Higher-order Aberrations Research Articles

Ray-Tracing Customization in Myopic and Myopic Astigmatism LASIK Treatments for Low and High Order Aberrations Treatment: 2-Year Visual Function and Psychometric Value Outcomes of a Consecutive Case Series.

The safety and long-term efficacy of automated ray-tracing customized myopic and myopic astigmatic femtosecond laser-assisted LASIK. This consecutive case series retrospective analysis, of 20 subjects (40 eyes) treated with automated raytracing named Wavelight Plus, to include low and high order aberrations based on a three-dimensional custom virtual eye for each case-calculated from interferometry data-obtained from a single diagnostic device that also provides Hartman-Shack Wavefront and Scheimpflug tomography data. We evaluated before and after the customized LASIK procedure: visual acuity, refractive error, high order aberrations, contrast sensitivity, and psychometric post-operative visual function data. At 24 months, the comparison of the pre-operative to the post-operative refractive and visual function value changes in average were: subjective manifest refraction from -4.38 ± 2.54 diopters (D) (range -9.75 to -1.25 D) to +0.11 ± 0.19 D; subjective manifest refractive astigmatism from -0.76 ± 0.91 D (range -2.75 to 0 D) to -0.13 ± 0.16 D, corneal astigmatism from -1.16 ± 0.64 D (range -0.2 to -2.8) to -0.47 ± 0.11 D. 65% of the eyes studied demonstrated an increase of at least one line of vision, while from the same group 38% demonstrated 2 lines of increase. High order aberrations, contrast sensitivity as well as the subjective psychometric input based on the VFQ-25 questionnaire demonstrated actual improvement. This longer-term follow-up, single-arm retrospective consecutive case series documents LASIK treatment customization that appears to be safe and effective in the correction of myopia and myopic astigmatism. Markedly improved objective and subjective visual function post-operatively, underlying the potential importance of simultaneously attempting to correct high order aberrations and improving the spatial alignment of total, measured human eye optics.

The Effects of Whole-Corneal and Whole-Eye Higher Order Aberrations on the Discrepancy Between Refractive and Corneal Astigmatism in Otherwise Healthy Candidates for Refractive Surgery.

To evaluate the effect of different whole-corneal and whole-eye higher order aberrations (HOAs) on levels of axis discrepancy. This was a retrospective study including healthy candidates for refractive surgery, with one eye being randomly selected. A total of 360 eyes were included. Whole-corneal and whole-eye HOAs were measured twice with a Pentacam AXL Wave (Oculus Optikgeräte GmbH), and subjective manifest refraction was obtained. Axis discrepancy was defined as the absolute difference between Total Corneal Refractive Power flat keratometry axis and manifest refractive axis. Two multiple linear regression models that sought to explore the effect of HOAs in predicting axis discrepancy while adjusting for corneal and refractive confounders were built. Mean age was 29.1 ± 5.8 years and 63.9% of the patients were women. Mean manifest sphere and cylinder were -3.09 ± 2.36 and -1.45 ± 1.37 diopters (D), respectively. Mean cylinder axis discrepancy was 14.4 ± 14.5°. On multiple linear regression, the only variables significantly associated with axis discrepancy were corneal cylinder and corneal lower order aberrations [F(5,339) = 29.746; P < .001; adjusted R2 = 0.295]. Lower levels of corneal cylinder are by far the main contributor to astigmatism axis mismatch (ß = -1.164). There was not a single HOA, either corneal or ocular, that significantly loaded into any models. Astigmatism axis mismatch decreases rapidly with increasing levels of corneal astigmatism. Corneal and whole-eye HOAs have no role in astigmatism axis mismatch in healthy candidates for refractive surgery. [J Refract Surg. 2024;40(2):e89-e97.].

