Cost-Utility Analysis of Extending Public Health Insurance Coverage to Include Diabetic Retinopathy Screening by Optometrists.

BACKGROUND: Diabetic retinopathy (DR) is one of the leading causes of vision loss and blindness in Canada. Eye examinations play an important role in early detection. However, DR screening by optometrists is not always universally covered by public or private health insurance plans. This study assessed whether expanding public health coverage to include diabetic eye examinations for retinopathy by optometrists is cost-effective from the perspective of the health care system. METHODS: We conducted a cost-utility analysis of extended coverage for diabetic eye examinations in Prince Edward Island to include examinations by optometrists, not currently publicly covered. We used a Markov chain to simulate disease burden based on eye examination rates and DR progression over a 30-year time horizon. Results were presented as an incremental cost per quality-adjusted life year (QALY) gained. A series of one-way and probabilistic sensitivity analyses were performed. RESULTS: Extending public health coverage to eye examinations by optometrists was associated with higher costs ($9,908,543.32) and improved QALYs (156,862.44), over 30 years, resulting in an incremental cost-effectiveness ratio of $1668.43/QALY gained. Sensitivity analysis showed that the most influential determinants of the results were the cost of optometric screening and selected utility scores. At the commonly used threshold of $50,000/QALY, the probability that the new policy was cost-effective was 99.99%. CONCLUSIONS: Extending public health coverage to eye examinations by optometrists is cost-effective based on a commonly used threshold of $50,000/QALY. Findings from this study can inform the decision to expand public-insured optometric services for patients with diabetes.

Assessment of the quality of glaucoma referral letters based on a survey of glaucoma specialists and a glaucoma guideline.

OBJECTIVE: To assess the quality of glaucoma referral letters and to report on the results of a survey of glaucoma specialists about referral letter content. DESIGN: Cross-sectional study. PARTICIPANTS: A survey of 135 glaucoma specialists and audit of 200 consecutive referral letters to a tertiary glaucoma unit. METHODS: An online questionnaire was sent to members of the Canadian and American Glaucoma Societies asking what they considered the most important data to be included in a glaucoma referral. Consecutive referral letters to a tertiary glaucoma unit were assessed for legibility and content on the basis of the survey results and information items in current guidelines. MAIN OUTCOME MEASURES: Survey outcome and proportion of included content items in referral letters. RESULTS: The survey revealed that the top 5 most important data that glaucoma specialists would like to be included in a referral letter for progressive glaucoma were serial visual fields (VFs), current glaucoma therapy, current intraocular pressure (IOP), maximum IOP, and serial disc imaging. These items often were omitted in the referral letters audited. A total of 200 referral letters were assessed, 46% from ophthalmologists, 42% from optometrists, 10% from family practitioners, and 2% from other sources. Reasons for referral were diagnosis of glaucoma (37%), unstable glaucoma (25%), angle assessment (17%), and others (21%). Some 26% of the referral letters were deemed illegible (18% from ophthalmologists vs. 6% from optometrists; P< 0.01). Degree of urgency was mentioned in 27% of referrals. Optometrists were more likely than ophthalmologists to provide visual acuity (VA), IOP, refraction, and VFs (P< 0.01 for each). Some 24% of referrals for progression included more than 10 of the 14 information points suggested by the Canadian glaucoma guidelines, and 34% included fewer than 8 of the 14 points. CONCLUSIONS: Referral letters frequently did not include important information, with 34% of referral letters deemed substandard. Optometrist referrals were better than ophthalmologist referrals in terms of content and legibility. A checklist of clinical details for referring physicians is suggested, which includes maximum and current IOP, disc evaluation, serial VFs, and serial disc imaging.

Using Fused Data from Perimetry and Optical Coherence Tomography to Improve the Detection of Visual Field Progression in Glaucoma.

Perimetry and optical coherence tomography (OCT) are both used to monitor glaucoma progression. However, combining these modalities can be a challenge due to differences in data types. To overcome this, we have developed an autoencoder data fusion (AEDF) model to learn compact encoding (AE-fused data) from both perimetry and OCT. The AEDF model, optimized specifically for visual field (VF) progression detection, incorporates an encoding loss to ensure the interpretation of the AE-fused data is similar to VF data while capturing key features from OCT measurements. For model training and evaluation, our study included 2504 longitudinal VF and OCT tests from 140 glaucoma patients. VF progression was determined from linear regression slopes of longitudinal mean deviations. Progression detection with AE-fused data was compared to VF-only data (standard clinical method) as well as data from a Bayesian linear regression (BLR) model. In the initial 2-year follow-up period, AE-fused data achieved a detection F1 score of 0.60 (95% CI: 0.57 to 0.62), significantly outperforming (p < 0.001) the clinical method (0.45, 95% CI: 0.43 to 0.47) and the BLR model (0.48, 95% CI: 0.45 to 0.51). The capacity of the AEDF model to generate clinically interpretable fused data that improves VF progression detection makes it a promising data integration tool in glaucoma management.

Binocular Summation of Visual Acuity at High and Low Contrast in Early Glaucoma.

PRCIS: This study examined the integrity of binocular summation function in patients with mild glaucoma. We found that binocular summation of visual acuity is preserved in these patients, despite their reduced monocular inputs. PURPOSE: Binocular summation represents superiority of binocular to monocular performance. In this study we examined the integrity of binocular summation function in patients with early glaucoma who had structural glaucomatous changes but otherwise had no significant interocular acuity asymmetry or other functional deficit detected with standard clinical measures. MATERIALS AND METHODS: Participants included 48 patients with early glaucoma according to Hodapp, Anderson, and Parrish 2 (HAP2) criteria (age 65±12 y) and 42 healthy controls (age 60±12 y), matched for stereoacuity. Visual acuity was assessed binocularly and monocularly at high (95%) and low (25%) contrast using the Early Treatment Diabetic Retinopathy Study (ETDRS) charts at 6 m. Binocular acuity summation was evaluated utilizing a binocular ratio (BR). RESULTS: Overall, binocular and monocular visual acuity of the control group was better than that of the glaucoma group for both contrast levels, P =0.001. For the glaucoma group, there was a significant difference between BRs at high and low contrast, 0.01±0.05 and 0.04±0.06 ( P =0.003), respectively. For the control group, the difference between BR at high and low contrast was not statistically significant, 0.00±0.07 and 0.02±0.06 ( P =0.25), respectively. CONCLUSION: For patients with early glaucoma, binocular summation function for visual acuity was preserved at both contrast levels. This suggests an adaptation of the visual system in early stages of glaucoma that allows for normal binocular summation in the presence of reduced monocular visual input.

A Data-Driven Model for Simulating Longitudinal Visual Field Tests in Glaucoma.

Purpose: To develop a simulation model for glaucomatous longitudinal visual field (VF) tests with controlled progression rates. Methods: Longitudinal VF tests of 1008 eyes from 755 patients with glaucoma were used to learn the statistical characteristics of VF progression. The learned statistics and known anatomic correlations between VF test points were used to automatically generate progression patterns for baseline fields of patients with glaucoma. VF sequences were constructed by adding spatially correlated noise templates to the generated progression patterns. The two one-sided test (TOST) procedure was used to analyze the equivalence between simulated data and data from patients with glaucoma. VF progression detection rates in the simulated VF data were compared to those in patients with glaucoma using mean deviation (MD), cluster, and pointwise trend analysis. Results: VF indices (MD, pattern standard deviation), MD linear regression slopes, and progression detection rates for the simulated and patients' data were practically equivalent (TOST P < 0.01). In patients with glaucoma, the detection rates in 7 years using MD, cluster, and pointwise trend analysis were 24.4%, 26.2%, and 38.4%, respectively. In the simulated data, the mean detection rates (95% confidence interval) for MD, cluster, and pointwise trend analysis were 24.7% (24.1%-25.2%), 24.9% (24.2%-25.5%), and 35.7% (34.9%-36.5%), respectively. Conclusions: A novel simulation model generates glaucomatous VF sequences that are practically equivalent to longitudinal VFs from patients with glaucoma. Translational Relevance: Simulated VF sequences with controlled progression rates can support the evaluation and optimization of methods to detect VF progression and can provide guidance for the interpretation of longitudinal VFs.

Atypical responses to faces during binocular rivalry in early glaucoma.

Purpose: Glaucoma is a progressive optic neuropathy that damages retinal ganglion cells and a neurodegenerative disease as it affects neural structures throughout the brain. In this study, we examined binocular rivalry responses in patients with early glaucoma in order to probe the function of stimulus-specific cortical areas involved in face perception. Methods: Participants included 14 individuals (10 females, mean age 65 ± 7 years) with early pre-perimetric glaucoma and 14 age-matched healthy controls (7 females, mean age 59 ± 11 years). The 2 groups were equivalent in visual acuity and stereo-acuity. Three binocular rivalry stimulus pairs were used: (1) real face/house, (2) synthetic face/noise patch, and (3) synthetic face/spiral. For each stimulus pair, the images were matched in size and contrast level; they were viewed dichotically, and presented centrally and eccentrically at 3 degrees in the right (RH) and in the left hemifield (LH), respectively. The outcome measures were rivalry rate (i.e., perceptual switches/min) and time of exclusive dominance of each stimulus. Results: For the face/house stimulus pair, rivalry rate of the glaucoma group (11 ± 6 switches/min) was significantly lower than that of the control group (15 ± 5 switches/min), but only in the LH location. The face dominated longer than the house in the LH for both groups. Likewise, for the synthetic face/noise patch stimulus pair, rivalry rate of the glaucoma group (11 ± 6 switches/min) was lower than that of the control group (16 ± 7 switches/min) in the LH, but the difference failed to reach significance. Interestingly, the mixed percept dominated less in glaucoma than in the control group. For the synthetic face/spiral stimulus pair, the glaucoma group had lower rivalry rate at all 3 stimulus locations. Conclusion: This study reveals atypical responses to faces during binocular rivalry in patients with early glaucoma. The results may be suggestive of early neurodegeneration affecting stimulus-specific neural structures involved in face processing starting in the pre-perimetric phase of the disease.

Prevalence of self-reported visual impairment among people in Canada with and without diabetes: findings from population-based surveys from 1994 to 2014.

BACKGROUND: Diabetes, a leading cause of visual impairment, is on the rise in Canada. We assessed trends in the prevalence of visual impairment among people in Canada with and without diabetes to inform the development of strategies and policies for the management of visual impairment. METHODS: We analyzed self-reported data from respondents aged 45 years and older in 7 cycles of nationwide surveys (National Population Health Survey and Canadian Community Health Survey) from 1994/95 to 2013/14. The age- and sex-standardized prevalence of visual impairment was calculated. We assessed comparisons by levels of education and income, using sex-standardized prevalence owing to sparse data. RESULTS: Among people in Canada with diabetes, the age- and sex-standardized prevalence of visual impairment was 7.37% (95% confidence interval [CI] 5.31%-9.43%) in 1994/95 and 1996/97 combined, decreasing to 3.03% (95% CI 2.48%-3.57%) in 2013/14, giving a standardized prevalence ratio of 0.41 (95% CI 0.30-0.56) comparing 2013/14 with 1994/95 and 1996/97 combined. Among people in Canada without diabetes, visual impairment prevalence decreased from 3.72% (95% CI 3.31%-4.14%) in 1994/95 and 1996/97 combined to 1.69% (95% CI 1.52%-1.87%) in 2013/14, with a standardized prevalence ratio of 0.45 (95% CI 0.40-0.52). Decreased sex-standardized prevalence of visual impairment was observed among people with high and low education levels and incomes among those with and without diabetes. INTERPRETATION: Visual impairment prevalence was roughly 2 times higher among those with versus without diabetes in all survey years; from 1994 to 2014, visual impairment prevalence decreased among those with and without diabetes irrespective of education and income levels. These results suggest effective collective efforts by clinicians, researchers, the public and government.

Subspecialization in glaucoma surgery.

