Prevalence of Signs and Symptoms of Dry Eye Disease 5 to 15 After Refractive Surgery

Figures & data

Table 1 Demographics, Pre- and Postoperative Refraction and Visual Acuity

		LVC, n=94	ICL, n=80	CTRL, n=83	p
		Mean ± SD (Range)	Mean ± SD (Range)	Mean ± SD (Range)
Sex: f %		47.9%	71.2%	49,4%	0.003 ^a*
Age, years		41.3 ± 6.3 (29 to 57)	40.8 ± 8.8 (25 to 64)	41.2 ± 8.1 (23 to 56)	0.905^b
Years since treatment		7.7 ± 1.3 (5.2 to 12.8)	10.2 ± 3.1 (5.0 to 14.7)		<0.001^c
Pre-Tx	MRSE, DS	−2.76 ± 1.75 (−8.00 to +2.37)	−6.10 ± 5.16 (−17.12 to +8.00)	−1.38 ± 3.45 (−9.37 to +6.87)	<0.001^d*
	CYL, DC	−0.94 ± 0.88 (−3.50 to 0)	−1.40 ± 1.43 (−8.75 to 0)	−0.87 ± 1.20 (−7.00–0)	0.001^e*
	BCVA, (logMAR)	−0.05 ± 0.04 (−0.18 to 0.05)	0.00 ± 0.07 (−0.18 to 0.3)	−0.06 ± 0.07 (−0.18 to 0.10)	<0.001^e*
Post-Tx	MRSE	−0.07 ± 0.38 (−2.37 to +0.75)	−0.19+0.59 (−2.25 to +1.50)		0.017^f*
	CYL	−0.19 ± 0.25 (−1.0 to 0)	−0.38 ± 0.38 (−1.50 to 0)		<0.001^f*
	UCVA (logMAR)	−0.03 ± 0.12 (−0.18 to 0.70)	0.06 ± 0.16 (−0.18 to 0.7)		<0.001^f*
	BCVA (logMAR)	−0.07 ± 0.05 (−0.18 to 0.02)	−0.03 ± 0.06 (−0.18 to 0.10)		<0.001^f*

Notes: ^aPearson´s χ² test ICL difference from CTRL, ^bAnova (unequal variance), ^cWilcoxon rank-sum test between ICL/LVC, ^dKruskal–Wallis rank-sum test, ^eWilcoxon rank-sum test difference between ICL and CTRL, ^fWilcoxon rank-sum test, *Statistically significant.

Abbreviations: LVC, Laser Vision Correction; ICL, Implantable Collamer Lens; CTRL, Control group; MRSE, mean spherical equivalent refraction; CYL, refractive cylinder; BCVA, best-corrected visual acuity (logMAR); UCVA, uncorrected visual acuity (logMAR); Pre-Tx, historic data before surgery; Post-Tx, post-treatment data (study examination).

Table 2 Mean Values and Standard Deviation of Different DED Tests (Test Eye)

	LVC		ICL		CTRL		p
	Mean ± SD (Range, IQR)	n	Mean ± SD (Range, IQR)	n	Mean ± SD (Range, IQR)	n
Osmolarity test eye (mOsm/L)	311 ± 17 (281 to 383, 16)	92	305.9 ± 11 (282 to 330, 12)	80	309.7 ± 14 (290 to 370, 14)	82	0.183^a
OSI Minimum	1.1 ± 0.6 (0.2 to 3.8, 0.7)	93	1.6 ± 1.1 (0.4 to 7.6,1.1)	79	1.2 ± 0.6 (0.3 to 3.2, 0.7)	81	<0.001^b*
OSI St.d OSI Difference VBUT	0.4 ± 0.4 (0.0 to 1.8, 0.4) 1.4 ± 1.3 (0.1 to 5.5, 1.5) 9.1 ± 2.5 (0.5 to 10.0, 0)		0.4 ± 0.5 (0.0 to 2.2, 0.5) 1.8 ± 1.8 (0.2 to 9.0, 2.0) 8.4 ± 3.2 (0.5 to 10.0, 1.75)		0.2 ± 0.3 (0.0 to 2.0, 0.2) 1.1 ± 1.1 (0.1 to 6.9, 1.0) 9.1 ± 2.2 (1.0 to 10.0, 0)		0.002^b* 0.003^b* 0.054^a
OSDI	10 ± 13 (0 to 67, 8)	94	11 ± 12 (0 to 65, 15)	80	10.9 ± 10.5 (0 to 50, 14)	83	0.438
NIKBUT avg. (seconds)	17.1 ± 5.6 (4.9 to 25.0, 9.0)	91	16.8 ± 5.6 (4.5 to 25, 9.2)	77	16.8 ± 6.0 (4.7 to 25.0, 9.8)	80	0.921
Meibography (Meiboscore)	0.5 ± 0.7 (0.0 to 3.0, 0.7)	94	0.3 ± 0.5 (0.0 to 2.2, 0.4)	78	0.4 ± 0.7 (0.0 to 3.0, 0.5)	80	0.300
Schirmer 1 (mm)	13 ± 9 0 to 35, 12	94	14 ± 11 0 to 35, 15.0	76	15 ± 11 (0 to 35, 20)	82	0.968

Notes: ^aKruskal–Wallis rank-sum test. ^bWilcoxon rank-sum between ICL and CTR, *Statistically significant.

Abbreviations: SD, standard deviation; IQR, Interquartile range; LVC, Laser Vision Correction; ICL, Implantable Collamer Lens; CTRL, Control group; OSDI, Ocular Surface Disease Index; NIKBUT, non-invasive keratograph break-up time; OSI, Ocular scatter index; OSI mean, mean OSI for each patient; OSI St.d =standard deviation of OSI for each patient; VBUT (Vision break-up time), the time before an increase in OSI of 1 unit due to tear break-up.

Table 3 Prevalence of DED as Determined by Signs and Symptoms

Treatment group	LVC			ICL			CTRL
Test variable (Cut-off values)	%	n	p^a	%	n	p^a	%	n
Osmolarity (≥316 either eye or ≥8 inter-eye diff.)	73.3%	90	0.002*	46.2%	80	0.63	50%	82
VBUT (≤10 seconds)	24.7%	93	0.23	32,9%	79	0.02*	17,3%	81
OSDI (≥13)	19.1%	94	0.06	31.2%	80	.99	31.3%	83
NIKBUT avg (≤10 seconds)	12.1%	91	0.32	15.6%	77	0.75	17.5%	80
Meibography (meiboscore ≥1.5)	10.6%	94	0.68	5.1%	78	0.37	8.8%	80
Schirmer (mm wetting ≤10mm)	51.1%	94	0.76	48.7%	76	0.99	48.8%	82
OSDI and one other indicator	18.1%	94	0.55	27,5%	80	0.39	21.7%	83

Notes: ^aPearson's χ²: difference from control. *Statistically significant.

Abbreviations: LVC, Laser Vision Correction; ICL, Implantable Collamer Lens; CTRL, Control group; OSDI, Ocular Surface Disease Index; NIKBUT avg, average non-invasive keratograph break-up time; VBUT, HD analyzer Vision break up time.

Figure 1 Comparing the prevalence of DED as determined by different tests between LVC or ICL and control group.

Notes: *Pearson's χ²: difference from control group.

Abbreviations: BUT, Break-up time; OSDI, ocular surface disease index; AVG, average; ICL, Implantable collamer lens; LVC, laser vision correction.

Figure 2 Example of weak correlations, here between osmolarity and age. Several outliers are influencing the fit. The single eye osmolarity cut-off value of 316 mOsm/L is shown for reference.