The comparison of corneal higher-order aberration and surgically induced astigmatism between the clear corneal incision and the limbus tunnel incision of posterior chamber implantable collamer lens implantation

BackgroundThis study aimed to compare the corneal high-order aberrations and surgically induced astigmatism between the clear corneal incision and limbus tunnel incision for posterior chamber implantable collamer lens (ICL/TICL) implantation.MethodsA total of 127 eyes from 73 myopic patients underwent ICL V4c implantation, with 70 eyes receiving clear corneal incisions and 57 eyes receiving limbus tunnel incisions. The anterior and back corneal surfaces were measured and the Root Mean Square of all activated aberrations (TRMS) was calculated, including higher-order aberration (HOA RMS), spherical aberration Z40, coma coefficients (Coma RMS) Z3−1 Z31, and surgically induced astigmatism (SIA). The measurements were taken preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months. In this study, the corneal higher-order aberration was estimated as the Zernike coefficient calculated up to 5th order. The measurements were taken at a maximum diameter of 6.5 mm using Pentacam.ResultsOne week after the operation, the corneal back Z31 of the clear corneal incision group was 0.06 ± 0.06, while the limbus tunnel incision group showed a measurement of 0.05 ± 0.06 (p = 0.031). The corneal back Z40 of the clear corneal incision group was -0.02 ± 0.25, compared to -0.04 ± 0.21 in the limbus tunnel incision group (p = 0.01). One month after the operation, the corneal back SIA of the clear corneal incision group was 0.11 ± 0.11, compared to 0.08 ± 0.11of the limbus tunnel incision group (p = 0.013), the corneal total SIA of the clear corneal incision group was 0.33 ± 0.30, compared to 0.15 ± 0.16 in the limbus tunnel incision group (p = 0.004); the clear corneal incision group exhibited higher levels of back astigmatism and total SIA than the limbus tunnel incision in the post-operation one month period. During the 6- month post-operative follow-up period, no significant difference in Z31, Z40, and other HOA RMS data was observed between the two groups. The total SIA of the corneal incision group and the limbus tunnel incision group were 0.24 ± 0.14 and 0.33 ± 0.32, respectively (p = 0.393), showing no significant difference between the two groups 6 months after the operation.ConclusionOur data showed no significant difference in the high-order aberration and SIA between clear corneal incision and limbus tunnel incision up to 6 months after ICL-V4c implantation.

Changes in Chord Mu (µ) Length Before and After Cataract Surgery

Aim: Comparison of chord  length, a potential marker that may gain importance especially in multifocal lens implantation, before and after phacoemulsification surgery and intraocular lens (IOL) implantation in patients with cataracts. Methods: This retrospective study included 33 eyes of 33 patients who underwent phacoemulsification surgery between December 2022 and February 2023. Corneal topography (Pentacam HR, Oculus, Wetzlar, optikgerate GmbH) was performed on each patient before and after surgery. The values obtained before and at least 3 months after surgery were compared using the Student-t test. Results: There were 18 (54.5%) males and 15 (45.5%) females among the 33 patients who participated in the study. The average age was 67.27 ± 10.93 years. The postoperative mean chord μ lenght was significantly lower than the preoperative mean chord μ lenght (p=0.002). Additionally, the mean postoperative pupil size was significantly lower than the mean preoperative pupil size (p=0.000). There is a weak positive relationship between the change in chord μ length and the change in pupil size, but this relationship is not statistically significant (p&gt;0.05). No statistically significant relationship was found between any of the other binary variables. Conclusion: Centralization is crucial in refractive surgery and multifocal IOL implantation to prevent high-order aberrations and photic phenomena. Therefore, it seems useful for surgeons to be familiar with chord μ measurements, especially regarding surgical preparation. It should be considered that changes in chord mu values may influence the development of photic phenomena. A decrease in chord mu after phacoemulsification may assist the surgeon in the preoperative decision-making process in patients at risk of photic phenomena or in patients with borderline values.

Changes in Corneal Higher-Order Aberrations and Ocular Biometric Measurements after Phacoemulsification Combined with Goniosynechialysis in Primary Angle Closure/Glaucoma Patients.

