Evaluation of Visual Outcomes in Patients With Aberrated Corneas Implanted With the IC-8 Small-Aperture IOL.

PURPOSE: To assess the visual outcomes in patients with cataract implanted with a small-aperture intraocular lens (IOL) in eyes with aberrated corneas. METHODS: This prospective, non-interventional, single-center clinical study was conducted at Singapore National Eye Centre, Singapore. Twenty-one patients with aberrated corneas had IC-8 IOL (Bausch & Lomb, Inc) implantation. An aberrated cornea was defined as from natural causes: keratoconus (n = 1, 4.8%), high coma (n = 2, 9.5%), corneal scar (n = 1, 4.8%), or iatrogenic causes: keratorefractive procedure (n = 17, 86%). Uncorrected and corrected visual acuities were measured at distance (600 cm) (UDVA and CDVA), intermediate (66.7 cm) (UIVA and CIVA), and near (40 cm) (UNVA and CIVA). Defocus curve was tested monocularly and binocularly. Contrast sensitivity (CS) was measured under photopic and mesopic conditions with and without glare. RESULTS: In IC-8 eyes, the mean ± standard deviation UDVA, UIVA, and UNVA was 0.24 ± 0.18, 0.19 ± 0.18, and 0.14 ± 0.14 logMAR, respectively. Mean CDVA, CIVA, and CNVA in IC-8 eyes was 0.12 ± 0.17, 0.16 ± 0.15, and 0.19 ± 0.13 logMAR, respectively. Binocular mean UDVA, UIVA, and UNVA was 0.07 ± 0.10, 0.07 ± 0.10, and 0.13 ± 0.12 logMAR, respectively. Defocus curve testing yielded a depth of focus of 1.50 D monocularly and 2.00 D binocularly at a 0.2 logMAR threshold. Photopic binocular CS with and without glare improved over monocular CS of IC-8 and fellow eyes under all spatial frequencies. Mesopic binocular CS with and without glare were similar among monocular IC-8 and fellow eyes across spatial frequencies. Most patients reported low levels of visual symptoms. CONCLUSIONS: The IC-8 IOL provides good monocular and binocular visual outcomes for patients with cataract who had aberrated corneas. [J Refract Surg. 2024;40(10):e716-e723.].

Statistical Model of Ocular Wavefronts With Accommodation.

Purpose: The purpose of this study was to determine the minimum number of orthonormal basis functions, applying Principal Component Analysis (PCA), to represent the most wavefront aberrations at different accommodation stages. The study also aims to generate synthetic wavefront data using these functions. Methods: Monocular wavefront data from 191 subjects (26.15 ± 5.56 years old) were measured with a Hartmann-Shack aberrometer, simulating accommodation from 0 diopters (D) to 5 D in 1 D steps. The wavefronts for each accommodative demand were rescaled for different pupil sizes: 4.66, 4.76, 4.40, 4.09, 4.07, and 3.68 mm. PCA was applied to 150 wavefront parameters (25 Zernike coefficients × 6 accommodation levels) to obtain eigenvectors for dimensional reduction. A total of 49 eigenvectors were modeled as a sum of 2 multivariate Gaussians, from which 1000 synthetic data sets were generated. Results: The first 49 eigenvectors preserved 99.97% of the original data variability. No significant differences were observed between the mean values and standard deviation of the generated and original 49 eigenvectors (two one-sided test [TOST], P > 0.05/49) and (F-test, P > 0.05/49), both with Bonferroni correction. The mean values of the generated parameters (1000) were statistically equal to those of the original data (TOST, P > 0.05/150). The variability of the generated data was similar to the original data for the most important Zernike coefficients (F-test, P > 0.05/150). Conclusions: PCA significantly reduces the dimensionality of wavefront aberration data across 6 accommodative demands, reducing the variable space by over 66%. The synthetic data generated by the proposed wavefront model for accommodation closely resemble the original clinical data.

Optical phase nullification partially restores visual and stereo acuity lost to simulated blur from higher-order wavefront aberrations of keratoconic eyes.

