The mediating role of health behaviors in the association between depression, anxiety and cancer incidence: an individual participant data meta-analysis.

BACKGROUND: Although behavioral mechanisms in the association among depression, anxiety, and cancer are plausible, few studies have empirically studied mediation by health behaviors. We aimed to examine the mediating role of several health behaviors in the associations among depression, anxiety, and the incidence of various cancer types (overall, breast, prostate, lung, colorectal, smoking-related, and alcohol-related cancers). METHODS: Two-stage individual participant data meta-analyses were performed based on 18 cohorts within the Psychosocial Factors and Cancer Incidence consortium that had a measure of depression or anxiety (N = 319 613, cancer incidence = 25 803). Health behaviors included smoking, physical inactivity, alcohol use, body mass index (BMI), sedentary behavior, and sleep duration and quality. In stage one, path-specific regression estimates were obtained in each cohort. In stage two, cohort-specific estimates were pooled using random-effects multivariate meta-analysis, and natural indirect effects (i.e. mediating effects) were calculated as hazard ratios (HRs). RESULTS: Smoking (HRs range 1.04-1.10) and physical inactivity (HRs range 1.01-1.02) significantly mediated the associations among depression, anxiety, and lung cancer. Smoking was also a mediator for smoking-related cancers (HRs range 1.03-1.06). There was mediation by health behaviors, especially smoking, physical inactivity, alcohol use, and a higher BMI, in the associations among depression, anxiety, and overall cancer or other types of cancer, but effects were small (HRs generally below 1.01). CONCLUSIONS: Smoking constitutes a mediating pathway linking depression and anxiety to lung cancer and smoking-related cancers. Our findings underline the importance of smoking cessation interventions for persons with depression or anxiety.

Psychosocial factors, health behaviors and risk of cancer incidence: Testing interaction and effect modification in an individual participant data meta-analysis.

Depression, anxiety and other psychosocial factors are hypothesized to be involved in cancer development. We examined whether psychosocial factors interact with or modify the effects of health behaviors, such as smoking and alcohol use, in relation to cancer incidence. Two-stage individual participant data meta-analyses were performed based on 22 cohorts of the PSYchosocial factors and CAncer (PSY-CA) study. We examined nine psychosocial factors (depression diagnosis, depression symptoms, anxiety diagnosis, anxiety symptoms, perceived social support, loss events, general distress, neuroticism, relationship status), seven health behaviors/behavior-related factors (smoking, alcohol use, physical activity, body mass index, sedentary behavior, sleep quality, sleep duration) and seven cancer outcomes (overall cancer, smoking-related, alcohol-related, breast, lung, prostate, colorectal). Effects of the psychosocial factor, health behavior and their product term on cancer incidence were estimated using Cox regression. We pooled cohort-specific estimates using multivariate random-effects meta-analyses. Additive and multiplicative interaction/effect modification was examined. This study involved 437,827 participants, 36,961 incident cancer diagnoses, and 4,749,481 person years of follow-up. Out of 744 combinations of psychosocial factors, health behaviors, and cancer outcomes, we found no evidence of interaction. Effect modification was found for some combinations, but there were no clear patterns for any particular factors or outcomes involved. In this first large study to systematically examine potential interaction and effect modification, we found no evidence for psychosocial factors to interact with or modify health behaviors in relation to cancer incidence. The behavioral risk profile for cancer incidence is similar in people with and without psychosocial stress.

Depression, anxiety, and the risk of cancer: An individual participant data meta-analysis.

BACKGROUND: Depression and anxiety have long been hypothesized to be related to an increased cancer risk. Despite the great amount of research that has been conducted, findings are inconclusive. To provide a stronger basis for addressing the associations between depression, anxiety, and the incidence of various cancer types (overall, breast, lung, prostate, colorectal, alcohol-related, and smoking-related cancers), individual participant data (IPD) meta-analyses were performed within the Psychosocial Factors and Cancer Incidence (PSY-CA) consortium. METHODS: The PSY-CA consortium includes data from 18 cohorts with measures of depression or anxiety (up to N = 319,613; cancer incidences, 25,803; person-years of follow-up, 3,254,714). Both symptoms and a diagnosis of depression and anxiety were examined as predictors of future cancer risk. Two-stage IPD meta-analyses were run, first by using Cox regression models in each cohort (stage 1), and then by aggregating the results in random-effects meta-analyses (stage 2). RESULTS: No associations were found between depression or anxiety and overall, breast, prostate, colorectal, and alcohol-related cancers. Depression and anxiety (symptoms and diagnoses) were associated with the incidence of lung cancer and smoking-related cancers (hazard ratios [HRs], 1.06-1.60). However, these associations were substantially attenuated when additionally adjusting for known risk factors including smoking, alcohol use, and body mass index (HRs, 1.04-1.23). CONCLUSIONS: Depression and anxiety are not related to increased risk for most cancer outcomes, except for lung and smoking-related cancers. This study shows that key covariates are likely to explain the relationship between depression, anxiety, and lung and smoking-related cancers. PREREGISTRATION NUMBER: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=157677.

Five-year absolute risk estimates of colorectal cancer based on CCRAT model and polygenic risk scores: A validation study using the Quebec population-based cohort CARTaGENE.

The objective was to evaluate the predictive performance of the Colorectal Cancer Risk Assessment Tool (CCRAT) and three polygenic risk scores (Hsu et al., 2015; Law et al., 2019, Archambault et al., 2020) to predict the occurrence of colorectal cancer at five years in a Quebec population-based cohort. By using the CARTaGENE cohort, we computed the absolute risk of colorectal cancer with the CCRAT model, the polygenic risk scores (PRS) and combined clinico-genetic models (CCRAT + PRS). We also tailored the CCRAT model by using the marginal age-specific colorectal incidence rates in Canada and the risk score distribution. We reported the calibration and the discrimination. Performances of the PRSs, combined and tailored CCRAT models were compared to the original CCRAT model. The expected-to-observed ratio of the original CCRAT model was 0.54 [0.43-0.68]. The c-index was 74.79 [68.3-80.5]. The tailored CCRAT model improved the expected-to-observed ratio (0.74 [0.59-0.94]) and c-index (76.39 [69.7-82.1]). All PRS improved the expected-to-observed ratios (around 0.83, confidence intervals including one). PRSs' c-indexes were not significantly different from CCRAT models. Results from the combined models were close to those from the PRS models, Archambault combined model's c-index being significantly higher than the original and tailored CCRAT models (78.67 [70.8-86.5]; p < 0.001 and p = 0.028, respectively). In this Quebec cohort, CCRAT model has a good discrimination with a poor calibration. While the tailored CCRAT provides some gain in calibration, clinico-genetic models improved both calibration and discrimination. However, better calibrations must be obtained before a practical use among the inhabitants of Quebec province.

Agreement in the CARTaGENE cohort between self-reported medication use and claim data.

OBJECTIVES: To describe the agreement of self-reported medication use with claim prescription records and to ascertain factors associated with agreement between the two data sources. METHODS: Baseline data on self-reported medication use was extracted from CARTaGENE, a cohort study in Quebec, Canada, and from the provincial health insurance records (dispensation database) of the same individuals. Kappa statistics were used to estimate concordance beyond chance between the two data sources. Logistic regression models were adjusted to estimate the association between agreement and selected individual's characteristics (sex, age, education, region, income, utilization of health care system, and comorbidities). RESULTS: Agreement between self-reported medication use and administrative data varied considerably across medication classes (kappa 0.54 for respiratory system and 0.91 for systemic hormonal preparations). Overall, agreement improved when a fixed time window of 90 days was used for exposure measurement. Sex, education level, frequency of health care use and the number of reported medications were associated with agreement. DISCUSSION: Overall, there was a reasonable agreement between the two data sources, but important variations were found for the different drug classes. These results could be used by researchers to more accurately assess drug exposures using real-world data, which are increasingly important to regulators.

Psychosocial factors and cancer incidence (PSY-CA): Protocol for individual participant data meta-analyses.

