title: Risk Factors and Incidence of Macular Edema after Cataract Surgery: A Database Study of 81984 Eyes.
abstract: OBJECTIVE
  To define the incidence of pseudophakic macular edema (PME) after cataract surgery and to identify contributory risk factors.
  
  
  METHODS
  Retrospective database study of electronic medical records (EMRs).
  
  
  METHODS
  A total of 81984 eyes undergoing cataract surgery between December 2010 and December 2014 from 8 independent United Kingdom clinical sites.
  
  
  METHODS
  Structured clinical data mandated by the EMR were anonymized and extracted for each eye undergoing cataract surgery including: perioperative visual acuity, copathologic features, simultaneous surgical procedures, and the presence or absence of a specified list of intraoperative complications. Diabetic status with matched Early Treatment Diabetic Retinopathy Study (ETDRS) grading also was mandated by the EMR. Eyes receiving prophylactic nonsteroidal anti-inflammatory drugs were excluded.
  
  
  METHODS
  Diagnosis of cystoid macular edema or new-onset macular edema in patients with diabetes, recorded by a healthcare professional within 90 days of surgery.
  
  
  RESULTS
  Baseline incidence of PME in eyes without operative complications, diabetes, or risk factors was 1.17%. Eyes in which PME developed were more likely to be male, older, and to demonstrate risk factors. The relative risk (RR) was increased in eyes with capsule rupture with or without vitreous loss (RR, 2.61; 95% confidence interval [CI], 1.57-4.34), a previous diagnosis of epiretinal membrane (RR, 5.60; 95% CI, 3.45-9.07), uveitis (RR, 2.88; 95% CI, 1.50-5.51), retinal vein occlusion (RR, 4.47; 95% CI, 2.56-5.92), or retinal detachment repair (RR, 3.93; 95% CI, 2.60-5.92). High myopia, age-related macular degeneration, or prostaglandin analog use were not shown to increase risk. Eyes with PME on average had poorer postoperative visual acuity, which persisted to the latest time point assessed, up to 24 weeks. Eyes from patients with diabetes, even in the absence of retinopathy, had an increased RR (RR, 1.80; 95% CI, 1.36-2.36) of new macular edema after surgery. The risk was higher in the presence of any diabetic retinopathy (DR; RR, 6.23; 95% CI, 5.12-7.58) and rose proportionately with increasing severity of DR.
  
  
  CONCLUSIONS
  Pseudophakic macular edema occurs commonly after phacoemulsification cataract surgery, even in the absence of complications and risk factors. This large retrospective study using structured EMR data quantified the RRs of PME and the risk with increasing ETDRS severity of DR. It highlights the need for prophylactic therapy, especially in those groups of eyes with the highest RRs.
authors.affiliation: School of Clinical Sciences, University of Bristol and Bristol Eye Hospital, Bristol, United Kingdom.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Chu
authors.affiliation: Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham, United Kingdom. Electronic address: Rob.Johnston@glos.nhs.uk.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnston
authors.affiliation: Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham, United Kingdom.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Buscombe
authors.affiliation: Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
authors.forename: Ahmed B
authors.initials: AB
authors.lastname: Sallam
authors.affiliation: Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham, United Kingdom.
authors.forename: Queresh
authors.initials: Q
authors.lastname: Mohamed
authors.affiliation: Wolverhampton Eye Infirmary, Royal Wolverhampton Hospitals NHS Trust, New Cross, Wolverhampton, United Kingdom; Sandwell and West Birmingham NHS Trust, Birmingham, United Kingdom.
authors.forename: Yit C
authors.initials: YC
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual / Q000706:statistics & numerical data; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D015994:Incidence; D019654:Lens Implantation, Intraocular; D008269:Macular Edema / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000706:statistics & numerical data*; D011183:Postoperative Complications; D019591:Pseudophakia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D013222:State Medicine; D006113:United Kingdom / Q000453:epidemiology; D014792:Visual Acuity / Q000502:physiology