PURPOSE: To evaluate trends in glaucoma surgery subspecialization. DESIGN: Population-based analysis of incisional glaucoma surgery and laser trabeculoplasty practice patterns among all ophthalmologists in Ontario, Canada, from 1995 through 2010. PARTICIPANTS: All ophthalmologists in Ontario, Canada, providing universal health care for the provincial population of approximately 12 million. METHODS: The province of Ontario provides government-funded universal health care insurance to all citizens through the Ontario Health Insurance Plan (OHIP). Anonymized physician services data were obtained from the OHIP database, which has excellent accuracy for procedure performance. MAIN OUTCOME MEASURES: Proportion of ophthalmologists providing incisional glaucoma surgery and laser trabeculoplasty and the distribution of these surgical and laser procedures among ophthalmologists. RESULTS: Between 1995 and 2010, the median number of ophthalmologists in Ontario was 427 (35.1 per 1 million population), ranging from 417 to 453 (32.9-40.3 per 1 million population). The percentage of ophthalmologists providing incisional glaucoma surgery dropped from 35% in 1995 to 19% in 2010, a 47% decline. Over the same period, the mean number of incisional glaucoma surgeries performed per surgeon doubled, and the percentage of incisional glaucoma operations provided by high-volume surgeons rose from 23% to 59%. The percentage of ophthalmologists performing laser trabeculoplasty was relatively stable (48% in 1995 to 50% in 2010). CONCLUSIONS: Over the past 16 years, the proportion of ophthalmologists providing incisional glaucoma surgery has declined significantly. At the same time, the proportion of incisional glaucoma surgery provided by high-volume glaucoma surgeons has more than doubled. These trends will have important implications for stakeholders from policy makers and hospitals to academic departments and residency education programs.

Effect of Prophylactic Aqueous Suppression on Ahmed Glaucoma Valve Surgery Success.

Purpose: To evaluate the effect of prophylactic aqueous suppressants immediately post-Ahmed glaucoma valve (AGV) surgery on the rate of hypertensive phase and success. Methods: Retrospective case-control study of 80 eyes with refractory glaucoma undergoing AGV surgery. Forty eyes in the intervention group (preoperative aqueous suppressants continued postoperatively) and 40 in the control group (all glaucoma drops stopped after surgery and reintroduced as required) were included in this study. Patients were followed for 1 year. Data collected included intraocular pressure (IOP), number of glaucoma medications, and number of eyes requiring further IOP lowering surgery. The frequency of hypertensive phase and 1-year success was compared between the groups. Results: Hypertensive phase occurred in 22.5% of the intervention group compared to 42.5% of the control group; however, this difference was not statistically significant (P = 0.06). Success at 1 year (IOP ≤21 mmHg but ≥5 mmHg and 20% reduction from baseline without additional surgery) was similar in each group: 77.5% in the intervention group and 62.5% in the control group (P = 0.22). However, at 1 year, significantly more eyes in the intervention group had an IOP ≤17 mmHg (95% vs. 80%, P = 0.04). The mean time interval to a second IOP lowering procedure was significantly shorter in the control group (P < 0.005). Conclusions: With prophylactic preoperative aqueous suppressants, more eyes achieved an IOP of ≤17 mmHg. The time interval to repeat the glaucoma procedure was significantly shorter in the control group.

Perceptual Grouping During Binocular Rivalry in Mild Glaucoma.

Purpose: This study tested perceptual grouping during binocular rivalry to probe the strength of neural connectivity of the visual cortex involved in early visual processing in patients with mild glaucoma. Methods: Seventeen patients with mild glaucoma with no significant visual field defects and 14 healthy controls participated. Rivalry stimuli were 1.8°-diameter discs, containing horizontal or vertical sine-wave gratings, viewed dichoptically. To test the grouping, two spatially separated identical stimuli were presented eccentrically to the same or different eyes and to the same or different hemifields. The outcome measures were the time of exclusive dominance of the grouped percept (i.e., percept with synchronized orientations), the rivalry rate, and the epochs of exclusive dominance. Results: For both groups, the grouping occurred primarily for the matching orientations in the same eye/same hemifield (MO SE/SH) and for the matching orientations in the same eye/different hemifield (MO SE/DH) conditions. Time dominance of the grouped percept of the glaucoma group was similar to that of the control group in all conditions. The rivalry rates in the MO SE/SH and MO SE/DH conditions were significantly larger in the control group than in the glaucoma group. The epochs of exclusive dominance of the grouped percept in the MO SE/SH condition were a median of 48-ms longer for the control group, but a median of 116-ms shorter for the glaucoma group when compared to those in the MO SE/DH condition. Conclusion: Patients with mild glaucoma show clear impairments in binocular rivalry while evidence for deficits in perceptual grouping could be inferred only indirectly. If these deficits truly exist, they may have implications for higher levels of visual processing, such as object recognition and scene segmentation, but these predictions remain to be tested in future studies.

Impact of discontinuing government-funded routine eye exams on new glaucoma diagnoses in Ontario.

