Values Of Higher-order Aberrations Research Articles

Liberty® by Medicontur, a Complex in Structure, Hydrophilic Intraocular Lens in the Correction of Eyes with Preoperative Myopia

A retrospective analysis of visual function in patients with preoperatively diagnosed myopia, after implantation of Liberty® intraocular lens, including the influence of some factors like a kind of surgery, values of angle alpha and kappa, pupil size, values of higher order aberrations generated by the lens on visual acuity to far and near distances was done. Lens removal and Liberty® implantation was done 47 eyes, including in 13 patients in both eyes. In 7 eyes, it was a toric lens. A mean preoperative value of myopia was -6.72 Dsph. Cataract removal accounted for 55% of all procedures performed, the rest being Refractive Lens Exchange. Preoperative pupil size was between 3.6 and 6,4 mm. The average postoperative visual acuity to far distances was 0.13 (logMar), and to near distances was 0.51 (Snellen). Rare cases of insufficient quality of vision to intermediate distances, when the postoperative pupil size was greater than 4 mm, resolved after increasing light intensity in the room. A bigger values of higher order aberrations corresponded with lower values of preoperative visual acuity to far distances. A bigger values of angle alpha corresponded with lower values of postoperative visual acuity to far distances, which were significantly higher in cataract group. Visual acuity to far distances was also better in eye with bigger pupil size. A specific structure of the lens allows patients to see good to the near distances, even if the light intensity not perfect.

The Value of Higher Order Aberrations Generated by the Lens in Three Groups of Patients Qualified for Lens Removal

Purpose: to determine if Higher Order Aberrations generated by the lens can influence on the visual acuity, in eyes qualified to lens removal. Methods: Three groups of patients (171 eyes) who were qualified to lens removal because of diagnosed cataract, untolerated refractive error, or not yet diagnosed Congenital Lens Dysfunction were examined preoperatively for the values of Higher Order Aberrations generated by the lenses. Each patient was examined using iTrace analyser, which allows for the separation of aberrations generated by the cornea from those generated by the inside of the eye. Results: The average values were statistically the lowest in the group of patients qualified for refractive lens exchange (85 eyes), reaching the level of 0.170 μm. In this group, the natural lens was completely transparent. In the group with cataract (59 eyes) the values were statistically higher, reaching an average value of 0.350μm. In the third group with the so-called Congenital Lens Dysfunction (27 eyes) the values were the highest, reaching an average level of 1.020μm. Conclusions: As the value of aberrations generated by the inside of the eye (mainly lens) increased, visual acuity to far distances, assessed preoperatively and with best correction, deteriorated statistically.

Comparative analysis of corneal parameters between DMEK and UT‐DSAEK eyes in 3‐year follow‐up

Aims/Purpose: The aim of the study was to provide a comparative analysis of corneal parameter changes compared to their preoperative values between Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT‐DSAEK) patients.Methods: The study included 27 eyes after UT‐DSAEK and 34 eyes after DMEK. Best corrected visual acuity (BCVA), endothelial cell count (ECC), central corneal thickness (CCT), mean keratometry (MK), mean astigmatism (MA), astigmatism asymmetry (AA) and higher order aberrations (HOAs) were assessed at baseline and 1, 3, 6, 12, 24 and 36 months after the surgery.Results: Patients after DMEK had significantly better BCVA than patients after UT‐DSAEK (mean 0.9 vs. 0.6 at 24th month, respectively, p = 0.002 and 0.9 vs. 0.7 at 36th month of follow‐up, respectively, p = 0.001). From the 3rd month post operation, ECC was higher in the DMEK eyes than in the UT‐DSAEK eyes (p = 0.01). However, the groups did not differ in this parameter at 24th and 36th month of observation. In a bivariate analysis that was adjusted for age, DMEK was associated with a smaller decrease in posterior MK at the 1‐month (β = −0.49, p = 0.002), 3‐month (β = −0.50, p < 0.001), 6‐month (β = −0.58, p < 0.001) and 12‐month (β = −0.49, p < 0.001) follow‐up visits. Significant differences in MK, AA and HOA values of the posterior surface of the cornea at 12th, 24th and 36th month of observation and MA of the posterior surface of the cornea at 24th month of observation were found as well, with no differences in the total values of these parameters. Accordingly, no significant differences in changes in MA, AA or HOAs compared to the baseline values were identified between the eyes after DMEK and UT‐DSAEK at any follow‐up time point.Conclusions: UT‐DSAEK seem to be an easier and safer technique than DMEK while maintaining similar outcomes regarding irregular astigmatism and total keratometry values. Nevertheless, DMEK produces significantly better BCVA outcomes.

