title: [Expected effect of retinal thickness after focal photocoagulation in diabetic macular oedema].
abstract: BACKGROUND
  Macular oedema is a form of diabetic retinopathy that can be treated with photocoagulation. The expected effect of treatment varies, and may depend on the previous characteristics of retinal thickening.
  
  
  OBJECTIVE
  To determine whether the change in retinal thickness after focal photocoagulation for diabetic macular oedema varies due to the presence of anatomical features that may justify a separate assessment.
  
  
  METHODS
  Non-experimental, comparative, retrospective, longitudinal study. The mean percentage change in macular volume was compared in eyes with diabetic macular oedema, 3 weeks after focal photocoagulation. The analysis was stratified according to the presence of central and perifoveal temporal thickening (Mann-Whitney U). A regression analysis was performed to identify the contribution of the anatomical variables before photocoagulation to the change in macular volume.
  
  
  RESULTS
  A total of 72 eyes were evaluated. The mean change of macular volume in the sample was -0.68±3.84%. In the multiple regression analysis, the changes of perifoveal temporal (beta 0.54, p<0.001) and central field thickness (beta 0.3, p =0.01) contributed to the change of macular volume (R=0.64). Macular volume decreased by a mean of -2.1±4.3% in eyes with temporal perifoveal thickening, and increased by 0.5±2.8% (p =0.007) in eyes with no thickening.
  
  
  CONCLUSIONS
  Perifoveal temporal thickening before photocoagulation changes the expected effect of this therapy on macular volume in eyes with focal diabetic macular oedema. It is recommended to evaluate the effect separately, and according to the perifoveal temporal thickness.
authors.affiliation: Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México.
authors.forename: Yatzul Zuhaila
authors.initials: YZ
authors.lastname: Garcia-Rubio
authors.affiliation: División de Investigación, Hospital Juárez de México, Ciudad de México, México.
authors.forename: Dulce Milagros
authors.initials: DM
authors.lastname: Razo Blanco-Hernández
authors.affiliation: Servicio de Oftalmología, Hospital Juárez de México, Ciudad de México, México. Electronic address: vlimag@eninfinitum.com.
authors.forename: Virgilio
authors.initials: V
authors.lastname: Lima-Gómez
mesh_terms: D001786:Blood Glucose; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D003930:Diabetic Retinopathy / Q000473:pathology / Q000601:surgery*; D005260:Female; D005584:Fovea Centralis / Q000473:pathology; D006801:Humans; D017075:Laser Coagulation; D008269:Macular Edema / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012160:Retina / Q000473:pathology*; D012189:Retrospective Studies; D014792:Visual Acuity
chemical_list: D001786:Blood Glucose
keywords: Diabetic macular oedema; Diabetic retinopathy; Edema macular diabético; Fotocoagulación; Macular volume; Photocoagulation; Retinopatía diabética; Volumen macular