title: In a randomized controlled trial, cataract surgery in both eyes increased benefits compared to surgery in one eye only.
abstract: OBJECTIVE
  Despite recommendation of surgery in both eyes in patients with bilateral cataract, there is little evidence about the benefits of second-eye surgery. The objective of this study was to compare the benefits of cataract surgery in both eyes with those of surgery in one eye only.
  
  
  METHODS
  Two-arm randomized controlled trial involving 296 patients with bilateral cataracts of two public teaching hospitals. Patients were randomly assigned to receive surgery in one eye only (control group) or surgery in both eyes, one eye at a time (intervention group). The main outcome measures were binocular visual acuity, binocular contrast sensitivity, stereopsis, and patient-reported visual disability (VF-14), measured 4-6 months postoperatively.
  
  
  RESULTS
  A total of 135 (91.2%) and 139 (93.9%) patients completed the trial in the control and intervention groups, respectively. Postoperatively, intervention group presented a better visual acuity (difference of 0.07; 95% CI = 0.03, 0.12), stereopsis (0.62 log sec arc; 95% CI = 0.45, 0.79), and VF-14 (8.2 points; 95% CI = 4.4, 12.4). No significant differences were found for contrast sensitivity.
  
  
  CONCLUSIONS
  Bilateral cataract patients should have surgery in both eyes. Including stereopsis and patient-reported visual disability in the assessment of cataract patients, especially after first-eye surgery, will improve the evaluation of effectiveness.
authors.affiliation: Evaluation and Clinical Epidemiology Department, Institut Municipal d'Assistència Sanitària (IMAS), Passeig Marítim 25-29, 08003 Barcelona, Spain. xcastells@imas.imim.es
authors.forename: Xavier
authors.initials: X
authors.lastname: Castells
authors.forename: Mercè
authors.initials: M
authors.lastname: Comas
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
authors.forename: Mireia
authors.initials: M
authors.lastname: Espallargues
authors.forename: Vicente
authors.initials: V
authors.lastname: Martínez
authors.forename: Josep
authors.initials: J
authors.lastname: García-Arumí
authors.forename: Miguel
authors.initials: M
authors.lastname: Castilla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000473:pathology / Q000523:psychology / Q000534:rehabilitation*; D002387:Cataract Extraction / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D016896:Treatment Outcome; D015348:Vision, Binocular