OBJECTIVES: Psychosocial factors have been hypothesized to increase the risk of cancer. This study aims (1) to test whether psychosocial factors (depression, anxiety, recent loss events, subjective social support, relationship status, general distress, and neuroticism) are associated with the incidence of any cancer (any, breast, lung, prostate, colorectal, smoking-related, and alcohol-related); (2) to test the interaction between psychosocial factors and factors related to cancer risk (smoking, alcohol use, weight, physical activity, sedentary behavior, sleep, age, sex, education, hormone replacement therapy, and menopausal status) with regard to the incidence of cancer; and (3) to test the mediating role of health behaviors (smoking, alcohol use, weight, physical activity, sedentary behavior, and sleep) in the relationship between psychosocial factors and the incidence of cancer. METHODS: The psychosocial factors and cancer incidence (PSY-CA) consortium was established involving experts in the field of (psycho-)oncology, methodology, and epidemiology. Using data collected in 18 cohorts (N = 617,355), a preplanned two-stage individual participant data (IPD) meta-analysis is proposed. Standardized analyses will be conducted on harmonized datasets for each cohort (stage 1), and meta-analyses will be performed on the risk estimates (stage 2). CONCLUSION: PSY-CA aims to elucidate the relationship between psychosocial factors and cancer risk by addressing several shortcomings of prior meta-analyses.

Epidemiological characteristics of the COVID-19 spring outbreak in Quebec, Canada: a population-based study.

BACKGROUND: By mid-July 2020, more than 108,000 COVID-19 cases had been diagnosed in Canada with more than half in the province of Quebec. In this context, we launched a study to analyze the epidemiological characteristics and the socio-economic impact of the spring outbreak in the population. METHOD: We conducted an online survey of the participants of the CARTaGENE population-based cohort, composed of middle-aged and older adults. We collected information on socio-demographic, lifestyle, health condition, COVID-19 related symptoms and COVID-19 testing. We studied the association between these factors and two outcomes: the status of having been tested for SARS-CoV-2 and the status of having received a positive test. These associations were measured with univariate and multivariate analyses using a hybrid tree-based regression model. RESULTS: Among the 8,129 respondents from the CARTaGENE cohort, 649 were tested for COVID-19 and 41 were positive. Medical workers and individuals having a contact with a COVID-19 patient had the highest probabilities of being tested (32% and 42.4%, respectively) and of being positive (17.2% and 13.0%, respectively) among those tested. Approximately 8% of the participants declared that they have experienced at least one of the four COVID-19 related symptoms chosen by the Public Health authorities (fever, cough, dyspnea, anosmia) but were not tested. Results from the tree-based model analyses adjusted on exposure factors showed that the combination of dyspnea, dry cough and fever was highly associated with being tested whereas anosmia, fever, and headache were the most discriminant factors for having a positive test among those tested. During the spring outbreak, more than one third of the participants have experienced a decrease in access to health services. There were gender and age differences in the socio-economic and emotional impacts of the pandemic. CONCLUSION: We have shown some discrepancies between the symptoms associated with being tested and being positive. In particular, the anosmia is a major discriminant symptom for positivity whereas ear-nose-throat symptoms seem not to be COVID-19 related. The results also emphasize the need of increasing the accessibility of testing for the general population.

Validation of breast cancer risk assessment tools on a French-Canadian population-based cohort.

