Corneal Topographic and Aberrometric Measurements Obtained with a Multidiagnostic Device in Healthy Eyes: Intrasession Repeatability

Validation of a New Test for Measuring the Contrast Sensitivity Function (Optopad-CSF) at Near Vision

Our purpose is to develop and validate a new iPad-based contrast sensitivity (CS) test for measuring the contrast sensitivity function at near vision (Optopad-CSF). A total of 200 eyes of 100 healthy subjects (ages 17-63) were evaluated in a comparative study between the Optopad-CSF test (near vision) and the CSV-1000E test (distance vision). The agreement between tests was assessed with the index of contrast sensitivity (ICS) and the area under the curve (AUC). CS for all the spatial frequencies in both eyes showed a negative significant correlation with age, and corrected distance, and near visual acuities (r ≤ -0.512, p ≤ 0.013). A significantly lower CS was found with the Optopad-CSF test in the over-40-year-old subgroup for all the spatial frequencies evaluated compared to the below-40 subgroup (p ≤ 0.008). The mean AUC of the Optopad-CSF test (5.84) was twice that of the CSV-1000E test (2.76). The mean ICS of the Optopad-CSF (-0.019) and CSV-1000E (-0.075) tests showed similar values, both close to 0 (p = 0.3). There was a weak but significant correlation between the Optopad-CSF and CSV-1000E ICS tests (r = 0.246, p < 0.02). A range of normality for the values obtained with the Optopad-CSF test was calculated. The mean CS values in 16 bilateral cataract patients were out of the normal range for all the spatial frequencies evaluated (p < 0.001). Optopad-CSF is a valid portable system for measuring CS at near vision for five spatial frequencies, allowing the detection of age-related changes in CSF with age and CSF loss in cataracts, with no ceiling effect.

Intrasession repeatability and agreement of the anterior corneal assessment provided by a multidiagnostic device

CLINICAL RELEVANCE

Multidiagnostic systems have recently appeared on the market. Knowledge of the repeatability and validity of any instrument is mandatory before its introduction in clinical practice.

BACKGROUND

The aim of this work is to examine the intrasession repeatability of anterior pole measurements provided by the multidiagnostic device Wave Analyzer Medica 700 (WAM700) and agreement with Pentacam measurements in normal eyes.

METHODS

In the right eyes of 113 participants, three repeat measurements of central keratometry, central corneal thickness, anterior chamber depth and corneal eccentricity were made with the WAM700 and Pentacam in random order. Intrasession repeatability and agreement were determined.

RESULTS

Employing WAM700, intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth was good (ICCs ≥ 0.992; CV 0.48-0.98%), yet worse than the values obtained for the Pentacam (ICCs ≥ 0.998; CV 0-0.33%). WAM700 showed excellent intrasession repeatability when used to measure the anterior chamber depth (Sw 0.03 mm). However, the repeatability of this device was inferior for central corneal thickness (Sw 4.24 μm) and keratometry measurements (Sw < 0.21 D) and was poor for corneal eccentricity (Sw 0.07; ICC 0.908; CV 14.58%). Agreement between WAM700 and Pentacam showed a high ICC for the keratometry measurements, central corneal thickness and anterior chamber depth (>0.972) but lower for corneal eccentricity (ICC 0.762).

CONCLUSIONS

In healthy eyes, the WAM700 multidiagnostic device showed good intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth measurements. Agreement between WAM700 and Pentacam was good for the anterior chamber depth measurement. However, these instruments cannot be considered interchangeable for keratometry, central corneal thickness and eccentricity readings.

Short-Term Effect of Wearing of Extended Depth-of-Focus Contact Lenses in Myopic Children: A Pilot Study

