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.

Exclusive cataract surgical focus among ophthalmologists: a population-based analysis.

OBJECTIVE: An important potential unintended consequence of the growth of surgical subspecialization is the narrowing of surgical practice among comprehensive ophthalmologists. We investigated trends in the narrowing of surgical practice and the exclusive provision of cataract surgery. DESIGN: Population-based, retrospective study. PARTICIPANTS: All ophthalmologists and all ophthalmologic surgical patients in Ontario from 1994 to 2016. METHODS: We linked several health care databases to evaluate the proportion of ophthalmologists who exclusively provided cataract surgery (and no other ophthalmologic surgery) and the proportion who provided other types of ophthalmologic surgical care. To further investigate surgical focus, we evaluated the proportion of surgical cases within each surgical area for each ophthalmologist. RESULTS: Between 1994 and 2016, the proportion of ophthalmologists who exclusively provided cataract surgery rose from 10.0% to 34.9% (p < 0.0001). In contrast, the proportions of ophthalmologists providing other types of subspecialized surgical care were stable over the study period. Cataract surgeons showed high degrees of focus with a median percentage of surgical cases approaching 100% in all years. Among exclusive cataract surgeons, the median annual cataract case volume increased from 138 (interquartile range: 87-214) to 529 (interquartile range: 346-643) between 1994 and 2009 (p < 0.0001) and then plateaued. CONCLUSIONS: Between 1994 and 2016, exclusive cataract surgical focus among ophthalmologists in Ontario rose dramatically from 1 in 10 to 1 in 3 surgeons. This evolution was similar among recent graduates and established ophthalmologists. Our data may have important implications for policies regarding surgeon human resources as well as residency and fellowship training programs.

Drug-Induced Intracranial Hypertension: A Systematic Review and Critical Assessment of Drug-Induced Causes.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition with increased intracranial pressure of unknown etiology. Its presenting symptoms include persistent headache, pulsatile tinnitus, and visual obscuration. It tends to occur in obese women of childbearing age, and its greatest risk is irreversible loss of vision. Some of the commonly used medications in dermatology, especially those for acne vulgaris, have been associated with IIH. However, the creation of specific risk categories for drugs as a guide for clinicians has never been performed. OBJECTIVE: The aim of this study was to critically assess all published cases of IIH and identify high-risk drugs associated with drug-induced intracranial hypertension (DIIH), to assist dermatologists and other physicians with patient education and monitoring of symptoms of secondary intracranial hypertension. METHODS: MEDLINE, EMBASE, and Cochrane Review Databases were searched for all cases of IIH thought to be drug-related between January 1900 and June 2019. A total of 5117 articles were identified, and 235 articles were found to be relevant. All cases were assessed to satisfy the modified Dandy criteria for diagnosis of IIH, and the likelihood of each case being a 'definite' adverse drug reaction (ADR) was determined using the Koh algorithm for ADR. An association category (from weakly associated [Category I] to strongly associated [Category V]) was assigned based on the number of cases meeting these two criteria. RESULTS: There were 259 verifiable cases of DIIH. Vitamin A derivatives, tetracycline-class antibiotics, recombinant growth hormone, and lithium were found to be most strongly associated with DIIH (Categories IV and V). Corticosteroids were moderately associated with DIIH (Category III). Drugs that were weakly associated with DIIH (Categories I and II) include cyclosporine, progestin-only contraceptives, combined oral contraceptives, second- and third-generation fluoroquinolones, sulfenazone, gonadotropin-releasing hormones and luteinizing hormone-releasing hormone agonist, nalidixic acid, amiodarone, stanozolol, danazol, divalproic acid, sulfasalazine, ketoconazole, and ustekinumab. CONCLUSION: We suggest using the term 'drug-induced intracranial hypertension' (DIIH) and propose a set of diagnostic criteria for DIIH. Our review attempts to identify DIIH-associated drugs based on a strict diagnostic and drug-causality algorithm, then stratify them into appropriate risks categories. This may ultimately assist physicians in counselling patients about the risk of DIIH when prescribing medications and recognizing this uncommon yet sight-threatening condition.

Intraocular calcidiol: Uncovering a role for vitamin D in the eye.

Vitamin D has emerged as a potentially important molecule in ophthalmology. To date, all ophthalmic data pertaining to vitamin D has been restricted primarily to tear and serum analysis in human patients. Considering the isolated nature of the eye, we sought to determine the presence of intraocular vitamin D in ocular disease. METHODS: 25-Hydroxyvitamin D3 (25(OH)D3) concentrations were measured in the eye and blood of 120 participants undergoing ophthalmic procedures. Ocular localization of the 1,25-dihydroxyvitamin D3-generating (CYP27B1) and deactivating (CYP24A1) hydroxylases was performed by immunohistochemistry. Gene expression of CYP27B1, CYP24A1 and VEGF-A was measured in eyes from patients with and without disease. RESULTS: 25(OH)D3 was quantified in 112 ocular samples. In 40 cataract patient samples, the average 25(OH)D3 concentration was 0.057 ng/mL, compared to 72 retinal disease patient samples, average of 0.502 ng/mL (p < 0.001). Intraocular 25(OH)D3 did not correlate with serum levels of 25(OH)D3. There was no difference between the level of 25(OH)D3 measured in the aqueous and vitreous humour. The vitamin D-specific CYPs 27B1 and 24A1, strongly localized to complementary regions of the ciliary body, retinal pigment epithelium and neural retina. Gene expression analysis confirmed retinal CYP27B1 correlated strongly with VEGF-A in eyes from diabetic patients (r = 0.92, p < 0.001). CONCLUSIONS: Our data confirms that vitamin D is present in the humours of the human eye and that local synthesis/degradation is possible via the ocular CYP27B1 and CYP24A1. This argues for a functional role for local vitamin D production and signaling in the eye and suggests that vitamin D may be an important intraocular mediator in disease pathogenesis.

Cataract Surgery Quality and Capacity.

Cataract surgery is the most common operation performed in most developed countries, including Canada. Nuanced, evidence-driven policies are needed to ensure appropriate access to this sight-saving operation while maintaining the highest standards in quality of care. The Vision Health Services Research Program at Queen's University, in partnership with members of the Ontario Provincial Vision Task Force, has developed evidence to inform policies aimed at optimizing both access and quality across the eye care spectrum.

The incidence of giant cell arteritis in Ontario, Canada.

OBJECTIVE: The incidence of giant cell arteritis (GCA) is insufficiently documented for Canada, but important to ascertain for public health planning. We estimate the incidence of biopsy-proven GCA (BPGCA) in Kingston, Ontario, and for the province of Ontario. METHOD: The number of cases of BPGCA was tabulated from retrospective chart review of all temporal artery biopsies (TABx) in Kingston, Ontario from 2011-15. The relevant population denominator was determined from the Canada census federal electoral district and the patient's postal code. The province-wide estimate for the incidence of BPGCA was calculated from provincial billing data of TABx from 2015-17, the Canada census for Ontario, and the expected positive yield of TABx. RESULTS: There were 35 subjects with BPGCA in the Kingston area over the 4-year period, from a population of 179 503 individuals 50 years of age or older (≥50 years). Ontario billing data identified 2404 patients who underwent TABx for suspected GCA over a 2-year period, from a population of 5 143 610 persons ≥50 years. Meta-analysis of 5 provincial TABx series suggested a 21% positive yield from TABx procedures (95% CI 0.18-0.24). The minimum cumulative incidence of BPGCA was 4.9 per 100 000 persons ≥50 years in Kingston, and 4.9 (95% CI 4.2-5.6) per 100 000 persons ≥50 years for Ontario as a whole. CONCLUSION: The estimated incidence of BPGCA in Ontario using 2 different estimation techniques was comparable, but low compared with other countries. The actual incidence of GCA in Ontario may be higher.

Neural network and logistic regression diagnostic prediction models for giant cell arteritis: development and validation.

