Intracorneal ring segments followed by collagen cross-linking and PRK for treatment of keratoconus A Iovieno, MD; ME Légaré, MD; DS Rootman, MD Department of Ophthalmology – Toronto Western Hospital University of Toronto Authors have no financial interest

Keratoconus Bilateral, non-symmetric and non-inflammatory corneal ectasia often leading to progressive visual deterioration At early stages visual defect can be managed with spectacles or contact lenses (CL), while advanced disease often requires intracorneal ring implantation, lamellar or penetrating keratoplasty Corneal collagen cross-linking (CXL) is a recently developed technique that retards or halts the progression of keratoconus, with a minimal effect on visual acuity Refractive surgery, with the exception of topographic- guided PRK treatments in selected cases, is contraindicated in patients with keratoconus Raiskup-Wolf et al, 2008; Lin et al, 2008;

Combined procedures CXL and intracorneal ring placement have been successfully combined in previous studies Superior results were obtained by performing corneal ring placement first followed by CXR The association of CXL and topographic-guided PRK treatments has also shown interesting results Performing PRK and CXL the same day was found to be more effective than sequential treatments Coskunseven et al, 2009; Kymionis et al, 2009; Kanellopoulos 2007, 2009

Aim Evaluate the effect of combining intrastromal ring implantation followed by same day CXL and PRK in patients with keratoconus

Methods 4 patients/5 eyes (5 M, mean age: range: 33-55) were included in our study Inclusion criteria: progressive keratoconus (changes in refraction and/or corneal topography in the last 6 months), CL intolerance and central corneal thickness ≥ 450 μm First, intracorneal stromal rings (Intacs©) placement was performed using a femtosecond laser (Intralase©). Average time between Intacs© and CXL/PRK: 21 ± 8.6 months.

Methods Then, patients underwent standard PRK and CXR procedure on the same day Undercorrection of the sphere and the cylinder was planned in order to minimize tissue ablation (< 50 μm) Follow-up: 5.9 ± 2.4 months Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), mean refractive spherical equivalent (MRSE), mean K, steepest K, were recorded at baseline, last follow-up before PRK/CXR, 3 months and 6 months after PRK/CXR.

Results 1.09 ± 0.25 vs ± 0.21 (p<0.01) ± 0.19 vs – 0.02 ± 0.18 (p<0.05)

44.37± 2.75 vs ± ± 3.11 vs ±3.26

MRSE and cylinder: good accuracy of PRK treatment MRSE CYL -1.9 ± 1.39 vs 0.31 ± 1.33 (p<0.05)

First visitAfter IntacsAfter PRK/CXR

First visitAfter IntacsAfter PRK/CXR

Conclusions Intracorneal rings placement followed by same day PRK/CXL has shown promising preliminary results in correction of keratoconus patients The use of topographic-guided treatments (not available in our facility) may result in more predictable and accurate ablation patterns Limited accessibility of corneal transplant (tissue availability) pushes towards newer strategies for vision rehabilitation in keratoconus Longer follow-up and a larger number of patients are needed to confirm our data.