title: Refractive changes in nuclear, cortical and posterior subcapsular cataracts. effect of the type and grade.
abstract: OBJECTIVE
  To determine the effect of main morphological types and grades of age-related cataracts on refractive error.
  
  
  METHODS
  We measured 276 subjects with optical compensation prior to the development of cataract. We evaluated 224 eyes with nuclear cataract, 125 with cortical cataract, and 103 with posterior subcapsular (PSC) cataract classified with LOCSIII. We measured visual acuity (VA) with their spectacles and best-corrected visual acuity (BCVA) with chart in decimal scale to obtain the optimal compensation with cataract. We evaluated the differences between compensations.
  
  
  RESULTS
  A significant myopic shift was observed in nuclear cataract from low to mild grade (p=0.031), the same as for PSC cataract from mild to advanced grade (p=0.025). No significant changes were found for cortical cataract (p=0.462). Regarding astigmatism, we observed power changes in cortical cataract from low to mild grade (p=0.03) and axis changes in PSC from low to mild grade (p=0.02) and in nuclear cataract from mild to advanced grade (p=0.02).
  
  
  CONCLUSIONS
  Cataract produces changes in patient's compensation which depend on severity and type of cataract. For nuclear and PSC cataract, we observed that the higher the grade of severity, the greater the myopic shift. Power astigmatic changes were found in cortical cataract and axis changes in PSC and nuclear cataract.
authors.affiliation: Fundación Oftalmológica del Mediterráneo (FOM), Bifurcación Pío Baroja-General Avilés, s/n, E46015 Valencia, Spain; Clínica Optomètrica, Fundació Lluís Alcanyís, Universitat de València, Guardia Civil, 22, E46020 Valencia, Spain. Electronic address: amparo.diez@uv.es.
authors.forename: Ma Amparo
authors.initials: MA
authors.lastname: Díez Ajenjo
authors.affiliation: Fundación Oftalmológica del Mediterráneo (FOM), Bifurcación Pío Baroja-General Avilés, s/n, E46015 Valencia, Spain.
authors.forename: Ma Carmen
authors.initials: MC
authors.lastname: García Domene
authors.affiliation: Fundación Oftalmológica del Mediterráneo (FOM), Bifurcación Pío Baroja-General Avilés, s/n, E46015 Valencia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Peris Martínez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001251:Astigmatism / Q000209:etiology; D002386:Cataract / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D015350:Contrast Sensitivity; D005260:Female; D006801:Humans; D007904:Lens Cortex, Crystalline / Q000473:pathology; D007907:Lens Nucleus, Crystalline / Q000473:pathology; D007908:Lens, Crystalline / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology; D012030:Refractive Errors / Q000209:etiology*; D014792:Visual Acuity
keywords: Cataract; Catarata; Compensación óptica; Cortical; Nuclear; Optical compensation; Posterior subcapsular; Subcapsular posterior