Transcript Toric ICL in Keratoconus

Results of Collagen Crosslinking followed by posterior
chamber toric implantable collamer lens implantation
in patients with Keratoconus & High Myopia
Dr Rajesh Fogla DNB, FRCS, MMed
Senior Consultant, Corneal Surgeon
Apollo Hospitals, Hyderabad
[email protected]
Financial Disclosure – No Financial Interest
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Collagen cross-linking
•
Collagen cross-linking (CXL) using riboflavin phosphate- UVA (365nm) treatment
leads to a significant increase in mechanical stiffness of the cornea.
•
Increase in intra- and inter-fibrillar covalent bonds by photosensitized oxidation.
•
Several studies have shown arrest of progression of keratoconus post CXL
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Implantable Collamer Lens (ICL)
• Phakic IOL
• Approved for high myopia, thin corneas,
suspicious corneal topography wherein
LASIK is contraindicated
• Safe and predictable
• Reversible
• Visian Toric ICL * corrects astigmatism as
well besides myopia
*STAAR Surgical Company AG, Nidau, Switzerland
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Introduction
• Keratoconus
– Subset of patients have high myopia
with astigmatism less than 6 diopters
– Best spectacle corrected visual acuity is
often > 20/40 in these patients
– Patients desire better unaided vision
In this study we evaluate visual outcome of collagen crosslinking
followed by posterior chamber toric ICL implantation in patients
with keratoconus & high myopia
Materials & Methods
• Prospective, non comparative, interventional case series of consecutive
patients undergoing Collagen crosslinking followed by ICL implantation
between March 2008 to September 2008.
• Keratoconus patients with astigmatism less than 6 diopters, minimal
pachymetry of 400 microns, absence of corneal scarring and best
spectacle corrected visual acuity (BSCVA) of 20/40 or better were included
in study. (specular microscopy & anterior chamber depth as per
requirements of ICL implantation were also assessed)
• Outcomes were measured in terms of uncorrected visual acuity (UCVA),
BSCVA, refraction, topography and adverse events.
Surgical Technique
Collagen Crosslinking
Technique - Epithelial debridement followed by application of riboflavin phosphate
1% for 30mins and UVA (365nm) exposure for 30 mins. Eye patched with topical
antibiotics till epithelial healing, followed by use of topical mild steroids,
antibiotics and lubricants for one month
Toric ICL implantation
Technique – Surgery was performed under topical anesthesia in all cases. Axis of
toric ICL was marked at the limbus. Standard technique of implantation
recommended by the manufacturer was followed in all cases. Single surgical
peripheral iridectomy (PI) was performed at 12 o clock position. Postoperatively
patients received topical steroids, antibiotics, & lubricants for one month.
Results
• 19 eyes of 15 patients (Male:Female = 11:4)
• All eyes underwent collagen crosslinking (CXL) followed by toric ICL
implantation. Average duration between these two procedures 5.4
months (range 3-9 months)
• Pre CXL average keratometry values 54.60 / 49.95, Post CXL 52.96 / 49.70
Pre toric ICL implantation data
UCVA
20/200 (0.1)
BSCVA
20/40 (0.5)
Sphere (Refraction)
-9.84 + 4.98
Astigmatism (Refraction)
3.4 + 1.29
Astigmatism (Corneal topography)
4.65 + 2.21
Anterior Chamber Depth (mm)
3.94 + 0.37
Specular Count (cells/mm2)
2879 + 450
Pachymetry (microns)
461.3 + 38.6
Results
Pre
Post
UCVA
20/200 (0.1)
20/40+ (0.62)
BSCVA
20/40(0.5)
20/25+ (0.91)
Astigmatism (Refraction)
3.4 + 1.29
1.08 + 1.15
Astigmatism Corneal Topography
4.39 + 2.15
4.03 + 2.04
Sphere (AutoRefractometer)
-9.84 + 4.98
-0.11 + 1.39
Cylinder (AutoRefractometer)
4.65 + 2.21
1.6 + 1.82
All patients had improvement in UCVA & BSCVA,
Mean improvement of 5 lines of UCVA & 2 lines of BSCVA.
None of the patients lost any line of BSCVA.
No progression of keratoconus was noted at last follow up. (mean follow up 14
months)
Complications
Collagen Crosslinking –
Trace corneal haze noted at 2-4 weeks post CXL which resolved by 8 weeks
None of the patients lost BSCVA post CXL
Toric ICL implantation
Intraoperative - Nil
Postoperative
•Pupillary block glaucoma 1 eye, due to blockage of tiny PI which
resolved following Nd YAG laser enlargement
•Rotation of IOL requiring IOL repositioning 1 eye
•Excessive vaulting (1000 microns) 1 eye, resolved at one month postop
possibly due to trapped viscoelastic behind IOL
Discussion
• Keratoconus patients with astigmatism less than 6 diopters often have
BSCVA of > 20/40. If associated with high myopia contact lens wear
becomes necessary.
• Keratoconus is a progressive condition. CXL is effective in stabilizing
progression of keratoconus
• In our study Toric ICL implantation provides fairly accurate correction of
spherical power, & reduces astigmatism significantly to improve quality of
unaided vision in keratoconic eyes with high myopia.
• Residual astigmatism of < 1 diopter may require spectacle correction
Conclusion
• Implantation of posterior chamber toric ICL to correct
refractive error in patients with stable keratoconus appears to
be a safe & effective procedure.
• Collagen crosslinking is essential to ensure stability of
keratoconus prior to ICL implantation.
Thank You
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