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Aspheric optics The new buzzword

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					   Update In Therapy Of Common
         Corneal Diseases




Dr Laurence Sullivan MB BS FRANZCO
         Bayside Eye Specialists, Brighton
        Melbourne Eye Specialists, Fitzroy
                     Lasersight
Corneal Clinic, Royal Victorian Eye and Ear Hospital
         Introductions……..
 Dr  Laurie Sullivan MB BS FRANZCO
 fellowship-trained Corneal Specialist

 specialising in Cataract Surgery, Laser
  Vision Correction, Corneal Transplants
 Cornea Clinic of the RVEEH

 examiner for RANZCO and the VCO
  GCOT


                  Laurie Sullivan 2006
 DrJessica Luzhansky MB BS FRANZCO
 Oculo-Plastics Fellowship in December
  2006 (RVEEH)
 Specialising in Oculo-Plastic Surgery,
  Cataract Surgery, General Ophthalmology
 speaks fluent Russian




                Laurie Sullivan 2006
 Dr  Michael S Loughnan MBBS PhD
  FRANZCO
 fellowship training in diseases of the
  anterior segment at Massachusetts Eye
  and Ear Infirmary (Harvard University,
  Boston USA)
 Cataract, Corneal Graft and Pterygium
  Surgery

                 Laurie Sullivan 2006
 Dr Joanne Dondey MB BS FRANZCO
 general ophthalmologist with a special
  interest in Cataract surgery and Paediatric
  Ophthalmology and Strabismus
 Two fellowships in Paediatric
  Ophthalmology and Strabismus, at the
  RCH in Melbourne and then at the
  Hospital for Sick Children, Toronto,
  Canada

                  Laurie Sullivan 2006
 Dr  Michael Shiu MB BS FRACGP
  FRANZCO
 fellowship trained Glaucoma Specialist

 special interests include Cataract,
  Glaucoma and Refractive Surgery
 Dr Shiu is fluent in spoken and written
  Mandarin and Cantonese


                  Laurie Sullivan 2006
 Dr  Andrew Atkins MBBS FRANZCO
 has been performing cataract procedures
  for the last 15 years in Melbourne and
  country Victoria.
 fellowship in Strabismus in the UKat the
  Royal Victorian Infirmary in Newcastle
 examiner for RANZCO
 interests are Cataract Surgery, Strabismus
  and General Ophthalmology
                 Laurie Sullivan 2006
What is everyone talking about?
Cornea
 Keratoconus
  C3R
  Intacs
  DALK - Deep lamellar keratoplasty
 Fuch’s Dystrophy, PBK
  DSAEK - Descemet’s Stripping Automated
  Lamellar Keratoplasty

                Laurie Sullivan 2006
   What else is everyone talking
              about?
 Our new Victoria Parade Surgery Centre
  @ 100 Victoria Parade, opposite St
  Vincent’s Hospital
 5 dedicated ophthalmic

theatres
 Lasersight has also

relocated to this building


                Laurie Sullivan 2006
              Keratoconus
 Incidence  1 in 2000
 Genetic (?dominant) predisposition

 Mechanism may be an excess of
  proteolytic enzymes (collagenase)
 breaks down corneal collagen

⃗ corneal thinning and stretching



                 Laurie Sullivan 2006
            Keratoconus
 Onset  in late teens / twenties
 Stabilises 30s, 40s (except PMCD)

 Associated atopy, eye rubbing




                 Laurie Sullivan 2006
   Keratoconus management
 Glasses

 RGP  contact lenses
 Transplant (penetrating or lamellar)

 Then: Glasses 33%, RGP 33%, nothing
  33%
 LASIK 1-5% 12 months after suture
  removal


                Laurie Sullivan 2006
               Keratoconus
   Why do corneas become “stiffer” with
 Q.
 age?

 Q.   Why does keratoconus stabilise?

 A.Increased collagen crosslinking -
 ?related to lifelong UV exposure.


