Inter-Eye Vault Differences of Implantable Collamer Lens Measured Using Anterior Segment Optical Coherence Tomography

Figures & data

Figure 1 Study protocol. The figures of excluded subjects due to missing or non-suitable exams resulted from data that had been collected in clinical practice and had errors not compatible with research purposes. In seven eyes, upon placement of the ICL with the haptics oriented horizontally the lenses were rotated to the vertical meridian due to excessive vaulting.

Abbreviations: ACD, anterior chamber depth; ATA, horizontal anterior angle distance; CLR, crystalline lens rise; ICL, implantable collamer lens; ICL SE, ICL spherical equivalent; KC, central keratometry

Figure 2 (A) Preoperative measurements for the right and left eye using the AS-OCT chamber calliper. (B) Postoperative measurements Vault and Pupil diameter using linear callipers.

Abbreviations: ACD, anterior chamber depth; ATA, horizontal anterior angle distance; CCT, central corneal thickness; CLR, crystalline lens rise.

Table 1 Sample’s Demographic Summary After Similarity Control Between Fellow Eyes (n=109). The Values are Represented by the Mean, Standard Deviation and Range

Parameter	Spherical		Toric
N	75		34
Gender (M/F)	20/55		14/20
Age (years)	32.2 ±7.6 (18–50)		30.1 ±6.2 (21–45)
Preoperative RX	RE	LE	RE	LE
Sphere (DS)	−9.88 ± 4.50 (−20.5 - −2.25)	−9.84 ± 4.31 (−20.5 - −2.50)	−8.26 ±3.58 (−16.00 - −3,75)	−8.03 ±3.49 (−16.50 - −3,50)
Cylinder (DC)	−0.68 ± 0.60 (−2.00–0.00)	−0.75 ± 0.58 (−2.00–0.00)	−2.73 ±0.99 (−5.50 - −1.50)	−2.88 ±0.81 (−5.00 - −1.75)
Preoperative BCVA (decimal VA)	0.84 ± 0.40 (0.4 −1.0)	0.82 ± 0.37 (0.1 −1.0)	0.81 ±0.41 (0.4 −1.0)	0.77 ±0.40 (0.3 −1.0)
Endothelial Cell Count (cells/mm^2)	2838 ± 376 (2091–3583)	2851 ± 357 (2113–3600)	2854 ± 362 (2123–3633)	2827 ± 368 (2057–3568)
Postoperative Follow-Up (weeks)	15 (8–25)		15 (8–25)

Abbreviations: BCVA, best corrected visual acuity; DS, dioptre spherical; DC, dioptre cylinder; VA, visual acuity.

Table 2 Pre- and Postoperative Anatomical and Lens Parameters After Control Between Fellow Eyes (n=109). Right Eye, Left Eye and Inter-Eye Differences (ΔE) Represented by the Mean, Standard Deviation and Range; Intraclass Correlation Coefficient (ICC) Presented with 95% Confidence Intervals

Total Number of Cases (n=109)
Parameter	Preoperative						Postoperative
	ATA (mm)	ACD (mm)	CLR (µm)	CCT (µm)	KC (D)	ICL SE (D)	Vault (µm)	Pupil (mm)
Right Eye	12.15±0.43 (11.1–13.12)	3.30±0.29 (2.80–4.28)	101.8±210.8 (−470 – +600)	533.6±39.4 (430.1–630.4)	43.9±1.7 (39.0–48.7)	−10.77±3.69 (−18.00– −3.00)	664.2±322.8 (0–1580)	5.59±1.01 (3.12–7.58)
Left Eye	12.14±0.44 (11.1–13.04)	3.31±0.30 (2.80–4.31)	0.10±0.21 (−510 – +650)	529.8±37.9 (430.9–651.3)	44.0±1.9 (38.3–48.1)	−10.90±3.60 (−18.00– −3.00)	638.1±333.1 (0–1580)	5.50±1.11 (3.09–7.91)
ΔE	0.01±0.15 (−0.34–0.33) p>0. 500*	−0.01±0.07 (−0.13–0.14) p>0. 500*	−0.01±0.07 (−170 – 150) p>0. 500*	4.74±15.88 (−39.2–41.4) p>0. 500**	−0.04±0.36 (−0.8–1.2) p>0. 500*	0.11±0.59 (−1.00– +1.00) p>0. 500**	26.5±122.1 (−250–350) p>0. 500**	0.09±0.69 (−3,61–1.48) p=0.384**
ICC 95% CI	0.94 (0.92–0.96)	0.98 (0.96–0.98)	0.94 (0.91–0.96)	0.90 (0.88–0.92)	0.98 (0.97–0.99)	0.99 (0.98–0.99)	0.93 (0.89–0.95)	0.79 (0.71–0.85)

Notes: Signs used in inter-eye difference (ΔE) comparison with zero: One-sample T-test (*) and One-sample Wilcoxon Test (**).

Abbreviations: ACD, anterior chamber depth; ATA, horizontal anterior angle distance; CCT, central corneal thickness; CLR, crystalline lens rise; ICL SE, implantable collamer lens spherical equivalent; KC, central keratometry.

Figure 3 (A) Bland-Altman plot, continuous line represents the mean inter-eye vault difference and the dashed line the limits of the 95% CI of the inter-eye differences. (B) Histogram of the inter-eye vault differences.

Figure 4 Association between average horizontal compression (HC= ICL Size – ATA) and absolute inter-eye vault differences.

Figure 5 Absolute inter-eye vault differences for all cases and divided in three vault ranges (average RE and LE vault) groups, low: <250 µm, intermediate: [250, 750] µm and high >750 µm. Box edges represent the limits of the 25% and 75% quartile, lines inside the boxes represent the median and the whiskers the 2.5 and 97.5% percentiles.

Table 3 Cumulative Percentage of Absolute Inter-Eye Vault Differences. Considering (Average RE and LE Vault) Low Vault <250, Intermediate 250 to 750 µm and High Vault >750 µm

	Inter-Eye Vault Differences (µm)
Cumulative Percentage	± 20	± 40	± 100	± 160	± 220	± 280	>280
All (n=109)	13.9%	30.6%	53.7%	77.8%	89.8%	99.1%	100%
Low vault (n=7)	42.6%	57.1%	71.5%	100%	100%	100%	100%
Intermediate vault (n=71)	12.6%	33.8%	62.0%	81.7%	91.5%	98.6%	100%
High vault (n=31)	6.5%	12.9%	32.3%	58.1%	83.9%	100%	100%