Visual perception changes and optical stability after intracorneal ring segment implantation: comparison between 3 months and 1 year after surgery

Figures & data

Table 1 Comparison of sphere, cylinder, spherical equivalent and K_max 3 months and 1 year after Keraring ICRS implantation

	3 months after surgery Mean (SD)^a	1 year after surgery Mean (SD)^a	P-value
Spherical	1.81 (0.30)	1.95 (0.26)	0.2696
Cylinder	1.78 (0.18)	1.96 (0.16)	0.0144
SE	1.68 (0.21)	1.82 (0.18)	0.0752
Kmax (D)	52.64 (0.67)	52.84 (0.63)	0.4715

Notes:

a Correction within subjects was taken into account; K_max = steep keratometric value.

Table 2 Comparison between patients’ current correction 4 months and 1 year after ICRS implantation

			Correction in use 1 year after surgery				Total
			Nothing	Spectacles	Soft lenses	RGP
Correction in use 4 months after surgery	Nothing	N	6	−	−	−	6
		%	100.0%				100.0%
	Spectacles	N	2	16	−	−	18
		%	11.1%	88.9%			100.0%
	Soft contact lenses	N	2	1	1	−	4
		%	50.0%	25.0%	25.0%	0.0%	100.0%
	RGP	N	4	2	1	1	8
		%	50.0%	25.0%	12.5%	12.5%	100.0%
	Total	N	14	19	2	1	36
		%	38.9%	52.8%	5.6%	2.8%	100.0%

Abbreviations: ICRS, intra-corneal ring segment; RGP, rigid gas permeable.

Table 3 Comparison between NEI-RQL scores 4 months and 1 year after Keraring ICRS implantation

Scales	4 months	1 year after	P-value
Clarity of vision
Mean (SD)	77.6 (21.5)	67.7 (21.5)	0.008
Expectation
Mean (SD)	14.7 (23.1)	19.1 (33.2)	0.422
Near vision
Mean (SD)	81.3 (19.4)	72.3 (18.1)	0.003
Far vision
Mean (SD)	80.5 (17.0)	72.5 (19.5)	0.017
Vision fluctuation
Mean (SD)	64.4 (23.9)	60.0 (26.1)	0.364
Activity limitation
Mean (SD)	86.0 (24.3)	83.3 (21.7)	0.528
Glare
Mean (SD)	57.4 (27.2)	52.6 (29.2)	0.326
Ocular symptoms
Mean (SD)	60.6 (18.8)	57.1 (19.0)	0.165
Dependence on correction
Mean (SD)	50.6 (34.9)	53.3 (29.1)	0.491
Suboptimal correction
Mean (SD)	22.8 (29.8)	15.4 (25.6)	0.134
Worry
Mean (SD)	88.2 (19.2)	88.2 (24.2)	>0.999
Appearance
Mean (SD)	87.1 (23.0)	85.7 (23.0)	0.734
Satisfaction with correction
Mean (SD)	81.8 (19.3)	82.9 (16.4)	0.711
General scale
Mean (SD)	65.6 (13.3)	62.2 (12.8)	0.110

Abbreviations: ICRS, intra-corneal ring segment; NEI-RQL, National Eye Institute Refractive Error Quality of Life.

Figure 1 Quality of life answers for mean binocular best corrected visual acuity (BBCVA) for groups A and B.