To compare corneal higher-order aberrations (HOAs), refractive error, and ocular biological parameters before and after phacoemulsification combined with goniosynechialysis (Phaco-GSL) in primary angle closure/glaucoma (PAC/PACG) patients with different axial lengths (ALs). In this prospective study, cataract patients diagnosed with PAC/PACG were categorized into two groups based on their ALs: the short AL group (AL ≤ 22.5 mm) and the normal AL group (22.5 < AL ≤ 24.5 mm). The pre- and postsurgery measurements of intraocular pressure (IOP) and best-corrected visual acuity (BCVA) were conducted at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months. Additionally, the assessments included corneal HOAs, the number of antiglaucoma medications, visual field parameters, manifest refraction, and other ocular biological parameters before surgery and at the final follow-up. Prior to surgery, the two groups exhibited no significant differences, except for AL, curvature value, and Z (4, 0) of the posterior corneal surface (all P < 0.01). Following surgery, BCVA improved, and IOP decreased significantly in both groups (P < 0.01). Both anterior and total corneal HOAs, along with Z (3, -3), increased in the two groups (all P < 0.05), with the normal AL group exhibiting a significantly greater increase in total cornea Z (3, -3) than the short AL group (P=0.047). The normal AL group also exhibited a slight tendency towards hyperopia (P < 0.01). Significant changes were observed in the visual field index and mean deviation in both groups (P < 0.05). Phaco-GSL resulted in an increased corneal HOAs, particularly trefoil, with variations based on the patient's AL. Patients with normal ALs tended to shift towards hyperopia after surgery.

The effect of pterygium on front and back corneal astigmatism and aberrations in natural-light and low-light conditions

BackgroundTo investigate the effect of different sizes of pterygium on the front and back corneal topography, refractive changes and aberrations in natural-light and low-light conditions.MethodsSixty subjects with unilateral primary nasal pterygium were enrolled in this study. All the patients’ uncorrected, best spectacle-corrected visual acuity, corneal topographic aberration data in 3 mm and 7 mm areas were collected. The pterygium size was evaluated by the slit-lamp photography and Sirius Scheimpflug Analyzer.ResultsThe front topographic astigmatism values, corneal total aberrations, and higher-order aberrations in 3 mm and 7 mm areas were higher in the pterygium group than those in the control group. The pterygium horizontal length and thickness were moderately to strongly correlated with astigmatism and RMS of aberrations, while pterygium vertical length showed no or just mild correlation with the corneal astigmatism and aberrations. Compared to the readings in 3 mm area, the front and back corneal astigmatism and aberrations were larger in 7 mm area.ConclusionsPterygium led to visual impairment by inducing astigmatism and aberrations. In low-light condition, the visual function worsened due to increased corneal astigmatism values and aberrations.

Head-mounted adaptive optics visual simulator.

Adaptive optics visual simulation is a powerful tool for vision testing and evaluation. However, the existing instruments either have fixed tabletop configurations or, being wearable, only offer the correction of defocus. This paper proposes a novel head-mounted adaptive optics visual simulator that can measure and modify complex ocular aberrations in real-time. The prototype is composed of two optical modules, one for the objective assessment of aberrations and the second for wavefront modulation, all of which are integrated into a wearable headset. The device incorporates a microdisplay for stimulus generation, a liquid crystal on silicon (LCoS) spatial light modulator for wavefront manipulation, and a Hartmann-Shack wavefront sensor. Miniature optical components and optical path folding structures, together with in-house 3D printed mounts and housing, were adapted to realize the compact size. The system was calibrated by characterizing and compensating the internal aberrations of the visual relay. The performance of the prototype was analyzed by evaluating the measurement and compensation of low-order and higher-order aberrations induced through trial lenses and phase masks in an artificial eye. The defocus curves for a simulated bifocal diffractive lens were evaluated in real eyes. The results show high accuracy while measuring and compensating for the induced defocus, astigmatism, and higher-order aberrations, whereas the MTF analysis shows post-correction resolution of up to 37.5 cycles/degree (VA 1.25). Moreover, the subjective test results show the defocus curves closely matched to a commercial desktop visual simulator.