PURPOSE: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic prediction models in patients with suspected giant cell arteritis (GCA). Design: Multicenter retrospective chart review. METHODS: An audit of consecutive patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at 14 international medical centers. The outcome variable was biopsy-proven GCA. The predictor variables were age, gender, headache, clinical temporal artery abnormality, jaw claudication, vision loss, diplopia, erythrocyte sedimentation rate, C-reactive protein, and platelet level. The data were divided into three groups to train, validate, and test the models. The NN model with the lowest false-negative rate was chosen. Internal and external validations were performed. RESULTS: Of 1,833 patients who underwent TABx, there was complete information on 1,201 patients, 300 (25%) of whom had a positive TABx. On multivariable LR age, platelets, jaw claudication, vision loss, log C-reactive protein, log erythrocyte sedimentation rate, headache, and clinical temporal artery abnormality were statistically significant predictors of a positive TABx (P≤0.05). The area under the receiver operating characteristic curve/Hosmer-Lemeshow P for LR was 0.867 (95% CI, 0.794, 0.917)/0.119 vs NN 0.860 (95% CI, 0.786, 0.911)/0.805, with no statistically significant difference of the area under the curves (P=0.316). The misclassification rate/false-negative rate of LR was 20.6%/47.5% vs 18.1%/30.5% for NN. Missing data analysis did not change the results. CONCLUSION: Statistical models can aid in the triage of patients with suspected GCA. Misclassification remains a concern, but cutoff values for 95% and 99% sensitivities are provided (https://goo.gl/THCnuU).

Evolution in the Risk of Cataract Surgical Complications among Patients Exposed to Tamsulosin: A Population-Based Study.

PURPOSE: Tamsulosin is associated with intraoperative floppy iris syndrome (IFIS), an important risk factor for complications during cataract surgery. Significant efforts have been made to increase awareness of the risks associated with tamsulosin, and educational initiatives have fostered the uptake of technical adjustments to decrease adverse event rates among tamsulosin-exposed patients. However, the effectiveness of these efforts at the population level has not been studied. DESIGN: Population-based study to evaluate cataract surgical adverse event rates over time among patients exposed to tamsulosin and those not exposed to this drug. PARTICIPANTS: All male patients 66 years of age and older undergoing cataract surgery in Ontario, Canada, between January 1, 2003, and December 31, 2013, were included in the study. METHODS: Linked healthcare databases were used to study the evolution in the risk of cataract surgical adverse events over time among tamsulosin-exposed and non-tamsulosin-exposed patients adjusting for patient-, surgeon-, and institution-level covariates. The study timeframe incorporated periods before and after the first reports of tamsulosin-associated IFIS. MAIN OUTCOME MEASURES: Four important cataract surgical adverse events were evaluated: posterior capsule rupture, dropped lens fragments, retinal detachment, and suspected endophthalmitis. RESULTS: Among patients exposed to tamsulosin, the risk of surgical adverse events decreased over time (odds ratio, 0.95 per year; 95% confidence interval, 0.91-0.99 per year). This trend was observed across patient age strata. Among patients not recently exposed to tamsulosin, the risk of surgical adverse events also decreased over time (odds ratio, 0.96 per year; 95% confidence interval, 0.95-0.98 per year). CONCLUSIONS: The risk of cataract surgical complications among both tamsulosin-exposed and non-tamsulosin-exposed patients declined between 2003 and 2013. Tamsulosin remains an important risk factor for cataract surgical adverse events, and ongoing efforts will be needed to develop and disseminate surgical approaches that mitigate the risks posed by tamsulosin.

Association of Cataract Surgical Outcomes With Late Surgeon Career Stages: A Population-Based Cohort Study.

Importance: Evidence suggests that the quality of some aspects of care provided by physicians may decrease during their late career stage. However, to our knowledge, data regarding the association of advancing surgeon career phase with cataract surgical outcomes have been lacking. Objective: To investigate whether an increase in cataract surgical adverse events occurs during later surgeon career stages. Design, Setting, and Participants: This population-based study of 499 650 cataract operations performed in Ontario, Canada, between January 1, 2009, and December 31, 2013, investigated the association between late surgeon career stage and the risk of surgical adverse events. Linked health care databases were used to study cataract surgical complications while controlling for patient-, surgeon-, and institution-level covariates. All ophthalmologists who performed cataract surgery in Ontario within the study period were included in the analysis. Exposures: Isolated cataract surgery performed by surgeons at early, mid, and late career stages. Main Outcomes and Measures: Four serious adverse events were evaluated: dropped lens fragments, posterior capsule rupture, suspected endophthalmitis, and retinal detachment. Results: Of 416 502 participants, 244 670 (58.7%) were women, 90 429 (21.7%) were age 66 to 70 years, 111 530 (26.8%) were age 71 to 75 years, 90 809 (21.8%) were age 76 to 80 years, and 123 734 (29.7%) were 81 years or older. Late-career surgeons performed 143 108 of 499 650 cataract operations (28.6%) during the study period. Late surgeon career stage was not associated with an increased overall risk of surgical adverse events (odds ratio [OR] vs midcareer, 1.06; 95% CI, 0.85-1.32). In a sensitivity analysis with surgeon volume removed from the model, late career stage was still not associated with overall adverse surgical events (OR, 1.10; 95% CI, 0.88-1.38). Among individual complications, late surgeon career stage was associated with an increased risk of dropped lens fragment (OR, 2.30; 95% CI, 1.50-3.54) and suspected endophthalmitis (OR, 1.41; 95% CI, 1.01-1.98). These corresponded with small absolute risk differences of 0.11% (95% CI, 0.085%-0.130%) and 0.045% (95% CI, 0.028%-0.063%) for dropped lens fragment and suspected endophthalmitis, respectively. Conclusions and Relevance: These findings suggest that later-career surgeons are performing a substantial proportion of cataract operations with overall low surgical adverse event rates. Future studies might extend evaluations to the frequency of secondary surgical interventions as additional measures of surgical care quality.

