Fyodorov Eye Microsurgery Complex, Moscow, Russia Calibrated Vacuum Ring for Intrastromal Corneal Ring Segment Implantation in Different Types of Keratectasia K. Takchidi, B. Malyugin, S. Izmaylova, I. Latipov, S. Avramenko

Intracorneal ring segment Scientific Experimental Production Plant, Fyodorov Eye Microsurgery Complex, Russia Arc length – 160º Arc length – 160º Cross-section – hemisphere Cross-section – hemisphere Inner diameter – 5.0 mm Inner diameter – 5.0 mm Outer diameter – 5.6 mm Outer diameter – 5.6 mm Thickness range – 0.15 – 0.45 mm Thickness range – 0.15 – 0.45 mm Material - PMMA Material - PMMA

Classical Ferrara method Post-op “Leakage effect”

Our method of implantation Implantation of 1 segment Implantation of 1 segment 80% of corneal thickness 80% of corneal thickness Incision doesn’t depend on meridian (steep, flat) Incision doesn’t depend on meridian (steep, flat) ICRS should cover the most ectatic area ICRS should cover the most ectatic area Implantation of 1 segment Implantation of 1 segment 80% of corneal thickness 80% of corneal thickness Incision doesn’t depend on meridian (steep, flat) Incision doesn’t depend on meridian (steep, flat) ICRS should cover the most ectatic area ICRS should cover the most ectatic area

Total: 65 patients (68 eyes) 1 st group – II stage keratoconus (40 eyes) 2 nd group – III stage keratoconus (18 eyes) 3 rd group – pellucid marginal degeneration (4 eyes) 4 th group – post-Lasik keratectasia (6 eyes) mfage 1 st group ±7 2 nd group ±8 3 rd group 31 29±2 4 th group 34 24±3

Calibrated Vacuum Ring (CVR)

UCVA and BCVA dynamic in 4 groups :

Pre-op 1 mon post-op 2 mon post-op OCT Visante

Pachymetry dynamic

pre-op post-op

Confocal microscopy pre-op post-op

Our results: Single ICRS implantation into the area of maximal corneal ectasia showed satisfactory orthopedic and functional result Single ICRS implantation into the area of maximal corneal ectasia showed satisfactory orthopedic and functional result Best functional results gained patients with II stage keratoconus and post-Lasik keratectasia Best functional results gained patients with II stage keratoconus and post-Lasik keratectasia Single ICRS implantation into the area of maximal corneal ectasia showed satisfactory orthopedic and functional result Single ICRS implantation into the area of maximal corneal ectasia showed satisfactory orthopedic and functional result Best functional results gained patients with II stage keratoconus and post-Lasik keratectasia Best functional results gained patients with II stage keratoconus and post-Lasik keratectasia

Our results : The use of new device – CVR helps to fix the eye properly, precisely mark corneal zones, ease tunnel formation and segment insertion that lead to reduction of surgery duration The use of new device – CVR helps to fix the eye properly, precisely mark corneal zones, ease tunnel formation and segment insertion that lead to reduction of surgery duration Final conclusion should be based on further observation Final conclusion should be based on further observation