Correlations of Straylight, Aberrometry, and Lens Scattering in Cataract Patients

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Correlations of Straylight, Aberrometry, and Lens
Scattering in Cataract Patients
Bruno Valbon, MD Frederico Guerra, MD Daniela
Jardim, MD Fernanda Fonyat, MD Renato Ambrosio
Jr., MD, PhD
Dr. Ambrósio is a consultant for Oculus and is on
the speaker bureau for Reichert, Allergan, Alcon
and Moria.
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Introduction

• Cataract is a major cause of visual decline in
  older people.
• The deterioration in visual function in these
  patients cannot be entirely explained by
  spherical or cylindrical refractive errors.
• Nuclear cataract can also decrease visual
  function by affecting contrast sensitivity.
  Deterioration in contrast sensitivity can be
  explained
• in terms of scatter and increased higher-order
  aberrations (HOAs)
• Quality of vision loss because of eye media
  disturbances is limited not only to visual acuity
  effects, but also to other effects such as caused
  by straylight
• Straylight increases with age in the perfectly
  healthy eye, but much more so with disturbances
  to the optical media, such as cataract.
• The present study sought to take the next step by
  evaluating changes in the density and optical
  properties of the crystalline lens in eyes with
  grades of nuclear cataract on LOCS III to
  establish the correlation between the widespread
  subjective clinical classification and other
  objective methods of quantifying nuclear lens
  opacification.

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Purpose

• To correlate straylight levels, lens scattering,
  lens opacity and total and intraocular
  aberrometry in patients with cataract.

SETTING INSTITUTO DE OLHOS RENATO AMBROSIO, RIO
DE JANEIRO, BRASIL
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Methods

• Retrospective Study
• Inclusion criteria diagnosis of cataract
• Exclusion criteria corneal disease (other than
  up to mild guttata) retinal or optic nerve
  disease and previous ocular surgery
• Ocular straylight was evaluated using the C-Quant
  (Oculus)
• Lens scattering was evaluated using the
  Scheimpflug Anterior Segment Tomography (Pentacam
  , Oculus), using the new software PNS
• Total wavefront was measured by ray tracing
  (iTrace), intraocular aberrations were calculated
  by the integration of the Placido topography
  (Vista, Tracy Technologies)
• Dilated slit lamp evaluation was performed and
  lens opacity was classified according to LOCS
  scale
• This is study analyzed was Kolmogorov-Smirnov for
  Normaliy
• Correlation tests were performed.
• Either variables with Normal Distribution
  Pearson
• One of the variables with no Normal Distribution
  Spearman

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Example 1 Early Cataract PNS 1 HOA t 1,949
C-quant log(s) 1,16 est 0,08 q 0,82
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Example 2 PNS 2 HOA t 0,508
C-quant log(s) 2,7est 0,64q -0,13

C-quant log(s) 2,7 est 0,64 q -0,13
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Example 3 PNS 3 HOA t 0,508
C-quant log(s) 1,27 est 0,05 q 2
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Example 4 PNS 4 HOA total 0,986
C-quant log(s) 1,85 est 0,06 q -0,13
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Example 5 PNS 5 HOA total 0,887
C-quant log(s) 1,74 est 0,06 q 0,63
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RESULTS

• 30 eyes of 19 consecutive patients with nuclear
  opacity between N01 and NO6 on the Lens Opacities
  Classification System III

C-quant Log(s) PNS LOCS III HOA t IO COMA IO
Mean 2,405 1,85 2,7 1,14 2,4 0,68 0,9118 0,35 0,5477 0,31
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RESULTS

• rho

rho LOCS III C-quant Tempo de cirugia FACO HOA t IO
PNS 0.7687 0.0203 -0.4167 -0.1248
rho LOCSIII HOAt IO
C-quant -0.0592 0.0341
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RESULTS

• Graphics LOCS x PNS, Log(s) x PNS, Log(s) x LOCS

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CONCLUSION

• New mehtods for diagnosing cataract have been
  introduced
• C-Quant measurement of the straylight (glare
  disability) is an important new functional
  parameter
• The Scheimpflug Tomography by the Pentacam
  calculates the PNS scale which has a very high
  correlation with the slit lamp biomicroscopy
  exam.
• Optical analysis with aberrometry also has weak
  correlation