Effect of basal metabolic rate on lifespan: a sex-specific Mendelian randomization study.

Observationally, the association of basal metabolic rate (BMR) with mortality is mixed, although some ageing theories suggest that higher BMR should reduce lifespan. It remains unclear whether a causal association exists. In this one-sample Mendelian randomization study, we aimed to estimate the casual effect of BMR on parental attained age, a proxy for lifespan, using two-sample Mendelian randomization methods. We obtained genetic variants strongly (p-value < 5 × 10-8) and independently (r2 < 0.001) predicting BMR from the UK Biobank and applied them to a genome-wide association study of parental attained age based on the UK Biobank. We meta-analyzed genetic variant-specific Wald ratios using inverse-variance weighting with multiplicative random effects by sex, supplemented by sensitivity analysis. A total of 178 and 180 genetic variants predicting BMR in men and women were available for father's and mother's attained age, respectively. Genetically predicted BMR was inversely associated with father's and mother's attained age (years of life lost per unit increase in effect size of genetically predicted BMR, 0.46 and 1.36; 95% confidence interval 0.07-0.85 and 0.89-1.82), with a stronger association in women than men. In conclusion, higher BMR might reduce lifespan. The underlying pathways linking to major causes of death and relevant interventions warrant further investigation.

Clinical outcome of a quadrifocal (trifocal) intraocular lens in Chinese patients: prospective, observational case series.

PURPOSE: To report the visual outcomes and quality of vision and life after bilateral implantation of a single-piece trifocal intraocular lens (IOL) in Chinese patients. SETTING: Hong Kong Sanatorium & Hospital, Hong Kong, China. DESIGN: Prospective, observational case series. METHODS: Patients with bilateral implantation of AcrySof IQ PanOptix multifocal IOL were included. Distance, intermediate (60 cm), and near (40 cm) visual acuities (VAs) and contrast sensitivity (CS), defocus curve, preoperative higher-order aberration (HOA), dysphotopsia (0 to 5), satisfaction (1 to 5), spectacle independence, and quality of life were evaluated. The association between preoperative HOA and postoperative halos was also assessed. RESULTS: 54 eyes of 27 patients were included. The mean binocular distance, intermediate, and near uncorrected VA was -0.05 ± 0.06 (20/18), 0.06 ± 0.10 (20/23), and 0.04 ± 0.05 (20/22), respectively. No eyes lost more than 1 line of vision. Binocular CS was comparable with the monocular population norm of older adults. The defocus curve demonstrated that the binocular VA of 20/25 or better was achieved at a power of -3.00 to +0.50 diopters. The mean scores for halos, glare, and starbursts were 2.4 ± 1.4, 0.2 ± 0.8, and 1.4 ± 1.4 (of 5), respectively. The mean satisfaction score was 4.3 ± 0.7 (of 5). All the patients (100%) reported total spectacle independence. The mean vision-targeted composite score of the vision-related quality-of-life questionnaire was 97.2 ± 9.7 (of 100). Preoperative HOA was not associated with postoperative halos. CONCLUSIONS: Implantation of the trifocal IOL provided satisfactory visual outcomes and quality of vision and life, which resulted in a high rate of spectacle independence.

Effect of time since primary laser-assisted in situ keratomileusis on flap relift success and epithelial ingrowth risk.

PURPOSE: To assess the association of time since primary laser-assisted in situ keratomileusis (LASIK) with flap relift success and risk for epithelial ingrowth (EI) in eyes undergoing flap relift after primary LASIK. SETTING: Hong Kong Sanatorium & Hospital, Hong Kong Special Administrative Region. DESIGN: Retrospective observational case series. METHODS: 73 eyes with flaps relifted for refractive enhancement LASIK were included. Main outcome measures included rate of relift success and EI; associations of time since primary LASIK, sex, age at relift, year of relift, and flap creation method in primary LASIK with relift success and EI. RESULTS: Of the 73 eyes included, relifting was successful in 71 eyes (97.3%). Among the successfully relifted eyes, 12 (16.9%) developed EI, of which 3 (4.2%) were clinically significant. No eyes lost more than 1 line of corrected distance visual acuity. The time since primary LASIK (up to 22 years), sex, age at relift, year of relift, and flap creation method in primary LASIK were not associated with relift success or EI. CONCLUSIONS: With the described surgical technique, flaps could be successfully relifted without much difficulty up to 22 years after primary LASIK with a low incidence of EI.