The association between dry eye with ocular aberrations and contrast sensitivity in 60 years old people and over

Aims/Purpose: To determine the association between dry eye with higher order aberrations (HOAs) and contrast sensitivity in 60 years old people and over.Methods: This population‐based study was conducted in Tehran, the capital of Iran, using stratified multistage random cluster sampling. All participants underwent complete ocular examination including measurement of uncorrected and best‐corrected visual acuity, refraction, slit‐lamp biomicroscopy. Zywave was used for measuring HOAs aberrations. Contrast sensitivity was measured with best correction visual acuity using the CVS1000 grating charts. Schirmer and tear break‐up time (TBUT) tests were used for evaluating dry eye in participants.Results: After applying exclusion criteria, the data of 397 individuals were analysed. A total of 415 people were invited, of whom 397 (62.8%) were females. The mean age of the participants was 68.32 ± 5.49 years. After adjusting with age and sex, in the multiple regression model that the TBUT test has a direct association with spherical aberration (p = 0.017) and an inverse association with coma, trefoil and the third, fourth and fifth order aberrations (p &lt; 0.05). Schirmer test results also had a positive relationship with spherical aberration (p = 0.046) and an inverse relationship with coma, trefoil and the third, fourth and fifth order aberrations (p &lt; 0.05). Contrast sensitivity had a significant association with Schirmer test result only in spatial frequency of 3CPD.Conclusions: The results of this study indicated the association between dry eyes and HOAs, and that the TBUT and Schirmer test results are of the most important factors in this relationship. Treating dry eye, can improve HOAs and quality of vision in elderly people.

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 &lt; 0.001), 6‐month (β = −0.58, p &lt; 0.001) and 12‐month (β = −0.49, p &lt; 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.

Evaluation of Visual Outcomes, Postoperative Angle Alpha, and Angle Kappa After Implantation of Isofocal Intraocular Lenses.

To evaluate the effect of angles kappa and alpha on the visual outcomes after implantation of isofocal intraocular lens (IOL) during cataract surgery. This prospective study involved 66 eyes undergoing cataract surgery with Isopure IOLs. Exclusion criteria comprised irregular corneal astigmatism exceeding 1.0D, and ocular co-morbidities affecting visual outcomes post-surgery. Evaluation parameters included postoperative refraction, uncorrected and corrected-distance visual acuity (UDVA, CDVA), uncorrected intermediate visual acuity (UIVA), and distance-corrected intermediate visual acuity (DCIVA) at 80 cm. Additionally, postoperative angles alpha, kappa, and wavefront aberrations at a 3-mm pupil using ray tracing were assessed post-surgery at least 60 days later. Patients had a mean age of 64.48 ± 9.92 years. Mean postoperative manifest refraction spherical equivalent (MRSE) was -0.21 ± 0.27 D. Mean UDVA and CDVA were LogMAR 0.06 ± 0.04 and 0.02 ± 0.06, respectively. Mean UIVA LogMAR 0.32 ± 0.08 while mean DCIVA was LogMAR 0.29 ± 0.08. Postoperative angles kappa and alpha were 0.39 ± 0.14 mm and 0.45 ± 0.15 mm, respectively. Mean postoperative ocular RMS higher-order aberrations (HOAs) 0.23 ± 0.08. Spherical aberration, coma, and trefoil averaged 0.05 ± 0.07, 0.12 ± 0.03, and 0.07 ± 0.03, respectively. No significant correlations were observed between postoperative angle kappa and alpha with UDVA, CDVA, or HOAs. A non-significant weak positive correlation was noted between angle kappa and UIVA/DCIVA, while no correlation was found between angle alpha and UIVA/DCIVA. No substantial correlations were found between various postoperative angles kappa and alpha values and postoperative visual acuity metrics (UDVA, CDVA, UIVA, and DCIVA) or higher order ocular aberrations (including, spherical aberration, coma, and trefoil with a 3.0 mm diameter) in pseudophakic eyes implanted with isofocal intraocular lenses (IOLs).

Long Term Evaluation of Surgically Induced Astigmatism and Corneal Higher-Order Aberrations After 2.2 Mm Clear Corneal Incisions in Femtosecond Laser-Assisted Cataract Surgery: Temporal versus Superior Approach.