Influence of perfluorohexyloctane (Evotears®) on higher order aberrations

PurposeTo prospectively assess the effect of regular application of perfluorohexyloctane (F6H8; Evotears®) on the tear film lipid layer, higher order aberrations (HOA) and the repeatability of measurements in healthy eyes.MethodsThis prospective clinical study included 104 eyes treated with F6H8 four times daily for four weeks (group A) and 101 eyes that served as controls (group B). Measurements were performed with the WASCA aberrometer (Carl Zeiss Meditec GmbH, Jena, Germany). Main outcome measurement in addition to subjective refraction were the root mean square values of HOA measured before and after the intervention.ResultsRegular use of F6H8 over a period of four weeks significantly increases HOA in healthy eyes (p < 0.05). In addition, the repeatability of measurement increases after the application of F6H8.ConclusionF6H8 may be a suitable treatment option to improve the accuracy of refractive assessment, although it increases HOA. Further studies are needed to confirm the effect on HOA and the repeatability of measurement.

Corneal higher order aberrations by Sirius topography and their relation to different refractive errors

PurposeTo compare the root mean square (RMS) of anterior corneal higher-order aberrations (HOAs) in ametropic and emmetropic eyes.MethodsThis retrospective observational study was conducted at the Department of Ophthalmology, Tishreen University Hospital, Latakia, Syria. Study eyes were divided into four groups based on refractive error: mild-to-moderate myopia, hypermetropia, myopic astigmatism, and emmetropic eyes as controls. The following anterior corneal HOAs were evaluated using the Scheimpflug-Placido Sirius (CSO, Italy) tomographer over 6 mm pupil: Root mean square (RMS) total corneal HOAs, RMS trefoil, RMS coma and RMS spherical aberrations.ResultsRMS values of total HOAs, trefoil and coma showed statistically significant differences in all four groups (P < 0.05, all). HOAs were noted to be lowest in the control group (0.18 ± 0.09, 011 ± 0.08 and 0.09 ± 0.08 μm, respectively) and highest in the myopic astigmatism group (0.31 ± 0.16, 0.15 ± 0.12, 0.17 ± 0.14 μm, respectively). RMS spherical aberration was lowest in the astigmatism group (0.00 ± 0.16 μm) with a statistically significant difference from that in the control group (0.05 ± 0.07 μm, P = 0.049).ConclusionThe mean RMS values of total HOAs, trefoil and coma were highest in the astigmatism group and lowest in the control group. However, spherical aberration was minimal in the astigmatism group. A better understanding and targeted treatment of higher-order aberrations in ametropic human eyes, and in particular eyes with astigmatism, may enhance visual quality and performance in the treatment of refractive errors. Recognising atypical HOAs may also assist in the early detection of pathological conditions such as keratoconus.