Effect of Basal Metabolic Rate on Cancer: A Mendelian Randomization Study.

Background: Basal metabolic rate is associated with cancer, but these observations are open to confounding. Limited evidence from Mendelian randomization studies exists, with inconclusive results. Moreover, whether basal metabolic rate has a similar role in cancer for men and women independent of insulin-like growth factor 1 increasing cancer risk has not been investigated. Methods: We conducted a two-sample Mendelian randomization study using summary data from the UK Biobank to estimate the causal effect of basal metabolic rate on cancer. Overall and sex-specific analysis and multiple sensitivity analyses were performed including multivariable Mendelian randomization to control for insulin-like growth factor 1. Results: We obtained 782 genetic variants strongly (p-value < 5 × 10-8) and independently (r 2 < 0.01) predicting basal metabolic rate. Genetically predicted higher basal metabolic rate was associated with an increase in cancer risk overall (odds ratio, 1.06; 95% confidence interval, 1.02-1.10) with similar estimates by sex (odds ratio for men, 1.07; 95% confidence interval, 1.002-1.14; odds ratio for women, 1.06; 95% confidence interval, 0.995-1.12). Sensitivity analyses including adjustment for insulin-like growth factor 1 showed directionally consistent results. Conclusion: Higher basal metabolic rate might increase cancer risk. Basal metabolic rate as a potential modifiable target of cancer prevention warrants further study.

Effect of Glucagon on Ischemic Heart Disease and Its Risk Factors: A Mendelian Randomization Study.

CONTEXT: Glucagon acts reciprocally with insulin to regular blood glucose. However, the effect of glucagon on cardiovascular disease has not been widely studied. It has been suggested that insulin may increase the risk of ischemic heart disease. OBJECTIVE: To investigate whether glucagon, the main counteracting hormone of insulin, plays a role in development of ischemic heart disease. DESIGN, SETTING, AND PARTICIPANTS: In this 2-sample Mendelian randomization study, we estimated the causal effect of glucagon on ischemic heart disease and its risk factors using the inverse-variance weighted method with multiplicative random effects and multiple sensitivity analyses. Genetic associations with glucagon and ischemic heart disease and its risk factors, including type 2 diabetes and fasting insulin, were obtained from publicly available genome-wide association studies. MAIN OUTCOME MEASURE: Odds ratio for ischemic heart disease and its risk factors per 1 standard deviation change in genetically predicted glucagon. RESULTS: Twenty-four single-nucleotide polymorphisms strongly (P < 5 × 10-6) and independently (r2 < 0.05) predicting glucagon were obtained. Genetically predicted higher glucagon was associated with an increased risk of ischemic heart disease (inverse-variance weighted odds ratio, 1.03; 95% confidence interval, 1.0003-1.05) but not with type 2 diabetes (inverse-variance weighted odds ratio, 0.998, 95% confidence interval, 0.97-1.03), log-transformed fasting insulin (inverse-variance weighted beta, 0.002, 95% confidence interval, -0.01 to 0.01), other glycemic traits, blood pressure, reticulocyte, or lipids. CONCLUSION: Glucagon might have an adverse impact on ischemic heart disease. Relevance of the underlying pathway to existing and potential interventions should be investigated.

Monovision with a Bifocal Diffractive Multifocal Intraocular Lens in Presbyopic Patients: A Prospective, Observational Case Series.