OBJECTIVE: In 2004, government-funded routine eye exams were discontinued for individuals aged 20-64 years in Ontario. We assessed whether this policy change reduced the rate of new glaucoma diagnoses. DESIGN: Cohort-based time-series analysis. PARTICIPANTS: Ontarians aged 20+ years in 2000-2014. METHODS: Province-wide physician billing data were analyzed using segmented regression analysis. New glaucoma diagnoses were defined as the first glaucoma diagnostic billing code submitted by an ophthalmologist or optometrist among Ontarians who did not visit an ophthalmologist or an optometrist in the year prior to the study year. RESULTS: Post- versus pre-2004, the rate of new glaucoma billings was reduced in all age groups: -2.7‰ (p < 0.0001) in the age group 20-39 years, -8.2‰ (p < 0.0001) in the age group 40-64 years (p < 0.0001), and -2.1‰ (p = 0.0003) in the age group 65+ years. This corresponds to a decreased number of individuals with a new glaucoma billing after 2004 versus before 2004: -8,800 (p < 0.001) in the age group 20-39 years, -32,234 (p < 0.0001) in the age group 40-64 years, and -3,255 (p = 0.0012) in the age group 65+ years. Reduced rates of new glaucoma diagnostic billings were seen in males, females and rural and urban residents among policy-affected and policy-unaffected age groups. Ontarians living in the wealthiest neighbourhood areas also had a significantly reduced rate after versus before 2004: -2.7‰ (p < 0.0001) for the age group 20-39 years, -9.0‰ (p < 0.0001) for the age group 40-64 years, and -2.3‰ (p < 0.001) for the age group 65+ years. CONCLUSIONS: Discontinuation of government-funding for routine eye exams was associated with a significantly reduced rate of new glaucoma diagnostic billings irrespective of sociodemographics. More research is needed to understand the reduced glaucoma billings in unaffected seniors and those living in the wealthiest neighbourhood areas.

Cost-related nonadherence with glaucoma medications in Ontario.

OBJECTIVE: To determine the proportion of glaucoma patients in Ontario aged 25-64 who lack insurance coverage for glaucoma medications and to assess the frequency of cost-related nonadherence to glaucoma medications. DESIGN: Cross-sectional study. PARTICIPANTS: Glaucoma patients on medication from 2 glaucoma clinics in Toronto, Ontario. METHODS: 100 consecutive glaucoma patients aged 25-64 (not entitled to provincial drug benefit) and 100 consecutive glaucoma patients aged 65+ (entitled to provincial drug benefit), all on topical glaucoma therapy, completed a standardized questionnaire. Questions included insurance coverage for glaucoma medications, cost concerns when paying for glaucoma medications, cost-related nonadherence, and sociodemographics. RESULTS: 25.8% of those aged 25-64 express concerns about the cost of their glaucoma medications compared to 7.1% of those aged 65+ (p < 0.001). Patients aged 25-64 were also significantly more likely to report at least one form of cost-related nonadherence (15.5% vs 2.0%, p = 0.001) and significantly more likely to report missing eye drops in a given week than patients aged 65+ (32.0% vs 16.7%, p = 0.01). 17% (95% confidence interval 11%-26%) of patients aged 25-64 self-reported having no insurance coverage for their glaucoma medications. Of those with coverage, the most common source of insurance was employer-sponsored (68.6%) with 44% requiring a copayment. The average copayment was $18 (range $2-$250) for those aged 25-64 compared with $5 in the 65+ group (range $0.62-$100). CONCLUSIONS: 17% of glaucoma patients aged 25-64 do not have coverage for their drops. One in four expressed concerns about the cost of their glaucoma medications, and 15.5% reported cost-related nonadherence.

Ophthalmology-focused publications and findings on COVID-19: A systematic review.