Agreement between anterior segment swept source‐OCT and Scheimpflug imaging corneal aberration measurements in healthy eyes

AbstractPurpose: To assess agreement between corneal aberration measurements made through swept‐source optical coherence tomography using a new anterior segment imaging device (Anterion) and a Scheimpflug imaging device (Pentacam HR) in healthy subjects.Methods: Cross‐sectional study. In 50 eyes of 50 healthy subjects, 14 aberration parameters (7 across the anterior corneal surface and 7 across the total surface) were measured in 4 mm and 6 mm optic zones using each device: oblique trefoil (Z3_‐3), vertical coma (Z3_‐1), horizontal coma (Z3_1), horizontal trefoil (Z3_3), spherical aberration (Z4_0), root mean square (RMS) lower order aberrations (LOA) and RMS higher order aberrations (HOA). Data for the two devices were compared through intraclass correlation coefficients (ICC), paired t tests, limits of agreement (LoA) and Bland Altman plots.Results: Vertical coma was the only corneal aberration parameter that consistently showed excellent agreement (ICC &gt; 0.8, mean difference −0.019, LoA −0.165 to 0.126). Good agreement (ICC = 0.75) between the devices was observed for RMS HOA, but this was slightly worse in the 6 mm optical zone (ICC = 0.667 for anterior RMS HOA). No over‐ or underestimation trend by one or other device was noted. Agreement was poor to moderate for the rest of the corneal parameters (ICC 0.2–0.7).Conclusions: Despite good agreement overall for vertical coma and RMS HOA values, agreement for the remaining corneal aberration measurements was poor to moderate. As mean differences in our sample were overall small, in normal eyes these devices could be clinically judged as interchangeable.

Diagnostic value of corneal higher-order aberrations in keratoconic eyes.

This study aimed to investigate the diagnostic value of corneal anterior, posterior, and total higher-order aberrations in keratoconic eyes. We enrolled 94 patients (152 eyes) with mild keratoconus (Group 1), 64 patients (101 eyes) with moderate keratoconus (Group 2), and 32 patients (52 eyes) with advanced keratoconus (Group 3) according to the Amsler-Krumeich classification system; 99 healthy controls (197 normal eyes) were likewise enrolled. Anterior, posterior, and total corneal higher-order aberrations were assessed using a rotating Scheimpflug camera. The 3rd-order and 4th-order root-mean-square values were calculated for higher-order aberrations, including coma, spherical, and trefoil aberrations. Differences between keratoconic and normal eyes were analyzed using Kruskal-Wallis tests. Receiver operating characteristic curves were evaluated for the keratoconus and control groups. The differences in coma 90, coma, trefoil, and spherical aberrations, as well as 3rd-order and 4th-order root-mean-square values, were statistically significant between the keratoconus and control groups for all anterior, posterior, and corneal aberrations. The absolute values of these higher-order aberrations were higher in the keratoconus groups than in the control group and increased with keratoconus severity in Groups 1-3. Coma and 3rd-order RMS values showed excellent sensitivity and specificity for discriminating between normal and keratoconus eyes for all anterior, posterior, and corneal aberrations. Coma aberrations and 3rd-order root-mean-square values may be valuable for diagnosing keratoconus. Combining these data with topography information may enable the effective and efficient detection of keratoconus in the future.

Correlation between higher-order aberration and photophobia after cataract surgery.

Cataract surgery impinges on the spatial properties and wavelength distribution of retinal images, which changes the degree of light-induced visual discomfort/photophobia. However, no study has analyzed the alteration in photophobia before and after cataract surgery or the association between retinal spatial property and photophobia. Here, we measured the higher-order aberrations (HOAs) of the entire eye and the subjective photophobia score. This study investigated 71 eyes in 71 patients who received conventional cataract surgery. Scaling of photophobia was based on the following grading system: when the patient is outdoor on a sunny day, score of 0 and 10 points were assigned to the absence of photophobia and the presence of severe photophobia prevents eye-opening, respectively. We decomposed wavefront errors using Zernike polynomials for a 3-mm pupil diameter and analyzed the association between photophobia scores and HOAs with Spearman's rank sum correlation (rs). We classified patients into two groups: photophobia (PP) unconcerned included patients who selected 0 both preoperatively or postoperatively and PP concerned included the remaining patients. After cataract surgery, photophobia scores increased, remained unchanged (stable), and decreased in 3, 41, and 27 cases, respectively. In the stable group, 35 of 41 cases belonged to PP unconcerned. In PP concerned, there were significant correlations between photophobia score and postoperative root-mean-square values of total HOAs (rs = 0.52, p = 0.002), total coma (rs = 0.52, p = 0.002), total trefoil (rs = 0.47, p = 0.006), and third-order group (rs = 0.53, p = 0.002). In contrast, there was no significant correlation between photophobia scores and preoperative HOAs. Our results suggest that the spatial properties of retinal image modified by HOAs may affect the degree of photophobia. Scattering light due to cataracts could contribute to photophobia more than HOAs, which may mask the effect of HOAs for photophobia preoperatively.

