The role of a ciliary GTPase in the regulation of neuronal maturation of olfactory sensory neurons.

Olfactory sensory neurons (OSNs) form embryonically and mature perinatally, innervating glomeruli and extending dendrites with multiple cilia. This process and its timing are crucial for odor detection and perception and continues throughout life. In the olfactory epithelium (OE), differentiated OSNs proceed from an immature (iOSN) to a mature (mOSN) state through well-defined sequential morphological and molecular transitions, but the precise mechanisms controlling OSN maturation remain largely unknown. We have identified that a GTPase, ARL13B, has a transient and maturation state-dependent expression in OSNs marking the emergence of a primary cilium. Utilizing an iOSN-specific Arl13b-null murine model, we examined the role of ARL13B in the maturation of OSNs. The loss of Arl13b in iOSNs caused a profound dysregulation of the cellular homeostasis and development of the OE. Importantly, Arl13b null OSNs demonstrated a delay in the timing of their maturation. Finally, the loss of Arl13b resulted in severe deformation in the structure and innervation of glomeruli. Our findings demonstrate a previously unknown role of ARL13B in the maturation of OSNs and development of the OE.

Characterizing the Impact of Procedure Funding on the Covid-19 Generated Procedure Gap in Ontario: A Population-Based Analysis.

BACKGROUND: Surgical procedures in Canada were historically funded through global hospital budgets. Activity-based funding models were developed to improve access, equity, timeliness, and value of care for priority areas. COVID-19 upended health priorities and resulted in unprecedented disruptions to surgical care, which created a significant procedure gap. We hypothesized that activity-based funding models influenced the magnitude and trajectory of this procedure gap. METHODS: Population-based analysis of procedure rates comparing the pandemic (March 1, 2020-December 31, 2021) to a prepandemic baseline (January 1, 2017-February 29, 2020) in Ontario, Canada. Poisson generalized estimating equation models were used to predict expected rates in the pandemic based on the prepandemic baseline. Analyses were stratified by procedure type (outpatient, inpatient), body region, and funding category (activity-based funding programs vs. global budget). RESULTS: In all, 281,328 fewer scheduled procedures were performed during the COVID-19 period compared with the prepandemic baseline (Rate Ratio 0.78; 95% CI 0.77-0.80). Inpatient procedures saw a larger reduction (24.8%) in volume compared with outpatient procedures (20.5%). An increase in the proportion of procedures funded through activity-based programs was seen during the pandemic (52%) relative to the prepandemic baseline (50%). Body systems funded predominantly through global hospital budgets (eg, gynecology, otologic surgery) saw the least months at or above baseline volumes, whereas those with multiple activity-based funding options (eg, musculoskeletal, abdominal) saw the most months at or above baseline volumes. CONCLUSIONS: Those needing procedures funded through global hospital budgets may have been disproportionately disadvantaged by pandemic-related health care disruptions.

Correlation between corneal and contact lens deformation with changes in intraocular pressure for wearable monitoring systems.

OBJECTIVE: The aim of this work is to evaluate the extent to which the eye's curvature deformation, due to changes in the intraocular pressure (IOP), can be directly tracked by an overlying contact lens. METHOD: In this experimental study, using 12 cadaveric eyes, the IOP was increased from 10 to 36 mmHg, while video imaging was used to capture the three experimental variations. The deformation of the bare eye was used as a control, while the deformation of an overlying silicone grided contact lens and an overlying microfluidic IOP-sensing contact lens were examined and compared. RESULTS: The relation between the slope of the radius of corneal curvature versus the IOP for both the bare eye and the marker contact lens yielded a linear relationship with a R2 value of 0.83. The microfluidic contact lens resulted in an average performance of 0.40 mm indicator movement/mmHg (SD 0.006). Comparing the slope of the marker contact lens deformation, to the performance of the microfluidic contact lens resulted in a R2 value of 0.78. The strain map of the overlaying grided contact lens showed most deformation occurring along the outer edge of the lens with increased deformation as increase IOP occurs; as well as with some negative, compressive movement near the central points. CONCLUSION: The deformation from the curvature of the eye is significant enough from 10 to 36 mmHg that a silicone contact lens can capture and mimic those changes. The results show promise for optimization in contact lens-based IOP monitoring.