To assess long term changes of the surgically induced astigmatism (SIA) and corneal higher-order aberrations (HOAs) after 2.2 mm clear corneal incisions (CCIs) in femtosecond laser-assisted cataract surgery and compare them between 2 types of CCIs: temporal and superior approach. Patients received the temporal CCIs (Group A) or the superior CCIs (Group B). Outcome measures included visual acuity, manifest refraction, corneal astigmatism, SIA, flattening effect, and corneal HOAs. Correlation between postoperative corneal HOA and SIA at each follow-up were analysed. This study assessed data from 106 eyes, of which 64 in Group A and 42 in Group B. The two groups had similar postoperative visual acuity of distance, intermediate and near (all P > 0.05). SIA and corneal HOAs were significantly lower in Group A than Group B in the early postoperative period, while there was no significant difference in the late postoperative period. At 6 months after surgery, the arithmetic mean of SIA over corneal 4mm zone was 0.33 ± 0.19D for temporal incision, and 0.37 ± 0.25D for superior incision. For Group A, the correlations of HOAs and SIA persisted from 1 week to 6 months after surgery. For Group B, the changes in corneal HOAs were significantly related to the SIA at 1 week and 1 month postoperatively. This study suggested the consistency of increasing and recovering process of corneal HOAs and SIA after surgery. Compared to the superior incisions, temporal incisions might induce quicker corneal recovery and less change in SIA and corneal HOAs.

Keratoconus Treatment Using Femtosecond Laser–Assisted Innovative Intracorneal Ring–Supported Graft Surgery: A Pilot Investigation

Purpose: To investigate clinical manifestations and response to a revision in the intrastromal corneal ring and implantation technique for the treatment of severe keratoconus at two private clinics in Iran. Methods: This prospective, non-comparative clinical study included 6 eyes from 6 patients treated with a new innovative sutureless ring-supported graft insertion technique. Refractive, topographic, corneal biomechanical, and anterior aberrometry outcomes were analyzed during the 6-month follow-up. Secondary variables included corneal stiffness and confocal microscopy. Results: No intraoperative and postoperative complications occurred. Six months after implantation of the RinGraft, the ring was centered at the pupil reflex, the eye was white and quiet, and the graft was clear. The mean topographic keratometry values decreased significantly postoperatively ( P = .025). Additionally, corneal stiffness increased significantly postoperatively ( P = .004). Anterior and posterior corneal aberrometry data collected over a 5-mm diameter revealed a significant decrease in higher order aberrations, spherical aberration, primary coma, and trefoil 6 months after surgery ( P = .019). Intraocular pressure changes were significantly greater than before surgery ( P = .006). Uncorrected distance visual acuity increased from 0.96 ± 0.52 logMAR preoperatively to 0.71 ± 0.22 logMAR postoperatively ( P = .078). No statistically significant change was found in corrected distance visual acuity ( P = .0221) Conclusions: Excellent structural support and stability of the cornea were observed immediately postoperatively and 6 months after RinGraft insertion. Considering the corneal instability and asymmetry, it appears to be a possible and safe therapy option for keratoconic eyes that can be performed easily. [ Journal of Refractive Surgery Case Reports. 2024;4(1):e1–e10.]

Optimization of Ray-Tracing-Guided LASIK Outcomes: A Prospective Comparative Study of ZZ InnovEyes Strategy versus Automated Strategy.