This pseudo-experimental, prospective, and longitudinal pilot study was conducted to characterize the optical and visual changes occurring in the short-term wear of a hydrophilic contact lens (CL) based on extended focus technology (EDOF). A total of 30 eyes of 15 children (age, 6–16 years) were fitted with the EDOF CL Mylo (Mark’ennovy Care SL), performing an exhaustive follow-up for one month evaluating changes in visual acuity (VA), accommodation, binocularity, ocular aberrometry, visual quality, pupillometry, keratometry and biometry. Far and near VA with the CL improved progressively (p < 0.001), obtaining mean final binocular values of −0.08 ± 0.01 and −0.07 ± 0.01 LogMAR, respectively. There was a mean reduction in the accommodative LAG of 0.30 D (p < 0.001), without associated alterations in the magnitude of the phoria and fusional vergences (p ≥ 0.066). A controlled but statistically significant increase (p ≤ 0.005) of ocular high order aberration (HOA) root mean square (RMS), primary coma RMS, primary spherical aberration Zernike term and secondary astigmatism RMS was found with the CL wear. In conclusion, the EDOF CL evaluated provides adequate visual acuity and quality, with associated increased of several HOAs and a trend to reduction in the accommodative LAG that should be confirmed in future studies.

Near Vision Tasks and Optical Quality of the Eye

Purpose

To study the effect of near-vision reading task on optical quality of the eye when performed on a computer monitor and on printed paper, and to identify which of the two results in greater changes.

Methods

Two groups of subjects performed a 30-min reading task in two different conditions: on a computer monitor and on printed paper. Ocular, corneal, and internal wavefront aberrations (Zernike coefficients up to 6 th order), root-mean-square of low- and high-order aberrations, spherical equivalent, vectoral components of ocular astigmatism (J45 and J0), and the compensation factor between internal and corneal aberrations were measured before and after the tasks. Their changes were analyzed in each group and between groups.

Results

Statistically significant changes in wavefront aberrations and in root mean square of low- and high-order aberrations were observed in both groups which was significantly greater when the task was performed on printed paper. Partial loss of compensation mechanism and variation in spherical equivalent in a negative direction occurred after both reading tasks; however, it was statistically significant only with printed paper reading task. The vectoral components of ocular astigmatism did not show statistically significant changes in either groups.

Conclusion

Near-vision reading tasks can change the optical quality of the eye, especially when the task is performed on printed paper.

Agreement of Anterior Segment Parameters Between Schiempflug Topography and Swept-Source Optic Coherence Based Optic Biometry in Keratoconus and Healthy Subjects

PURPOSE

The aim of this study is to compare anterior segment parameters, including corneal thickness (CCT), keratometry and anterior chamber depth (ACD), and white to white corneal diameter (WTW), obtained by Pentacam Schiempflug imaging and intraocular lens (IOL) Master 700 swept-source optic coherence tomography biometry in keratoconus patients and healthy subjects.

METHODS

This prospective cross-sectional instrument agreement analysis includes 88 eyes of 50 keratoconus patients and 87 eyes of 50 healthy subjects. Biometry was performed using IOL Master 700, and topography was performed using Pentacam. The keratometry values (Kf, Ks, Km, and Kmax), ACD, WTW, CCT, axial length (AL), anterior chamber angle (ACA), and lens thickness (LT) were evaluated. Levels of agreement between devices were evaluated by Bland-Altman plots with 95% limits of agreement.

RESULTS

Intraocular lens Master 700 showed higher WTW, ACD, pupil diameter, and CCT values than Pentacam in both the keratoconus and control groups. However, there were no statistically significant differences in flat keratometry (Kf) and steep keratometry (Ks) values between the groups.

CONCLUSION

Pentacam and IOL Master 700 may be used interchangeably in normal eyes and keratoconus eyes for the measurement of keratometry values and axis; however, these two devices should not be considered interchangeable for WTW, ACD, pupil diameter, and CCT measurements in both keratoconus patients and healthy subjects.

Corneal Eccentricity in a Rural Japanese Population: The Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS)

PURPOSE

To determine normal corneal eccentricity in a rural Japanese population and to examine factors associated with eccentricity value.

METHODS

This used data from the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS) project between 2009 and 2012. Residents of Minamiaizu and Tadami in Fukushima, Japan, who were aged 40 years or over, were invited for a comprehensive eye examination. For 1371 patients with no history of internal eye surgery, corneal eccentricity was measured using a Pentacam.

RESULTS

Of 1371 people recruited to the study, 1215 (1215 eyes) met the inclusion criteria. The overall mean eccentricity was 0.46 (SD = 0.18; range, -0.85 to 0.88). Corneal eccentricity was significantly associated with age, spherical equivalent, pupil diameter, anterior chamber angle, anterior chamber volume, and central corneal thickness, but not with gender or body mass index.