Association of topical glaucoma medications with lacrimal drainage obstruction and eyelid malposition.

BACKGROUND/OBJECTIVES: Adverse effects of topical glaucoma medications (TGMs) may include development of ocular adnexal disorders. We undertook a study to determine the effect of TGMs on the risk of developing lacrimal drainage obstruction (LDO) and eyelid malposition. SUBJECTS/METHODS: All patients 66 years of age and older in Ontario, Canada initiating TGM and all patients diagnosed with glaucoma/suspected glaucoma but not receiving TGM from 2002 to 2018 were eligible for inclusion in this retrospective cohort study. Using validated healthcare administrative databases, cohorts were identified with TGM and no TGM patients matched 1:2 on sex and birth year. The effect of TGM treatment on risk of surgery for LDO and lid malpositions was estimated using Kaplan-Meier and Cox proportional hazards models. RESULTS: Cohorts included 122,582 patients in the TGM cohort and 232,336 patients in the no TGM cohort. Among the TGM cohort there was decreased event-free survival for entropion (log-rank P < 0.001), trichiasis (P < 0.001), and LDO (P = 0.006), and increased ectropion-free survival (P = 0.007). No difference in ptosis-free survival was detected (P = 0.78). For the TGM cohort there were increased hazards for entropion (hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.12-1.37; P < 0.001), trichiasis (HR 1.74, 95% CI 1.57-1.94; P < 0.001), and LDO (at 15 years: HR 2.39, 95% CI 1.49-3.85; P = 0.004), and a decreased hazard for ectropion (HR 0.89, 95% CI 0.81-0.97; P = 0.008). No association between TGM treatment and ptosis hazard was detected (HR 0.99, 95% CI 0.89-1.09; P = 0.78). CONCLUSIONS: TGMs are associated with an increased risk of undergoing surgery for LDO, entropion, and trichiasis.

Ontario Cataract Quality Outcome Initiative: appropriateness and prioritization of cataract surgery.

OBJECTIVE: To explore the utility of the Catquest 9SF visual function (VF) questionnaire along with visual acuity (VA) for determining appropriateness and priority for cataract surgery. To evaluate the feasibility of administering the Catquest-9SF in a clinical setting using web-based electronic data capture and interpretation. DESIGN: Prospective multicentred interventional observational study. PARTICIPANTS: Subjects undergoing sequential cataract surgery in both eyes at 4 sites in Ontario. METHODS: We recorded best-corrected VA (BCVA) and VA with current correction (CCVA) in each eye and both eyes (OU) and Catquest-9SF responses on a tablet before and after cataract surgery. Linear regression models were employed to test for associations between VA and visual function (VF). RESULTS: Preoperative BCVA and CCVA in the worse eye were significant predictors of change in VF (p = 0.006 and p = 0.008, respectively); subjects with worse VA had a greater improvement in VF after surgery. There was a significant association between improvement in VF and improvement in CCVA OU (p = 0.001). Fourteen of 151 subjects (9%) had no improvement or worse VF scores after surgery. Within this group, 10 of 14 subjects had a preoperative score ≤-3, which is suggestive of minimal visual disability. Within this subset, 4 of 14 subjects (2.6%) had a preoperative BCVA of 20/30 or better in their worse eye. CONCLUSIONS: For patient groups with equal VA, the Catquest-9SF score can help determine priority for surgery. Web-based data capture and interpretation allow for efficient virtual assessments of VF. A BCVA in the worse eye of 20/30 or better combined with a Catquest-9SF score <-3 can be used as a guideline for lowest priority.

Expanding the scope of an eConsult service: acceptability and feasibility of an optometry-ophthalmology pilot project.