To evaluate the effectiveness of Zhang and Zheng's InnovEyes (ZZ InnovEyes) strategy for optimizing outcomes of ray-tracing-guided laser in situ keratomileusis (LASIK) compared to the standard automated strategy. A total of 38 patients (71 eyes) undergoing therapeutic refractive surgery at Hangzhou MSK Eye Hospital were randomly assigned to the ZZ InnovEyes and automated groups using double-masked randomization. The study assessed visual acuity, refractive outcomes, and higher-order aberrations preoperatively and at 1-day, 2-week, 1-month, and 3-month follow-ups. Statistical analysis was done with Microsoft Excel and SPSS 19.0. The exposure and control groups comprised 36 and 35 eyes, respectively. The ZZ InnovEyes group demonstrated significant advantages in manifest refraction spherical equivalent (MRSE) correction compared to the automated approach group (0.13 ± 0.30 D vs 0.62 ± 0.40 D, p < 0.001), achieving 97.22% uncorrected distance visual acuity (UDVA) of 20/16 or better compared to 85.71% in the automated group at the 3-month follow-up (p = 0.08), and achieving 50.00% UDVA of 20/12.5 or better compared to 28.57% in the automated group at the 3-month follow-up (p = 0.06). Loss lines from preoperative corrected distance visual acuity to postoperative UDVA were lower in the ZZ InnovEyes group (0.00%) than the automated group (8.57%; p = 0.07). Both groups exhibited similar astigmatism corrections and higher-order aberrations. The ZZ InnovEyes strategy, which incorporates manifest and wavefront refraction for ray-tracing-guided LASIK, demonstrated superior MRSE correction and potential advantages in visual acuity outcomes compared to the standard automated strategy. This study highlights the need for ongoing optimization and research in refractive surgery. ChiCTR2300078709.

Repeatability of Corneal Aberrations and Ocular Biometry Measurements Using the Pentacam® AXL: A Cross-sectional Study

Introduction: Accurate assessment of ocular biometry and corneal aberrations for diagnosis and therapy is crucial in many clinical settings. Devices to improve the measurements of these parameters are constantly being developed. Aim: To evaluate the repeatability of ocular biometry and corneal aberrations obtained by the Pentacam® AXL in normal eyes. Materials and Methods: This cross-sectional study was conducted in the Optometry Department of King Saud Universiy, Riyadh, Saudi Arabia from September 2021 to February 2022. The study included a total of 120 eyes from 60 normally sighted adult participants whose of ocular biometry and corneal aberrations were measured three times in a single session using the Pentacam® AXL. Biometric parameters include Axial Length (AL), mean K-reading (Km), Anterior Chamber Depth (ACD), Central Corneal Thickness (CCT), and Horizontal White-toWhite Distance (HWTW). The aberrometry parameters include the most significant corneal higher-order aberrations (coma, trefoil, spherical aberration), and the Root Mean Square (RMS) of the higher-order aberrations. Repeatability was assessed using within-subject Standard Deviation (SDw), the repeatability limit (r), and the Intraclass Correlation Coefficient (ICC). Results: The current study included 120 eyes of 60 subjects with a mean age of 21±2.08 years (range: 18 to 28 years). The repeatability was good for all recorded biometric measurements, with the most repeatable being AL (r=0.028, SD=0.01). All values of ICC for biometric measurements revealed excellent repeatability, being over 0.994. In addition, coma and spherical aberrations had excellent repeatability with ICC ≥0.935, and RMS, trefoil, secondary astigmatism, and quadrafoil aberrations had good repeatability with ICC 0.938, 0.823, 0.898, and 0.827, respectively. Conclusion: The Pentacam® AXL demonstrated good repeatability for ocular biometry and corneal aberrations in healthy eyes.

Analysis of visual quality improvement after implantation of PanOptix trifocal intraocular lens in cataract patients with different axial lengths.