Contrast demodulation and phase distortions are exaggerated in retinal images blurred by the higher-order wavefront aberrations of keratoconic eyes. While the performance loss from the former parameter is well understood, little is known about the impact of the latter on visual functions in this disease condition. The present study investigated the impact of phase distortions on the monocular logMAR visual acuity, letter discriminability and random-dot stereoacuity of seventeen visually healthy adults (ten for visual acuity and letter discriminability; ten for stereoacuity and three common to both experiments) using images that were computationally blurred by four different higher-order wavefront aberration profiles of keratoconic eyes that showed significant distortions in the phase spectrum. Participants viewed these images through 2 mm artificial pupils to negate their native ocular wavefront aberrations. The results showed progressive losses in visual acuity and stereoacuity with increasing blur, a third of which could be recovered following phase nullification. Letter discriminability also improved following phase nullification, more so for smaller than larger optotypes. Stereoacuity loss and, consequently, its recovery following phase nullification was more prominent for profiles simulating unilateral asymmetric keratoconus than for profiles simulating bilateral symmetric keratoconus. These results agree with previous reports obtained from blur induced with lower-order aberrations and indicate that a similar trend may be observed for more complex patterns of blur like keratoconus. Overall, both contrast demodulation and misalignment of the local features of the blurred image may contribute to losses of spatial and depth vision in keratoconus. Phase nullification may partially mitigate these losses, thereby allowing the processing of finer spatial details and veridical disparity estimations for improved depth perception.

Spherical Aberration Changes in Patients With Early Presbyopia Wearing Aspheric Multifocal Soft Contact Lenses in South Korea.

OBJECTIVES: The aim of this study was to evaluate the impact of wearing center-near (CN) and center-distance (CD) multifocal contact lenses (MFCLs) on spherical aberrations and visual acuity in patients with early presbyopia. METHODS: Fifty participants with early presbyopia wore CN-MFCLs and CD-MFCLs for 1 week. The average corrected refractive power was -2.65±1.67 D. Spherical aberration was measured using an auto-refractor after 1 week of lens use. RESULTS: No significant difference in overall visual acuity was observed when using either lens. Participants favored CD-MFCLs for distance vision and CN-MFCLs for near vision. This study highlighted variations in aberration and satisfaction based on age, refractive errors, and individual responses. Patients with positive spherical aberrations tended to benefit from CN-MFCLs, which improved both distance and near vision, although additional correction was required for clear distance vision. Patients with early presbyopia generally preferred CN-MFCLs when positive aberration was prevalent, whereas those with negative aberration reported greater satisfaction with distance vision when wearing CD-MFCLs. CONCLUSIONS: This study confirmed that wearing MFCLs leads to changes in spherical aberration and visual acuity in patients with early presbyopia, particularly when positive aberration prevails. Future research should investigate these effects across different stages of presbyopia.

Comparison of Objective and Subjective Visual Outcomes Between Pentafocal and Trifocal Diffractive Intraocular Lenses.

PURPOSE: To compare the clinical and aberrometric outcomes obtained with a new diffractive pentafocal intraocular lens (IOL) and a diffractive trifocal IOL. METHODS: Patients bilaterally implanted with the pentafocal Intensity SeeLens IOL (Hanita Lenses) (n = 30) and the trifocal FineVision POD F IOL (PhysIOL) (n = 30) during cataract surgery were studied after 1 month for refraction, visual acuity, defocus curve, contrast sensitivity, Hartmann-Shack aberration, and double-pass aberration. The Quality of Vision (QoV) questionnaire was used to evaluate visual comfort. RESULTS: Distance and near visual acuities were similar with the two IOLs, but distance-corrected intermediate visual acuity was better with the Intensity IOLs (0.03 ± 0.04 vs 0.11 ± 0.04 logMAR in the FineVision eyes, P < .01). The difference between objective and subjective refraction was more myopic for the Intensity IOL (-1.15 vs -0.29 diopters [D]). The defocus curve was flatter with the Intensity IOL. Contrast sensitivity was similar in both IOLs. Hartmann-Shack aberration and double-pass aberration were similar, but the modulation transfer function cut-off value was worse with the Intensity IOL: 11.6 ± 2.7 vs 15.3 ± 4.9 (P < .01). QoV scores were better with the Intensity IOL, in particular for glare, halos, and starburst. CONCLUSIONS: In this comparative series, the pentafocal Intensity IOL provided better intermediate vision and better defocus curve than the FineVision IOL, with comparable distance and near vision. The optical disturbances as reported by the patients were higher with the FineVision IOL. Additional studies will better define the aberration profile obtained with the pentafocal IOL. [J Refract Surg. 2024;40(9):e604-e613.].

Repeatability of a Combined Adaptive Optics Visual Simulator and Hartman-Shack Aberrometer in Pseudophakic Eyes With and Without Previous Corneal Refractive Surgery.