OBJECTIVES: Evaluate the accuracy of the Breast Cancer Risk Assessment Tool (BCRAT), International Breast Cancer Intervention Study risk evaluation tool (IBIS), Polygenic Risk Scores (PRS) and combined scores (BCRAT+PRS and IBIS +PRS) to predict the occurrence of invasive breast cancers at 5 years in a French-Canadian population. DESIGN: Population-based cohort study. SETTING: We used the population-based cohort CARTaGENE, composed of 43 037 Quebec residents aged between 40 and 69 years and broadly representative of the population recorded on the Quebec administrative health insurance registries. PARTICIPANTS: 10 200 women recruited in 2009-2010 were included for validating BCRAT and IBIS and 4555 with genetic information for validating the PRS and combined scores. OUTCOME MEASURES: We computed the absolute risks of breast cancer at 5 years using BCRAT, IBIS, four published PRS and combined models. We reported the overall calibration performance, goodness-of-fit test and discriminatory accuracy. RESULTS: 131 (1.28%) women developed a breast cancer at 5 years for validating BCRAT and IBIS and 58 (1.27%) for validating PRS and combined scores. Median follow-up was 5 years. BCRAT and IBIS had an overall expected-to-observed ratio of 1.01 (0.85-1.19) and 1.02 (0.86-1.21) but with significant differences when partitioning by risk groups (p<0.05). IBIS' c-index was significantly higher than BCRAT (63.42 (59.35-67.49) vs 58.63 (54.05-63.21), p=0.013). PRS scores had a global calibration around 0.82, with a CI including one, and non-significant goodness-of-fit tests. PRS' c-indexes were non-significantly higher than BCRAT and IBIS, the highest being 64.43 (58.23-70.63). Combined models did not improve the results. CONCLUSIONS: In this French-Canadian population-based cohort, BCRAT and IBIS have good mean calibration that could be improved for risk subgroups, and modest discriminatory accuracy. Despite this modest discriminatory power, these tools can be of interest for primary care physicians for delivering a personalised message to their high-risk patients, regarding screening and lifestyle counselling.

Quantifying the Predictive Accuracy of a Polygenic Risk Score for Predicting Incident Cancer Cases : Application to the CARTaGENE Cohort.

With the increasing use of polygenic risk scores (PRS) there is a need for adapted methods to evaluate the predictivity of these tools. In this work, we propose a new pseudo-R 2 criterion to evaluate PRS predictive accuracy for time-to-event data. This new criterion is related to the score statistic derived under a two-component mixture model. It evaluates the effect of the PRS on both the propensity to experience the event and on the dynamic of the event among the susceptible subjects. Simulation results show that our index has good properties. We compared our index to other implemented pseudo-R 2 for survival data. Along with our index, two other indices have comparable good behavior when the PRS has a non-null propensity effect, and our index is the only one to detect when the PRS has only a dynamic effect. We evaluated the 5-year predictivity of an 18-single-nucleotide-polymorphism PRS for incident breast cancer cases on the CARTaGENE cohort using several pseudo-R 2 indices. We report that our index, which summarizes both a propensity and a dynamic effect, had the highest predictive accuracy. In conclusion, our proposed pseudo-R 2 is easy to implement and well suited to evaluate PRS for predicting incident events in cohort studies.

Green space associations with mental health and cognitive function: Results from the Quebec CARTaGENE cohort.

Urban green space may be important to mental health, but the association between long-term green space exposures and depression, anxiety, and cognitive function in adults remains unknown. METHODS: We examined 8,144 adults enrolled in the CARTaGENE cohort in Quebec Canada. Average green space and change in green space with residential mobility were assessed using satellite-derived normalized difference vegetation index from 5-year residential address histories. Outcomes included depression and anxiety determined through medical record linkages, self-reported doctor diagnosis of depression, and the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7scales. Cognitive function was available for 6,658 individuals from computerized tests of reaction time, working memory, and executive function. We used linear and logistic multivariate models to assess associations between green space and each mental health and cognitive function measure. RESULTS: In fully adjusted analyses, a 0.1 increase in residential normalized difference vegetation index within 500 m was associated with an odds ratio of 0.85 (95% CI: 0.76, 0.95) for a self-reported doctor diagnosis of depression and 0.81 (95% CI: 0.70, 0.93) for moderate anxiety assessed using the Generalized Anxiety Disorder 7 scale. Other models showed protective effects of urban green space on depression and anxiety but were not statistically significant, and the magnitude of association varied by green space exposure and mental health outcome assessment method. We did not observe any evidence of associations between green space and cognitive function. CONCLUSIONS: We observed some evidence to support the hypothesis that urban green space is associated with decreased depression and anxiety but not cognitive function.

Cohort profile of the CARTaGENE study: Quebec's population-based biobank for public health and personalized genomics.

