title: Immediate versus Delayed Sequential Bilateral Cataract Surgery: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Immediately sequential bilateral cataract surgery (ISBCS), the cataract surgery that is performed in both eyes simultaneously, is gaining popularity worldwide compared to the traditional treatment paradigm: delayed sequential bilateral cataract surgery (DSBCS), the surgery that is performed in each eye on a different day as a completely separate operation. ISBCS provides advantages to patients and patients' families in the form of fewer hospital visits. Additionally, patients enjoy rapid rehabilitation, lack of anisometropia - potentially reducing accidents and falls, and avoid suboptimal visual function in daily life. The hospital may benefit due to lower cost.
  
  
  OBJECTIVE
  To perform a systematic review and meta-analysis to evaluate ISBCS and DSBCS.
  
  
  METHODS
  Databases including MEDLINE, EMBASE, BIOSIS, CINAHL, Health Economic Evaluations Database (HEED), ISI Web of Science (Thomson-Reuters) and the Cochrane Library were searched.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Literature was systematically reviewed using EPPI-Reviewer 4 gateway. Meta-analysis was conducted using STATA v. 13.0. Standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated and heterogeneity was assessed using I2 statistics. Fixed-effect and random-effect models were computed based on heterogeneity. Meta-analysis was done by instrument used to calculate utility score.
  
  
  RESULTS
  In total, 9,133 records were retrieved from multiple databases and an additional 128 records were identified through grey literature search. Eleven articles with 3,657 subjects were included for analysis. Our meta-analysis results indicated significant improvement in post-operative utility score using TTO, EQ5D, HUI3, VF-7, and VF-14 and a non-significant improvement using Catquest questionnaire for both surgeries. For ISBCS versus DSBCS, utility-specific fixed-effect model provided an overall SMD of the utility score using the TTO method as 0.12 (95% CI: -0.15, 0.40), EQ5D as 0.14 (95% CI: -0.14, 0.41), HUI3 as 0.12 (95% CI: -0.15, 0.40), VF-7 as -0.02 (95% CI: -0.15, 0.10), and Catquest Questionnaire as 1.45 (95% CI: -0.88, 2.01). The results for utility score, which were measured using various instruments, indicated non-significant improvement in the utility due to DSBCS compared to ISBCS. However, a significant improvement in post-operative utility score was seen using Catquest questionnaire for ISBCS compared to DSBCS. The included studies using VF-14 instrument were highly heterogeneous (I2 = 97.1%). Results provided SMD of -0.25 (95% CI:-1.06, 0.57) using VF-14 indicating non-significant improvement in the utility due to DSBCS compared to ISBCS surgery. Best corrected visual acuity (BCVA) significantly improved after both surgeries (overall SMD of BCVA due to ISBCS was -1.79 (95% CI: -2.45, -1.14) and due to DSBCS was -1.53 (95% CI: -2.25, -0.81)). A non-significant improvement was seen in BCVA due to ISBCS when compared to DSBCS (SMD = -0.18; 95% CI: -0.37, 0.01).
  
  
  CONCLUSIONS
  Both surgeries, ISBCS and DSBCS significantly improve patients' quality of life and visual acuity. Further, ISBCS may deliver certain additional benefits at the individual and societal levels as well.
authors.affiliation: Department of Ophthalmology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Monali S
authors.initials: MS
authors.lastname: Malvankar-Mehta
authors.affiliation: Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Yufeng Nancy
authors.initials: YN
authors.lastname: Chen
authors.affiliation: Faculty of Health Sciences, University of Western Ontario, London, ON, Canada.
authors.forename: Sangita
authors.initials: S
authors.lastname: Patel
authors.affiliation: Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Angela Pui-Kei
authors.initials: AP
authors.lastname: Leung
authors.affiliation: Department of Ophthalmology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Man Mohan
authors.initials: MM
authors.lastname: Merchea
authors.affiliation: Department of Ophthalmology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: William G
authors.initials: WG
authors.lastname: Hodge
mesh_terms: D002387:Cataract Extraction / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000009:adverse effects / Q000379:methods; D011788:Quality of Life; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology