Journal of Refractive Surgery

Original Article Supplemental Data

Determining the Potential Role of Crystalline Lens Rise in Vaulting in Posterior Chamber Phakic Collamer Lens Surgery for Correction of Myopia

Felix Gonzalez-Lopez, MD; Rafael Bilbao-Calabuig, MD, PhD, FEBO-CR; Blas Mompean, MD; Jorge Luezas, MD; Julio Ortega-Usobiaga, MD, PhD, FEBO-CR; Vasyl Druchkiv, MSc

Abstract

PURPOSE:

To assess the effect of crystalline lens rise (CLR) on postoperative vault in eyes implanted with a phakic Visian Implantable Collamer Lens (ICL) (STAAR Surgical Company, Monrovia, CA) with a central port for myopic correction.

METHODS:

Non-invasive Fourier-domain swept-source anterior segment optical coherence tomography was used for dynamic assessment of the study eyes under changing light conditions. Phakic intraocular lens (IOL) vault, anterior chamber depth (ACD), and CLR were recorded after surgery, and intra-eye differences were analyzed under scotopic and photopic ambient light conditions. Inter-group analysis and regression analysis were performed to investigate any potential correlation between these biometric variables.

RESULTS:

This retrospective observational study comprised 111 eyes (65 patients) implanted with a myopic Visian ICL. The mean change in CLR from mydriasis to miosis was 59 ± 60 µm (P < .001). The sample was further divided into four groups according to the CLR value in miosis: CLR < 0, 0 to 200, 201 to 350, and > 350 µm. A significant difference in central vault values was observed between the < 0 and > 350 µm groups, the 0 to 200 and 201 to 350 µm groups, and the 0 to 200 and > 350 µm groups (P < .05). Eyes with a high vault value (> 750 µm in mydriasis) had lower CLR values (P < .001) and higher ACD values (P < .001) than eyes with a low vault value (< 100 µm in miosis). The linear correlation observed was negative between CLR and ACD, positive between postoperative vault and ACD, and negative between postoperative vault and CLR (P < .001).

CONCLUSIONS:

CLR significantly affected anterior chamber depth and postoperative ICL vault.

[J Refract Surg. 2019;35(3):177–183.]

Abstract

PURPOSE:

To assess the effect of crystalline lens rise (CLR) on postoperative vault in eyes implanted with a phakic Visian Implantable Collamer Lens (ICL) (STAAR Surgical Company, Monrovia, CA) with a central port for myopic correction.

METHODS:

Non-invasive Fourier-domain swept-source anterior segment optical coherence tomography was used for dynamic assessment of the study eyes under changing light conditions. Phakic intraocular lens (IOL) vault, anterior chamber depth (ACD), and CLR were recorded after surgery, and intra-eye differences were analyzed under scotopic and photopic ambient light conditions. Inter-group analysis and regression analysis were performed to investigate any potential correlation between these biometric variables.

RESULTS:

This retrospective observational study comprised 111 eyes (65 patients) implanted with a myopic Visian ICL. The mean change in CLR from mydriasis to miosis was 59 ± 60 µm (P < .001). The sample was further divided into four groups according to the CLR value in miosis: CLR < 0, 0 to 200, 201 to 350, and > 350 µm. A significant difference in central vault values was observed between the < 0 and > 350 µm groups, the 0 to 200 and 201 to 350 µm groups, and the 0 to 200 and > 350 µm groups (P < .05). Eyes with a high vault value (> 750 µm in mydriasis) had lower CLR values (P < .001) and higher ACD values (P < .001) than eyes with a low vault value (< 100 µm in miosis). The linear correlation observed was negative between CLR and ACD, positive between postoperative vault and ACD, and negative between postoperative vault and CLR (P < .001).

CONCLUSIONS:

CLR significantly affected anterior chamber depth and postoperative ICL vault.

[J Refract Surg. 2019;35(3):177–183.]

Obtaining an appropriate separation between the posterior surface of the intraocular lens (IOL) and the anterior surface of the crystalline lens (ie, the distance defined as vault) is a major safety concern after implantation of a posterior chamber phakic IOL. In the case of the Visian Implantable Collamer Lens (ICL) (STAAR Surgical Company, Monrovia, CA), vault is determined to a large extent by the size of the lens. Conventionally, ICL size is estimated using the manufacturer's nomogram, which considers only two parameters: horizontal white-to-white (hWTW) corneal diameter and anterior chamber depth (ACD) measured from the corneal endothelium to the anterior lens capsule (Visian ICL Product Information: Visian ICL For Myopia. Available at http://www.accessdata.fda.gov/cdrh_docs/pdf3/p030016c.pdf). In an effort to overcome any potential errors in lens sizing, some authors have devised custom algorithms based on ocular biometric landmarks: iris pigment end to iris pigment end distance,1 horizontal sulcus-to-sulcus distance,2–4 distance between STS plane and anterior crystalline lens surface (STSL),5 the central curvature radius of the anterior surface of the lens,6 keratometry,7 anterior chamber width,8 and crystalline lens rise (CLR).8

As early as 2006, Baikoff9 defined CLR as the distance between the anterior pole of the crystalline lens and a line joining the two opposite iridocorneal angles along the horizontal corneal diameter and was the first to emphasize the non-static condition of CLR. In this regard, we recently analyzed dynamic changes in lens vaulting using a three-dimensional, high-resolution, anterior segment optical coherence tomography (ASOCT) device. We described how the iris pushes the phakic IOL down and warps the ICL during miosis, to the extent that it adapts to the posterior surface of the iris, thus decreasing the central vault. We also show how, in a synergetic opposite movement, a significant increase in CLR further reduces vault under photopic conditions. We measured these changes in vault value and proposed two new dynamic metrics: vault interval (VI) and vault range (VR).10 VI was defined as central vault values measured in maximum mydriasis and maximum miosis after light-induced changes in pupil diameter; VR was defined as the absolute difference between the two interval values.

Continuing with this line of research, the current study aims to establish precise measurements for CLR in dynamic terms and to investigate any correlations with postoperative phakic IOL vault, because this could be clinically relevant when calculating ICL size.

Patients and Methods

The sample for this retrospective observational study comprised 111 non-consecutive eyes that underwent uneventful implantation of spherical and toric central-hole phakic IOLs (Visian ICL V4c and EVO+/EVO models; STAAR Surgical Company) to treat myopia and myopic astigmatism at Clínica Baviera (Madrid, Spain). All procedures were performed by the same experienced surgeon (FG-L). All phakic IOLs are designed with a 360-µm hole in the center of the optic and the same intrinsic vaulting. The phakic IOLs are available in four sizes (12.1, 12.6, 13.2, and 13.7 mm). The choice of the phakic IOL diameter was made individually following the manufacturer's recommendations based on two measurements: the hWTW distance, measured using the Orbscan II device (Bausch & Lomb, Rochester, NY), and the ACD value, calculated using the IOLMaster 500 (Carl Zeiss Meditec, Jena, Germany) after subtracting the central corneal pachymetry value obtained using Orbscan II. The technical features of the phakic IOLs and the inclusion criteria and implantation technique have been described elsewhere.11

All patients gave their written informed consent for the surgical procedure and for the use of their personal data for medical and scientific research. The Medico-Legal Committee of Clínica Baviera approved the study. Data collection fulfilled Spanish legal requirements.

Study Outcome Parameters

A commercially available three-dimensional swept-source dynamic AS-OCT device (CASIA SS-1000; Tomey Corporation, Nagoya, Japan) was used for imaging. The built-in software “angle analysis” protocol was used to acquire an OCT video made of a sequence of frames after exposing the study eyes to extreme ambient light conditions (0.5 to 18,500 lux). The images acquired were subsequently processed by freezing the OCT frame at minimum and maximum pupil size, and the study biometric parameters were measured. Details of the analysis have been reported elsewhere.10

Intra-eye differences for CLR, ACD, and vault values obtained under scotopic and photopic light conditions were analyzed. The study sample was further divided into subgroups with high and low vault values, and an inter-group analysis was done to compare the results obtained for ACD, the distance between the endothelium and the anterior surface of the phakic IOL (ACD-ASpIOL), VR, angle-to-angle distance (ATA), pupil size, and the length of the ICL.

Regression analysis was performed to investigate potential correlations between CLR and ACD, vault, ATA, and hWTW. Potential correlations between ACD and vault were also investigated.

