Increase In Total Higher Order Aberrations Research Articles

The visual impact of higher-order aberrations in patients with pediatric blepharokeratoconjunctivitis.

To analyze higher-order aberrations (HOAs) and their visual impact in a pediatric blepharokeratoconjunctivitis (PBKC) cohort compared with healthy controls. Prospective case-control study of pediatric patients (≤ 16 years old). Subjects underwent wavefront aberrometry analysis to compare HOAs and their impact on visual quality. A total of 150 eyes from 76 patients were included in the analysis. The PBKC group consisted of 50 eyes and the control group of 100 healthy eyes. Mean age was 10.39 ± 3.81 years for the PBKC group and 10.80 ± 3.61 years for the controls. Mean corrected-distance visual acuity (CDVA) was 0.24 ± 0.21 logMAR in the PBKC group and 0.07 ± 0.1 in the controls (P < 0.001). Mean astigmatism was 1.6 ± 1.98D in the PBKC group vs. 0.67 ± 0.76D in the control group (P = 0.01). Mean RMS of HOAs was 1.05 ± 1.7mm in the PBKC group and 0.41 ± 0.18mm in the controls (P < 0.001). The mean modulation transfer function (MTF) in the PBKC group was significantly lower (16.37 ± 16.32) than controls (30.3 ± 23.57) (P < 0.001). Corneal leukomas, stromal vascularization, peripheral nummular subepithelial scars, and pannus formation are associated with increased HOAs. There was a significant increase in total HOAs of eyes with PBKC compared to healthy controls. Corneal opacity, vascularization, and scarring are associated with increased HOAs. The PBKC eye aberration profile: coma, secondary astigmatism, quadrafoil, and pentafoil, were associated with decreased CDVA and visual quality (PSF and MTF).

Ray-tracing-guided myopic LASIK: real-world clinical outcomes.

To assess effectiveness of individualized ray-trace based laser in situ keratomileusis (LASIK) for correction of myopia in everyday clinical practice. Single-site private practice. Retrospective nonrandomised unmasked chart review. Consecutive, myopic eyes (range ≤-8.25 diopters [D] sphere; astigmatism 0 to -4.25 D) treated with ray-trace based LASIK were included. Patients underwent wavefront, tomography, and biometry assessment using the InnovEyes Sightmap diagnostic device. The ray-trace based algorithm (InnovEyes algorithm) then generated an individualized 3D eye model and calculated a customized LASIK ablation profile. Postoperative visual acuity, refractive error and whole eye higher-order aberrations (HOAs) were evaluated over 3 months. The procedure was performed on 400 eyes (200 patients). Mean preoperative manifest refraction spherical equivalent was -3.39 ± 1.58 D (right eye -3.84 ± 1.63 D, left eye -3.98 ± 1.75 D). At month 3, uncorrected distance visual acuity (UDVA) was ≥20/20 in all eyes, ≥20/16 in 89% (right eye 90%, left eye 89%), ≥20/12 in 51% (54% right eye; 47% left eye), and 20/10 in 8% (right eye 8%; left eye 9%) of eyes respectively. UDVA was within 1 line of preoperative corrected distance visual acuity in 98% of eyes (right eye 98.5%; left eye 98%) and 39% of eyes (right eye 38%; left eye 39%) gained 1 line improvement. There was a statistically but not clinically significant increase in total HOAs (right eye 0.06 ± 0.133 μm; left eye 0.057 ± 0.125 μm; P < .001). The spherical aberration decreased (right eye -0.047 ± 0.095 μm, P < .001; left eye -0.051 ± 0.091 μm, P < .001). Ray-trace based LASIK was safe and effective for correction of myopia with and without astigmatism. Approximately, half the eyes achieved ≥20/12.5 UDVA and 8% achieved 20/10. There was no clinically significant increase in total whole eye HOAs.