OBJECTIVE: To determine the feasibility and acceptability of connecting optometrists to ophthalmologists on an eConsult service. DESIGN: Descriptive analysis of utilization data and an anonymous survey. PARTICIPANTS: All eConsult cases sent by optometrists between March 2019 and February 2020 (utilization data); optometrists and ophthalmologists participating in the eConsult Vision Pilot Project (survey). METHODS: Utilization data for the study period were collected automatically and underwent descriptive analysis. Participating optometrists and ophthalmologists received an email invitation to a survey assessing the project. RESULTS: Thirteen optometrists from 5 clinics in the southeast region and 7 ophthalmologists were recruited to participate in the pilot project. Optometrists sent 109 eConsults in a 13-month period, representing 33% of all cases submitted to ophthalmology through the eConsult service provincially (March 2019-March 2020). Sixty-eight percent of respondents to an anonymous online survey valued the recruitment and engagement of eye care professionals from the same health region. The influence of the eConsult service was reported to have a "somewhat positive" (27%) to "very positive" (50%) influence on the relationship between the two professional groups. CONCLUSION: The eConsult Vision Pilot Project fills a gap in service and provides an opportunity for patients to get access to specialty advice. We demonstrated that allowing optometrists to solicit specialist advice from ophthalmologists was acceptable and feasible.

Evolution of first-line glaucoma therapy, 2007-2018: a population-based analysis.

OBJECTIVE: To evaluate the long-term evolution of first-line glaucoma therapy (FLGT) initiated by ophthalmologists and optometrists. DESIGN: Retrospective population-based study using validated provincial health care databases. PARTICIPANTS: 194,759 Ontario residents, 66 years of age or older, who received FLGT between 2007 and 2018. METHODS: A total of 194,759 individuals from 12 annual cohorts were enrolled, and rates of first-line medical treatment (prostaglandin analogue [PGA], beta-blocker, alpha-2-agonist, and carbonic anhydrase inhibitor) and laser trabeculoplasty (LT) were calculated. Provider (ophthalmologist or optometrist) rates also were assessed. RESULTS: Across the entire study period, of the 194,759 enrolled individuals who received FLGT, 60.2% initially received medical treatment and 39.8% underwent LT. Approximately 94.6% were treated by ophthalmologists. PGA therapy was the most common therapy prior to 2010, whereupon LT became the most common FLGT. By 2015, LT exceeded the total of all medications as FLGT. The annual rate of initial medication prescriptions by optometrists rose to 101.4 per 100,000 population between 2011 and 2018. In 2018, PGA and non-PGA prescription rates by ophthalmologists were 2.6 and 5.0 times higher, respectively, than prescription rates by optometrists. CONCLUSION: LT therapy has become the most common FLGT for Ontario residents 66 years of age or older. PGAs remain the most frequently prescribed glaucoma medication. While ophthalmologists continue to provide the majority of FLGT, optometrists now provide a small but growing fraction of FLGT following the introduction of glaucoma medication prescribing privileges.

Hearing aid utilization in Ontario - a population based study.

BACKGROUND: Hearing loss is one of the most common sensory impairments and hearing aids are the most common unmet assistive device need among individuals with a disability. The benefits of hearing interventions are well-documented as they are known to deter the sequalae of hearing loss including social isolation, poor mental health, falls and cognitive decline. Identifying trends in hearing aid users can provide valuable information for improving access to hearing loss interventions. METHODS: Data were retrieved from ICES databases that were used to generate a cohort of 372,448 individuals in Ontario, Canada, who first claimed hearing aids between April 2007 and March 2018 through the Assistive Devices Program. RESULTS: The data indicated that the frequency distribution of hearing aids has steadily inclined since 2007. The mean age of hearing aid users was 70.25 ± 14.70 years and higher neighbourhood income quintile was associated with greater hearing aid use (p < 0.001). Most first claims occurred after visiting primary care physicians (70.60%) compared with otolaryngology (13.39%). An examination of clinical comorbidities revealed hypertension (63.41%), and diabetes (24.93%) to be the most common. Regression analysis demonstrated a positive associated between age and most comorbidities. Furthermore, higher neighbourhood income quintiles were associated with a reduced risk of having the examined comorbidities. CONCLUSIONS: This study examines patient demographics and clinical comorbidities in a cohort of hearing aid users in Ontario. The results identify associations between demographics and comorbidities that provide information relevant for improving access to hearing interventions and clinical decision-making in primary care.Implications for RehabilitationScreening for hearing loss (using an audiogram) in elderly individuals that manage multiple comorbidities, and any patient with significant risk factors for hearing loss (e.g., noise exposure history, prior ototoxic medications, prior head injury, history of ear surgery, family history of hearing loss) will identify deficits and direct appropriate hearing interventions.Improving access to care in low-income communities should include community-based education around expectation management and communication strategies to reinforce proper use and care of hearing devices.Geographic proximity to hearing testing facilities and hearing aid dispensaries is a significant barrier to hearing rehabilitation strategies.