PURPOSE: We report the visual outcomes and patient satisfaction after bilateral implantation of a bifocal diffractive intraocular lens with monovision. DESIGN: Prospective, observational case series. METHODS: Twenty-one subjects underwent cataract surgery or refractive lens exchange with bilateral implantation of the ZMB00 intraocular lens, with the dominant eye and nondominant eye targeted for plano and -1.25 to -1.00 diopters, respectively. Postoperative assessments included visual acuity (VA) at various distances under photopic and mesopic conditions; defocus curve, contrast sensitivity, and stereopsis; and Visual Function Questionnaire-25 and supplementary questionnaire. RESULTS: Mean binocular uncorrected VA at distance, intermediate (67 cm), and near (30 cm) were -0.03 ± 0.06, 0.12 ± 0.18, and 0.11 ± 0.05, respectively. No eyes lost >1 line of corrected distance VA. Binocular intermediate VA was significantly better in the uncorrected condition (P = .004) whereas binocular distance VA was better in the distance-corrected condition (P = .014). Near VA was similar in both conditions (P > .05). Stereoacuity and contrast sensitivity were within normal limits. All subjects had a composite score of ≥90 for vision-targeted items in the National Eye Institute Visual Function Questionnaire-25. Halos, glare, and starbursts occurred in 52%, 29%, and 24% of subjects, respectively. All subjects reported a satisfaction score of ≥3.5 of 5 and required no spectacles postoperatively. No intraocular lens exchange was required. CONCLUSIONS: Monovision with bilateral bifocal multifocal intraocular lens was safe and provided satisfactory vision at various distances, with good stereopsis and contrast sensitivity. Complete spectacle independence and high satisfaction score were achieved. In comparison with bilateral emmetropic bifocal multifocal intraocular lens, it provided better vision at intermediate and at very near distances without inducing more dysphotopsia.

Reproduction and longevity: A Mendelian randomization study of gonadotropin-releasing hormone and ischemic heart disease.

BACKGROUND: According to well-established evolutionary biology theory there is a trade-off between reproduction and longevity, implying that upregulating the reproductive axis might drive major diseases. We assessed whether the central driver of reproduction gonadotropin-releasing hormone 1 (GnRH1) had a causal effect on the leading cause of global morbidity and mortality, i.e. ischemic heart disease (IHD). As a contrast we similarly examined the role of GnRH2 because it is more a driver of female sexual behavior. METHODS: We applied strong (p-value <5 × 10-6) and independent genetic predictors of GnRH1 and GnRH2 to an extensively genotyped IHD case (n = 76,014) - control (n = 264,785) study and combined the genetic variant specific Wald estimates using inverse variance weighting (IVW) with multiplicative random effects, and as a sensitivity analysis used weighted median, MR-Egger and MR-PRESSO estimates, and repeated the analysis only using genome wide significant genetic predictors. FINDINGS: GnRH1, predicted by 11 genetic variants, was positively associated with IHD (IVW odds ratio (OR) 1.04 per effect size, 95% confidence interval (CI) 1.01 to 1.08), but GnRH2, predicted by 15 genetic variants, was not (IVW OR 0.98, 95% CI 0.95 to 1.02). Estimates from sensitivity analysis were similar. INTERPRETATION: GnRH1 is a potential IHD genetic target. Apart from demonstrating a central tenet of evolutionary biology in humans, our study suggests that existing treatments and environmental factors targeting GnRH1, its drivers or consequences could be re-purposed to prevent and treat IHD. Given, the importance of reproduction to the human species, many such exposures likely exist.

Femtosecond Laser in situ Keratomileusis Flap Creation in Narrow Palpebral Fissure Eyes without Suction.

