equal to 4.26 were obtained. Furthermore, the performance of the models improves as far as the correlation coefficient increases. Therefore, it is concluded that the results obtained using random fields are better than those obtained using the deterministic analysis.