Statistical Methods

We included both eyes from each patient; therefore, we used statistical methods that correct for the intra-eye correlation. Normality was assessed numerically using the Shapiro–Wilk test and graphically. When the assumption of normality was met, we ran a multilevel model with the patient as a random effect and the group identifier as a predictor. In the case of non-normally distributed variables, we applied the modified Wilcoxon rank-sum test for clustered data, as discussed by Rosner et al.12 In the case of paired data, if the distribution of the differences was approximately normally distributed, we applied a multi-level model with the patient as a random effect and light conditions as a fixed effect. When the assumption of normality was not met, we used the Wilcoxon signed-rank test for paired comparisons for clustered data.13

When analyzing the correlation between any two variables, we used different regression methods depending on the regression assumptions. To improve the reliability of statistical inference, we mostly used multi-level modeling. Only the most reliable results are reported. Pseudo R2 values are also reported, combining both within and between variances compared to the null model. Note that the estimated level 2 variance can increase when adding a level 1 covariate, thus potentially producing a negative R2 value.

Data were analyzed using R Core Team (R Foundation for Statistical Computing, Vienna, Austria, 2016. https://www.R-project.org/).

Results

The study sample comprised 111 eyes (57 right) from 65 patients (40 women) implanted with spherical phakic IOLs (85) and toric phakic IOLs (26) with a central port (45 Visian ICL model V4c and 66 model EVO/EVO+). The mean age of the patients was 33 ± 6 years (range: 21 to 49 years). Eyes had a mean baseline preoperative spherical equivalent of −8.49 ± 3.67 diopters (D) (range: −1.75 to −23.13 D). Lens size was distributed as follows: 12.1 mm in 4 eyes, 12.6 mm in 36 eyes, 13.2 mm in 66 eyes, and 13.7 mm in 5 eyes. There were no significant differences between the two ICL models in terms of the preoperative variables (age, spherical equivalent, hWTW, and ACD).

Descriptive Statistics

The mean postoperative CLR value was 106 ± 176 µm (range: −247 to 575 µm) in mydriasis and 165 ± 173 µm (range: −185 to 604 µm) in miosis. The mean change in CLR from mydriasis to miosis was 59 ± 60 µm (range: 248 to −123 µm) (P < .001). A decrease in the CLR value in miosis (median: −27 µm, -range: 51 to −12 µm) was observed in 13 eyes (11.7%) from 12 patients.

The mean central vault value was 320 ± 205 µm (range: 16 to 1,083 µm) under photopic light conditions and 473 ± 247 µm (range: 63 to 1,329 µm) under scotopic conditions. The mean VR was 153 ± 73 µm (range: 8 to 366 µm). There were statistically significant intra-eye differences (P < .001) between the values measured in mydriasis and miosis for CLR, ACDASpIOL, pupil size (in the corneal and iris planes), and ATA. No differences were seen for hWTW and ACD. Table 1 shows the changes in vault and anterior chamber structures under different light conditions.

Changes in Vault and Anterior Chamber Structures Under Different Light Conditions

Table 1:

Changes in Vault and Anterior Chamber Structures Under Different Light Conditions

The sample was stratified into four groups according to CLR in miosis. Figure 1 shows the distribution of these groups. Table 2 and Figure 2 show the distribution of vault in the groups according to the CLR value. Multiple comparisons revealed statistically significant differences in vault value between the less than 0 and greater than 350 µm groups, the 0 to 200 and 201 to 350 µm groups, and the 0 to 200 and greater than 350 µm groups (P < .05) (Table 3). We estimated the slope coefficient based on the whole range of CLR, and all resulting models confirmed the significant effect of CLR. The results of the generalized least squares model without outliers and adjusted standard errors provided the most reliable equation and inference with βCLR = −0.442.

Distribution of groups according to crystalline lens rise (CLR).

Figure 1.

Distribution of groups according to crystalline lens rise (CLR).

Distribution of Vault in the CLR Groupsa

Table 2:

Distribution of Vault in the CLR Groups

Distribution of vault according to the crystalline lens rise (CLR) groups.

Figure 2.

Distribution of vault according to the crystalline lens rise (CLR) groups.