Agreement between anterior segment swept source-OCT and Scheimpflug imaging corneal aberration measurements in healthy eyes

To assess agreement between corneal aberration measurements made through swept-source optical coherence tomography using a new anterior segment imaging device (Anterion) and a Scheimpflug imaging device (Pentacam HR) in healthy subjects. Cross-sectional study. In 50 eyes of 50 healthy subjects, 14 aberration parameters (7 across the anterior corneal surface and 7 across the total surface) were measured in 4 mm and 6 mm optic zones using each device: oblique trefoil (Z3_-3), vertical coma (Z3_-1), horizontal coma (Z3_1), horizontal trefoil (Z3_3), spherical aberration (Z4_0), root mean square (RMS) lower order aberrations (LOA) and RMS higher order aberrations (HOA). Data for the two devices were compared through intraclass correlation coefficients (ICC), paired t tests, limits of agreement (LoA) and Bland Altman plots. Vertical coma was the only corneal aberration parameter that consistently showed excellent agreement (ICC > 0.8, mean difference -0.019, LoA -0.165 to 0.126). Good agreement (ICC = 0.75) between the devices was observed for RMS HOA, but this was slightly worse in the 6 mm optical zone (ICC = 0.667 for anterior RMS HOA). No over- or underestimation trend by one or other device was noted. Agreement was poor to moderate for the rest of the corneal parameters (ICC 0.2 to 0.7). Despite good agreement overall for vertical coma and RMS HOA values, agreement for the remaining corneal aberration measurements was poor to moderate. As mean differences in our sample were overall small, in normal eyes these devices could be clinically judged as interchangeable.

Effect of Wavefront Aberrations on Night Vision Problems and Mesopic Contrast Threshold After SMILE

To investigate the effect of wavefront aberrations on night vision problems and mesopic contrast threshold after small incision lenticule extraction (SMILE). Forty-two participants (84 eyes) who underwent SMILE were included in this prospective observational study. Visual outcomes including uncorrected distance visual acuity (UDVA), subjective manifest refraction, mesopic contrast threshold (Binoptometer 4P; Oculus Optikgeräte GmbH), and higher order aberrations (HOAs) were analyzed before and 3 months after surgery. The patient's night vision satisfaction was assessed using a questionnaire. The mean spherical equivalent was -5.30 ± 1.38 diopters (D) preoperatively and -0.06 ± 0.15 D postoperatively. UDVA was better than 20/20 in 98.81% of the patients and better than 20/25 in all patients. Scores of night vision satisfaction and glare changed significantly in the postoperative period (F = 8.463, P = .001; F = 69.518, P < .001, respectively). Preoperative spherical diopters (lower order aberrations) were positively correlated with night vision satisfaction (r = -0.329, P = .041) and glare score (r =-0.332, P = .039). Age (odds ratio [OR] = 1.272, 95% CI = 1.019 to 1.589) and preoperative spherical diopter (OR = 0.437, 95% CI = 0.199 to 0.975) were correlated with night vision satisfaction scores by analysis of binary regression. The root mean square value of total HOAs increased 3 months after surgery (t = -6.873, P < .001) with an increase in horizontal coma (Z31) and spherical aberration (Z40) (P < .001). No correlation was observed between glare score and HOAs; however, patients with higher preoperative myopia demonstrated continuously decreasing contrast under mesopic conditions and higher postoperative horizontal coma. Myopic patients with higher preoperative spherical errors experienced more glare at night after SMILE surgery. Postoperative horizontal coma was associated with worse mesopic contrast thresholds. [J Refract Surg. 2021;37(7):446-452.].