CONCLUSIONS

In this study, the normal cornea in this Japanese population was prolate. Corneal eccentricity was likely to decrease with increasing age. Also, spherical equivalent and other anterior segment parameters had an influence on corneal eccentricity. Corneal eccentricity measurements might be helpful in the diagnosis of corneal diseases and in calculations for intraocular lens implantation and corneal refractive surgery.

Contrast sensitivity and higher-order aberrations in Keratoconus subjects

This study analyzes the relationship between contrast-sensitivity and higher-order aberrations (HOA) in mild and subclinical-keratoconus in subjects with good visual-acuity (VA). Keratoconus group (including subclinical-keratoconus) and controls underwent autokeratometry, corneal-tomography, autorefraction and HOA measurement. Contrast-sensitivity was tested using a psychophysical two-alternative forced-choice Gabor patches in three blocks (6, 9, 12 cycles/deg). Controls were compared to the keratoconus group and to a keratoconus subgroup with VA of 0.00 LogMar group ("keratoconus-0.00VA"). Spearman correlation tested association between HOA and contrast-sensitivity. Twenty-two keratoconus subjects (38 eyes: 28 keratoconus, 10 subclinical-keratoconus, 20 keratoconus-0.00VA) and 35 controls were included. There was a significant difference between control and keratoconus, and between control and keratoconus-0.00VA, for keratometry, cylinder, thinnest and central corneal thickness (p < 0.001). Controls showed lower HOA and higher contrast-sensitivity for all spatial-frequencies (p < 0.001). Most HOA were negatively correlated with contrast-sensitivity for all spatial-frequencies for keratoconus group and for 9 and 12 cycles/deg for keratoconus-0.00VA. Keratoconus subjects with good VA showed reduction in contrast-sensitivity and increased HOAs compared to controls. HOA and contrast-sensitivity are inversely correlated in subjects with mild keratoconus despite good VA. This suggests that the main mechanism underlying the decreased vision quality in keratoconus is the increase of HOA.

Relationship between Axial Length and Corneo-Scleral Topography: A Preliminary Study

The main objective of the current study was to investigate further the relationship of the overall length of the eye with a great variety of anterior segment parameters, including scleral geometry. A total of 64 eyes of 32 participants with ages from 12 to 52 years were included in this prospective non-randomized single-center study. All participants underwent a complete eye examination, including an analysis of corneo-scleral shape with a Fourier-domain profilometer. A strong negative correlation was found between axial length and temporal-nasal ocular sagittal height difference for different chord lengths. For the right eye, a consistent and stable linear model was obtained to predict the axial length from the spherical equivalent, the corneal diameter, the high-order aberrations root mean square, and the minimum sagittal height for 13- and 14-mm chord. For the left eye, a model was obtained to predict the axial length from the spherical equivalent and the mean corneal curvature, including other parameters such as corneal diameter or high-order aberrations, depending on the chord length, considered for estimating the sagittal height values. More studies with larger samples are needed to confirm these preliminary outcomes.

Repeatability of non-invasive break-up time measures with a new automated dry eye platform in healthy eyes

PURPOSE

To evaluate the intrasession repeatability for non-invasive break-up time (NIBUT) and tear meniscus height (TMH) measurements provided by a new multi-diagnostic platform, and to assess the interobserver reproducibility of TMH measures.

METHODS

Twenty-one healthy eyes of 21 patients (age, 23-65 years) were enrolled. A complete eye examination was performed in all cases with the VX120+ device (Visionix-Luneau Technologies), including an analysis with the new Dry Eye module, performing three consecutive measurements. The within-subject standard deviation (S_w) and Bland-Altman plots were used to assess intersession repeatability. Differences between examiners for TMH were also analysed.

RESULTS

No statistically significant differences were found between repeated measures of NIBUT (time associated with the first break) and TMH (p > 0.05). However, significant differences were found for NIBUT50% (time associated with half of breaks of the tear film) (p < 0.05). Mean S_w was 0.9 s, 1.4 s and 0.05 mm for NIBUT, NIBUT50% and TMH, respectively. Ranges of agreement between consecutive measures were below 3.5 s and 4.5 s for NIBUT and NIBUT50%, respectively, and below 0.16 mm for TMH. Furthermore, no significant differences were found between examiners in TMH measure, with an inter-examiner range of agreement of 0.12 mm.