Reversal of ciliary mechanisms of disassembly rescues olfactory dysfunction in ciliopathies.

Ciliopathies are a class of genetic diseases resulting in cilia dysfunction in multiple organ systems, including the olfactory system. Currently, there are no available curative treatments for olfactory dysfunction and other symptoms in ciliopathies. The loss or shortening of olfactory cilia, as seen in multiple mouse models of the ciliopathy Bardet-Biedl syndrome (BBS), results in olfactory dysfunction. However, the underlying mechanism of the olfactory cilia reduction is unknown, thus limiting the development of therapeutic approaches for BBS and other ciliopathies. Here, we demonstrated that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], a phosphoinositide typically excluded from olfactory cilia, aberrantly redistributed into the residual cilia of BBS mouse models, which caused F-actin ciliary infiltration. Importantly, PI(4,5)P2 and F-actin were necessary for olfactory cilia shortening. Using a gene therapeutic approach, the hydrolyzation of PI(4,5)P2 by overexpression of inositol polyphosphate-5-phosphatase E (INPP5E) restored cilia length and rescued odor detection and odor perception in BBS. Together, our data indicate that PI(4,5)P2/F-actin-dependent cilia disassembly is a common mechanism contributing to the loss of olfactory cilia in BBS and provide valuable pan-therapeutic intervention targets for the treatment of ciliopathies.

Supply and demographic characteristics of Ontario's ophthalmologists from 2010 to 2019: a population-based analysis.

BACKGROUND: With an aging population in Ontario, ophthalmologists provide most of their care to older adults, which has prominent human resource implications. In this study, we sought to investigate the supply and demographic characteristics of Ontario's ophthalmologists. METHODS: In this retrospective, population-based analysis, we evaluated cohort demographics, including sex and career stage, of Ontario's ophthalmologists from 2010 to 2019, which we reported using descriptive statistics. Similarly, we detailed ophthalmologist supply within different areas of care using descriptive statistics. RESULTS: Over the study period, a median of 464 ophthalmologists were practising in Ontario each year. The proportion of female ophthalmologists increased from 18.7% in 2010 to 24.1% in 2019. The proportion of late-career ophthalmologists (aged > 55 yr) significantly increased by 6.4% over the study period and constituted 45.3% of the workforce in 2019. Comprehensive cataract surgery was the most common area of care. Although the number of ophthalmologists per 100 000 people remained stable over the study period (3.27 ophthalmologists/100 000 people in 2019), the number of ophthalmologists per 100 000 people aged 65 years and older fell by 18.4% from 2010 to 2019. The greatest supply reduction was among moderate-volume comprehensive cataract surgeons (-20.2% overall and -35.4% relative to the population aged ≥ 65 yr). INTERPRETATION: Between 2010 and 2019, the overall number of ophthalmologists in Ontario remained stable; however, we observed declines in the number of ophthalmologists per 100 000 people aged 65 years and older for most areas of care. Nearly half of the ophthalmology workforce is now older than 55 years and female representation is increasing.

Preoperative anesthesiology consult utilization in Ontario - a population-based study.