Statistical Comparisons Between CLR Groups Regarding Vaulta,b

Table 3:

Statistical Comparisons Between CLR Groups Regarding Vault

Two additional subgroups were arbitrarily created for further analysis based on the amount of their postoperative vault. The high-vault group included eyes with a vault of greater than 750 µm in mydriasis (13 eyes), whereas the low-vault group included eyes with a vault of less than 100 µm in miosis (15 eyes). We compared changes in biometric parameters under scotopic and photopic light conditions and found statistically significant inter-group differences for CLR, VR, ACD, and ACD-ASpIOL (P < .001 for all parameters, except for CLR in miosis [P = .004]). When the measurements were taken in miosis, the mean CLR and ACD were 73 ± 126 µm and 3.36 ± 0.16 mm, respectively, for the high-vault group and 352 ± 163 µm and 3.07 ± 0.17 mm, respectively, for the low-vault group. Following a similar trend, in mydriasis, the mean CLR and the ACD were −25 ± 117 µm and 3.35 ± 0.15 mm, respectively, in the high-vault group and 271 ± 149 µm and 3.07 ± 0.18 mm, respectively, in the low-vault group. Significant inter-group differences were also observed for the variables pupil size (miosis and mydriasis), phakic IOL size, and hWTW (P < .05), whereas no significant differences were observed for pupil size (corneal plane) or ATA in either miotic or mydriatic status. Analysis of the difference in CLR between miotic and mydriatic status for each group revealed no statistically significant inter-group differences (P = .584). Table 4 shows the comparison between the groups.

Comparison Between High and Low Vault Groups

Table 4:

Comparison Between High and Low Vault Groups

Regression Analysis

The scatter plots in Figure 3 show the negative linear correlation between postoperative values of CLR and ACD in miosis (P < .001) and mydriasis (P < .001) for the whole sample (n = 111).

Correlation between crystalline lens rise (CLR) and anterior chamber depth (ACD) in miosis and mydriasis. The dots represent the eyes. Eyes from the same patient are connected with a black line. Fitted lines from two regression models are shown: the red line is the fitted line using mixed effect regression modelling, which takes into account the effect intraclass correlation (ICC). The blue dashed line is the fitted line from the simple ordinary least square (OLS) regression.

Figure 3.

Correlation between crystalline lens rise (CLR) and anterior chamber depth (ACD) in miosis and mydriasis. The dots represent the eyes. Eyes from the same patient are connected with a black line. Fitted lines from two regression models are shown: the red line is the fitted line using mixed effect regression modelling, which takes into account the effect intraclass correlation (ICC). The blue dashed line is the fitted line from the simple ordinary least square (OLS) regression.

Figures AB (available in the online version of this article) represent bivariate relationships between vault and ACD, and between vault and CLR under photopic and scotopic external light conditions. These relationships are similar with respect to the distribution around the regression line, although in the first case the relationship is positive and in the second it is negative. Taking the model with CLR and improving on it by including ACD only marginally improves the prediction of the model in miosis (R2 = 0.26) and results in a nonsignificant marginal effect of ACD. In mydriasis, the improvement is slightly better (R2 = 0.28), and both variables are significant. In any case, the models suggest that CLR can be used alone to predict vaulting.

Correlation between vault and anterior chamber depth (ACD) in miosis and mydriasis.

Figure A.

Correlation between vault and anterior chamber depth (ACD) in miosis and mydriasis.

Correlation between vault and crystalline lens rise (CLR) in miosis and mydriasis.

Figure B.

Correlation between vault and crystalline lens rise (CLR) in miosis and mydriasis.

To analyze the correlation between CLR and ATA, it was necessary to select one eye randomly because of the strong intra-eye correlation (ATA ICC was 0.96 in mydriasis and 0.94 in miosis). We concluded that there was no significant correlation between CLR and ATA (Figure C, available in the online version of this article) or between CLR and hWTW (Figure D, available in the online version of this article).

Correlation between crystalline lens rise (CLR) and angle-to-angle distance in miosis and mydriasis.

Figure C.

Correlation between crystalline lens rise (CLR) and angle-to-angle distance in miosis and mydriasis.

Correlation between crystalline lens rise (CLR) and horizontal white-to-white distance (WTW) in miosis and mydriasis.

Figure D.