PURPOSE: To evaluate the intrasession repeatability of wavefront aberrations obtained by a combined adaptive optics visual simulator and Hartman-Shack aberrometer in pseudophakic eyes with and without previous corneal refractive surgery. METHODS: Three consecutive measurements were performed in one eye of each individual. Total ocular aberrations were recorded up to the 5th Zernike order for a 4.5-mm pupil. Repeatability was assessed by calculating the within-subject standard deviation (Sw), the repeatability limit (R), and the intraclass correlation coefficient (ICC). Vector analysis was performed to assess astigmatism variability between scans. RESULTS: The study enrolled 32 normal individuals and 24 individuals with a history of refractive surgery. In normal and eyes that had previous refractive surgery, respectively, the Sw values were 0.155 and 0.176 diopters (D) for sphere and 0.184 and 0.265 D for cylinder. The Sw values for all 3rd order terms ranged from 0.037 to 0.047 µm in normal eyes and 0.044 to 0.063 µm in eyes that had previous refractive surgery. The Sw for primary spherical aberration was 0.020 µm in normal eyes and 0.026 µm in eyes that had previous refractive surgery. ICC values for measurements of astigmatism yielded larger variability (ICC = 0.751 and 0.879). However, both groups demonstrated excellent repeatability (ICC > 0.9) for root mean square higher order aberrations (RMS-HOA) and total RMS values. CONCLUSIONS: In pseudophakic eyes, the adaptive optics Hartmann-Shack device demonstrated acceptable repeatability for measurement of sphere and 3rd and 4th order HOAs with higher variability for astigmatism measurements, especially in eyes with a prior history of corneal refractive surgery. [J Refract Surg. 2024;40(9):e645-e653.].

Comparison of long-term changes in the effective optical zone following SMILE and FS-LASIK for moderate and high myopia.

BACKGROUND: Visual quality after corneal refractive surgery is linked to the postoperative effective optical zone (EOZ). This study aims to compare long-term changes in the EOZ following small incision lenticule extraction (SMILE) and femtosecond laser-assisted in-situ keratomileusis (FS-LASIK) for moderate and high myopia. METHODS: This study included 42 patients (72 eyes) who underwent either SMILE (36 eyes) or FS-LASIK (36 eyes). A custom software program based on the tangential curvature difference map of the Pentacam HR (Oculus Optikgeräte GmbH) was used to define the EOZ at 3 and 7 years postoperatively. The EOZ, its chronological changes compared to the programmed optical zone (POZ), and the corneal wavefront aberrations following SMILE and FS-LASIK were analyzed. Correlations between the EOZ changes and relevant parameters were evaluated. RESULTS: Three years postoperatively, EOZ following SMILE and FS-LASIK were 5.13 ± 0.27 mm and 4.70 ± 0.24 mm (P < 0.001), respectively. Seven years postoperatively, EOZ following SMILE and FS-LASIK decreased to 5.03 ± 0.28 mm and 4.63 ± 0.23 mm (P < 0.001), respectively. At postoperative 7 years, the percentages of EOZ/POZ were negatively correlated with Q-value changes (ß = -5.120, P = 0.009) following SMILE and positively correlated with the cylinder correction (ß = 1.184, P = 0.004) following FS-LASIK. The induced spherical aberrations in the SMILE group were less than those in the FS-LASIK group (P < 0.05) and were negatively correlated with the EOZ/POZ (ß = -16.653, P < 0.001). CONCLUSIONS: The EOZ following SMILE was larger than that following FS-LASIK in the long postoperative term for moderate and high myopia. Furthermore, a continual reduction in the EOZ was noted after both surgical modalities.

Higher Order Aberrations in Patients with Unilateral Nasolacrimal Duct Obstruction.