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter

PurposeTo compare changes in ocular aberrations in children wearing orthokeratology (ortho-k) lenses with a back optic zone diameter (BOZD) of 6 mm (6-MM group) or 5 mm (5-MM group) and their associations with axial elongation (AE) over two years.MethodsSeventy Chinese children, aged 6 to < 11 years, with myopia between − 4.00 to − 0.75 D, were randomly allocated to 5-MM and 6-MM groups. Ocular aberrations were measured, rescaled to a 4-mm pupil, and fitted with a 6th order Zernike expansion. Measurements, including axial length, were taken prior to commencing ortho-k treatment and then every six months over two years.ResultsAfter two years, the 5-MM group displayed a smaller horizontal treatment zone (TZ) diameter (by 1.14 ± 0.11 mm, P < 0.001) and less AE (by 0.22 ± 0.07 mm, P = 0.002) compared with the 6-MM group. A greater increase in total root mean square (RMS) of higher-order aberrations (HOAs), primary spherical aberration (SA) ({mathrm{C}}_{4}^{0}), and coma were also observed in the 5-MM group at all follow-up visits. The horizontal TZ diameter was significantly associated with changes in RMS HOAs, SA (RMS, primary and secondary SA), and RMS coma. After controlling for baseline parameters, RMS HOAs, RMS SA, RMS coma, and primary ({mathrm{C}}_{4}^{0}) and secondary ({mathrm{C}}_{6}^{0}) SA were significantly associated with AE.ConclusionsOrtho-k lenses with a smaller BOZD created a smaller horizontal TZ diameter and a significant increase in total HOAs, total SA, total coma, and primary SA and a decrease in secondary SA. Of these ocular aberrations, total HOAs, total SA, and primary SA were negatively correlated with AE over two years.Trial registration: ClinicalTrial.gov, NCT03191942. Registered 19 June 2017, https://clinicaltrials.gov/ct2/show/NCT03191942.

Implantable collamer lens versus small incision lenticule extraction for high myopia correction: A systematic review and meta-analysis

PurposeTo compare the efficacy, safety, predictability and visual quality between implantable collamer lens (ICL) implantation and small incision lenticule extraction (SMILE) for high myopia correction in adults.MethodsA systematic review and meta-analysis was conducted. A comprehensive literature search was done based on databases including PubMed, Science Direct, Embase, and the Cochrane Central Register of Controlled Trials. The efficacy index, safety index, changes in Snellen lines of corrected distance visual acuity (CDVA), predictability (difference between post-operative and attempted spherical equivalent error, SER), incidence of halos, and change in higher-order aberrations (HOAs) were compared. Mean difference (MD) and 95% confidence interval (CI) was used to estimate continuous outcomes, risk ratio (RR) and 95%CI was used to estimate categorical outcomes.ResultsFive observational studies involving 555 eyes were included in this review. Studies’ sample sizes (eyes) ranged from 76 to 197. Subjects’ refraction ranged from -6 diopter (D) to -12D. Study duration of most researches were 6 months or 12 months. Compared to SMILE, ICL implantation showed better efficacy index (MD=0.09, 95%CI:0.01 to 0.16) and better safety index (MD=0.08, 95%CI: 0.00 to 0.16). Compared with SMILE, more ICL-treated eyes gained one or more Snellen lines of CDVA (RR=1.54, 95%CI:1.28 to 1.86), more gained two or more lines (RR=2.09, 95%CI:1.40 to 3.13), less lost one or more lines (RR=0.17, 95%CI:0.05 to 0.63). There was no difference in predictability between two treatments, RRs of predictability of within ±0.5D and ±1D were 1.13 (95%CI: 0.94 to 1.36) and 1.00 (95%CI: 0.98 to 1.02). Compared with SMILE, ICL implantation came with a higher risk of halos [RR=1.79, 95%CI: 1.48 to 2.16] and less increase in total HOAs (MD=-0.23, 95%CI: -0.42 to -0.03).ConclusionCompared with SMILE, ICL implantation showed a higher risk of halos, but equal performance on SER control, and better performance on efficacy index, safety index, CDVA improvement and HOAs control. Overall, ICL implantation might be a better choice for high myopia correction in adults.