Multivariable prediction model for suspected giant cell arteritis: development and validation.

PURPOSE: To develop and validate a diagnostic prediction model for patients with suspected giant cell arteritis (GCA). METHODS: A retrospective review of records of consecutive adult patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at seven university centers. The pathologic diagnosis was considered the final diagnosis. The predictor variables were age, gender, new onset headache, clinical temporal artery abnormality, jaw claudication, ischemic vision loss (VL), diplopia, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelet level. Multiple imputation was performed for missing data. Logistic regression was used to compare our models with the non-histologic American College of Rheumatology (ACR) GCA classification criteria. Internal validation was performed with 10-fold cross validation and bootstrap techniques. External validation was performed by geographic site. RESULTS: There were 530 complete TABx records: 397 were negative and 133 positive for GCA. Age, jaw claudication, VL, platelets, and log CRP were statistically significant predictors of positive TABx, whereas ESR, gender, headache, and temporal artery abnormality were not. The parsimonious model had a cross-validated bootstrap area under the receiver operating characteristic curve (AUROC) of 0.810 (95% CI =0.766-0.854), geographic external validation AUROC's in the range of 0.75-0.85, calibration pH-L of 0.812, sensitivity of 43.6%, and specificity of 95.2%, which outperformed the ACR criteria. CONCLUSION: Our prediction rule with calculator and nomogram aids in the triage of patients with suspected GCA and may decrease the need for TABx in select low-score at-risk subjects. However, misclassification remains a concern.

Three-Dimensional Printing of a Transconjunctival Vitrectomy Trocar-Cannula System.

PURPOSE: The aim of this paper was to study the feasibility of manufacturing a customizable trocar-cannula system for vitreoretinal surgery utilizing commercially available three-dimensional (3D) printing technology. METHODS: A digital model of a trocar-cannula system for vitreoretinal surgery was created using computer-aided design (CAD) software and printed utilizing a laser-sintering 3D printer in modified ABS thermoplastic material. The trocar-cannula prototypes were tested in pig eyes. RESULTS: A customizable digital model was created using commercially available CAD software. Three trocar-cannulas were printed. The smallest cannulas that could be printed had dimensions between 21 and 22G. The trocar-cannulas were inserted in pig eyes after performing sclerotomies with a commercially available 20G MVR blade. One cannula broke during insertion. CONCLUSIONS: This study demonstrates the feasibility of printing a transconjunctival vitrectomy trocar-cannula system with commercially available 3D print technology. The 3D printer and build material used resulted in trocar-cannulas with functional limitations including a minimum size achievable and mechanical resistance.

New Surgeon Outcomes and the Effectiveness of Surgical Training: A Population-Based Cohort Study.