Relationship between Higher Order Aberrations and Astigmatism in Hyperopic Amblyopia

Aim. To study the dynamics of changes in the values of higher order aberrations in amblyopia treatment and the correlation between higher-order aberrations and astigmatism in patients with hyperopic amblyopia.Methods. This cohort prospective study included 36 patients (36 eyes) with refractive amblyopia aged 4 to 16 years. All patients had anisometropia: emmetropia in one eye and hyperopic astigmatism combined with refractive amblyopia of varying degrees in the other eye. Patients were divided into two groups depending on the degree of astigmatism. Astigmatism greater than 1.5 D was detected in 20 patients (55.5%) and astigmatism less than 1.5 D was detected in 16 patients (44.5%). All patients underwent a complex treatment, including twenty half-hour sessions of videocomputer autotraining using “Amblyotron” device during 20 days, in addition to constant wearing of glasses. Higher order aberrations were measured using the WaveScan Wavefront System aberrometer at the first visit and at 3-, 6 - and 12-month follow-up. A correlation analysis was performed to assess the relationship between higher order aberrations and astigmatism.Results. There was a statistically significant difference in treatment success between groups with high and low astigmatism. In both groups, higher order aberrations were reduced during the treatment of amblyopia. When comparing the two groups, a significant difference in coma was found at 12-month follow-up (p = 0.043). At 12-month follow-up, coma showed a statistically significant correlation with astigmatism, and a stronger correlation with astigmatism was found in the group of patients with high astigmatism.Conclusions. In patients with refractive amblyopia associated with astigmatism, the decrease in visual acuity is directly dependent on the values of higher-order aberrations, especially on the values of coma, which should be considered as the cause of the development of amblyopia.

Evaluation of corneal safety in systemic lupus erythematosus patients undergoing long-term hydroxychloroquine treatment

Purpose The aim of this study was to examine the effects of long-term use of hydroxychloroquine (HQ) on the pachymetric, aberrometric, and densitometric values of the cornea and corneal endothelium in lupus patients. Method Twenty-two eyes (study group) of 22 patients using HQ for treatment of lupus and 25 eyes (control group) of 25 healthy individuals were included in this prospective study. A specular microscopy was used to measure corneal endothelial cell density (ECD), percentage of hexagonal cells (HEX%), coefficient of variation of the cell size (CV). Then, a Pentacam® HR corneal tomography system was used to measure central corneal thickness (CCT), corneal aberrometry values in 6-mm pupil diameters and corneal densitometry values in 6-mm corneal zones (0–2 mm and 2–6 mm). Results While ECD was significantly lower in the study group than in the control group (p = 0.034), CCT was significantly higher in the study group (p = 0.032). The higher-order aberrations values and the anterior corneal densitometry values in the 0–2 mm and 2–6 mm corneal zones in the study group were found to be significantly higher than the control group (p = 0.021, p = 0.007 and p = 0.013). Conclusion Prolonged use of HQ may cause some changes in the cornea. In the follow-up of these cases, detailed examination of the cornea as well as the macula may be important for the protection of corneal health.

Usefulness of Itrace in Diagnosing Unclear Cases of the Deterioration in Visual Acuity. Congenital Lens Dysfunction as a New Disease Entity. Preliminary Reports.