CONCLUSIONS

The new dry eye platform of the VX120+ platform evaluated provides objective automated measures of NIBUT and TMH, with acceptable level of intrasession repeatability for clinical screening purposes.

Validation of corneal topographic and aberrometric measurements obtained by color light-emitting diode reflection topography in healthy eyes

PURPOSE

To evaluate the intrasession repeatability of anterior corneal topographic and aberrometric measurements provided by a color-LED topographer as well as their interchangeability with those provided by a Scheimpflug-based system in healthy eyes.

METHODS

Thirty-five healthy eyes of 35 patients (age, 16-66 years) were enrolled. A complete eye examination was performed in all cases including a complete corneal analysis with the Scheimpflug-based system Pentacam (Oculus Optikgeräte) (one measurement) and the Cassini system (i-Optics) (three consecutive measurements). Intrasession repeatability of the Cassini measurements was assessed with the within-subject standard deviation (S_w) and the intraclass correlation coefficient (ICC). The Bland-Altman analysis was used to evaluate the agreement between both devices.

RESULTS

Mean S_w for keratometric readings was 0.02 mm (ICC ≥ 0.992), ranging between 0.16 and 0.05 D (ICC 0.930-0.978) for anterior and total astigmatic measurements. Mean S_w for asphericity and corneal diameter were 0.06 (ICC 0.926) and 0.03 mm (IC 0.997), respectively. Aberrometric parameters showed ICCs ≥ 0.816, except for Z₄² (ICC 0.741) and Z₄⁴ (ICC 0.544). When comparing devices, statistically significant differences were found for most of topographic and aberrometric data (p ≤ 0.044). Likewise, ranges of agreement between devices were clinically relevant (keratometry > 0.06 mm; total astigmatic components > 0.69 D; asphericity 0.35; second-, third-, and fourth-order Zernike terms, more than 0.20, 0.13, and 0.01 μm, respectively).

CONCLUSIONS

Consistent anterior corneal topographic, total corneal astigmatic, and aberrometric measurements are obtained with color-LED topography in healthy eyes, which are not interchangeable with those provided by the Scheimpflug-based topography.

Comparison of corneal curvature parameters obtained from two different instruments-Pentacam and VX120

AIM

To explore whether the same corneal curvature parameters and anterior chamber depth measured by Pentacam and VX120 have a good consistency and can replace each other.

METHODS

This study enrolled 140 eyes of 70 patients ranging in age from 19 to 53y. All eyes underwent a comprehensive ophthalmologic examination including an anterior segment analysis with the VX120 system (Visionix-Luneau Technologies, Chartres, France) and Pentacam (Oculus Optikgerate GmbH) respectively. The comparison on corneal curvature parameters was done between Pentacam and VX120 using clustered signed rank test; the interclass correlation coefficients (ICC) with 95% confidence intervals (CI) was calculated for each parameter between Pentacam and VX120; the Bland-Altman plot of each parameter was supplemented.

RESULTS

The anterior corneal curvature measured by VX120 was Ks: 44.00±1.78 D, KsAt: 89.45±22.18, Kf: 42.84±1.58 D, KfAt: 93.91±79.34; which measured by Pentacam was Ks: 43.80±1.82 D, KsAt: 91.17±21.40, Kf: 42.61±1.64 D, KfAt: 91.16±78.69. There was statistical difference between Pentacam and VX120 for anterior corneal curvature parameter (P<0.001). The posterior corneal curvature measured by VX120 was Ks: -6.42±1.23 D, KsAt: 91.00±23.45, Kf: -5.85±1.24 D, KfAt: 95.93±79.11; which measured by Pentacam was Ks: -6.44±0.32 D, KsAt: 92.24±11.75, Kf: -6.01±1.05 D, KfAt: 74.43±80.64. There was statistical difference between Pentacam and VX120 for posterior corneal curvature parameters (P<0.001). Anterior chamber depth (ACD) measured by Pentacam and VX120 was statistically different. Pentacam and VX120 achieved high consistency only on corneal anterior surface, including Ks and Kf. The ICCs were 0.96 (95%CI: 0.95, 0.97) and 0.95 (95%CI: 0.94, 0.97) respectively. For other corneal surface curvature parameters, all ICCs of between Pentacam and VX120 were below 0.87. Bland-Altman plots indicated of low consistency of corneal surface curvature parameters measured by Pentacam and VX120.

