Unilateral presentation of Vogt-Koyanagi-Harada syndrome

Purpose: To report a case of acute Vogt-Koyanagi-Harada (VKH) disease with unilateral clinical manifestations followed by late fellow eye involvement. Case Report: This case report reviews the 12-month follow-up observation of a 44-year old woman who presented to the emergency department with unilateral progressive and painless visual blurring. Ophthalmoscopic findings, best-corrected visual acuity (BCVA), fluorescein angiography (FAG), enhanced-depth optical coherence tomography (EDI-OCT), indocyanine green angiography, and response to treatment were evaluated. Her BCVA was 20/50 (logMAR: 0.4) in the right eye and 20/20 (logMAR: 0) in the left eye. Eye examination revealed optic disc swelling and multiple serous retinal detachments in the right eye and a normal left eye. She had headache, dysacusia, and mild hearing problem. Her past ocular and drug histories were unremarkable. Retinal imaging revealed characteristic features of VKH in the right eye. All laboratory testing results were inconclusive. VA and OCT findings significantly improved following the treatment with methylprednisolone 1 g/day continued by tapering dose of oral prednisolone. Two months after the presentation and during prednisolone tapering, VA of the left eye decreased and fundus examination revealed multiple serous retinal detachments in this eye. Conclusion: Ophthalmologists should recognize unilateral and asymmetrical VKH disease with subtle systemic involvement. © 2020 JOURNAL OF OPHTHALMIC AND VISION RESEARCH | PUBLISHED BY KNOWLEDGE

A Risk-Averse Preview-based QQ-Learning Algorithm: Application to Highway Driving of Autonomous Vehicles

A risk-averse preview-based $Q$-learning planner is presented for navigation of autonomous vehicles. To this end, the multi-lane road ahead of a vehicle is represented by a finite-state non-stationary Markov decision process (MDP). A risk assessment unit module is then presented that leverages the preview information provided by sensors along with a stochastic reachability module to assign reward values to the MDP states and update them as scenarios develop. A sampling-based risk-averse preview-based $Q$-learning algorithm is finally developed that generates samples using the preview information and reward function to learn risk-averse optimal planning strategies without actual interaction with the environment. The risk factor is imposed on the objective function to avoid fluctuation of the $Q$ values, which can jeopardize the vehicle's safety and/or performance. The overall hybrid automaton model of the system is leveraged to develop a feasibility check unit module that detects unfeasible plans and enables the planner system to proactively react to the changes of the environment. Theoretical results are provided to bound the number of samples required to guarantee $\epsilon$-optimal planning with a high probability. Finally, to verify the efficiency of the presented algorithm, its implementation on highway driving of an autonomous vehicle in a varying traffic density is considered

Vogt-Koyanagi-Harada with Unilateral Clinical Presentation: A Case Report

Purpose: To report a case of acute Vogt-Koyanagi-Harada (VKH) disease with unilateral clinical manifestations followed by late fellow eye involvement. Case Report: This case report reviews the 12-month follow-up observation of a 44-year old woman who presented to the emergency department with unilateral progressive and painless visual blurring. Ophthalmoscopic findings, best-corrected visual acuity (BCVA), fluorescein angiography (FAG), enhanced-depth optical coherence tomography (EDIOCT), indocyanine green angiography, and response to treatment were evaluated. Her BCVA was 20/50 (logMAR: 0.4) in the right eye and 20/20 (logMAR: 0) in the left eye. Eye examination revealed optic disc swelling and multiple serous retinal detachments in the right eye and a normal left eye. She had headache, dysacusia, and mild hearing problems. Her past ocular and drug histories were unremarkable. Retinal imaging revealed characteristic features of VKH in the right eye. All laboratory testing results were inconclusive. VA and OCT findings significantly improved following the treatment with methylprednisolone 1 g/day continued by tapering dose of oral prednisolone. Two months after the presentation and during prednisolone tapering, VA of the left eye decreased and fundus examination revealed multiple serous retinal detachments in this eye. Conclusion: Ophthalmologists should recognize unilateral and asymmetrical VKH disease with subtle systemic involvement

Clinical Outcomes of Femtosecond Laser-assisted Implantation of 325-Degree Versus 340-Degree Arc Length Intracorneal Ring Segments in Naive Keratoconic Eyes

Purpose: To evaluate and compare clinical outcomes after femtosecond laser-assisted implantation of 325-degree versus 340-degree arc length intracorneal ring segments (ICRS) in eyes with keratoconus (KCN). Methods: In this prospective non-randomized interventional case series, 23 eyes of 21 patients diagnosed with KCN, underwent femtosecond laser-assisted implantation of two types of ICRS, which included a 325-degree ICRS (Group 325) and a 340-degree ICRS (Group 340). The primary outcome measures were uncorrected distance visual acuity (UDVA), and the secondary outcome measures included corrected distance visual acuity (CDVA), sphere, cylinder, mean refractive spherical equivalent (MRSE), keratometry, vectorial change in corneal astigmatism, and the location of maximum keratometry relative to the corneal apex. The study groups were compared using the primary and secondary outcome measures obtained at postoperative months six and 12. Results: Groups 325 and 340 consisted of 10 and 13 eyes, respectively. The two groups were comparable in terms of parameters measured preoperatively. On comparison to the baseline values, both study groups exhibited a significant increase in UDVA and CDVA measured at postoperative month six (Ps < 0.05) and a significant decrease in the sphere, cylinder, spherical equivalent refraction, and keratometry readings measured at postoperative months six and 12 (Ps < 0.05). No significant differences were observed between the two groups in terms of visual, refractive, and keratometric outcomes at any time point. No intraoperative or postoperative complications were observed in any of the study groups. Conclusion: Both the 325-degree ICRS and the 340-degree ICRS effectively and equally improved visual, refractive, and keratometric outcomes in keratoconic eyes

An efficient adaptive multigrid algorithm for predicting thin film flow on surfaces containing localised topographic features

Gravity-driven continuous thin film flow over a plane, containing well-defined single and grouped topographic features, is modelled as a Stokes flow using lubrication theory. The associated time dependent, nonlinear, coupled set of governing equations are solved using a Full Approximation Storage (FAS) Multigrid algorithm by employing automatic mesh adaptivity, the power efficiency and accuracy of which is demonstrated by comparing the results with corresponding global fine-mesh solutions.. These show that automatic grid refinement effectively restricts the use of find grids to regions of rapid flow development which, for flow over the topographies considered, includes the topography itself, the upstream Capillary ridge, downstream sure region, and the characteristic bow wave. It is shown that for the accurate solution of such flow problems, adaptive Multigridding offers increased flexibility together with a significant reduction in memory requirement. This is further demonstrated by solving the problem of transient flow over a trench topography, generated by a sinusoidally varying inlet condition