                   Laurie Sullivan 2006
      C3R =“Corneal Collagen
    Crosslinking With Riboflavin”

 Keratoconic corneas show less crosslinking of
  collagen fibrils than normals
 This causes decreased resistance to stretch

 Treatment with UVA light can promote collagen
  x-linking
 Riboflavin is a very good sensitiser to UVA



                   Laurie Sullivan 2006
    RVEEH C3R Trial - Inclusion
            Criteria
 400 µm minimum thickness (UVA is toxic
  to endothelium) – i.e. early keratoconics.
  Ideally soon after definitive diagnosis with
  progression.
 >16 years old

 No other corneal pathology




                   Laurie Sullivan 2006
    RVEEH C3R Trial - Inclusion
            Criteria
 Progression   of KCN:
  – A decrease in the BOZR of ≥ 0.1mm in RGP
    wearers.
  – A myopic shift (SE) on manifest refraction of
    ≥ 0.50D
  – An increase in regular astigmatism on
    manifest refraction of ≥ 1.00D
  – An increase in the steepest K / sim K
    measured by keratometry or computerised
    videokeratography of ≥ 1.00D

                   Laurie Sullivan 2006
 Can   refer suitable patients directly to
  RVEEH with refractive and keratometric
  data
 Pachymetry may not be available to you
  all – can be done in clinic (or we can do it
  here for you)




                   Laurie Sullivan 2006
       Aims of C3R Treatment
 Slow   or stop progression of KCN
 Some reversal in ~20%?

 Better spectacle corrected vision

 longer duration of tolerability, fittability of
  rigid contact lenses
 Fewer transplants?




                    Laurie Sullivan 2006
              C3R - the treatment
   8mm epithelial debridement
    –   Sore eye
    –   Blurry(er) vision for a week
    –   Risk of infection
    –   2- 4 weeks out of RGP CL
 Soaked with riboflavin drops every 5 minutes
 30 minutes UVA light under an operating
  microscope
 Padded, ointment, antibiotics, steroids,
  lubricants

                           Laurie Sullivan 2006
Corneal Collagen Crosslinking –
             C3R




            Laurie Sullivan 2006
C3R side effects and complications
   Postoperative pain or irritation
   Postoperative corneal haze (generally temporary)
   Changes in the focus of the eye
   Contact lens intolerance for 2 to 4 weeks

   Delayed healing of the surface of the eye
   Infection (microbial keratitis)
   Worsening of keratoconus
   Allergy to medications including antibiotic and steroid
    eye drops


                          Laurie Sullivan 2006
Crosslinking treatment of progressive keratoconus: new
  hope. Curr Opin Ophthalmol. 2006 Aug;17(4):356-60
  Authors: Wollensak G et al

   Biomechanical measurements have shown an increase
    in corneal rigidity of 300% in human corneas after
    crosslinking.
   The 3 and 5-year results of the Dresden clinical study
    have shown that in all treated 60 eyes the progression of
    keratoconus was at least stopped.
   In 31 eyes there also was a slight reversal and flattening
    of the keratoconus by up to 2.87 diopters.
   BCVA improved slightly by 1.4 lines.
   A cytotoxic level of UVA for endothelium was found to be
    0.36 mW/cm which would be reached in human corneas
    with a stromal thickness of less than 400 µm at the
    intensity used.

                         Laurie Sullivan 2006
 Durationof effect? –may need repeat
  treatment at 5 years
 ??Long term adverse effects (later OSSN /
  CIN?)




                 Laurie Sullivan 2006
Intacs for KCN




   Laurie Sullivan 2006
 Intacs for KCN – who can benefit
 Mild to moderate keratoconus
 Decreased or decreasing spectacle
  corrected vision, intolerant of RGP
 Can expect improved BCVA with
  spectacles




                 Laurie Sullivan 2006
        Intacs – who can benefit
 Not for advanced keratoconus
 May be combined with C3R to “set” the
  cornea in the new shape?
 The Intacs procedure is safer with
  channels formed with the femtosecond
  laser (Intralase)
 May also be used in post LASIK ectasia



                 Laurie Sullivan 2006
                  DALK
 “Deep Anterior Lamellar Keratoplasty”
 Remove full thickness cornea, leaving only
  endothelium, Descemet’s membrane and
  minimal posterior stroma
 Less stroma, less interface haze




                 Laurie Sullivan 2006
              DALK benefits
 Maintains  host endothelium, which cannot
  be rejected
 Slightly better structural integrity than full
  thickness transplant




                   Laurie Sullivan 2006
                   DALK
 Who?