CONCLUSION

The corneal curvature parameters and anterior chamber depth measured by Pentacam and VX120 were statistically different. Data measured by Pentacam and VX120 is not suggested to replace each other, mixing data measured by Pentacam and VX120 together is not suggested either.

Interchangeability of corneal curvature and asphericity measurements provided by three different devices

AIM

To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles.

METHODS

A total of 40 eyes of 40 patients with a mean age of 34.1y were included. In all cases, a corneal curvature analysis was performed with IOL-Master (IOLM), iDesign 2 (ID2), and Sirius systems (SIR). Differences between instruments for flattest (K1) and steepest (K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity (Q) between SIR and ID2 were also evaluated.

RESULTS

Mean differences between devices for K1 were 0.20±0.21 (P<0.001), -0.12±0.36 (P=0.046) and -0.32±0.36 D (P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33 (P<0.001), -0.08±0.43 (P=0.265) and -0.39±0.38 D (P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance (0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis (26.68°, 33.83° and 18.37°, P≥0.121) and for Q between SIR and ID2 (0.16, P<0.001).

CONCLUSION

The keratometric corneal power, astigmatic axis and asphericity measurements provide by the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.

Intrasession Repeatability and Intersession Reproducibility Measurements Using VX120 Multidiagnostic Unit

OBJECTIVE

The VX120 multidiagnostic unit is a multidiagnostic instrument that combines several functions: autorefraction, keratometry, corneal topography, aberrometry, pachymetry, and noncontact tonometry. The purpose of this study was to determine the intrasession repeatability and the intersession reproducibility of all parameters measured by the VX120 multidiagnostic unit in a sample of normal healthy eyes.

METHODS

Three repeated measurements in the right eye of the volunteers were taken with VX120. Repeatability of the sphere, cylinder, axis, anterior corneal powers (K flat and K steep, 3-mm pupil), high- and low-order aberration root mean square (HOA-RMS and LOA-RMS, 3-mm pupil), eccentricity, white-to-white (WTW), anterior chamber depth (ACD), and central corneal thickness (CCT) (2-mm central) was analyzed. Within-subject SD (Sw), precision, repeatability, coefficient of variation (CV), and the intraclass correlation coefficient (ICC) were calculated.

RESULTS

The CV was low for K flat and K steep, WTW, ACD, and CCT with a range from 0.34% to 1.16%. The CV was higher for sphere, cylinder, HOA-RMS, and LOA-RMS and eccentricity with a range among 6.92% to 54.24%. The ICC showed high values in all parameters except in HOA-RMS (0.720-0.776) and eccentricity (0.889) in first session with moderate agreement. Comparing the intrasession repeatability of first and second session, statistically significant differences (P<0.01) were found between both sessions just to the CV for all parameters (except cylinder values) measured with VX120. However, nonstatistically significant differences (P>0.13) were found for Sw, precision, and repeatability values.

CONCLUSIONS

The VX120 multidiagnostic unit provides repeatable measurements in anterior corneal power (K flat and K steep), WTW, ACD, and CCT. However sphere, cylinder, HOA-RMS, LOA-RMS, and eccentricity showed worse repeatability. Intersession reproducibility showed good results with little differences between sessions in healthy subjects.

Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120)

BACKGROUND

The VX120 (Visionix Luneau, France) is a novel multi-diagnostic platform that combines Hartmann-Shack based autorefraction, Placido-disk based corneal-topography and anterior segment measurements made with a stationary-Scheimpflug camera. We investigate the agreement between different parameters measured by the VX120 with accepted or gold-standard techniques to test if they are interchangeable, as well as to evaluate the repeatability and reproducibility.

METHODS

The right-eyes of healthy subjects were included in the study. Autorefraction of the VX120 was compared to subjective refraction. Agreement of anterior segment parameters was compared to the Sirius (CSO, Italy) including autokeratometry, central corneal thickness (CCT), iridiocorneal angle (IA). Inter and intra-test repeatability of the above parameters was assessed. Results were analyzed using Bland and Altman analyses.