Comparison of objective and subjective visual quality early after implantable collamer lens V4c (ICL V4c) and small incision lenticule extraction (SMILE) for high myopia correction

To investigate differences in the objective and subjective visual quality of patients with high myopia following implantable collamer lens V4c (ICL V4c) versus small incision lenticule extraction (SMILE) early postoperatively. This prospective analysis included 94 eyes of 57 patients (8 males) in the ICL V4c group (mean spherical equivalent (SE), -8.07±1.03 dioptres (D)) and 103 eyes of 57 patients (13 males) in the SMILE group (mean SE, -7.85±0.78 D). Refractive parameters and wavefront aberrations were recorded preoperatively and 6months postoperatively. Subjective visual quality was scored with the Quality of Vision questionnaire, and operation satisfaction was evaluated 6months postoperatively. At 6months postoperatively, the efficacy index was 1.17±0.16 in the ICL and 1.09±0.20 in the SMILE group; the safety index was 1.21±0.18 in the ICL and 1.12±0.16 in the SMILE group. A significant increase in total higher-order aberrations (HOAs) in both the ICL and SMILE groups was observed, but to a lesser degree in ICL (p<0.05). In the ICL group, trefoil significantly increased (p<0.05), whereas in the SMILE group, coma, trefoil and spherical aberration significantly increased (p<0.05). Glare, haloes and blurred vision had the highest incidences after both types of surgery, and postoperative haloes were significantly more common following ICL; 96.1% of ICL-treated and 94.9% of SMILE-treated patients were satisfied with their visual outcomes. ICL V4c caused lower HOAs induction than SMILE. Despite the postoperative visual disturbances, both ICL and SMILE provided good efficacy, safety, predictability and high satisfaction in correcting high myopia.

Clinical study on combining femtosecond thin- flap and LASIK with the Triple-A profile for high myopia correction

BackgroundFemtosecond laser–assisted LASIK (FS-LASIK) can make ultra-thin corneal flap accurately. MEL 90 excimer laser provides Triple-A ablation mode, which significantly reduces the amount of corneal tissue cutting. This study aimed to investigate the visual and refractive outcomes in patients with high myopia after thin-flap FS-LASIK using the 500 Hz pulse rate of the Triple-A profile.MethodsThis prospective study included 90 eyes from 90 patients received thin-flap FS-LASIK using the 500 Hz pulse rate of the Triple-A profile. According to the pre-operative spherical equivalence (SE), the treated eyes were divided into two groups: the first group (ranged from − 9.0D to − 6.0D) and the second group (ranged from − 11.15D to − 9.0 D). The parameters evaluated pre-operatively and 6 month post-operatively included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), SE, efficacy and safety index, posterior central elevation, and corneal higher-order aberrations (HOAs).ResultsThe efficacy indexes were 1.149 ± 0.150 for the first group and 1.173 ± 0.136 for the second group (P > 0.05), whereas safety indexes were 1.135 ± 0.154 and 1.158 ± 0.137 (P > 0.05) respectively. Moreover, 93.8 and 90.6% of patients had an UDVA of 20/20, 51.2 and 49.8% had a UDVA of 20/16 for the first and second groups, respectively; yet, there were no significant differences between both groups at the 20/20 and the 20/16 levels (P > 0.05). 84 and 100% of the firse group patients had a SE within ±0.5 D and ± 1.0 D, and 82 and 100% of the second group patients. There was no significant myopia regression in both groups after 6 months follow-up. At 1, 3 and 6-month after surgery, there were no significant differences in the posterior central elevation between the two groups (P > 0.05). The induction of total HOAs, spherical aberration, and horizontal coma in the first group were significantly less than that in the second group at the 6- month follow-up (P < 0.05), while the differences of the RMS value of vertical coma between both groups were not significant (P > 0.05). The ablation was significantly associated with the post-operative increase in total HOAs, spherical aberration and horizontal coma (P < 0.05),but not with vertical coma (P > 0.05).ConclusionOur results indicate that using the Triple-A ablation profile of the MEL 90 excimer laser associated with thin-flap is a safe, efficient, and predictable method to correct SE up to − 11.15D. However, for patients with high myopia, under the premise of ensuring a certain optical zone diameter, the ablation depth should be minimized to reduce the increase of the post-operative HOAs so as to improve the visual quality.

