Extrusion of Femtosecond Laser-Implanted Intrastromal Corneal Ring Segments in Keratoconic Eyes: Prevalence, Risk Factors, and Clinical Outcomes

Table 1

Refractive changes in all eyes comparing the eyes with extrusion with eyes of no extrusion and pre- and postimplantation of ICRS.

	Eyes with ring extrusion (n = 7)		Eyes with no extrusion (n = 326)		value of preimplantation values in both groups	value of postimplantation values in both groups
	Preimplantation	Postimplantation	Preimplantation	Postimplantation
Sphere	7.1 ± 3.2	4.8 ± 2.1	8.2 ± 2.8	5.2 ± 2.1	0.53	0.44
Cylinder	6.5 ± 1.7	3.3 ± 1.9	6.1 ± 2.1	4.1 ± 1.4	0.35	0.43
UCVA (logMar)	1.2	0.8	1.2	0.7	0.93	0.81
BSCVA (logMar)	0.8	0.6	0.8	0.6	0.32	0.27
Thinnest CT (μm)	404	401	405	402	0.63	0.56
Max K (D)	61.1	56.3	61.7	57.2	0.23	0.33

UCVA, uncorrected visual acuity; BSCVA, best spectacle corrected visual acuity; CT, corneal thickness; K, keratometry.