Policy implications of regional variations in eye disease detection and treatment on Prince Edward Island: a repeated cross-sectional analysis, 2010-2012.

BACKGROUND: In Canada, government insurance covers eye care services provided by ophthalmologists and other physicians. However, government coverage for services provided by optometrists, non-medical school trained primary eye care providers, varies regionally. Little is known about the impact of a funding model in which ophthalmologist services are government-insured but services provided by optometrists are not, on eye care utilization and eye disease detection and treatment. We aimed to address this question by examining geographic variations in eye care service utilization on Prince Edward Island (PEI). METHODS: PEI physician-billing data from 2010 to 2012 was analyzed across five distinct geographic regions (Charlottetown, Summerside, Prince, Queens & Kings and Stratford). The residential location of patients and practice locations of eye care providers were identified using the first three digits of their respective postal code. Age-standardized rates were computed for comparisons across different regions. RESULTS: There were six ophthalmologists practicing on PEI, five with offices in Charlottetown. Twenty optometrists practiced on the island with offices across the province. Stratford is closest and Prince farthest from Charlottetown. Age-standardized utilization rates of ophthalmologists per 100 populations were 10.44 in Charlottetown and 10.90 in Stratford, which was significantly higher than in other regions (7.74-8.92; p < 0.05). The disparities were most pronounced amongst the elderly. The prevalence of glaucoma visits was higher in Charlottetown (6.10%) and Stratford (6.38%) and lower in other regions. A similar pattern was observed for the prevalence of cataract visits. While the prevalence of diabetes visits was higher in Prince and Summerside, the utilization of ophthalmologists by people with diabetes was almost twice as high in Charlottetown (6.49%) than in Prince (3.88%). CONCLUSIONS: The observed discrepancies in vision care utilization across geographic regions were likely attributed to barriers in accessing government-insured, geographically concentrated ophthalmologists, as opposed to a reflection of the true differences in eye disease occurrence. The lower prevalence of glaucoma visits in regions farther away from ophthalmologist offices may result in delayed detection and blindness in this population. Encouraging ophthalmologists to work in other areas of the province and/or to publicly fund services provided by optometrists may mitigate the observed disparities. TRIAL REGISTRATION: Not applicable.

Approach for gait analysis in persons with limb loss including residuum and prosthesis socket dynamics.

Musculoskeletal modeling and marker-based motion capture techniques are commonly used to quantify the motions of body segments, and the forces acting on them during human gait. However, when these techniques are applied to analyze the gait of people with lower limb loss, the clinically relevant interaction between the residual limb and prosthesis socket is typically overlooked. It is known that there is considerable motion and loading at the residuum-socket interface, yet traditional gait analysis techniques do not account for these factors due to the inability to place tracking markers on the residual limb inside of the socket. In the present work, we used a global optimization technique and anatomical constraints to estimate the motion and loading at the residuum-socket interface as part of standard gait analysis procedures. We systematically evaluated a range of parameters related to the residuum-socket interface, such as the number of degrees of freedom, and determined the configuration that yields the best compromise between faithfully tracking experimental marker positions while yielding anatomically realistic residuum-socket kinematics and loads that agree with data from the literature. Application of the present model to gait analysis for people with lower limb loss will deepen our understanding of the biomechanics of walking with a prosthesis, which should facilitate the development of enhanced rehabilitation protocols and improved assistive devices.

Peer reviewed: evaluating impacts of hormonally active agents in the environment.

Information about endocrine disrupters is limited, with sparse data, few answers, great uncertainties, and a definite need for further research.

Studies towards a disposable screen-printed amperometric biosensor for progesterone.

A screen-printed carbon electrode (SPCE) has been investigated as the base transducer for a disposable amperometric progesterone biosensor. The biorecognition element was a monoclonal sheep anti-progesterone antibody (mAb). This was immobilized onto the transducer by interaction with a layer of rabbit IgG which had been previously coated onto the SPCE; optimum conditions for these loadings were deduced experimentally. The device was employed in a competitive assay using alkaline phosphatase-labelled progester-one. Three possible substrates for the enzyme were considered, namely, phenyl phosphate, phenolphthalein phosphate and 4-aminophenol phosphate. Cyclic voltammetry and amperometry were carried out on the corresponding aromatic phenols and phenol itself was found to give the best electrochemical characteristics; consequently, phenyl phosphate was employed as the substrate. Chronoamperometry was used to measure the phenol produced by the reaction of bound enzyme-labelled progesterone and substrate. The chronoamperometric response was dependent on unlabelled progesterone over at least three orders of magnitude with a detection limit of about 1 x 10(-9) mol/dm3. This suggests that the device may have applications for the analysis of biological fluids.