PURPOSE: To summarize COVID-19 research endeavors by ophthalmologists/researchers in terms of publication numbers, journals and author countries, and to detail key findings. METHODS: The LitCovid database was systematically reviewed for ophthalmology-focused COVID-19 articles. The quality of the evidence was assessed for articles investigating conjunctivitis in COVID-19 patients. RESULTS: There were 21,364 articles in LitCovid on June 12, 2020, of which 215 (1%) were ophthalmology-focused. Of articles on COVID-19 transmission, 3.3% were ophthalmology-focused. Ophthalmology-focused articles were published in 68 journals and originated from 25 countries. The top five countries publishing ophthalmology-focused articles (China, India, United States of America, Italy, and United Kingdom) produced 145/215 (67%) articles. A total of 16 case reports/series from eight countries reported that conjunctivitis can be the initial or the only symptom of COVID-19 infection. Conjunctivitis may occur in the middle phase of COVID-19 illness. A total of 10 hospital-based cross-sectional studies reported that between 0% and 31.6% of COVID-19 patients have conjunctivitis or other ocular conditions, with a pooled prevalence of 5.5% reported in a meta-analysis. Viral RNA was detected in conjunctival swabs of patients with and without ocular manifestations, after resolution of conjunctivitis, after nasopharyngeal swabs turned negative and in retina of deceased COVID-19 patients. CONCLUSION: Within 3 months of declaring the COVID-19 pandemic, 215 ophthalmology-focused articles were published in PubMed, concentrating on disease manifestations and transmission. The reported presence of conjunctivitis or other ocular conditions in COVID-19 patients is varied. Clinicians should be alert for ocular involvement in COVID-19 infections and possible ocular transmission even in patients without ocular symptoms.

Cataract prevalence following a nationwide policy to shorten wait time for cataract surgery.

Background: Cataract is an age-related eye disease. Visual impairment from cataract can be restored by cataract surgery. In 2004 the Canadian federal government invested in a multibillion dollar wait time strategy to shorten the wait time for cataract surgery, a government-insured health service in all Canadian jurisdictions. We assessed if this nationwide policy reduced the number of Canadians waiting for cataract surgery as more individuals with cataract were free of cataract following the rapidly conducted surgery. Methods: In this cross-sectional study we analyzed data from randomly selected individuals aged ≥ 45 years responding to the Canadian Community Health Survey (CCHS) in 2000/2001, 2003, 2005, and the CCHS Healthy Aging in 2008/2009. Information on cataract was obtained from self-reported questionnaire. The age- and sex-standardized prevalence of cataract was calculated for comparisons. Results: Cataract was reported by 0.93 million Canadians in 2000/2001, 0.99 million in 2003, 1.10 million in 2005, and 1.34 million in 2008/2009. This corresponds to an age- and sex-standardized prevalence of 8.9% in 2000/2001, 9.0% in 2003, 9.5% in 2005, and 10.2% (P <0.05) in 2008/2009. The increase in age- and sex-standardized prevalence was greater in individuals without secondary school graduation than those with secondary school graduation or higher (4.3% versus 1.3%, P < 0.05) and was seen in all Canadian provinces. The largest increase was documented in a province (Saskatchewan, from 9.8% in 2000/2001 to 12.6% in 2008/2009, P < 0.05) with the longest median wait times for cataract surgery (118 days in 2008) and the lowest number of ophthalmologists per 100 000 population (1.96 versus 3.35 national average). Conclusions: The age- and sex-standardized prevalence of cataract increased 4‒5 years after the multibil- lion-dollar wait time strategy was launched in 2004. A lower threshold to diagnose cataract may be one potential reason for this finding. Further research is needed to understand the true reasons for the increase.

The Effect of Government-Uninsured Optometric Services on the Use of Primary Care Providers.