PURPOSE: To compare corneal higher order aberrations (HOAs) in patients with epiphora caused by unilateral primary acquired nasolacrimal duct obstruction (PANDO) and their fellow eyes. METHODS: A total of 122 eyes of 61 patients with unilateral PANDO were included. Affected eyes were named as group 1 and contralateral eyes as group 2. The Munk score and fluorescein dye disappearance test (FDDT) were assessed. Corneal topographic and HOAs measurements were taken by Sirius topography. RESULTS: There were 47 female and 14 male patients. The mean keratometry was 43.84 ± 1.4 in group 1 and 43.96 ± 1.4 in group 2 (p = 0.73). The mean corneal topographic astigmatism was 0.81 ± 0.7 in group 1 and 0.78 ± 0.5 in group 2 (p = 0.57). The mean coma-like aberration was 0.19 ± 0.2 in group 1 and 0.10 ± 0.1 in group 2 (p = 0.03). The mean spherical-like aberration was 0.16 ± 0.1 in group 1 and 0.11 ± 0.1 in group 2 (p = 0.04). The mean total corneal HOA was 0.30 ± 0.5 in group 1 and 0.23 ± 0.2 in group 2 (p = 0.04). The mean Munk score was 3.47 ± 1.0 in group 1. There was a positive correlation between the Munk score and both coma-like aberration (r = 0.53, p = 0.003) and total corneal HOAs (r = 0.44, p = 0.010). The mean FDDT grade was 2.60 ± 0.1 in group 1. A positive correlation was observed between the FDDT grade and both coma-like aberration (r = 0.48, p = 0.001) and total corneal HOAs (r = 0.33, p = 0.001). CONCLUSIONS: Epiphora in patients with PANDO can affect corneal HOAs. As patients' symptoms and tear pooling were increased as corneal HOA levels increased.

Corneal aberrations are associated with low-energy meniscus injuries.

BACKGROUND: Visual impairment can cause balance problems. Therefore, visual impairment caused by an increase in corneal deviations can lead to sudden and unstable loads in the lower extremities. We aimed to investigate the possible relationship between low-energy meniscal injuries and corneal structural measures. METHODS: This prospective, observational study included individuals aged between 18-40 years with a normal body-mass index. The study group consisted of 54 patients with grade 2 or 3 meniscus injuries after low-energy activity. The control group consisted of 54 healthy individuals without any complaints in the knee joint. The corneal parameters of all participants were evaluated with a Scheimpflug corneal topography and specular microscopy device. Simulated keratometry (SimK), minimum central corneal thickness (MCCT), cylindrical diopter (ClyD), corneal volume (CVol) spheric aberrations (SphAbb), high-order aberration (HOA), coma values, and endothelial parameters were recorded. RESULTS: The research and control groups were similar in terms of age, body mass index, and gender distribution. There was no significant difference between the groups in the corneal SimK and CylD, parameters. However, HOA, Coma, SphAbb, and cell variability (Cv) values were significantly higher in the study group, and contrarily MCCT, CVol, and endothelial count (Cd) values were significantly lower. CONCLUSIONS: Our findings suggest that individuals with relatively lower MCCT values tend to develop meniscal damage after low-energy activity. Hence, the loss of corneal strength in these patients may be a sign of possible weakness in the meniscus. The HOA value above 0.26, the coma value above 0.16, and the SphAbb value above 0.1 may significantly increase the possible meniscus injury.

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

Purpose: 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. Methods: 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. Results: 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). Conclusions: 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.

Comparison of Objective Visual Quality Following SMILE and SmartPulse Technology-Assisted TransPRK at a 1,050-Hz Ablation Frequency for Moderate-to-High Myopia.

PURPOSE: To compare the objective visual quality of moderate-to-high myopia corrected by small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (TransPRK) at a 1,050-Hz ablation frequency, assisted by Smart-Pulse technology (SCHWIND eye-tech-solutions). METHODS: This study involved 123 patients (123 eyes) with moderate-to-high myopia between July 2020 and January 2021. They were categorized into the SMILE group (67 patients, 67 eyes) and the TransPRK group (56 patients, 56 eyes). Follow-ups were conducted at 6 months postoperatively to record the logarithm of the minimum angle of resolution visual acuity, and the Strehl ratio and higher order aberrations were measured using the Sirius anterior segment analysis device (SCHWIND eye-tech-solutions) under a 6-mm pupil diameter at various postoperative intervals. RESULTS: At 1 week and 1 month postoperatively, the uncorrected distance visual acuity (UDVA) in the SMILE group was superior to that in the TransPRK group (P < .05 for both). At 1 week and 1 month postoperatively, the Strehl ratio value in the SMILE group was higher than that in the TransPRK group (P < .05 for both). At 1, 3, and 6 months postoperatively, coma was greater in the SMILE group than in the TransPRK group (P < .05 for all). Spherical aberrations were lower in the SMILE group than in the TransPRK group at 3 and 6 months postoperatively (P < .05). At 6 months postoperatively, UDVA was -0.09 ± 0.08 and -0.11 ± 0.05 logMAR in the SMILE and TransPRK groups, respectively, which exceeded their preoperative corrected distance visual acuity of -0.05 ± 0.04 and -0.09 ± 0.08 logMAR (all P < .001). Compared with preoperative values, the Strehl ratio, total higher order, coma, and spherical aberration differences were significantly increased postoperatively in both groups (all P < .001). CONCLUSIONS: Both surgical methods improved UDVA and each had its advantages. The visual quality of SMILE was superior at 1 week and 1 month postoperatively (Strehl ratio values were higher than those of the TransPRK group), and its spherical aberration was lower than that of the TransPRK group at 3 and 6 months; TransPRK with SmartPulse technology with a 1,050-Hz ablation frequency showed that coma was significantly lower than that of the SMILE group at 1, 3, and 6 months postoperatively. [J Refract Surg. 2024;40(7):e490-e498.].