To assess the visual quality, both subjective and objective, of cataract patients with varying axial lengths (AL) after PanOptix trifocal intraocular lens (IOL) implantation and investigated the lens tilt and its correlation with visual outcomes. From July 2020 to June 2022, 70 patients (140 eyes) diagnosed with age-related cataracts and undergoing PanOptix implantation at Chongqing Eye and Vision Care Hospital, Aier Eye Hospital Group, were included. Patients were assigned to either the observation group (35 cases, 70 eyes with PanOptix trifocal IOL) or the control group (35 cases, 70 eyes with bifocal IOL). Patients were further subdivided based on AL into AL < 24 mm (observation group: 23 eyes; control group: 26 eyes) and AL ≥ 24 mm (observation group: 47 eyes; control group: 44 eyes). Postoperative follow-up lasted three months. Visual acuity (distant, intermediate, near), objective visual quality (Strehl ratio: SR, total eye modulation transfer function (MTF)), and visual aberrations were measured preoperatively and at 3 months post-operation. Postoperatively, all groups saw significant improvements in uncorrected distance visual acuity (UCDVA), uncorrected intermediate visual acuity (UCIVA), and uncorrected near visual acuity (UCNVA) compared to preoperative values (T0) (all P < 0.05). Notably, UCIVA was significantly better in the observation group than in the control group (P < 0.05). At three months (T1), reductions in total high-order aberration (tHOA), internal high-order aberration (iHOA), coma, and trefoil aberrations were observed in both groups compared to baseline, with more significant decreases in the observation group (all P < 0.05). Both SR and MTF cutoff showed marked improvement from T0 to T1, with the observation group experiencing greater enhancements (both P < 0.05). The defocus curve of the observation group showed a gentle slope between +0.5 D and -3.0 D, maintaining superior visual acuity compared to the control group (P < 0.05). Subjective visual quality scores at T1 were significantly higher than at T0 for both groups (P < 0.05), with patients in the observation group scoring higher than those in the control group across all AL categories (P < 0.05). Spearman correlation analysis indicated that the tilt after PanOptix trifocal IOL implantation was associated with tHOA (r = 0.273, P = 0.022), iHOA (r = 0.433, P < 0.001), Trefoil (r = 0.360, P = 0.002) and coma (r = 0.688, P < 0.001). PanOptix trifocal IOL implantation in cataract patients across different AL significantly enhances visual quality compared to bifocal IOLs, suggesting a strong case for its clinical adoption.

Wavefront characteristics in amblyopia of different etiologies in children

Forty-five patients (90 eyes) were examined. All patients were divided into five groups: 1 - with dysbinocular amblyopia; 2 - with refractive amblyopia; 3 - with anisometropic amblyopia; 4 - with relative amblyopia due to congenital myopia; 5 (control) - fellow eyes without amblyopia. Aberrometry was performed using the OPD-Scan III device (Nidek, Japan). Fixation parameters were studied on the MP-3 microperimeter (Nidek, Japan). Correlation analysis was performed using Pearson's linear correlation coefficient (r). In amblyopia associated with congenital myopia, a significant increase in corneal and internal aberrations RMS, Total HOA, astigmatism (V) (0.65±0.26; 1.01±0.31; 4.22±1.17; -2.17±0.72; 0.86±0.3, respectively; control group - 0.44±0.19; 0.58±0.27; 1.0±0.75; -0.94±0.89; 0.47±0.65) and internal spherical aberration (0.06±0.02; control group - 0.04±0.03) was found. In dysbinocular amblyopia, a significant increase in internal aberrations Trefoil (V) and Coma (H) (0.75±0.52 and 0.17±0.35, respectively; control group - 0.05±0.28 and -0.07±0.21) was found, which correlated with a decrease in fixation density in the 2° ring (r= -0.40, r= -0.41). The increased level of higher-order aberrations in amblyopia associated with congenital myopia is due to the anatomical and optical features of the eyes. The increase in internal aberrations Trefoil (V) and Coma (H) in dysbinocular amblyopia is associated with a mismatch of the optical elements of the eye due to impaired fixation, i.e., it is not the cause, but the consequence of amblyopia.

角膜高阶像差在临床中的应用

角膜高阶像差在临床中的应用

Comparison of visual quality after wavefront-guided LASIK in patients with different levels of preoperative total ocular higher-order aberrations: a retrospective study.