INTRODUCTION: Eye care in many countries is provided by optometrists, ophthalmologists, primary care providers (PCPs, including family physicians and pediatricians) and emergency department (ED) physicians. In the province of Prince Edward Island (PEI), Canada, optometric services are not government-insured, while services provided by other eye care providers are government-insured. Clinics of optometrists, PCPs and ED physicians are widely distributed across the island. Clinics of ophthalmologists however are concentrated in the capital city Charlottetown. PURPOSE: To investigate if more patients visited government-insured PCPs and EDs for eye care when local optometric services are government-uninsured and government-insured ophthalmologists are potentially distant. METHODS: From PEI physician billing database, we identified all patients with an ocular diagnosis from 2010-2012 using International Classification of Diseases, 9th Revision (ICD-9) codes. The utilization of government-insured PCPs and EDs in five geographical regions was assessed utilizing patients' residential postal code. Of the five regions, Prince was the region farthest from the capital Charlottetown. RESULTS: Compared to utilization of government-insured PCPs for ocular diagnoses in Charlottetown (13.5% in 2010, 95% confidence interval [CI] 12.9-14.0%), the utilization in Prince (22.4% in 2010, 95% CI 21.7-23.1%) was nearly double (p<0.05). The utilization of ED physicians for ocular diagnoses was similarly double in Prince (8.8%, 95% CI 8.3-9.3%) versus Charlottetown (4.1%, 95% CI 3.8-4.5%). The utilization of ophthalmologists however was significantly lower in Prince (43%, 95% CI 41.4-42.9%) versus Charlottetown (56.3%, 95% CI 55.6-57.1%). Similar trends remained throughout 2010-2012. CONCLUSION: When optometric services are government-uninsured and government-insured ophthalmologist services are geographically distant, ocular patients utilized PCPs and ED physicians more frequently. Due to different levels of training and available equipment for eye examinations among PCPs, ED physicians and optometrists, the quality of eye care and cost-effectiveness of increased use of PCPs and ED physicians for ocular management warrant further investigation. TRIAL REGISTRATION: Not applicable.

Frequency and source of prescription eyewear insurance coverage in Ontario: a repeated population-based cross-sectional study using survey data.

BACKGROUND: Insurance coverage may reduce cost barriers to obtain vision correction. Our aim was to determine the frequency and source of prescription eyewear insurance to understand how Canadians finance optical correction. METHODS: We conducted a repeated population-based cross-sectional study using 2003, 2005 and 2013-2014 Canadian Community Health Survey data from respondents aged 12 years or older from Ontario, Canada. In this group, the cost of prescription eyewear is not covered by the government unless one is registered with a social assistance program or belongs to a specific population. We determined the frequency and source of insurance coverage for prescription eyewear in proportions. We used survey weights provided by Statistics Canada in all analyses to account for sample selection, a complex survey, and adjustments for seasonal effect, poststratification, nonresponse and calibration. We compared unadjusted proportions and adjusted prevalence ratios (PRs) of having insurance. RESULTS: Insurance covered all or part of the costs of prescription eyewear for 62% of Ontarians in all 3 survey years. Of those insured, 84.1%-86.0% had employer-sponsored coverage, 9.0%-10.3% had government-sponsored coverage, and 5.7%-6.8% had private plans. Employer-sponsored coverage remained constant for those in households with postsecondary graduation but decreased significantly for those in households with less than secondary school graduation, from 67.0% (95% confidence interval [CI] 63.2%-70.8%) (n = 175 000) in 2005 to 54.6% (95% CI 50.1%-59.2%) (n = 123 500) in 2013-2014. Government-sponsored coverage increased significantly for those in households with less than secondary school graduation, from 29.2% (95% CI 25.5%-32.9%) (n = 76 400) in 2005 to 41.7% (95% CI 37.2%-46.1%) (n = 93 900) in 2013-2014. In 2013-2014, Ontarians in households with less than secondary school graduation were less likely than those with secondary school graduation to report employer-sponsored coverage (adjusted PR 0.79, 95% CI 0.75-0.84) but were more likely to have government-sponsored coverage (adjusted PR 1.27, 95% CI 1.06-1.53). INTERPRETATION: Sixty-two percent of Ontarians had prescription eyewear insurance in 2003, 2005 and 2013-2014; the largest source of insurance was employers, primarily covering those with higher education levels, whereas government-sponsored insurance increased significantly among those with lower education levels. Further research is needed to elucidate barriers to obtaining prescription eyewear and the degree to which affordability impairs access to vision correction.

Effect of sleeping in a head-up position on intraocular pressure in patients with glaucoma.

