Demographic and visual outcomes on keratoconus patients with failed

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Demographic and visual outcomes on keratoconus
patients with failed epi- onC3R cross-linking
procedures

• Yaron S. Rabinowitz M.D.
• Oana Dumitrascu M.D.
• The authors have no financial interest in the
  materials presented in this poster

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Background

• The standard procedure in collagen
  cross-linking is to remove the epithelium. Recent
  reports suggest that it is not necessary to
  remove the epithelium using the epi-on C3R
  procedure. This study was undertaken to
  illustrate C3R failures.

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Abstract

• PURPOSE To present data on unhappy keratoconus
  patients
• who presented to our office following C3R
  epi-on cross-linking.
• METHODS Retrospective chart review 1 year post
  procedure
• RESULTS 13 eyes were identified. Mean age was 33
  yrs
• (range 23 41). Mean uncorrected acuity was
  20/200
• (range 20/40-20/200). Mean best-corrected acuity
  was 20/60
• (range 20/30-20/200). Mean central pachymetry
  was 435um
• (range 380-485). Mean K value was 50.27(range
  43-58).
• Mean I-S value was 4.25(range 1.84-10.86). 4 eyes
  had
• repeat cross-linking with the standard epi-off
  procedure, 4 eyes
• had corneal transplants and 5 eyes had no
  further treatment
• CONCLUSIONS These data suggest that the epi-on
  C3R
• procedure may not be optimal for treating
  keratoconus.

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Results - Demographics of failed epi-on
N Age Reason for consult UCVA BSCVA Ks Pach Additional findings/surgery
1 14 Progressed 7D in 1 year 20/400 20/80 57/53 417 Clear cornea
2 14 Progressed 8D in 1 year 20/400 20/70 58/52 444 Intacs
3 26 Progressed by 3D CF 2 ft 20/400 54/48 446 Paracentral scar
4 28 No visual improvement 20/150 20/30 51/49 409 Intacs and ICL
5 28 No visual improvement 20/80 20/40 46/42 473 Intacs and ICL
6 32 No improvement in VA 20/40 20/25 45/42 479 Intacs and 2nd C3R
7 32 No improvement in VA 20/80 20/40 50/51 454 Intacs and 2nd C3R
8 33 Rapid progression CF 20/400 54/41 381 Intacs
9 36 Progression worse VA 20/40 20/40 56/45 418 Intacs, CK and ICL
10 36 Progression worse VA 20/70 20/40 57/48 435 Intacs, CK and ICL
11 42 Progression worse VA 20/400 20/70 53/48 380 Paracentral scar
12 42 Progression worse VA 20/150 20/70 50/47 461 Paracentral scar
13 51 No improvement in VA CF 1ft CF 1ft 63/56 381 Paracentral scar/Epi Lasik
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Results - DemographicsSummary of findings at
presentation

• 4/13 (30) eyes had paracentral scars
• 9/13 (70) eyes had 1 additional surgery
• 6/13 (46) eyes had 2 additional surgeries
• 3/13 (23) eyes had 3 additional surgeries

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Results - reasons why patients not happy

• 8/13(60) patients noted progression after C3R,
  we were able to document this in 5 patients one
  progressed up to 8D
• 5/13(40) did not experience an improvement in
  their vision which was their reason for doing the
  procedure

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Eye 2 - Pre op and 1 year Post op topography C3R
- 8 D change
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Results - Disposition of Failed C3R patients
N Age UCVA BSCVA Ks Pach Disposition and results
1 14 20/400 20/80 57/53 417 I.E.K./AK UCVA 20/30
2 14 20/400 20/70 58/52 444 I.E.K./LASIK UCVA 20/25
3 26 CF 2 ft 20/400 54/48 446 RGP BCVA 20/60-
4 28 20/150 20/30 51/49 409 Glasses BSCVA 20/30-
5 28 20/80 20/40 46/42 473 Glasses BSCVA 20/80-
6 32 20/40 20/25 45/42 479 Repeat CXL epi off UCVA 20/30
7 32 20/80 20/40 50/51 454 Repeat CXL epi off UCVA 20/50
8 33 CF 20/400 54/41 381 I.E.K/LASIK UCVA 20/20
9 36 20/40 20/40 56/45 418 Repeat CXL epi off UCVA 20/40
10 36 20/70 20/40 57/48 435 Repeat CXL epi off UCVA 20/70
11 42 20/400 20/70 53/48 380 RGP BCVA 20/60-
12 42 20/150 20/70 50/47 461 RGP BCVA 20/70
13 51 CF 1ft CF 1ft 63/56 381 I.E.K./AK UCVA 20/30
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Discussion

• Collagen Cross Linking(CXL) involves the removal
  of the corneal epithelium, soaking the cornea
  with riboflavin and applying a homogenous beam of
  UV light for about 30 minutes to the cornea.
• Several studies in the published literature
  suggest that this is a safe and effective method
  for retarding the progression of keratoconus
• C3R is a variation of this procedure in which the
  epithelium is retained and a lamp of unknown
  origin is used for UV radiation. It is not FDA
  approved but done on an off label basis
• This procedure is heavily marketed as being safe
  and effective, with a lt 2 retreatment rate being
  quoted
• For C3R,there have been no scientific studies to
  date demonstrating a high safety profile as has
  been done for CXL

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Discussion

• In this study we demonstrate that 13 eyes from
  one practice performing C3R had an unfavorable
  outcome in a 1 year period
• This suggests that the failure rate for C3R may
  be higher than the quoted 1.4 retreatment rate
• 5/13 eyes were unhappy because they noticed no
  visual improvement, 4 had paracentral scars
• 8/13 eyes noted definite progression within 1
  year of receiving the treatment
• This suggests that patient selection for this
  particular procedure might have been less than
  optimal

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Conclusion

• While Collagen Cross linking (CXL) appears to be
  safe and effective as described by the pioneers
  of this procedure, it appears that performing
  this procedure leaving the epithelium on requires
  further study for safety and efficacy, before
  being universally adopted.
• Patients expectations for improved vision should
  be tempered with the emphasis being placed on
  retarding the progression, which currently has a
  quoted 7.6 retreatment rate using the standard
  epi-off CXL procedure