The CARTaGENE (CaG) study is both a population-based biobank and the largest ongoing prospective health study of men and women in Quebec. In population-based cohorts, participants are not recruited for a particular disease but represent a random selection among the population, minimizing the need to correct for bias in measured phenotypes. CaG targeted the segment of the population that is most at risk of developing chronic disorders, that is 40-69 years of age, from four metropolitan areas in Quebec. Over 20,000 participants consented to visiting 1 of 12 assessment sites where detailed health and socio-demographic information, physiological measures and biological samples (blood, serum and urine) were captured for a total of 650 variables. Significant correlations of diseases and chronic conditions are observed across these regions, implicating complex interactions, some of which we describe for major chronic conditions. The CaG study is one of the few population-based cohorts in the world where blood is stored not only for DNA and protein based science but also for gene expression analyses, opening the door for multiple systems genomics approaches that identify genetic and environmental factors associated with disease-related quantitative traits. Interested researchers are encouraged to submit project proposals on the study website (www.cartagene.qc.ca).

Use and reimbursement costs of smoking cessation medication under the Quebec public drug insurance plan.

OBJECTIVES: Since October 2000, the nicotine patch, nicotine gum and bupropion have been reimbursed under Quebec's public drug insurance plan. The objective of this study is to describe use of these medications between October 2000 and December 2004 by smokers covered by the public plan, as well as the costs of reimbursing these medications. METHODS: Data from the Régie de l'assurance maladie du Québec were used to analyze prescriptions for smoking cessation medication issued to persons insured under the public drug insurance plan. RESULTS: Between October 1, 2000, and December 31, 2004, more than 300,000 Quebeckers covered by the public drug insurance plan were reimbursed for smoking cessation medications. This corresponds to a yearly average of 14% of all smokers insured under the public plan. The proportion of employment assistance recipients who used these medications was higher than the proportion of seniors or "other" insurance plan participants. Nicotine patches were the treatment of choice for most users. A total of $55 million was reimbursed by the public drug insurance plan for the nicotine patch, nicotine gum and bupropion over this four-year period. CONCLUSION: The reimbursement provisions put in place in Quebec in 2000 were successful in reaching financially disadvantaged smokers, at a cost that was comparable with other effective smoking cessation services.

Correlation of wavefront data and corneal asphericity with contrast sensitivity after laser in situ keratomileusis for myopia.

PURPOSE: To investigate the relationship between contrast sensitivity (CS), Zernike wavefront aberrations (WFA), and asphericity after laser in situ keratomileusis (LASIK) for myopia. METHODS: LASIK was performed using the Nidek EC-5000 excimer laser with custom aspheric transition zone (CATz) ablations. Total and high order (HO) WFA of 71 eyes (37 patients) undergoing LASIK in March 2003 were measured before and at 1 month postoperatively with the Nidek OPD-Scan aberrometer at a 4-mm pupil entrance; asphericity was measured at 6 mm (Q index). Preoperative and 1 to 3-month postoperative contrast sensitivity were evaluated with the Vector Vision CSV-1000 at 3, 6, 12, and 18 CPD; the Area Under the Log Contrast Sensitivity Function (AULCSF) was calculated. Uncorrected-visual acuity (UCVA) was evaluated. RESULTS: One month after LASIK, CS decreased significantly at 6 CPD and above (P<.05), then returned to normal at 3 months (P=.33). Postoperative AULCSF correlated with patient age (P=.04) but not with total WFA (P=.13), HO WFA (P=.50), or asphericity (P=.22). Postoperative Logmar UCVA correlated with postoperative total and HO WFA (P<.05). Postoperative total WFA correlated with spherical equivalent refraction (P<.0001); HO WFA correlated with Strehl ratio (P=.004) and asphericity (P=.03). The HO WFA increase was 0.065 microm (P<.05) and did not correlate with preoperative refraction (P=.40). Increase in asphericity correlated with corneal refractive change and was predicted by the parabolic Munnerlyn equation (P<.0001). CONCLUSIONS: After LASIK, AULCSF was not dependent on WFA, but mainly on patient age. WFA results correlated well with postoperative spherical equivalent refraction, asphericity, and Strehl ratio. These conclusions support a published hypothesis that postoperative low amount of WFA does not completely fit contrast sensitivity measurements.