PURPOSE: To evaluate a surgical technique used in eyes with narrow palpebral fissure undergoing femtosecond laser flap creation without suction during laser in situ keratomileusis (LASIK). METHODS: All data of 2 patient groups were collected through chart review. Group 1 consisted of 6 eyes with narrow palpebral fissure in which the suction ring was manually fixated and femtosecond laser was applied accordingly. Thirty comparison cases were randomly drawn from among eyes that underwent a standard LASIK procedure matched for age and preoperative refraction (group 2). Only 1 eye of each patient was selected to compare the refractive and visual outcomes between groups. RESULTS: In all group 1 eyes, the flaps were created successfully with manual fixation of the suction ring without suction. No eyes lost 2 or more lines of vision. No significant difference was found in the safety and refractive outcomes between groups. CONCLUSION: Manual fixation of the suction ring in eyes with narrow palpebral fissure without suction was feasible for flap creation during LASIK.

Visual Outcomes, Quality of Vision, and Quality of Life of Diffractive Multifocal Intraocular Lens Implantation after Myopic Laser In Situ Keratomileusis: A Prospective, Observational Case Series.

Purpose. To report visual performance and quality of life after implantation of a bifocal diffractive multifocal intraocular lens (MIOL) in postmyopic laser in situ keratomileusis (LASIK) patients. Methods. Prospective, observational case series. Patients with prior myopic LASIK who had implantation of Tecnis ZMA00/ZMB00 MIOL (Abbott Medical Optics) at Hong Kong Sanatorium and Hospital were included. Postoperative examinations included monocular and binocular distance, intermediate and near visual acuity (VA), and contrast sensitivity; visual symptoms (0-5); satisfaction (1-5); spectacle independence rate; and quality of life. Results. Twenty-three patients (27 eyes) were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate, and near were 0.13 ± 0.15 (standard deviation), 0.22 ± 0.15, and 0.16 ± 0.15, respectively. Corresponding mean values for binocular uncorrected VA were 0.00 ± 0.10, 0.08 ± 0.13, and 0.13 ± 0.10, respectively. No eyes lost >1 line of corrected distance VA. Contrast sensitivity at different spatial frequencies between operated and unoperated eyes did not differ significantly (all P > 0.05). Mean score for halos, night glare, starbursts, and satisfaction were 1.46 ± 1.62, 1.85 ± 1.69, 0.78 ± 1.31, and 3.50 ± 1.02, respectively. Eighteen patients (78%) reported complete spectacle independence. Mean composite score of the quality-of-life questionnaire was 90.31 ± 8.50 out of 100. Conclusions. Implantation of the MIOL after myopic LASIK was safe and achieved good visual performance.

Cataract Surgery with a New Fluidics Control Phacoemulsification System in Nanophthalmic Eyes.

PURPOSE: To report visual outcomes and complications after cataract surgery in nanophthalmic eyes with a phacoemulsification system using the active fluidics control strategy. METHODS: This is a retrospective case series. All eyes with an axial length of less than 20 mm that underwent cataract surgery or refractive lens exchange using the Centurion Vision System (Alcon Laboratories Inc.) in Hong Kong Sanatorium and Hospital were evaluated. The visual acuity and intraoperative and postoperative complications were reported. Prior approval from the Hospital Research Committee has been granted. RESULTS: Five eyes of 3 patients were included. The mean follow-up period was 10.2 ± 5.3 months (range, 4-18). Two eyes (40%) had a one-line loss of corrected distance visual acuity. No uveal effusion and posterior capsular tear developed. An optic crack and haptic breakage in the intraocular lens developed in 1 eye (20%) and 2 eyes (40%), respectively. Additional surgeries to treat high postoperative intraocular pressure were required in 1 eye (20%). CONCLUSION: The use of a new phacoemulsification system, which actively monitors and maintains the intraoperative pressure, facilitated anterior chamber stability during cataract surgery in nanophthalmic eyes. This minimized the risk of major complications related to unstable anterior chambers such as uveal effusion and posterior capsular tear. Development of intraoperative crack/breakage in a high-power intraocular lens was common.

Visual Performance after Bilateral Implantation of a Four-Haptic Diffractive Toric Multifocal Intraocular Lens in High Myopes.