PURPOSE: To determine whether a 30-degree head-up sleeping position decreases nocturnal intraocular pressure (IOP) compared with lying flat in patients with glaucoma. DESIGN: Prospective, nonrandomized comparative case series. PARTICIPANTS: Seventeen eyes of 17 patients with glaucoma with controlled IOP and new disc hemorrhage. METHODS: Patients with a new disc hemorrhage despite well-controlled IOP were evaluated in a sleep laboratory on 2 separate nights, the first night lying flat and the second night in a 30-degree head-up position. Intraocular pressure and blood pressure (BP) were measured every 2 hours from 6 PM to 8 AM. For the 6 PM, 8 PM, 10 PM, and 8 AM measurements (awake period) the subjects were sitting for both nights. For the midnight, 2 AM, 4 AM, and 6 AM measurements (sleep period), the subjects were supine for the first night and 30 degrees head up for the second night. MAIN OUTCOME MEASURE: Difference in IOP during the sleep period (midnight to 6 AM) between lying flat and 30-degree head-up positions. RESULTS: Seventeen eyes of 17 patients were included. There were no significant differences (P=0.68) between the 2 study visits in IOP during the awake period (6 PM, 8 PM, 10 PM, and 8 AM) when patients were sitting upright. During the sleep period (midnight to 6 AM) the mean IOP was 3.2 mmHg lower in the 30-degree head-up position compared with the flat position (P=0.03; 95% confidence interval, 0.25-6.1 mmHg). Sixteen of 17 patients (94.1%) had lower IOP in the 30-degree head-up position. The reduction in IOP in the 30-degree head-up position was 20% or more in 35% of patients (6/17). There were no differences in BP or ocular perfusion pressure between the 2 positions. CONCLUSIONS: The 30-degree head-up sleeping position lowers IOP compared with the flat position. Although this effect varies between individual patients, mean IOP was 20% lower in one third of patients in this series. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Intra- and inter-hemispheric processing during binocular rivalry in mild glaucoma.

Glaucoma is considered a progressive optic neuropathy because of the damage and death of the retinal ganglion cells. It is also a neurodegenerative disease because it affects neural structures in the visual system and beyond, including the corpus callosum-the largest white matter structure involved in inter-hemispheric transfer of information. In this study we probed the dysfunction of the inter-hemispheric processing in patients with mild glaucoma using the phenomenon of binocular rivalry. Patients with mild glaucoma and no measurable visual field defects and age-matched controls underwent a thorough visual assessment. Then they participated in a series of psychophysical tests designed to examine the binocular rivalry derived from intra- and inter-hemispheric processing. Static horizontal and vertical sinewave gratings were presented dichoptically using a double-mirror stereoscope in 3 locations: centrally, to probe inter-hemispheric processing, and peripherally to the left or to the right, to probe intra-hemispheric processing. Although the two groups were matched in functional measures, rivalry rate of the glaucoma group was significantly lower than that of the control group for the central location, but not for the peripheral location. These results were driven mainly by the patients with normal tension glaucoma whose average rivalry rate for the central location (from which information reaches the two hemispheres) was almost half (46% lower) that of the controls. These results indicate a dysfunction in inter-hemispheric transfer in mild glaucoma that can be detected behaviourally before any changes in standard functional measures.

The cost of publishing in an indexed ophthalmology journal in 2019.

OBJECTIVE: To determine the proportion of indexed ophthalmology journals with article processing charges (APCs) and potential factors associated with APCs. DESIGN: Cross-sectional study. PARTICIPANTS: Web of Science-indexed Ophthalmology journals in 2019. METHODS: Indexed ophthalmology journal web sites were reviewed to obtain information on APCs, impact factor (IF), publication mode, publisher type, journal affiliation, waiver discount, and continent of origin. For data unavailable on the web site, the journal was contacted. Journal publication mode was categorized into subscription, fully open access, and hybrid (open access and subscription combined). Linear regression analysis was used to evaluate the association between APCs and the above variables. MAIN OUTCOME MEASURE: Proportion of ophthalmology journals with APCs. RESULTS: 59 indexed ophthalmology journals were identified; 3 (5.1%) subscription only, 10 (16.9%) open access, and 46 (78.0%) hybrid. Overall 52/59 (88.1%) journals had APCs; 10 of 59 journals (16.9%) required APCs for publication (7 fully open access and 3 hybrid journals), whereas 42/59 (71.2%, all hybrid journals) had optional APCs for open access. The 7/59 journals (11.9%) without APCs included 100% (3/3) of the subscription-only journals, 30% (3/10) of the open access, and 2% (1/46) of the hybrid journals. The mean cost for journals with APCs was US$2854 ± 708.9 (range US$490-5000). Higher IF, publication mode, and commercial publishers were associated with higher APCs. CONCLUSIONS: 16.9% of indexed ophthalmology journals in 2019 required APCs, and additional 71.2% hybrid journals had APCs for the option of open access. Independent predictors of APCs were IF and publication mode.