Initial results of endothelial cell counts after Artisan lens for phakic eyes: an evaluation of the United States Food and Drug Administration Ophtec Study.

PURPOSE: To evaluate the endothelial cell count change in eyes implanted with the iris-claw phakic Artisan lens for treatment of moderate to high myopia. DESIGN: Prospective, multicenter clinical trial. PARTICIPANTS: The first 765 eyes enrolled at 25 North American sites in the United States Food and Drug Administration Ophtec clinical trial of the myopic Artisan IOL. Outcome analyses of endothelial cell count measurements were based on those obtained before surgery and at 6, 12, and 24 months after surgery performed between October 1998 and December 2001. SETTING: Multiple private and university practices. METHODS: Percentage change in endothelial cell count from baseline to 6, 12, and 24 months were analyzed using specular microscopy. Upper limit of detecting endothelial cell density change was estimated using 3 repeated counts at preoperative and postoperative time frames. MAIN OUTCOME MEASURES: Percentage change in endothelial cell loss. RESULTS: The mean preoperative endothelial cell count was 2631+/-442 cells/mm(2). Percentage change from baseline at 6, 12, and 24 months was -0.09%+/-16.39%, -0.87%+/-16.35%, and -0.78%+/-17.41%. No statistically significative postoperative endothelial cell loss was found. The endothelial cell loss rate was higher among patients who wore spectacles before surgery and was correlated negatively with preoperative endothelial cell density (P<0.001). No relationships were noted between endothelial cell loss and either patient age or implant power. A 4.1% repeatability of measurements was found based on the average of 3 repeated counts, whereas single cell count estimates were associated with a 23% accuracy in detecting endothelial cell density change. In a worst-case scenario, adjusting for measurement accuracy, 9% of all eyes were at higher risk of a 10% loss of cell density at 12 months after surgery, although eyes at higher risk were found to have high preoperative endothelial cell counts (P<0.0001). CONCLUSIONS: The Artisan iris-claw phakic intraocular lens did not result in significant loss of endothelial cell density up to 2 years after implantation of the myopic Artisan phakic lens.

Refractive lens exchange versus iris-claw Artisan phakic intraocular lens for hyperopia.

PURPOSE: To study a paired-match comparison between refractive lens exchange with pseudophakic IOL implant (RLE) and Artisan phakic IOL for high hyperopia. METHODS: Nineteen eyes (12 patients, 20 to 41 years old) with an Artisan phakic IOL (Model 203: 1.00-D increment) for hyperopia from +2.75 to +9.25 D were matched to 19 eyes (15 patients, 26 to 46 yr) with hyperopia from +2.75 to +7.50 D, who had refractive lens exchange (pseudophakic IOL implantation; lenses: 0.50-D increment). Average paired-match difference was 1.13 D and 7.7 years of age. RESULTS: At 1 month after surgery, 84% of refractive lens exchange/pseudophakic IOL eyes and 94% of Artisan phakic IOL eyes had a spherical equivalent refraction within +/- 1.00 D of emmetropia; 58% and 68% of eyes, respectively, were within +/- 0.50 D (P = .97). No eye lost lines of best spectacle-corrected visual acuity (BSCVA) and no significant changes in BSCVA were found in any eye at 1 month after surgery (P = .17). The percentage of eyes with uncorrected visual acuity (UCVA) of 20/40 or better improved from 79% to 89% of eyes at 1 to 2 months after phakic IOL; it remained at 89% to 82% of eyes from 1 to 2 months after refractive lens exchange/ pseudophakic IOL. The coefficient of correlation showed statistically better accuracy (intended vs. achieved refraction; P = .035) for the Artisan phakic IOL (R = 0.83) than for refractive lens exchange/ pseudophakic IOL (R = 0.50). CONCLUSIONS: Spherical equivalent refraction outcome and BSCVA after surgery were similar for both procedures. The Artisan phakic IOL in carefully selected patients provided a better overall outcome for young patients with high hyperopia whose accommodation was preserved, as compared to refractive lens exchange.

