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Clinical science
Grading nuclear, cortical and posterior subcapsular cataracts using an objective scatter index measured with a double-pass system
  1. Meritxell Vilaseca1,
  2. Maria José Romero2,
  3. Montserrat Arjona1,
  4. Sergio Oscar Luque1,
  5. Juan Carlos Ondategui3,
  6. Antoni Salvador2,
  7. José L Güell4,
  8. Pablo Artal5,
  9. Jaume Pujol1
  1. 1Centre for Sensors, Instruments and Systems Development (CD6), Universitat Politècnica de Catalunya, Terrassa, Barcelona, Spain
  2. 2Hospital Universitari Mútua de Terrassa, Terrassa, Barcelona, Spain
  3. 3University Vision Centre (CUV), Universitat Politècnica de Catalunya, Terrassa, Barcelona, Spain
  4. 4Cornea-Refractive Surgery Unit, Instituto de Microcirugía Ocular (IMO), Barcelona, Spain
  5. 5Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain
  1. Correspondence to Dr Meritxell Vilaseca, Centre de Desenvolupament de Sensors, Instrumentació i Sistemes (CD6), Universitat Politècnica de Catalunya (UPC), Rambla Sant Nebridi 10, 08222 Terrassa, Barcelona, Spain; mvilasec{at}


Purpose To evaluate objectively intraocular scattering in eyes with nuclear, cortical and posterior subcapsular cataracts by means of an objective scatter index (OSI) obtained from double-pass images. To compare the results with those obtained using clinical conventional procedures.

Methods In this prospective, observational, cross-sectional, non-consecutive case series study, 188 eyes with cataracts of 136 patients were analysed (123 eyes had nuclear, 41 eyes had cortical and 24 eyes had posterior subcapsular cataracts). The control group consisted of 117 eyes of 68 healthy patients. Patient examination included subjective refraction, best spectacle-corrected visual acuity (BSCVA), cataract grade using the lens opacities classification system III (LOCS III) and OSI.

Results We found a decrease in the BSCVA and an increase in the OSI with increasing cataract grade. Statistically significant differences were observed when the OSI of eyes without cataracts and those with different LOCS III were compared. The comparison between the OSI and LOCS III reported good percentages of agreement regarding the number of eyes classified in equivalent levels: 72.4% (nuclear cataracts), 86.6% (cortical cataracts) and 84.3% (posterior subcapsular cataracts). A non-linear regression model was applied between OSI and BSCVA, which resulted in the following multiple correlation coefficients: r=0.878 (nuclear), r=0.843 (cortical) and r=0.844 (posterior subcapsular).

Conclusions The results of the study showed that OSI is a useful parameter for evaluating large amounts of intraocular scattering that can be used, in combination with other conventional procedures, as a valuable tool in clinical practice to grade cataracts objectively.

  • Cataract
  • cornea
  • double-pass technique
  • epidemiology
  • imaging
  • intraocular scattering
  • ocular surface
  • optical quality
  • optics and refraction
  • physiology
  • psychophysics
  • treatment surgery
  • vision
  • visual perception

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  • Funding This study was supported by the Spanish Ministry of Education and Science under grant DPI2008-06455-C02-01, and the Spanish Agency for International Cooperation under grant D/030286/10.

  • Competing interests MA is an investor for Visiometrics SL. JLG, PA and JP are investors and consultants for Visiometrics SL. MV, MJR, SOL, JCO and AS have no interests to declare.

  • Patient consent Obtained.

  • Ethics approval Ethics approval was provided by Comité Ético del IMO, Comité Ètic de l'Hospital Universitari Mútua de Terrassa.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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