RATIONALE, AIMS AND OBJECTIVES: Physician consultations are a limited resource. Anesthesiologists provide anaesthesia during surgery and procedures, prepare patients for surgery in preoperative clinics, and provide postoperative care. This study sought to evaluate current consultation usage patterns, with an aim to determine possible opportunities for efficiency. METHOD: A retrospective comprehensive population-based cohort study was performed, evaluating all hospitals in the Canadian province of Ontario from 2002 to 2018. The main outcome measures were American Society of Anesthesiologists (ASA) classification of the patients, and whether the patients underwent surgery within 3 months following the anaesthesia consultation. RESULTS: A cohort of 2,023,499 patients, and a total of 2,920,100 preoperative anaesthesia consultations was obtained. The number of consults per year doubled between 2003 (112,983/year) and 2017 (246,427/year), despite a less than 40% increase in practicing Canadian Anesthesiologists over this same timeframe. Each year, an average of 19.3% of the consults (range: 17.7-20.5%) were for patients that did not progress to having surgery. Of those that did have surgery following the anaesthesia consult, 37.2% were ASA Classification I or II. The most common surgical procedures (percent of total) following anaesthesia consult were: Knee arthroplasty (9.5%), hip arthroplasty (5.8%), cataract extraction (4.1%), repair of muscle of chest/abdomen (3.3%), hysterectomy (2.8%), and cholecystectomy (2.7%). CONCLUSIONS: This study reveals data on utilization and trends over time of preoperative anaesthesia consultations. Potential opportunities for optimization were found, including patients who did not proceed to surgery, and healthier patients undergoing low to moderate risk surgery.

Opioid Prescriptions Following Otologic Surgery: A Population-Based Study.

OBJECTIVE: To examine postoperative opioid-prescribing patterns following otologic surgery. STUDY DESIGN: Retrospective population-based descriptive study. SETTING: All hospitals in the Canadian province of Ontario. METHODS: Of all patients with advanced ear surgery between July 1, 2012, and March 31, 2019, 7 cohorts were constructed: tympanoplasty with or without ossiculoplasty (n = 7812), atticotomy/limited mastoidectomy (n = 1371), mastoidectomy (n = 3717), semicircular canal occlusion (SCO; n = 179), stapedectomy (n = 2735), bone-implanted hearing aid insertion (n = 280), and cochlear implant (n = 2169). Prescriptions filled for narcotics postoperatively were calculated per morphine milligram equivalent (MME) opioid dose. Multivariable regression was used to determine predictors of higher opioid doses. RESULTS: The mean ± SD MMEs prescribed were as follows: tympanoplasty with or without ossiculoplasty, 246.77 ± 1380.78; atticotomy/limited mastoidectomy, 283.32 ± 956.10; mastoidectomy, 280.56 ± 1018.50; SCO, 328.61 ± 1090.86; stapedectomy, 164.64 ± 657.18; bone-implanted hearing aid insertion, 326.11 ± 1054.66; and cochlear implant, 200.87 ± 639.93. SCO (odds ratio [OR], 1.69 [95% CI, 1.16-2.48]) and mastoidectomy (OR, 1.50 [95% CI, 1.36-1.66]) were associated with higher opioid doses than tympanoplasty-ossiculoplasty. Asthma (OR, 1.24 [95% CI, 1.12-1.38]), chronic obstructive pulmonary disease (OR, 1.29 [95% CI, 1.12-1.47]), myocardial infarction (OR, 1.33 [95% CI, 1.05-1.68]), diabetes (OR, 1.22 [95% CI, 1.08-1.39]), and substance-related and addictive disorders (OR, 2.59 [95% CI, 1.67-4.00]) were associated with higher opioid doses prescribed. Overall MME prescribed by year demonstrates a sharp drop from 2017-2018 to 2018-2019. CONCLUSION: This large comprehensive population study provides insight into the prescribing patterns following otologic surgery. The large amounts prescribed and substantial variation require further study to determine barriers that limit good opioid-prescribing stewardship in the postoperative period.

The ophthalmic surgical backlog associated with the COVID-19 pandemic: a population-based and microsimulation modelling study.