The article analyses 22 cases of severe impairment of vision to far distances for no apparent reason. Visual impairment was observed regardless of patients’ age and type of eye defect diagnosed, with the majority of people suffering from myopia and accompanying astigmatism. The exclusion of causes related to the cornea and retina, optic nerve damage and the lack of visible pathologies of the lens in the physical examination did not allow for the determination of the cause of deterioration in visual acuity to far distances despite good vision to near distances. The results of examinations using iTrace indicated the lens as the cause of visual impairment despite the apparent lack of opacity and other pathologies within it. The results of examinations in the field of Higher Order Aberration, Opacity Map, Modulation Transfer Function™ and their graphical presentation using the Dysfunctional Lens Index™ module were analysed. Low values of visual contrast sensitivity and high values of higher order aberrations for the internal optics were observed, with the correct values for the cornea. The more pathological the results of the visual contrast sensitivity and higher order aberration, the lower the values of visual acuity to far distances. In most cases removing the dysfunctional lens and replacing it with an artificial lens allowed for a significant improvement in vision to far distances while maintaining proper vision to near distances. The procedure was performed on patients over 18 years of age. The medical history in the study group may indicate a congenital nature of the abnormal structure of the lens. Thus, it is necessary to consider verification of the diagnosis made in some patients, pointing to a new disease entity, i.e. congenital lens dysfunction.

Impact of asteroid hyalosis on internal higher-order aberrations in eyes with cataract accompanied by acoustic shadows on swept-source optical coherence tomography examination.

Increased internal higher-order aberrations (HOAs) have been reported in eyes with asteroid hyalosis, which is usually asymptomatic. This report describes 2 patients with cataract and concurrent asteroid hyalosis. In the first case, internal HOAs were within the normal range, and swept-source optical coherence tomography (SS-OCT) did not show acoustic shadows. After cataract surgery, visual acuity improved and internal HOAs remained within normal limits. However, in the second case, SS-OCT revealed multiple acoustic shadows, presumably due to asteroid hyalosis, and internal HOAs increased in both eyes. After combined vitrectomy and cataract surgery, visual acuity and the internal HOA values improved in both eyes, and acoustic shadows disappeared on SS-OCT. Phacovitrectomy should be considered if the cause of visual impairment is cataract and asteroid hyalosis. Objective assessment of internal HOAs by a wavefront sensor and checking for acoustic shadows on SS-OCT might be useful in detecting this combination of ophthalmic conditions.

Comparison of wavefront aberrations in eyes with multifocal and monofocal iols before and after Nd:YAG laser capsulotomy for posterior capsule opacification.

The aim of this study was to compare wavefront aberrations before and after Nd:YAG capsulotomy in multifocal intraocular lens (MfIOL) and monofocal (MoIOL) pseudophakic eyes with posterior capsule opacification (PCO). Wavefront aberrations were measured using a ARK-10000 topographer before and after Nd:YAG capsulotomy in eyes that underwent MfIOL or MoIOL implantation and developed PCO. Total and higher-order aberrations (HOAs) values were evaluated as root mean square (RMS). The study included 64 eyes with MfIOLs (64 patients) and 72 with MoIOLs (72 patients) that developed PCO. Total RMS values before and 1month after Nd:YAG capsulotomy were 0.863 ± 0.27 and 0.504 ± 0.24 in the MFIOL group and 0.862 ± 0.31 and 0.466 ± 0.26 in the MoIOL group, respectively. Total RMS values did not differ significantly between the groups before (p = 0.914) or 1month after Nd:YAG laser capsulotomy (p = 0.357), but decreased significantly after Nd:YAG capsulotomy compared to baseline in both the MfIOL (p = 0.027) and MoIOL (p = 0.012) groups. HOA values before and 1month after Nd:YAG capsulotomy were 0.546 ± 0.23 and 0.364 ± 0.19 in the MfIOL group and 0.500 ± 0.21 and 0.346 ± 0.18 in the MoIOL group, respectively. HOA values did not differ significantly before (p = 0.828) or after Nd:YAG capsulotomy (p = 0.111), while both groups showed significant reduction in HOAs after Nd:YAG capsulotomy (MfIOL: p = 0.021, MoIOL: p = 0.027). Nd:YAG capsulotomy reduces total and HOAs to the same extent in eyes with both MfIOLs and MoIOLs, with no significant impact of the IOL design.