Correlation between crystalline lens rise (CLR) and horizontal white-to-white distance (WTW) in miosis and mydriasis.

Discussion

In the current study, we measured the dynamism of the CLR under changing light conditions and demonstrated a relationship between CLR and ACD. We also showed how both biometric parameters can influence the final postoperative vault in eyes implanted with an ICL whose size had been calculated according to the currently recommended manufacturer nomogram.

Previous studies considered the relationship between the crystalline lens and the phakic IOL. In his AS-OCT–based study, Baikoff9 was the first to highlight the potential role of the CLR as a safety criterion in phakic IOL surgery. Kojima et al.5 focused on the convexity of the anterior pole of the crystalline lens and used high-frequency ultrasound biomicroscopy (UBM) to define the STSL as a new parameter for lens sizing. Using specific imaging software on an eye scan acquired by UBM, Zheng et al.6 proposed a novel ICL sizing equation that took into account parameters such as the central curvature radius of the anterior surface of the lens value, hypothesizing that this value could predict postoperative vault better than STSL. In their AS-OCT–based research, Nakamura et al.8 recently developed the NK-formula, which included the CLR as a result of a multiple regression analysis. Although all aforementioned alternative sizing methods use different measurement techniques and to some extent consider the influence exerted on lens vault by the anterior crystalline lens curvature, none approached this dynamically or, at least, by describing the ambient lighting conditions under which measurements were taken. In our study, we demonstrated and measured the CLR values in experimentally simulated scotopic and photopic external ambient light and found a mean change in CLR values of 59 ± 60 µm from mydriasis to miosis. In miosis, the crystalline lens tends to bulge forward, and this may have a significant clinical impact because the combination of the downward push of the iris on the anterior surface of the phakic IOL, together with the forward protrusion of the crystalline lens dome (increasing CLR), results in relevant vault decrease. The extent of this vault variation, which was named VR by our group,10 reached an average value of 167 ± 70 µm in our pilot study and 153 ± 73 µm in this wider series. In addition to the above-mentioned issues, we observed a decrease in the value of CLR in miosis in 11.7% of the eyes, thus indicating an idiosyncratic aspect of each eye and further supporting the need to include the study of CLR dynamism in the estimation of ICL size.

When we compared CLR between the high-vault and low-vault subgroups, we found that it was significantly higher in both mydriasis and miosis in the low-vault group (P < .001) (Table 4). However, when we compared the dynamism of the CLR between both subgroups, which we might call the “CLR range,” we did not find statistically significant differences. In other words, in our study sample, the dynamism of the CLR had no association with vault. The fact that the lens protrudes anatomically more or less is related to the vault in eyes implanted with ICLs whose size was calculated according to the nomogram provided by the manufacturer, although there was no difference between the subgroups regarding how much the lens oscillates from mydriasis to miosis.

Other studies have highlighted the relationship between ACD and vault. Seo et al.14 investigated the effects of ACD on vault measured by UBM, showing that when the ICL diameter was selected following the manufacturer's recommendation, postoperative vault seemed to be larger than expected if preoperative ACD was also larger than normal. Using the Visante OCT and similar phakic IOLs (V4 model, without a central port), Alfonso et al.15 found comparable results. In a recent study, Lee et al.16 analyzed the preoperative factors affecting the range of optimal vaulting in a V4c model and found a significant association between postoperative vaulting and preoperative ACD. This value was the most relevant variable, with higher central vaulting observed in eyes with greater ACD. In the current research study, ACD was wider and CLR was lower in the high-vault group under both scotopic and photopic light conditions, if compared with the low-vault group. This finding is consistent with those of the previously cited studies.

The classic STAAR sizing formula, which is the most widely used, is based on two biometric parameters: hWTW and ACD. In several borderline scenarios, this algorithm proposes a different ICL size depending on the actual ACD value, with the proposed cut-off ACD value of 3.5 mm. In this regard, the correlations demonstrated between the ACD, the CLR, and postoperative vault are of considerable importance. For some hWTW values, the algorithm offers a lower lens size when the ACD is lower. Furthermore, because the CLR is also expected to be higher in these cases, as shown by their negative linear correlation, the size selected frequently results in suboptimal vault values and vice versa; in other words, when the ACD is wider, the calculated phakic IOL size is larger although the CLR tends to be lower, and this may result in a higher vault value than desired. For this reason, in our opinion, these lens size changes are ill-founded and demonstrate a significant weakness in the manufacturer's formula. In addition, we did not find any correlation between CLR and ATA and hWTW. CLR is therefore an independent variable with respect to these parameters, making it more relevant when calculating phakic IOL size.