To compare the visual quality after wavefront-guided femtosecond LASIK (WFG FS-LASIK) in patients with different levels of preoperative total ocular higher-order aberrations to guide clinical decision-making regarding patient selection and treatment strategies. This study included 112 right eyes of 112 patients who previously underwent WFG FS-LASIK for correcting myopia and myopic astigmatism. The patients were divided into two groups based on the mean values of preoperative total ocular HOAs (0.30 ± 0.09 µm): HOA ≤ 0.3 and > 0.3 groups. The visual acuity, manifest refraction, corneal Strehl ratio (SR), root mean square (RMS) of corneal and ocular aberrations, and area under the log contrast sensitivity function (AULCSF) of both groups were compared preoperatively and at 1, 3, 6, and 12 months postoperatively. The induced ocular HOAs and coma (Δ = 1 mo - Preop) were significantly lower in the HOAs > 0.3 group than in the HOAs ≤ 0.3 group (ΔHOAs: 0.39 ± 0.19 vs. 0.29 ± 0.18 μm, t = 2.797, P = 0.006; Δ coma: 0.30 ± 0.19 vs. 0.20 ± 0.21 μm, t = 2.542, P = 0.012). In the HOAs > 0.3 group, ΔHOAs were negatively correlated with the preoperative ocular HOAs (r = -0.315, P = 0.019). In the HOAs ≤ 0.3 group, the regression equation for Δ HOAs = 0.098 + 0.053 |SE| (F = 21.756, P < 0.001). In the HOAs > 0.3 group, the regression equation for ΔHOAs = 0.534 - 1.081 HOAs + 0.038|Sphere| (F = 7.954, P = 0.001). The postoperative uncorrected distance visual acuity, spherical equivalent, corneal aberrations, SR and AULCSF of both groups were similar (all P > 0.05). Furthermore, the ocular aberrations were not significantly different between both groups at 3, 6, and 12 months postoperatively (all P > 0.05). In addition, compared with the preoperative period, the AULCSF of both groups were significantly increased in the postoperative period (all P < 0.05). The induced ocular HOAs and coma in HOAs > 0.3 group were lower. However, both groups achieved equivalent and excellent visual quality after WFG FS-LASIK. WFG FS-LASIK may provide significant visual benefits for a wider range of patients.

Remote focusing optical tweezers for 3D imaging.

We present a remote focusing optical tweezer utilizing a 4f symmetrical optical system to compensate the high-order aberration during annular light refocusing. The position of the optical trap can be adjusted beyond the range of one hundred micrometers in the axial direction by means of tuning the position of the mirror placed in the focal region of the illumination objective lens. This optical tweezer can be combined with a sectioning microscope to realize three-dimensional (3D) imaging, e.g., a confocal microscope using a single water immersion objective lens. All optical elements are placed in one side of the sample, which is very useful for application in fields such as radiation biology, where radiation or magnetism disturbance must be introduced on the other side of the sample. In the experiment, a 10 µm diameter silicon dioxide microsphere and pollen cells immersed in the water are translated along the axis using the optical tweezer and, meanwhile, the sectioning images are obtained using the confocal microscope.

Comparative Analysis of the Visual, Refractive and Aberrometric Outcome with the Use of 2 Intraocular Refractive Segment Multifocal Lenses.

To demonstrate the results of ray tracing higher- and lower-order aberrations in pseudophakic eyes with rotationally asymmetrical segment multifocal lenses, total high- and low-order aberrations, measured by root mean square value (RMS), refraction, uncorrected distance and uncorrected near visual acuity (UCDVA and UCNVA), and tear break-up time, were measured at scotopic size in 42 eyes of patients implanted with bifocal refractive Mplus15/Mplus30 IOL with +1.5 dpt near addition (42 eyes of patients implanted with Mplus15)/+3.0 dpt near addition (91 eyes of patients implanted with Mplus30), and 107 eyes of control group. No significant differences were noticed between the examined groups concerning UCDVA, UCNVA, and tear break-up time (p < 0.001). Coma and total high-order aberrations were significantly higher for the Mplus30 lens in comparison to the Mplus15 lens and the control group (Coma, Trefoil p < 0.001, Secondary Astigmatism p = 0.002). The spherical aberrations were significantly higher in the lower-addition lens (p = 0.016) in comparison to the control group and to the higher-addition lens group (p < 0.001). Both intraocular lens models were successful at reaching refractive aim, good distance, and near function with the lower higher-order aberrations for the low-addition lens.