Comparison of clinical outcomes of a corneal wavefront- and topography-guided platforms for laser in situ keratomileusis on virgin eyes: an expanded cohort study.

PURPOSE: To compare the clinical outcomes of myopiacorrected with corneal-wavefront-guided (CWG) laser in situ keratomileusis (LASIK) with AMARIS 1050S (SCHWIND eye-tech-solutions GmbH & Co. KG) and corneal-topography-guided (CTG) LASIK with WaveLight EX500 (Alcon Laboratories, Fort Worth, TX). METHODS: In this prospective, pseudo-randomized expanded cohort study, a total of 266 patients were subjected to binocular LASIK surgery, either with WaveLight EX500 (WaveLight group) or Amaris 1050S (AMARIS group) platforms. Data related to right eyes were selected for analysis. Corneal higher-order aberration (HOA) was selected as the primary endpoint; while visual acuity and refraction were the secondary endpoints. All the endpoints were assessed at 3 months postoperatively. RESULTS: There were 134 eyes in the AMARIS group and 132 eyes in the WaveLight group. After 3 months of postoperative follow-up, spherical and coma aberrations were significantly lower (P < 0.05) in the WaveLight group (spherical aberration: - 0.104 ± 0.199 µm; coma aberration: - 0.117 ± 0.202 µm) in comparison with the AMARIS group (spherical aberrations: 0.254 ± 0.146 µm; coma aberrations: 0.316 ± 0.297 µm). In the AMARIS group, 96.3% of the eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 while in the WaveLight group, 96.2% of the eyes achieved an UDVA of 20/20. Furthermore, the mean postoperative manifest refraction spherical equivalent (MRSE) was - 0.02 ± 0.28 in the AMARIS group and - 0.05 ± 0.21 in the WaveLight group (P = 0.34). CONCLUSIONS: Both WaveLight EX500 and Amaris 1050S LASIK showed excellent refractive and visual outcomes. In addition, the WaveLight group showed minimal spherical and coma aberrations when compared to the AMARIS group.

Postoperative Visual Function of Extended Depth-of-Focus Intraocular Lenses Versus Monofocal Lenses.

PURPOSE: To assess the effects of intraocular lens (IOL) decentration and tilt, as well as age, on postoperative visual function (corrected distance visual acuity [CDVA] and contrast sensitivity) by comparing an extended depth-of-focus IOL using higher order aspheric optics against a monofocal IOL from the same platform. METHODS: This retrospective observational study targeted patients without other eye diseases who underwent surgery to implant the Tecnis Eyhance OptiBlue or the monofocal IOL Tecnis OptiBlue 1-Piece (J&J Vision) during cataract surgery from November 2021 to December 2022. The effects of age, axial length, IOL decentration, tilt, and corneal higher order aberrations (HOAs) on the postoperative 5 m CDVA and area under log contrast sensitivity function (AULCSF) under photopic and scotopic conditions were evaluated within 3 months of surgery. RESULTS: No significant difference was found in postoperative CDVA between the Tecnis Eyhance OptiBlue group (n = 61 eyes) and the Tecnis OptiBlue 1-Piece group (n = 35 eyes), but AULCSF was significantly better in the Tecnis Eyhance OptiBlue group for photopic (1.58 ± 0.13 vs 1.46 ± 0.18; P = .002) and scotopic (1.71 ± 0.11 vs 1.59 ± 0.19; P = .002) eyes. Multivariate analysis showed a negative correlation between AULCSF and IOL decentration and age in the Tecnis Eyhance OptiBlue group (P < .01), with no significant correlation with tilt, axial length, and corneal HOAs. CONCLUSIONS: The Tecnis Eyhance OptiBlue yielded significantly better contrast sensitivity under photopic and scotopic conditions than the Tecnis OptiBlue 1-Piece. However, it is important to consider the effects of IOL decentration and age when evaluating the contrast sensitivity of the Tecnis Eyhance OptiBlue. [J Refract Surg. 2024;40(7):e499-e505.].