Higher-Order Aberrations and Axial Elongation in Myopic Children Treated With Orthokeratology.

PurposeThis retrospective longitudinal study aimed to examine the relationship between ocular higher-order aberrations (HOA) and axial eye growth in young myopic children undergoing orthokeratology (ortho-k) treatment.MethodsAxial length and ocular HOA, measured under cycloplegia annually over a 2-year period from the right eyes of myopic children, who previously completed ortho-k clinical trials, were retrieved. Linear mixed model analyses were applied to determine the association between ocular HOA, other known confounding variables (age, sex, and refractive error), and axial eye growth.ResultsData from 103 subjects were analyzed. The root-mean square (RMS) values of total ocular HOA (third to sixth orders combined), spherical ( and combined), and comatic (, , , and combined) aberrations increased by approximately 3, 9, and 2 times, respectively, after 2 years of ortho-k treatment. After adjusting for age, sex, and refractive error, higher RMS values of total HOA and spherical aberrations were associated with both longer axial length and slower axial elongation (all P < 0.01). For individual Zernike term coefficients, a higher level of positive spherical aberration () was also associated with longer axial length and slower axial elongation (both P < 0.01), after adjusting for baseline HOA.ConclusionsOrtho-k for myopia control significantly increases the Zernike coefficients and therefore the RMS values for a range of total ocular HOA terms or metrics in children. These findings suggest the potential role of HOA, particularly spherical aberration, as the possible mechanism of slowing axial elongation in ortho-k treatment.

Analysis of high-order aberrations in the eyes of elite police officers from the military police of São Paulo

Background: Recent advances in ophthalmic evaluation technology allow the measurement and quantification of high-order optical aberrations (HOAs). Several professionals have superior visual function compared to the general population. Objective: This study is to characterize the profile of HOAs in the elite police of the Sao Paulo military police. Material and Methods: This is an observational clinical study of a case series with 42 eyes of 21 patients. The objective was to compare HOAs between snipers and civilians, through assessments of visual acuity and ocular aberrometry. The patients were divided into two groups: elite and control according to their profession. The elite group had more eyes with visual acuity better than or equal to 20/15. Results: The elite group had slightly lower values of higher order aberrations: 0.26 and 0.29 in the elite group and 0.30 and 0.31 in the control group. It was possible to verify that visual acuity both with and without correction was better in patients in the Elite group, even though high-order aberrations did not present significant differences in the mean. Conclusion: It was possible to verify that visual acuity both with and without correction was better in patients in the Elite group, even though high-order aberrations did not present significant differences in the mean values.

The effects of implantable collamer lens implantation on higher order aberrations.

To evaluate the changes in higher order aberrations (HOAs) after implantable collamer lens (ICL; Staar Surgical, Nidau, Switzerland) implantation. Totally 30 eyes of 18 patients with myopia were included in this study with an average age of 25.77y (min: 21, max: 40). Refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), HOAs (entire, corneal and internal) were evaluated preoperatively and three months postoperatively. Ocular aberrations were measured by using iTrace (Tracey Technology, Houston, Texas, USA). SPSS (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp) was used for the statistical analysis and the interpretation of the data. P values of less than 0.05 were considered statistically significant. The preoperative mean spherical power was -9.01 D (min: -5.00, max: -13.00) and the mean cylindrical error was -2.40 D (min: -0.50, max: -4.75). The postoperative mean residual spherical power was -0.73 D (min: -0.20, max: -1.75) and the mean cylindrical error was -0.89 D (min: -0.18, max: -2.09). Analyses were made on root mean square (RMS) values of total HOAs (tHOAs), spherical aberration, coma and trefoil as entire, corneal and internal components. The differences in entire tHOAs and in internal tHOAs were significant. There was no significant change found in spherical aberrations. The differences in entire coma and in internal coma were significant. There was no significant change found in corneal coma. With respect to trefoil, the only significant difference was in internal trefoil. The ICL implantation corrects the refractive error successfully and changes entire and internal HOAs of the eye.