RESULTS

A total of 164 eyes were evaluated. The mean difference between VX120 autorefraction and subjective refraction for sphere, spherical equivalent (SE), and cylinder was 0.01±0.43D, 0.14±0.47D, and -0.26±0.30D, respectively and high correlation was found to all parameter (r>0.75) except for J₄₅ (r=0.61). The mean difference between VX120 and the Sirius system for CCT, IA, and keratometry (k1 and k2) was -3.51±8.64μm, 7.6±4.2°, 0.003±0.06mm and 0.004±0.04mm, respectively and high correlation was found to all parameter (r>0.97) except for IA (r=0.67). Intrasession repeatability of VX120 refraction, CCT, IA and keratometry yielded low within-subject standard deviations. Inter-session repeatability showed no statistically significant difference for most of the parameters measured.

CONCLUSIONS

The VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability.

The normal distribution of corneal eccentricity and its determinants in two rural areas of north and south of Iran

Purpose

The aim of this study was to determine the distribution of corneal eccentricity (E-value) in a normal population and to examine related factors.

Methods

In this cross-sectional study, two villages were selected in Iran using multistage cluster sampling. Selected persons were invited to have a comprehensive eye examination. Examinations in each village were performed at a specific location under standard conditions. After testing for vision and refraction and conducting the slit-lamp exam, E-value was measured with Pentacam.

Results

Of the 3851 selected individuals, 3314 participated in the study. After applying the exclusion criteria, data from 2610 subjects was used in the analysis for this report. Mean E-value was 0.53 [95% confidence interval (CI): 0.52 to 0.54]. E-value was not significantly different between males and females. Mean E-value reduced with age from 0.60 in subjects aged 6–20 years to 0.47 in subjects older than 70 years. The hyperopic group of participants had significantly lower E-value than myopic and emmetropic ones (P < 0.001). The relationship of E-value with age, gender, and other anterior segment variables and spherical equivalent was examined in a multiple linear regression model. In multiple linear regression model, age (coef = −0.003), spherical equivalent refraction (coef = −0.005), pupil diameter (coef = 0.018), anterior chamber volume (coef = −0.001), and anterior chamber angle (coef = 0.003) significantly correlated with E-value.

Conclusions

The results of this study showed that the cornea in normal populations is prolate, and the degree of prolateness varies by age, such that older age is associated with a less prolate cornea. This study showed that factors such as age and refractive errors and anterior chamber indices influence the E-value.

Intrasession repeatability of refractive and ocular aberrometric measurements obtained using a multidiagnostic device in healthy eyes

PURPOSE

To evaluate the intrasession repeatability of refractive and ocular aberrometric measurements obtained using a new multidiagnostic device in healthy eyes.

PATIENTS AND METHODS

A total of 107 eyes of 107 patients, age ranging from 23 to 65 years, were enrolled in this study. A complete eye examination was performed in all eyes, including an ocular examination using the VX120 system. Three consecutive measurements were obtained using this device to assess the intrasession repeatability of different refractive and ocular aber-rometric parameters. The within-subject standard deviation (S_w), intrasubject precision (1.96×S_w), and intraclass correlation coefficient (ICC) were calculated.

RESULTS

S_w and intrasubject precision for refractive data were below 0.12 and 0.20 D, respectively, in all cases. The ICC ranged from 0.947 for the J₄₅ power vector component to 0.997 for the sphere. Concerning aberrometric measurements S_w and intrasubject precision values were below 0.05 µm and 0.10 µm, respectively. Likewise, the ICC ranged from 0.805 for the quadrafoil root mean square to 0.954 for the primary spherical aberration. Poor correlations were found between most of the refractive parameters and their S_w (-0.033≤r≤0.053, p≥0.064). Moderate and significant positive correlations were found between the magnitude of the aberrometric parameters evaluated and their S_w (r≥0.446, p<0.001).

CONCLUSION

The new multidiagnostic device evaluated is able to provide consistent measurements of refraction and ocular aberrations in healthy eyes. Future studies should confirm if this consistency is also observed in highly aberrated eyes.