Background. The vision with diffractive toric multifocal intraocular lenses after cataract surgery in long eyes has not been studied previously. Objectives. To report visual performance after bilateral implantation of a diffractive toric multifocal intraocular lens in high myopes. Methods. Prospective, observational case series to include patients with axial length of ≥26 mm and corneal astigmatism of >1 dioptre who underwent bilateral AT LISA 909M implantation. Postoperative examinations included photopic and mesopic distance, intermediate, and near visual acuity; photopic contrast sensitivity; visual symptoms (0-5); satisfaction (1-5); and spectacle independence rate. Results. Twenty-eight eyes (14 patients) were included. Postoperatively, mean photopic monocular uncorrected distance, intermediate, and near visual acuities (logMAR) were 0.12 ± 0.20 (standard deviation), 0.24 ± 0.16, and 0.29 ± 0.21, respectively. Corresponding binocular values were -0.01 ± 0.14, 0.13 ± 0.12, and 0.20 ± 0.19, respectively. One eye (4%) had one-line loss in vision. Under mesopic condition, intermediate vision and near vision decreased significantly (all P ≤ 0.001). Contrast sensitivity at all spatial frequencies did not improve significantly under binocular condition (all P > 0.05). Median scores for halos, night glare, starbursts, and satisfaction were 0.50, 0.00, 0.00, and 4.25, respectively. Ten patients (71%) reported complete spectacle independence. Conclusions. Bilateral implantation of the intraocular lens in high myopes appeared to be safe and achieved good visual performance and high satisfaction.

Comparison of refractive and visual outcomes with centration points 80% and 100% from pupil center toward the coaxially sighted corneal light reflex.

PURPOSE: To compare the refractive and visual outcomes between 2 ablation centration points, 80% and 100% from the pupil center toward the coaxially sighted corneal light reflex. SETTING: Hong Kong Sanatorium and Hospital, Hong Kong, China. DESIGN: Retrospective comparative study. METHODS: All eyes had myopic laser in situ keratomileusis with the ablation 80% or 100% from the pupil center toward the coaxially sighted corneal light reflex. Three months postoperatively, the refractive and visual outcomes were compared between groups. Subgroup analysis was also performed for the large-angle κ and small-angle κ groups. RESULTS: There were no differences in the preoperative variables between groups. Three months postoperatively, the sphere was significantly more hyperopic in the 80% group than in the 100% group (0.19 diopter [D] versus 0.09 D) (P = .009) and the cylinder was significantly lower in the 80% group (0.25 D versus 0.33 D) (P = .011). More eyes achieved zero astigmatism in the 80% group than in the 100% group (43.9% versus 34.2%), and fewer eyes had astigmatism greater than 0.75 D in the 80% group (0.9% versus 6.1%) (P = .039). The error from the target refraction indicated that the 80% group tended to have significantly less undercorrection (P = .045). There were no significant differences in the other outcomes. Subgroup analysis did not show significant findings for the large-angle κ. CONCLUSIONS: Both 80% centration and 100% centration were safe and effective. Compared with the 100% group, the 80% group had less astigmatism and less undercorrection.

Visual outcomes and patient satisfaction after refractive lens exchange with a single-piece diffractive multifocal intraocular lens.

Purpose. To report visual outcomes and patient satisfaction after unilateral or bilateral refractive lens exchange (RLE) with a single-piece bifocal diffractive multifocal intraocular lens (MIOL). Methods. All patients underwent RLE with the ZMB00 MIOL (Abbott Medical Optics). Patient charts were reviewed to evaluate the distance, intermediate, and near visual acuity (VA), contrast sensitivity, extent of visual symptoms (0-5), satisfaction (1-5), and rate of spectacle independence between unilateral and bilateral RLE group. Results. Forty-seven eyes of 28 patients were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate (67 cm), and near (30 cm) were 0.01 ± 0.12 (standard deviation), 0.27 ± 0.18, and 0.15 ± 0.11, respectively. No eyes lost >1 line of corrected distance VA. Monocular contrast sensitivity remained at normal level. Median scores of halos, night glare, and starbursts for 27 patients were 2.0, 3.0, and 0.0, respectively. Median score of satisfaction was 4.0. There were no differences in visual symptom scores or satisfaction between unilateral and bilateral group (P > 0.05). Eighty percent of 25 patients reported total spectacle freedom, with similar rate between bilateral (82%) and unilateral group (75%) (P = 1.000). Conclusions. RLE with the bifocal diffractive MIOL was safe in presbyopic patients and resulted in a high rate of spectacle independence.