 Keratoconus,   anterior scars
 Severe  atopy
 Rejection other eye

 Unreliable patients, Down’s syndrome,
  trauma risk

                   Laurie Sullivan 2006
             DALK results
 Best  VA on average 6/7.5 to 6/9
  (compared to 6/6) due to interface haze or
  irregularity
 No benefit for astigmatism

 Slightly earlier suture removal

 Can still have wound and suture problems,
  infection


                 Laurie Sullivan 2006
  DSAEK in endothelial failure
 Fuch’s   dystrophy or PBK




                   Laurie Sullivan 2006
          Fuch’s Dystrophy
 Heritable

 Dominant

 Females  more than males
 Corneal guttae (bumps in Descemet’s
  Membrane)
 Endothelium decreased in number and
  increased in size. Variable size, shape.


                  Laurie Sullivan 2006
         Fuch’s Dystrophy
Symptoms
 Morning blur which clears

 Poor low contrast acuity

Signs
 Corneal thickening

⃗ Microcystic corneal oedema
⃗ Bullae

                Laurie Sullivan 2006
Fuch’s Dystrophy




     Laurie Sullivan 2006
          Fuch’s Dystrophy
 Avoid intraocular (cataract) surgery
 Avoid low Dk SCL

 Avoid SCL? (RGP)

 Control IOP

 Dehydrate cornea
  – Hair dryer
  – 5% Saline drops


                  Laurie Sullivan 2006
                DSAEK
 “Descemet’s Stripping Automated
 Endothelial Keratoplasty”




                Laurie Sullivan 2006
                 DSAEK
 Indications

 Fuch’sDystrophy
 Endothelial failure / PBK




                  Laurie Sullivan 2006
                  DSAEK
 Remove   host Descemet’s membrane
 Replace with lenticle of donor Descemet’s
  membrane and posterior stroma (100 µm)
 Air bubble to hold in place

 No corneal sutures, minimal astigmatism



 Only   for pseudophakic patients

                   Laurie Sullivan 2006
DSAEK




Laurie Sullivan 2006
                     DSAEK
 Main   benefit is rapid rehabilitation
  – 1 to 2 months compared to 3 to 12 months for PK
  – Better structural integrity than PK




                       Laurie Sullivan 2006
                 DSAEK
 Main  disadvantage is increased
  postoperative interventions for detached
  and displaced donor lenticles
 Shorter survival of transplanted tissue due
  to trauma (to endothelium) of insertion




                  Laurie Sullivan 2006
             PTERYGIUM
 UV  exposure, inflammation
 Surgery for cosmesis, comfort, VA (wtr
  astigmatism)
 No Bray now

 Autologous conjunctival grafting is routine




                  Laurie Sullivan 2006
              PTERYGIUM
 The procedure takes
  about 45 minutes,
 requires a hospital
  day stay and the use
  of the operating
  microscope.
 Local anaesthetic

 Topical steroid drops
  for 6 weeks

                    Laurie Sullivan 2006
      RECURRENT CORNEAL
      EROSION SYNDROME
           basement membrane dystrophy
 Epithelial
  (EBMD) + trauma
 Sudden onset of unilateral pain watering
  photophobia and redness
 Usually overnight or on first waking
  (?hypoxia)
 Debride, CL, micropuncture, PTK



                 Laurie Sullivan 2006
        Atopic Eye Disease
 New  drugs: Olapatadine (Patanol) MCS
  and anti-H1, topical cyclosporine A
  (CSA)(RVEEH) as steroid sparing agent
 CSA also of benefit in Thygeson’s SPK




                Laurie Sullivan 2006
        Corneal hysteresis
 Measurement  of corneal hysteresis with
 the Reichert Ocular Response Analyzer
 provides useful information on the
 dynamic biomechanical properties of the
 cornea before and after refractive surgery,
 and it may have a role in predicting
 postoperative keratectasia



                 Laurie Sullivan 2006
Thank You



 Questions?




  Laurie Sullivan 2006


				
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posted:11/16/2010
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