PURPOSE: Reports have questioned the technical proficiency of newly graduating surgeons. However, objective data supporting these concerns are limited. Surgical outcomes among recent graduates are an important indicator of residency programs' ability to graduate surgeons who are ready to meet the needs of their patients. This study aimed to investigate the association between a surgeon's number of years of independent practice and the risk of surgical adverse events. DESIGN: Population-based cohort study. PARTICIPANTS: All patients 66 years of age or older undergoing isolated cataract operations in Ontario, Canada, between January 1, 1997, and December 31, 2013. METHODS: Cataract surgical outcomes for all operations performed by surgeons commencing practice in the study period were evaluated using linked health care databases. MAIN OUTCOME MEASURES: Four serious complications were evaluated: posterior capsule rupture, dropped lens fragments, retinal detachment, and suspected endophthalmitis. Analyses controlled for patient-, surgeon-, and institution-level covariates. RESULTS: The study evaluated 1 431 320 cataract operations. Surgeons in their first year of independent practice were more than 9 times more likely to have high complication rates (≥2%) than surgeons in their tenth year (odds ratio [OR], 9.3; 95% confidence interval [CI], 2.7-31.9). Each additional year of independent practice was associated with a 10% decrease in the risk of patients experiencing an adverse surgical event (OR, 0.90 per year of surgeon independent practice; 95% CI, 0.87-0.94). CONCLUSIONS: In this population-based study, surgical complications were significantly more likely early in surgeons' careers. Interventions may be needed in postgraduate surgical training and early independent career monitoring and mentoring processes to ensure patient safety while continually renewing the surgical workforce.

Effect of cataract surgery volume constraints on recently graduated ophthalmologists: a population-based cohort study.

BACKGROUND: Across Canada, graduates from several medical and surgical specialties have recently had difficulty securing practice opportunities, especially in specialties dependent on limited resources such as ophthalmology. We aimed to investigate whether resource constraints in the health care system have a greater impact on the volume of cataract surgery performed by recent graduates than on established physicians. METHODS: We used population-based administrative data from Ontario for the period Jan. 1, 1994, to June 30, 2013, to compare health services provided by recent graduates and established ophthalmologists. The primary outcome was volume of cataract surgery, a resource-intensive service for which volume is controlled by the province. RESULTS: When cataract surgery volume in Ontario entered a period of government-mandated zero growth in 2007, the mean number of cataract operations performed by recent graduates dropped significantly (-46.37 operations/quarter, 95% confidence interval [CI] -62.73 to -30.00 operations/quarter), whereas the mean rate for established ophthalmologists remained stable (+5.89 operations/quarter, 95% CI 95% CI -1.47 to +13.24 operations/quarter). Decreases in service provision among recent graduates did not occur for services without volume control. The proportion of recent graduates providing exclusively cataract surgery increased over the study period, and recent graduates in this group were 5.24 times (95% CI 2.15 to 12.76 times) more likely to fall within the lowest quartile for cataract surgical volume during the period of zero growth in provincial cataract volume (2007-2013) than in the preceding period (1996-2006). INTERPRETATION: Recent ophthalmology graduates performed many fewer cataract surgery procedures after volume controls were implemented in Ontario. Integrated initiatives involving multiple stakeholders are needed to address the issues facing recently graduated physicians in Canada.

Safety and Tolerability of Acetazolamide in the Idiopathic Intracranial Hypertension Treatment Trial.

OBJECTIVE: To examine the tolerability and adverse events reported in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT). METHODS: Randomized, double-masked, placebo-controlled clinical trial. Trial participants (n = 165) with mild visual loss concurrently receiving low-sodium weight-reduction diet plus the maximally tolerated dosage of acetazolamide (up to 4 g/d) or placebo for 6 months. MAIN OUTCOMES MEASURES: adverse events (AEs), assessment of clinical and laboratory findings at study visits. RESULTS: Thirty-eight of 86 participants randomized to the acetazolamide group (44.1%) tolerated the maximum allowed dosage of 4 g/d. The average time to achieve maximum study dosage in the acetazolamide group was 13 weeks (median 12 weeks; range 10-24 weeks). A total of 676 AEs (acetazolamide, n = 480; placebo, n = 196) and 9 serious AEs (acetazolamide, n = 6; placebo, n = 3) were reported. Notably, the percentages of participants reporting at least 1 AE in the nervous, gastrointestinal, metabolic, and renal organ systems were significantly higher in the acetazolamide group (P < 0.05). The odds of paresthesia (OR 9.82; 95% CI 3.87-27.82), dysgeusia (OR ∞; 95% CI 3.99-∞), vomiting and diarrhea (OR 4.11; 95% CI 1.04-23.41), nausea (OR 2.99; 95% CI 1.26-7.49) and fatigue (OR 16.48; 95% CI 2.39-702.40) were higher in the acetazolamide group than in the placebo group. CONCLUSION: Acetazolamide appears to have an acceptable safety profile at dosages up to 4 g/d in the treatment of idiopathic intracranial hypertension. The majority of participants in the Idiopathic Intracranial Hypertension Treatment Trial were able to tolerate acetazolamide above 1 g/d for 6 months.