Wavefront Aberrations in Subjects Wearing Soft Aspheric Contact Lenses and Those Wearing Spherical Ones

Purpose: To measure the level of higher order aberrations (HOA) when wearing a soft aspheric contact lens (CL), compared to a spherical CL, in myopic subjects.&#x0D; Method: Fifteen myopic subjects aged 20-30 years were tested for the presence of dry eye. Aberrometry measurements were done without a contact lens as well as with a spherical CL and an aspheric CL. Root mean square error (RMS) of HOA, spherical aberration (SA) and coma were measured five times in an interval of 15 seconds without blinking for each of the 3 conditions.&#x0D; Results: Wearing a spherical CL produced a significant increase of SA and horizontal coma compared to an eye without a contact lens. When wearing an aspheric CL, there was a trend towards a smaller increase of these aberrations. However, the difference between both types of lens was not statistically significant. In terms of total HOA, these were higher when wearing the spherical CL, while they tended to be less with the aspheric CL. As for the variations between blinks, there was a similar increase in total HOA and individual modes with time for the three conditions.&#x0D; Conclusion : Wearers of aspheric CL seem to show a tendency towards smaller amounts of SA, horizontal coma and HOA in general in comparison with wearers of SCL. However, total HOA increases during a long interval between blinks, no matter the condition.

Advanced corneal surface ablation efficacy in myopia: changes in higher order aberrations

Objective: To evaluate the change of ocular and corneal higher order aberrations (HOAs) after wavefront-guided advanced surface ablation (WF-ASA) for myopia using 4 different epithelial management techniques (AA-PRK, LASEK, Epi-PRK, and Epi-LASIK). Design: Retrospective single centre excimer database analysis. Participants: Two hundred and forty eyes equally divided between the 4 WF-ASA techniques, matched for mean and range of required spherical correction. Methods: Ocular wavefront aberrations were measured using the wavescan aberrometer and corneal aberrations were obtained from corneal topography elevation maps and calculated by ray-tracing. All data were collected preoperatively and 3 months following treatment. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs and spherical aberration (SA). Results: Three months postoperatively, there was a statistically significant surgically induced increase in total HOAs and SA both for ocular and corneal analysis ( p < 0.001). There was no statistically significant difference in the induced ocular SA and HOAs between the groups, but the differences in induced corneal SA and HOAs were significant ( p = 0.010). Ocular changes in SA were weakly correlated to preoperative SA (−0.30, p < 0.001) but strongly correlated to applied spherical correction (−0.68, p < 0.001). Surgically induced corneal SA was weakly correlated to preoperative corneal SA (−0.34, p < 0.001) and applied spherical correction (−0.46, p < 0.001). Conclusions: Three months postoperatively, all procedures resulted in an increase in ocular and corneal HOAs and SA. Induced aberrations were most strongly correlated to the applied spherical power correction. Modifying the existing ablation pattern to compensate for induced HOAs might improve the outcome.

A Preliminary In Vivo Assessment of Higher-Order Aberrations Induced by a Silicone Hydrogel Monofocal Contact Lens

To evaluate the effect of negatively powered soft contact lenses on ocular higher-order aberrations (HOAs). HOA measurements were performed with fixed optical zones of 4.0 and 6.0 mm on 20 eyes of 10 participants before and minutes after wearing extended-wear Focus NIGHT & DAY contact lenses. For each eye, three contact lens powers were used: -2.00 diopters (D), -4.00 D, and a power equal to the spherical equivalent of each eye. The change in spherical aberration was highly correlated with the change in negative power of the contact lens at an optical zone of 4 and 6 mm (Pearson correlation coefficient=0.914 and 0.743, respectively, P<0.0001). Total HOAs had a weaker but important correlation at an optical zone of 6 mm (Pearson correlation coefficient=0.470, P=0.037) and insignificant correlation at an optical zone of 4 mm. Coma and trefoil were poorly correlated with contact lens power in either optical zone. Compared to the control using both optical zones, the -2.00 D contact lens resulted in a significant increase in total HOAs and spherical aberration, whereas the -6.00 D lens yielded a marked decrease in spherical aberration and a mild, statistically insignificant increase in total HOAs. Both contact lens powers yielded larger ocular coma and unchanged trefoil levels. The change from induction to reduction of spherical aberration occurred at -4.00 D. The Focus NIGHT & DAY lens vehicle harbors positive spherical aberration and coma, independently of the lens power. The negative power of contact lenses induces negative spherical aberration, which, at large values, compensates for the lens vehicle positive spherical aberration to produce a net negative spherical aberration.