BACKGROUND: Jurisdictions worldwide ramped down ophthalmic surgeries to mitigate the effects of COVID-19, creating a global surgical backlog. We sought to predict the long-term impact of COVID-19 on the timely delivery of non-emergent ophthalmology sub-specialty surgical care in Ontario. METHODS: This is a microsimulation modelling study. We used provincial population-based administrative data from the Wait Time Information System database in Ontario for January 2019 to May 2021 and facility-level data for March 2018 to May 2021 to estimate the backlog size and wait times associated with the COVID-19 pandemic. For the postpandemic recovery phase, we estimated the resources required to clear the backlog of patients accumulated on the wait-list during the pandemic. Outcomes were accrued over a time horizon of 3 years. RESULTS: A total of 56 923 patients were on the wait-list in the province of Ontario awaiting non-emergency ophthalmic surgery as of Mar. 15, 2020. The number of non-emergency surgeries performed in the province decreased by 97% in May 2020 and by 80% in May 2021 compared with the same months in 2019. By 2 years and 3 years since the start of the pandemic, the overall estimated number of patients awaiting surgery grew by 129% and 150%, respectively. The estimated mean wait time for patients for all subspecialty surgeries increased to 282 (standard deviation [SD] 91) days in March 2023 compared with 94 (SD 97) days in 2019. The provincial monthly additional resources required to clear the backlog by March 2023 was estimated to be a 34% escalation from the prepandemic volumes (4626 additional surgeries). INTERPRETATION: The estimates from this microsimulation modelling study suggest that the magnitude of the ophthalmic surgical backlog from the COVID-19 pandemic has important implications for the recovery phase. This model can be adapted to other jurisdictions to assist with recovery planning for vision-saving surgeries.

Predictors of Postoperative Complications in Vestibular Schwannoma Surgery-A Population-Based Study.

OBJECTIVE: To investigate preoperative patient demographics and comorbidities in relation with postsurgical complications following vestibular schwannoma surgery. STUDY DESIGN: Retrospective population-based cohort study. SETTING: All hospitals in the Canadian province of Ontario. PATIENTS: This study includes 1,456 patients who underwent vestibular schwannoma surgery from April 1, 2002 to March 31, 2018 in Ontario, Canada. INTERVENTION/OUTCOME MEASURES: For all surgical patients, the demographic data, preoperative comorbidities, and postoperative complications were evaluated. Postoperative complications were examined immediately following surgery in the hospital as well as 1 year following the hospital discharge. RESULTS: The most common comorbidities in this cohort were hypertension (30.22%), diabetes (9.48%), asthma (13.53%), and chronic obstructive pulmonary disease (6.73%). Diabetes was the most impactful comorbidity and was associated with higher risk of myocardial infarction (RR = 4.58, p < 0.01), pneumonia (RR = 1.80, p = 0.02), dysphagia (RR = 1.58, p < 0.01), and meningitis (RR = 3.62, p < 0.01). Analysis of surgical approaches revealed that the translabyrinthine approach, compared with the open craniotomy approach, was negatively associated with postoperative complications including pneumonia (RR = 0.43, p < 0.01), urinary tract infection (RR = 0.55, p = 0.01), dysphagia (RR = 0.66, p < 0.01), and readmission (RR = 0.45, p < 0.01). CONCLUSION: This study examines patient demographics, preoperative comorbidities, and postoperative complications in patients who have undergone vestibular schwannoma surgery. The results highlight associations between patient characteristics and postoperative outcomes that can aid in preoperative decision-making and counselling.

Effect of variations of corneal physiology on novel non-invasive intraocular pressure monitoring soft contact lens.

Glaucoma is the leading cause of irreversible blindness around the world. With its slow asymptomatic progression, there is an emphasis on early detection and frequent monitoring. A novel microfluidic contact lens has been established as a potential way to track the fluctuations of the intraocular pressure (IOP) which is a key indicator for diagnosing and monitoring glaucoma progression. The purpose of this article is to determine the effect of physiological variations of the eye on the performance of the microfluidic contact lens. Ultrasound biomicroscopy (UBM) was used to measure the central corneal thickness (CCT) and radius of corneal curvature (RCC) for a series of 16 fresh enucleated porcine eyes. The effect of these corneal anatomic features on device performance was then assessed by systematically adjusting intraocular pressure from 10 to 34 mmHg and monitoring the device indicator response. The performance of the microfluidic contact lens was determined by finding the amount the indicator fluid shifted in position as a result of 1 mmHg IOP increase. The relationship between IOP and indicator fluid was found to be linear for all eyes. The slope of the indicator fluid movement as a result of the IOP was evaluated against the CCT and RCC of each porcine eye. This yielded low correlation coefficients, 0.057 for CCT and 0.024 for RCC, meaning that these physiological differences showed no systematic impact on the measurements made with the contact lens.

Surgical Outcomes among Focused versus Diversified Cataract Surgeons.

PURPOSE: Narrowly focused surgical practice has become increasingly common in ophthalmology and may have an effect on surgical outcomes. Previous research evaluating the influence of surgical focus on cataract surgical outcomes has been lacking. This study aimed to evaluate whether surgeons' exclusive surgical focus on cataract surgery influences the risk of cataract surgical adverse events. DESIGN: Population-based cohort study. PARTICIPANTS: All patients 66 years of age or older undergoing cataract surgery in Ontario, Canada, between January 1, 2002, and December 31, 2013. METHODS: Outcomes of isolated cataract surgery performed by exclusive cataract surgeons (no other types of surgery performed), moderately diversified cataract surgeons (1%-50% noncataract procedures), and highly diversified cataract surgeons (>50% noncataract procedures) were evaluated using linked healthcare databases and controlling for patient-, surgeon-, and institution-level covariates. Surgeon-level covariates included both surgeon experience and surgical volume. MAIN OUTCOME MEASURES: Composite outcome incorporating 4 adverse events: posterior capsule rupture, dropped lens fragments, retinal detachment, and suspected endophthalmitis. RESULTS: The study included 1 101 864 cataract operations. Patients had a median age of 76 years, and 60.2% were female. Patients treated by the 3 groups of surgeons were similar at baseline. Adverse events occurred in 0.73%, 0.78%, and 2.31% of cases performed by exclusive cataract surgeons, moderately diversified surgeons, and highly diversified surgeons, respectively. The risk of cataract surgical adverse events for patients operated on by moderately diversified surgeons was not different than for patients operated on by exclusive cataract surgeons (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.00-1.18). Patients operated on by highly diversified surgeons had a higher risk of adverse events than patients operated on by exclusive cataract surgeons (OR, 1.52; 95% CI, 1.09-2.14). This resulted in an absolute risk difference of 0.016 (95% CI, 0.012-0.020) and a number needed to harm of 64 (95% CI, 50-87). CONCLUSIONS: Exclusive surgical focus did not affect the safety of cataract surgery when compared with moderate levels of surgical diversification. The risk of cataract surgical adverse events was higher among surgeons whose practice was dedicated mainly to noncataract surgery.

Distribution and Predictors of Initial Glaucoma Care Among Ophthalmologists and Optometrists: A Population-based Study.

PURPOSE: To evaluate evolution in the distribution of new glaucoma patients between ophthalmologists and optometrists, and to examine factors predicting provider type, in the context of expansion in the scope of optometry practice. PATIENTS AND METHODS: A population-based study was undertaken using validated datasets in Ontario, Canada from 2007 to 2018, encompassing time before and after optometry practice scope expansion in 2011. All patients aged 66 and older receiving a glaucoma suspect diagnosis or first-line therapy for glaucoma from ophthalmologists or optometrists were enrolled. Predictors of provider type were evaluated using logistic regression. RESULTS: From 2007 to 2018, 401,560 patients received initial glaucoma care, including 303,440 by ophthalmologists and 98,120 by optometrists. Population rates of glaucoma suspect diagnosis increased for both providers over the study period. The rate of therapy initiation increased annually among optometrists after 2011, while the rate remained stable over that period among ophthalmologists. By 2018, 88% of patients initiating therapy and 59% of patients first diagnosed as a glaucoma suspect received that care from ophthalmologists. In the final study year, therapy initiations per provider were lower among optometrists (median: 2/provider; interquartile range: 1 to 3) than among ophthalmologists (median: 26.5/provider, interquartile range: 10 to 53). Patients were more likely to receive care from an ophthalmologist than an optometrist if they were older, had higher ocular or systemic comorbidity, or lived in urban settings. CONCLUSIONS: Optometrists have a large and growing role in diagnosing glaucoma suspects; however, despite scope expansion, optometrists play a much smaller role in initiating glaucoma therapy.