Visual Performance and High-Order Aberrations with Different Contact Lens Prototypes with Potential for Myopia Control

ABSTRACT Purpose Contact lenses (CLs) used for myopia control incorporate variable power distribution across the optic zone potentially creating degradation of the high-order aberrations. The present study aims to evaluate the retinal image quality and visual performance in three prototypes of CLs intended to control axial elongation of the eye before they are considered for clinical trials. Methods This is a non-dispensing cross-over, double-blind study where 30 right eyes of myopic subjects worn 3 multifocal test lenses and 1 monofocal control lens in random order. Lens 1 was a radial refractive gradient design (center distance) and Lens 2 and 3 center-near with an additional annular ring for near. Nominal add power was 2.00D, 1.50D, and 2.00D, respectively. Subjects had an age 21.96 ± 2.23 years [18–30] and mean spherical equivalent refraction M = −2.23 ± 1.50D [−0.75 to −5.50] with refractive astigmatism below −0.75D. Higher-order aberrations (HOA), glare formation (halo), high- and low-contrast LogMAR visual acuity (VA), and contrast sensitivity function (CSF) was measured under monocular conditions. Results All individual terms of HOA and total root mean square from 3rd to 8th order increased significantly with the 3 test lenses compared to control. Between test lenses, Lens 1 increased significantly the higher HOA compared with Lens 2 and Lens 3. Halo size was significantly larger with test lenses compared with control, with Lens 1 showing the largest. VA under high-contrast conditions was similar for all lenses. Under low-contrast conditions, Lens 1 and Lens 2 performed significantly worse than control (Bonferroni post hoc correction, p < 0.001). CSF was below normal limits with Lens 1 for 3 and 6 cpd spatial frequency but was not significantly different between test lenses and control. Conclusions Lenses with larger stabilized areas for distance vision interfere less with VA and induce lower values of HOA and image degradation.

Refractive changes after different modifications of endothelial keratoplasty

To evaluate changes in clinical refraction after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) and Descemet Membrane Endothelial Keratoplasty (DMEK), and assess their correlation to the thickness of the transplant. The main study group included 40 patients (40 eyes) after DSAEK and 20 patients (20 eyes) after DMEK, the control group consisted of 20 patients (20 eyes) without any corneal pathologies or history of surgical treatment. In addition to standard examination, patients of the main group had central corneal thickness and transplant thickness regularly measured; they were also monitored by optical coherence tomography (Optovue, U.S.A.), computed tomography and aberrometry of the cornea performed on Pentacam device. The control group had the same examination regimen. Best corrected visual acuity after 6 months was on average 0.2 higher in DMEK patients compared to those who underwent DSAEK; after one year - 0.1 higher. Clinical refraction data shows presence of hypermetropic changes after DSAEK surgery. Induced astigmatism after one year was 0.4 Diopters in DSAEK patients, but did not exceed 0.1 Diopters in DMEK patients. Stabilization of the corneal thickness in DMEK group occurred on the 3-4th month, in DSAEK group - 6-7th month. Certain values of higher-order aberrations (3-6) and root-mean-square deviation (RMS) of the wave-front of anterior corneal surface in DSAEK and DMEK groups were higher than in the control group. Aberrations on the posterior corneal surface in DMEK group were significantly lower than in DSAEK group. There were no statistically significant differences in 'final' RMS higher-order aberrations between DMEK and DSAEK groups.