Initial evaluation of a femtosecond laser system in cataract surgery.

PURPOSE: To report the early experience and complications during cataract surgery with a noncontact femtosecond laser system. SETTING: Hong Kong Sanatorium and Hospital, Hong Kong Special Administrative Region, China. DESIGN: Retrospective case series. METHODS: All patients had anterior capsulotomy or combined anterior capsulotomy and lens fragmentation using a noncontact femtosecond laser system (Lensar) before phacoemulsification. Chart and video reviews were performed retrospectively to determine the intraoperative complication rate. Risk factors associated with the complications were also analyzed. RESULTS: One hundred seventy eyes were included. Free-floating capsule buttons were found in 151 eyes (88.8%). No suction break occurred in any case. Radial anterior capsule tears occurred in 9 eyes (5.3%); they did not extend to the equator or posterior capsule. One eye (0.6%) had a posterior capsule tear. No capsular block syndrome developed, and no nuclei were dropped during irrigation/aspiration (I/A). Anterior capsule tags and miosis occurred in 4 eyes (2.4%) and 17 eyes (10.0%), respectively. Different severities of subconjunctival hemorrhages developed in 71 (43.8%) of 162 eyes after the laser procedure. The mean surgical time from the beginning to the end of suction was 6.72 minutes ± 4.57 (SD) (range 2 to 28 minutes). CONCLUSIONS: Cataract surgery with the noncontact femtosecond laser system was safe. No eye lost vision because of complications. Caution should be taken during phacoemulsification and I/A to avoid radial anterior capsule tears and posterior capsule tears.

Visual outcomes and patient satisfaction after presbyopic lens exchange with a diffractive multifocal intraocular lens.

PURPOSE: To investigate the visual outcomes, severity of symptoms, and patient satisfaction after refractive lens exchange (RLE) with a diffractive multifocal intraocular lens (IOL). METHODS: A nonrandomized, unmasked, retrospective chart review study was performed. Patients who underwent RLE with ZMA00 (Abbott Laboratories) were identified from a hospital database. Eyes with preoperative uncorrected distance visual acuity or corrected distance visual acuity 20/20 or better were included. The study cohort comprised 45 eyes from 29 patients. Monocular uncorrected and distance-corrected visual acuity at distance, 67 cm, and 30 cm were measured 6 months postoperatively. A patient questionnaire assessing visual symptoms (halo, night glare, and starburst) and satisfaction with visual performance was administered. RESULTS: Six months postoperatively, mean uncorrected visual acuity (logMAR) was -0.10±0.13, 0.43±0.25 at 67 m (intermediate), and 0.18±0.05 at 30 m (near). Mean distance-corrected visual acuity at these distances was -0.02±0.06, 0.40±0.21, and 0.17±0.02, respectively. Twenty-seven patients completed the questionnaire. Patients reported postoperative halos (78%), night glare (26%), and starbursts (48%). All bilateral RLE patients were spectacle-free at all distances, whereas 50% of unilateral RLE patients required spectacles postoperatively. Bilateral RLE patients with habitual spectacle use preoperatively were the most satisfied with their postoperative visual performance. CONCLUSIONS: Refractive lens exchange with the ZMA00 is an option for presbyopic correction; however, significant glare, halo, and starburst issues are subjectively reported.