Prospective randomized trial of wavefront-guided laser in situ keratomileusis with the CustomCornea and CustomVue laser systems

To compare visual function, safety, and higher-order aberrations (HOAs) after wavefront-guided laser in situ keratomileusis (LASIK) with the LadarVision CustomCornea (Alcon Laboratories, Inc.) and Star S4 CustomVue (Visx) laser systems. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Seventy-eight eyes of 39 patients with myopia with or without astigmatism were randomized for LASIK treatment in 1 eye with the CustomCornea laser; the other eye was treated with the CustomVue laser. Patients were followed for 6 months after surgery. The primary outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and changes in HOAs. At 6 months, the mean logarithm of the minimum angle of resolution (logMAR) UCVA was -0.0135 +/- 0.07 (SD) in the CustomVue group and 0.0417 +/- 0.12 in the CustomCornea group (P = .023). Eighty-eight percent of eyes in the CustomVue group had 20/20 or better UCVA compared with 67% in the CustomCornea group (P<.02). At 6 months, 91% of eyes in the CustomVue group and 79% in the CustomCornea group were within +/-0.50 diopter (D) of emmetropia (P<.1); 88% and 50%, respectively, were within +/-0.25 D (P<.001). Both platforms led to a small increase in total HOAs. The CustomVue system reduced trefoil and induced less of an increase in total HOAs, whereas the CustomCornea platform increased trefoil but induced less of an increase in spherical aberrations and coma. Both laser systems were effective, safe, and predictable. Wavefront-guided LASIK with the CustomVue system resulted in better visual acuity, with more eyes having 20/20 acuity than in the CustomCornea group.

Comparison of Changes in Higher-order Aberrations between Conventional and Wavefront-guided LASEK

Purpose: To evaluate the postoperative higher-order aberrations (HOAs) and factors affecting postoperative changes in HOAs in eyes that underwent wavefront-guided LASEK (laser-assisted subepithelial keratectomy), compared with the eyes that underwent conventional LASEK. Methods: We reviewed the medical records of 221 patients who had undergone LASEK or wavefront guided LASEK with VISX WaveScan and VISX Star S4 eximer laser by a single surgeon (427 total eye operations). We matched 29 eyes of the LASEK and the wavefront LASEK groups (58 eyes total) according to the guideline: preoperative refractive power differences must be within 1 diopter and preoperative root-mean-square (RMS) of total HOAs differences must be within 0.01 ?m. Preoperative wavefront aberrations and two-months postoperative wavefront aberrations and associated factors were compared and analyzed. Results: Postoperative total HOAs, comas, and spherical aberrations increased significantly from 0.36±0.10 ?m to 0.49±0.16 ?m (p=.001), 0.21±0.09 ?m to 0.31±0.14 ?m (p=.003), and 0.03±0.10 ?m to 0.10±0.20 ?m (p=.043), respectively, in the conventional LASEK group. In the wavefront LASEK group, postoperative HOAs, comas, and spherical aberrations significantly increased from 0.36±0.10 μm to 0.46±0.14 μm (p=.004), 0.18±0.10 ?m to 0.29±0.14 ?m (p=.002), and 0.09±0.14 ?m to 0.19±0.14 ?m (p=.006), respectively. There were no significant differences in HOAs between the two groups. A strong negative correlation between preoperative total HOAs and a multiple of increase in total HOAs postoperatively was found, with the negative correlation being stronger in the wavefront-guided LASEK group (Pearson’s correlation coefficient =-0.697, p