A new intraocular lens marker to guide the implantation of toric intraocular lenses in small and mid-dilating pupils

Insufficient pupillary dilatation is a significant challenge during cataract surgery, as it increases the risk of various intraoperative complications. Implantation of toric intraocular lenses (TIOL) is particularly difficult in eyes with small pupils, as the toric marks are provided in the periphery of the IOL optic, making the visualization of the same difficult for proper alignment. Attempts at visualizing these marks using a second instrument such as a dialler or iris retractor lead to additional manipulations in the anterior chamber resulting in increased chances of postoperative inflammation and intraocular pressure rise. A new intraocular lens (IOL) marker to guide the implantation of TIOLs in eyes with small pupils is described, which can potentially be beneficial in achieving accurate alignment of toric IOLs in small pupils, without the need for additional manipulations, thus improving safety, efficacy, and success rates of TIOL implantation in these eyes.

Assessment of psychosocial impact of primary glaucoma and its effect on quality of life of patients in Western India

Purpose:

To assess the impact of primary glaucoma of varying severity and duration on psychosocial functioning and quality of life of patients.

Methods:

A cross-sectional observational study was carried on 200 patients attending the glaucoma clinic of a tertiary care hospital in western India. After obtaining approval from the institutional ethics committee, written informed consent was taken. All patients underwent a thorough ophthalmic examination. Those with primary glaucoma were classified as per Hodapp–Parrish–Anderson criteria and asked to respond to the National Eye Institute Visual Function Questionnaire (NEIVFQ)-25 questionnaire. Responses were analyzed statistically.

Results:

Overall mean NEIVFQ 25 composite score was 74.4 ± 18.6. Mean scores were 87.0 (SD 7.2) for mild, 75.9 (SD 8.1) for moderate, and 47.0 (SD 13.7) for severe glaucoma groups. Lower scores were associated with males. Driving (62.2, SD 34.6) and ocular pain (63.5, SD 18.7) were maximally affected while color vision (90.1, SD 18.7) and social health (86.7, SD 20.1) were least affected. The duration of treatment had no effect on mean composite scores with impaired scores seen even in newly diagnosed cases. Age of the patient negatively correlated with NEIVFQ 25 composite score.

Conclusion:

With disease progression, the psychosocial functioning of the patients is negatively affected. This effect is irrespective of treatment duration and newly diagnosed cases can have impaired Quality of life scores. Quantification of psychosocial status along with education and counseling for all patients may play a definitive role in customizing treatment and providing patients with a better quality of Life.

IPCS: an integrated process control system for enhanced in-situ bioremediation

To date, there has been little or no research related to process control of subsurface remediation systems. In this study, a framework to develop an integrated process control system for improving remediation efficiencies and reducing operating costs was proposed based on physical and numerical models, stepwise cluster analysis, non-linear optimization and artificial neural networks. Process control for enhanced in-situ bioremediation was accomplished through incorporating the developed forecasters and optimizers with methods of genetic algorithm and neural networks modeling. Application of the proposed approach to a bioremediation process in a pilot-scale system indicated that it was effective in dynamic optimization and real-time process control of the sophisticated bioremediation systems.

Simulation-based process optimization for surfactant-enhanced aquifer remediation at heterogeneous DNAPL-contaminated sites

Widespread use of dense non-aqueous phase liquids (DNAPLs) such as TCE and PCE has resulted in contamination of enormous valuable groundwater resources and become high-priority environmental problems. However, experiences from the past decades have demonstrated that DNAPL-contaminated sites were difficult to investigate and challenging to remediate. In this study, a simulation-based process optimization system was developed through integrating a multidimensional simulator, a multivariate statistical tool and an optimization model within a general framework for supporting decisions of surfactant-enhanced aquifer remediation (SEAR). A 3D multiphase and multi-component subsurface model was first provided to simulate SEAR process; dual-response surface models were then established to build a bridge between remediation actions and system performance; a nonlinear optimization model was then formulated for identifying optimal operating conditions for SEAR operations. The results in simulating a typical PCE spill event and the associated SEAR remediation operations in a heterogeneous subsurface indicated that SEAR would be capable of cleaning up the contaminated aquifer with improved efficiencies and cost-effectiveness compared with direct pump-and-treat actions. The regression-analysis results demonstrated that the proposed dual-response surface models were able to predict system responses under given operating conditions. The optimization results demonstrated that the developed simulation-optimization approach was effective in seeking cost-effective SEAR strategies for DNAPL-contaminated sites. With the developed method, optimum operation conditions under various environmental and economic considerations could be compiled into a database that would supports further studies of on-site process-control with injection and extraction rates being the main control variables.

An integrated numerical and physical modeling system for an enhanced in situ bioremediation process

Groundwater contamination due to releases of petroleum products is a major environmental concern in many urban districts and industrial zones. Over the past years, a few studies were undertaken to address in situ bioremediation processes coupled with contaminant transport in two- or three-dimensional domains. However, they were concentrated on natural attenuation processes for petroleum contaminants or enhanced in situ bioremediation processes in laboratory columns. In this study, an integrated numerical and physical modeling system is developed for simulating an enhanced in situ biodegradation (EISB) process coupled with three-dimensional multiphase multicomponent flow and transport simulation in a multi-dimensional pilot-scale physical model. The designed pilot-scale physical model is effective in tackling natural attenuation and EISB processes for site remediation. The simulation results demonstrate that the developed system is effective in modeling the EISB process, and can thus be used for investigating the effects of various uncertainties.

Estimation of atmospheric mixing heights using data from airport meteorological stations

In this study, ground and sounding meteorological data at the Beijing Airport during 1991 to 1995 were used for estimating the local atmospheric mixing heights. Three methods were compared for this purpose, including the dry adiabatic method, the Nozaki model, and a modified Nozaki model. The modification of the Nozaki model included joint frequencies for wind-velocity and stability based on the complexities of local meteorological conditions. The estimated values from the three methods were verified through the data measured by the Beijing Meteorological Center. The results indicated that the dry adiabatic method has the best performance. The modified Nozaki model was better than the commonly used. This study is a new attempt in utilizing airport meteorological data to estimate atmospheric mixing heights.