LIMBARE: An Advanced Linear Mixed-Effects Breakpoint Analysis With Robust Estimation Method With Applications to Longitudinal Ophthalmic Studies.

Purpose: Broken stick analysis is a widely used approach for detecting unknown breakpoints where the association between measurements is nonlinear. We propose LIMBARE, an advanced linear mixed-effects breakpoint analysis with robust estimation, especially designed for longitudinal ophthalmic studies. LIMBARE accommodates repeated measurements from both eyes and over time, and it effectively addresses the presence of outliers. Methods: The model setup of LIMBARE and the computing algorithm for point and confidence interval estimates of the breakpoint were introduced. The performance of LIMBARE and other competing methods was assessed via comprehensive simulation studies and application to a longitudinal ophthalmic study with 216 eyes (145 subjects) followed for an average of 3.7 ± 1.3 years to examine the longitudinal association between structural and functional measurements. Results: In simulation studies, LIMBARE showed the smallest bias and mean squared error for estimating the breakpoint, with an empirical coverage probability of corresponding confidence interval estimates closest to the nominal level for scenarios with and without outlier data points. In the application to the longitudinal ophthalmic study, LIMBARE detected two breakpoints between visual field mean deviation (MD) and retinal nerve fiber layer thickness and one breakpoint between MD and cup-to-disc ratio, whereas the cross-sectional analysis approach detected only one and none, respectively. Conclusions: LIMBARE enhances breakpoint estimation accuracy in longitudinal ophthalmic studies, and the cross-sectional analysis approach is not recommended for future studies. Translational Relevance: Our proposed method and companion R package provide a valuable computational tool for advancing longitudinal ophthalmology research and exploring the association relationships among ophthalmic variables.

How Ophthalmologists Can Decarbonize Eye Care: A Review of Existing Sustainability Strategies and Steps Ophthalmologists Can Take.

TOPIC: Understanding approaches to sustainability in cataract surgery and their risks and benefits. CLINICAL RELEVANCE: In the United States, health care is responsible for approximately 8.5% of greenhouse gas (GHG), and cataract surgery is one of the most commonly performed surgical procedures. Ophthalmologists can contribute to reducing GHG emissions, which lead to a steadily increasing list of health concerns ranging from trauma to food instability. METHODS: We conducted a literature review to identify the benefits and risks of sustainability interventions. We then organized these interventions into a decision tree for use by individual surgeons. RESULTS: Identified sustainability interventions fall into the domains of advocacy and education, pharmaceuticals, process, and supplies and waste. Existing literature shows certain interventions may be safe, cost-effective, and environmentally friendly. These include dispensing medications at home to patients after surgery, multi-dosing appropriate medications, training staff to properly sort medical waste, reducing the number of supplies used during surgery, and implementing immediate sequential bilateral cataract surgery where clinically appropriate. The literature was lacking on the benefits or risks for some interventions, such as switching specific single-use supplies to reusables or implementing a hub-and-spoke-style operating room setup. Many of the advocacy and education interventions have inadequate literature specific to ophthalmology but are likely to have minimal risks. CONCLUSIONS: Ophthalmologists can engage in a variety of safe and effective approaches to reduce or eliminate dangerous GHG emissions associated with cataract surgery. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

LIMBARE: an Advanced Linear Mixed-effects Breakpoint Analysis with Robust Estimation Method with Applications to Longitudinal Ophthalmic Studies.

Purpose: Broken stick analysis is a widely used approach for detecting unknown breakpoints where association between measurements is non-linear. We propose LIMBARE, an advanced li near m ixed-effects b reakpoint a nalysis with r obust e stimation, especially designed for longitudinal ophthalmic studies. LIMBARE accommodates repeated measurements from both eyes and overtime, and effectively address the presence of outliers. Methods: The model setup of LIMBARE and computing algorithm for point and confidence interval estimates of the breakpoint was introduced. The performance of LIMBARE and other competing methods was assessed via comprehensive simulation studies and application to a longitudinal ophthalmic study with 216 eyes (145 subjects) followed for an average of 3.7±1.3 years to examine the longitudinal association between structural and functional measurements. Results: In simulation studies, LIMBARE showed the smallest bias and mean squared error (MSE) for estimating the breakpoint, with empirical coverage probability of corresponding CI estimate closest to the nominal level for scenarios with and without outlier data points. In the application to the longitudinal ophthalmic study, LIMBARE detected two breakpoints between visual field mean deviation (MD) and retinal nerve fiber layer thickness (RNFL) and one breakpoint between MD and cup to disc ratio (CDR), while the cross-sectional analysis approach only detected one and none, respectively. Conclusions: LIMBARE enhances breakpoint estimation accuracy in longitudinal ophthalmic studies, while cross-sectional analysis approach is not recommended for future studies. Translational Relevance: Our proposed method and companion software R package provides a valuable computational tool for advancing longitudinal ophthalmology research and exploring the association relationships between ophthalmic variables.

Cost of glaucoma treatment in a developing country over a 5-year period.

The aim of the study was to disclose a realistic estimate of primary open-angle glaucoma treatment, follow-up costs, and patients' monthly glaucoma-economic burden in an ophthalmology hospital in Mexico City.Prospective survey of 462 primary open-angle glaucoma patients from 2007 to 2012 was carried out. Costs from visits, glaucoma follow-up studies, laser, and glaucoma surgical procedures were obtained from hospital pricings. Education, employment, and monthly income were interrogated. Total cost was divided into hypotensive treatment cost, nonpharmacologic treatment cost (laser and surgeries), and follow-up studies and consults. Average wholesale price for drugs analyzed was obtained from IMS Health data; monthly cost was calculated using: Monthly cost  = ([average wholesale price/number of drops per eye dropper] × number of daily applications) × 30 days.Patients were classified according to their glaucoma severity, and data were analyzed based on monthly income (average annual exchange rate: 12.85 Mexican pesos = 1 USD).The mean age was 70 ±â€Š10 years, women = 81%, elementary school = 39%, and unemployed = 53%. Low-income group = 266 patients (57%), 146 with mild glaucoma; moderate-income group = 176 patients (38%), 81 with mild glaucoma; high-income group = 20 patients (4.3%), 10 with mild glaucoma. Patients' monthly average economic burden in glaucoma treatment: low-income patients = 61.5%, moderate-income patients = 19.5%, and high-income patients = 7.9%.Glaucoma-economic burden is substantial not only for health systems, but for the family and the patient. Therefore, screening plans for earlier diagnosis, and health policies that lessen the cost of disease management and increase adherence to treatment, and reduce the prevalence of blindness attributed to glaucoma are essential. These would improve quality of life, reduce personal and national expenditure, and help increase national economy.