Comparing the Early Changes in Classified Higher-Order Aberrations Before and After Non-Toric and Toric Implantable Collamer Lens V4c Implantation.

PURPOSE: This study aimed to compare early changes in classified higher-order aberrations (HOAs) pre- and postsurgery in patients who received nontoric versus toric implantable collamer lenses (ICL; ICL Model V4c; STAAR Surgical, Monrovia, CA, USA). METHODS: This prospective study included 124 eyes of 64 patients: 49 eyes were treated using a nontoric implantable collamer lens (ICL), and 75 eyes were treated using a toric implantable collamer lenses (TICL). Refractive parameters and ocular aberrations were examined before and 1 month after surgery. RESULTS: At one month, the safety indices were 1.24 ± 0.17 in the ICL group and 1.20 ± 0.25 in the TICL group (p = 0.39). The efficacy indices were 1.07 ± 0.17 in the ICL group and 1.15 ± 0.26 in the TICL group (p = 0.02). The root mean square (RMS) values of whole-eye total HOAs, trefoil, corneal total HOAs, spherical aberration, and intraocular spherical aberration significantly increased postoperatively in both groups. The RMS of intraocular total HOAs in the TICL group significantly increased 1 month postoperatively. No statistically significant differences were observed in HOA changes between the ICL and TICL groups. CONCLUSIONS: The dominant increases in short-term aberrations after ICL and TICL V4c implantation were in corneal trefoil and intraocular spherical aberrations, which were related to the corneal incision and implanted lens. The HOA changes post-surgery were not statistically different between the two lens types.

Comparison of Outcomes after Wavefront-optimized and Topography-guided Transepithelial Photorefractive Keratectomy.

PURPOSE: To evaluate the outcomes of wavefront-optimized (WFO) and topography-guided (TG) transepithelial photorefractive keratectomy (transPRK) in the treatment of myopia and myopic astigmatism. METHODS: Patients who underwent transPRK using the WaveLight EX500 excimer laser for the correction of myopia and myopic astigmatism between January 2022 and March 2023 were divided into groups of WFO transPRK (77 eyes of 36 patients) or TG transPRK (63 eyes of 31 patients) in this retrospective, observational cohort study. The preoperative and postoperative 3-month refractive and visual outcomes of the two groups were analyzed. RESULTS: In both groups, the uncorrected distance visual acuity was 0.0 logarithm of the minimum angle of resolution or better in 95% of eyes 3 months postoperatively, and the mean manifest refraction spherical equivalent was within ±1.0 diopter in 90% of eyes. No significant differences were observed between the groups in terms of the uncorrected distance visual acuity or astigmatism. A significant induction of higher order aberrations (HOAs) was observed in both groups. However, the induction of total corneal HOAs (p = 0.014) and spherical aberrations (p < 0.001) was significantly lower in the TG group than that in the WFO group. CONCLUSIONS: WFO and TG transPRK effectively improved the visual and refractive outcomes; however, the induction of total corneal HOAs and spherical aberration was lesser following the TG ablation.

Statistical optimal parameters obtained by using clinical human ocular aberrations for high-precision aberration measurement.

PURPOSE: Compared to Shack-Hartmann wavefront sensor (SHWS), the parameters of virtual SHWS (vSHWS) can be easily adjusted to obtain the optimal performance of aberration measurement. Its current optimal parameters are obtained with only a set of statistical aberrations and not statistically significant. Whether the above parameters are consistent with the statistical results of the optimal parameters corresponding to each set of aberrations, and which performance is better if not? The purpose of this study was to answer these questions. METHODS: The optimal parameters to reconstruct 624 sets of clinical ocular aberrations in the highest accuracy, including the numbers of sub-apertures (NSAs) and the expansion ratios (ERs) of electric field zero-padding, were determined sequentially in this work. By using wavefront-reconstruction accuracy as an evaluation index, the statistical optimal parameter configuration was selected from some possible configurations determined by the optimal NSAs and ERs. RESULTS: The statistical optimal parameters are consistent for normal and abnormal eyes. They are different from the optimal parameters obtained with a set of statistical aberrations from the same 624 sets of aberrations, and the performance using the former is better than that using the latter. The performance using a fixed set of statistical optimal parameters is even close to that using the respective optimal parameters corresponding to each set of aberrations. CONCLUSION: The vSHWS configured with a fixed set of statistical optimal parameters can be used for high-precision aberration measurement of both normal and abnormal eyes. The statistical optimal parameters are more suitable for vSHWS than the parameters obtained with a set of statistical aberrations. These conclusions are significant for the designs of vSHWS and also SHWS.