The current study has several limitations. Biometric parameters were analyzed postoperatively; consequently, we cannot know whether the dynamic nature of CLR is influenced by the implanted phakic IOL. In addition, the potential differences between toric and spherical lenses and between the V4c phakic IOLs and EVO+ were not investigated. Nevertheless, considering that all of these phakic IOLs share the same material, size, and design-related intrinsic vault, we understand that significant differences in their dynamic vault behavior should not be expected.

The results of this study highlight important aspects for ICL sizing. To our knowledge, this is the first study to evaluate CRL and its relationship with postoperative ICL vault dynamically. Our findings underline how the anterior ocular segment is in continuous motion according to the intensity of external ambient light, which modulates the measurement of postoperative vault. Pupillary and crystalline lens dynamism are key features of this movement, where the forward protrusion of the crystalline lens dome measured as CLR should not be ignored in the clinical evaluation of vaulting. Second, the negative linear correlations demonstrated between CLR and ACD and between CLR and postoperative vault, as well as the positive linear correlations between vault and ACD, highlight the systematic error in the current conventional method for determining ICL size. Third, CLR should be considered as a calculating parameter in future ICL sizing algorithms.

Further studies that take aqueous humor fluidic dynamics and vault dynamics into account are needed to propose new safety margins for the new generation of phakic IOLs with a central port.

References

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Changes in Vault and Anterior Chamber Structures Under Different Light Conditions

ParameterMiosisMydriasisP


Range (Min/Max)Mean ± SDMedian (Q25/Q75)Range (Min/Max)Mean ± SDMedian (Q25/Q75)
ACD (endo) (mm)2.64/3.743.26 ± 0.233.26 (3.13/3.42)2.6/3.713.26 ± 0.233.25 (3.13/3.4).160a
ACD-ASpIOL (mm)1.92/3.282.74 ± 0.242.79 (2.56/2.9)1.73/3.12.56 ± 0.252.55 (2.43/2.75)< .001a
Vault (µm)16/1,083320 ± 205302 (195/406)63/1329473 ± 247463 (299/587)< .001a
Pupil size (real) (mm)1.84/52.86 ± 0.562.76 (2.51/3.03)3.26/7.385.54 ± 0.925.7 (4.93/6.14)< .001a
Pupil size (cornea) (mm)2.47/5.663.27 ± 0.673.08 (2.78/3.55)4.33/8.376.38 ± 0.986.44 (5.73/7.02)< .001a
ATA (mm)11.37/13.1212.22 ± 0.3812.28 (11.94/12.5)11.26/13.0312.15 ± 0.412.21 (11.82/12.46)< .001a
WTW (mm)10.9/12.9811.96 ± 0.4412 (11.59/12.27)11.03/12.9811.95 ± 0.4312 (11.59/12.27).990b
CLR (µm)−185/604165 ± 173148 (44/292)−247/575106 ± 17693 (−1/231)< .001a

Distribution of Vault in the CLR Groupsa

Group (µm)NMean ± SD95% Bootstrap CIsMedianQ25Q75

LowerUpper
< 0b15459 ± 250346593414328484
0 to 200b56354 ± 181309401322226413
201 to 35024240 ± 141188298214109328
> 350a,b16192 ± 21610230618348236

Statistical Comparisons Between CLR Groups Regarding Vaulta,b

Group (µm)< 0 µm0 to 200 µm201 to 350 µm> 350 µm
< 0NANANANA
0 to 2001.000NANANA
201 to 350.126.046NANA
> 350.047.0031.000NA