Risk factors for night vision complaints after LASIK for myopia.

PURPOSE: To study the preoperative risk factors for night vision complaints (NVCs) after LASIK in a clinical setting. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Seven hundred ninety-five patients (1488 eyes) who underwent LASIK for myopia up to -9.75 diopters (D) (from January 1 to December 31, 1999). SETTING: Private clinic. METHODS: A complete preoperative examination was performed. Patients had bilateral LASIK surgery using the Nidek EC-5000 non-wavefront guided slit-scanning excimer laser and the Moria LSK One microkeratome. Patients were observed postoperatively for 12 months. MAIN OUTCOME MEASURES: The reported NVCs for each eye were rated on a subjective scale based on functional visual comfort. Clinically important NVC odds ratios (ORs) were calculated. RESULTS: Reports of NVCs decreased considerably from 25.6% at 1 month to 4.7% at 12 months postoperatively, at which time all patients reported similar NVCs in both eyes. Stratification of risk factors at 12 months postoperatively showed a 2.8-times increase in NVCs for initial myopia of >5 D, a 2.5-times increase for an optical zone of

Ultrasound biomicroscopy of the Artisan phakic intraocular lens in hyperopic eyes.

PURPOSE: To study in situ the intraocular position of the Artisan iris-claw intraocular lens (IOL) (model 203) (Ophtec) in phakic hyperopic eyes using ultrasound biomicroscopy (UBM). METHODS: Echograms of the anterior chamber were taken preoperatively and 24 to 317 days postoperatively in 4 eyes implanted with the Artisan IOL (power +4.0 to +6.0 diopters). The preoperative anterior chamber depth (ACD) and the postoperative distance between the IOL and the corneal endothelium (endothelium-optic distance) and between the IOL and the lens were measured. The echograms were assessed for the effect of the IOL on iris tissue. RESULTS: The preoperative ACD ranged from 3.10 to 3.56 mm and the postoperative endothelium-optic distance, from 2.03 to 2.54 mm. The distance between the lens and the posterior surface of the IOL ranged from 0.35 to 0.79 mm. Several UBM echograms showed indentation of iris tissue by the IOL haptics and optic edge, although no pigmentary dispersion was noted. CONCLUSIONS: Adequate space was maintained between the Artisan hyperopic IOL and the corneal endothelium, angle, and crystalline lens. Haptic indentation of the iris, which could lead to pigment erosion, was observed. Preoperative gonioscopy and maintenance of normal intraocular pressure postoperatively suggest the indentation was secondary to inadequate lens vaulting relative to the high natural arch of the iris in hyperopic eyes. Shortening the haptics or increasing the lens vault might resolve this problem.

Comparison of the pupil card and pupillometer in measuring pupil size.

PURPOSE: To determine the difference in pupil size measured with the Colvard pupillometer in mesopic and scotopic luminance and with the Rosenbaum pupil card in mesopic luminance between 2 examiners. SETTING: Michel Pop Clinics, Montreal, Quebec, Canada. METHODS: Two examiners used the Colvard pupillometer and the Rosenbaum card to measure pupil size in 58 eyes. The Colvard pupillometer was used in mesopic and scotopic light conditions. The Rosenbaum card was used in mesopic luminance only. Pupil size was evaluated with a 1.0 mm interval scale at the nearest half millimeter. RESULTS: For the 3 sets of data, the limits of agreement and coefficient of interrater repeatability were calculated and a 2 x 2 factorial analysis of variance was performed. Because of interexaminer bias, measurements done in mesopic luminance with the Rosenbaum card were not statistically different from those with the Colvard pupillometer in scotopic luminance, although interrater repeatability of the Colvard pupillometer (0.8 mm) was superior to that of the Rosenbaum card (1.3 mm). CONCLUSIONS: Examiner bias was the greatest statistical bias in all sets of measures. Surgeons may want to opt for a "safe" limit of pupil size (ie, 0.5 to 0.8 mm greater than the measured size) when calculating optical zones in refractive surgery. Future devices for pupil measurement should be based on automatic adjustment sizing.