Wavefront Changes during a Sustained Reading Task in Presbyopic Eyes.

The objective of this study was to assess the effect of sustained reading on the temporal changes in the wavefront error in the presbyopic eye. The wavefront aberration of the eyes was measured using an IRX3 Shack-Hartmann aberrometer before and after (immediately, 5 min, and 10 min after) a reading task. Temporal changes in C20, C40, and C3-1 coefficient values of the eyes were plotted, showing a predominant number of V-shaped patterns (for C40 and C3-1) and inverse V-shaped patterns (for C20) among the study group, and the percentages (between 27 and 73%) were reported. The median of the total RMS of aberrations and the RMS of HOA (higher-order aberrations), which included comatic (3rd order) and spherical-like aberrations (4th and 6th order), increased immediately after finishing the near-vision reading task and then decreased. The median of RMS of comatic aberrations had a similar pattern of variations, while the median of RMS of spherical-like aberrations displayed an opposite pattern. Simulating the aberration changes due to lens decentration caused by relaxed zonules during 4 D accommodation in an eye model demonstrated that the expected range of changes for the vertical coma and spherical aberrations are in the order of 0.001 and 0.01 µm, respectively, which could justify why the observed changes were not statistically significant. The observed dynamic changes in HOA might be linked to the biomechanical characteristics and alterations in the displacement of the crystalline lens following prolonged near-vision tasks in presbyopic people. Although some predominant patterns under some conditions were shown, they exhibit considerable inter-subject and inter-ocular variability. This might be due to slight misalignments while fixating on the internal extended object in the aberrometer.

Comparison of visual outcomes and optical aberrations after SMILE with intraoperative Kappa angle adjustments between small and large Kappa angles.

This study compares postoperative visual outcomes and optical aberrations after Small Incision Lenticule Extraction (SMILE) in patients with both small (S-Kappa: Kappa angle < 0.2 mm) and large Kappa (L-Kappa: Kappa angle ≥ 0.2 mm) angles. The evaluated aberrations include total higher-order aberrations (HOAs), horizontal coma (HC), vertical coma (VC), and spherical aberrations (SA), with procedures incorporating intraoperative Kappa angle adjustments. We retrospectively analyzed patient records undergoing SMILE utilizing linear mixed models (LMM). We assessed adjusted mean uncorrected distance visual acuity (UDVA), Strehl ratio (SR), total HOAs, VC, and SA at pupils of 3 mm and 6 mm for both S-Kappa and L-Kappa. The disparities between S-Kappa and L-Kappa were evaluated by LMM's adjusted mean differences. The differences in optical metrics were also assessed in eyes grouped by myopia levels: low, moderate, and high. A sensitivity analysis was conducted on a threshold of Kappa angle at 0.3 mm. Eight-five patients (169 eyes) were analyzed, and no significant pre-operative difference was found in UDVA (p = .222) or spherical equivalent (p = .433). Post-operative differences were found in SR at 3 mm pupil size (-0.06, p = .022), total HOA 3 mm (0.15, p = .022), HC 3 mm (0.04, p = .042), VC 3 mm and 6 mm (-0.08, p = .041; 0.04, p = .041). The stratified analysis for high myopia revealed significant differences in UDVA (-0.04, p = .037), HC 3 mm (0.07, p = .03), VC 6 mm (-0.21, p = .001), and SA 3 mm and 6 mm (0.07, p = .037; -0.09, p = .037). Sensitivity analysis showed no significant difference using a 0.3 mm Kappa threshold. While some optical aberrations exhibited statistical differences between S-Kappa and L-Kappa, their clinical significance is limited. Thus, a large Kappa angle might not substantially influence post-operative optical aberrations when intraoperative Kappa angle adjustments are implemented.