Comparison Between High and Low Vault Groups

ParameterHigh VaultLow VaultP


NMin/MaxMean ± SDMedian (Q25/Q75)NMin/MaxMean ± SDMedian (Q25/Q75)
Vault (miosis) (µm)13533/1,083739 ± 183687 (587/893)1516/9460 ± 2561 (45/81)< .001a
Vault (mydriasis) (µm)13758/1,329954 ± 184905 (808/1065)1563/253133 ± 49133 (95/154)< .001a
Vault range (µm)1393/366215 ± 78205 (172/257)158/19273 ± 4357 (47/95)< .001b
CLR (miosis) (µm)13−51/42573 ± 12650 (12/83)1545/604352 ± 163349 (243/466).004b
CLR (mydriasis) (µm)13−171/218−25 ± 1172 (−131/43)153/532271 ± 149245 (189/309)< .001a
CLR difference (mydriasis–miosis) (µm)13−248/9−97 ± 83−80 (−156/−24)15−194/−22−81 ± 52−77 (−108/−36).584a
ACD endothelium (miosis) (mm)133.18/3.733.36 ± 0.163.32 (3.24/3.44)152.77/3.393.07 ± 0.173.10 (2.96/3.18)< .001a
ACD endothelium (mydriasis) (mm)133.15/3.693.35 ± 0.153.32 (3.23/3.44)152.77/3.383.07 ± 0.183.10 (2.94/3.18)< .001a
ACD-ASpIOL (miosis) (mm)131.92/2.852.39 ± 0.252.36 (2.23/2.47)152.49/3.132.82 ± 0.182.83 (2.70/2.92)< .001a
ACD-ASpIOL (mydriasis) (mm)121.73/2.712.20 ± 0.252.20 (2.05/2.32)152.30/3.102.71 ± 0.212.76 (2.60/2.85)< .001a
Pupil size real (miosis) (mm)132.36/3.512.84 ± 0.362.88 (2.46/3.02)151.95/2.982.56 ± 0.302.65 (2.41/2.75).036a
Pupil size real (mydriasis) (mm)133.63/6.495.59 ± 0.965.88 (5.65/6.30)153.85/6.025.21 ± 0.685.18 (4.85/5.83).048b
Pupil size cornea (miosis) (mm)112.50/3.783.16 ± 0.413.20 (2.97/3.42)82.53/3.262.94 ± 0.252.98 (2.77/3.10).231a
Pupil size cornea (mydriasis) (mm)114.33/7.166.32 ± 0.946.44 (6.30/7.02)144.48/6.925.97 ± 0.705.90 (5.63/6.59).078b
ATA (miosis) (mm)1311.66/12.4612.07 ± 0.2612.10 (11.91/12.29)1511.46/12.7012.16 ± 0.3712.21 (11.91/12.35).831a
ATA (mydriasis) (mm)1311.51/12.3811.95 ± 0.2811.90 (11.79/12.22)1511.52/12.5312.06 ± 0.3312.22 (11.77/12.32).704a
pIOL size (mm)1312.60/13.2013.11 ± 0.2313.20 (13.20/13.20)1512.10/13.2012.69 ± 0.3612.60 (12.60/12.90).003b
WTW (Orbscan II) (mm)1311.50/12.1011.79 ± 0.1811.80 (11.70/11.90)1511.10/12.1011.59 ± 0.3011.60 (11.45/11.80).036a
Authors

From the Department of Refractive Surgery, Clínica Baviera, Instituto Oftalmológico Europeo, Spain (FG-L, RB-C, BM, JL, JO-U); the Department of Ophthalmology, Hospital Torrevieja, Alicante, Spain (BM); and the Department of Research & Development. Clínica Baviera, Instituto Oftalmológico Europeo, Spain (VD).

The authors have no financial or proprietary interest in the materials presented herein.

AUTHOR CONTRIBUTIONS

Study concept and design (FG-L, RB-C, BM, JL, JO-U, VD); data collection (FG-L, RB-C, BM, JL, JO-U, VD); analysis and interpretation of data (FG-L, RB-C, BM, JL, JO-U, VD); writing the manuscript (FG-L, RB-C, BM, JL, JO-U, VD); critical revision of the manuscript (FG-L, RB-C, BM, JL, JO-U, VD)

Correspondence: Felix Gonzalez-Lopez, MD, Clínica Baviera, Melchor Fernández Almagro, 9, 28029 Madrid, Spain. E-mail: felixbavi@hotmail.com

Received: October 02, 2018
Accepted: January 30, 2019

10.3928/1081597X-20190204-01

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