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Investigative Ophthalmology & Visual... Jun 2024The purpose of this study was to investigate the functional effects of peripheral refractive errors on mobility performance through a stair negotiation task.
PURPOSE
The purpose of this study was to investigate the functional effects of peripheral refractive errors on mobility performance through a stair negotiation task.
METHODS
Twenty-one young, normal sighted subjects navigated through an obstacle with steps, wearing spectacles that altered only their peripheral refraction. Lenses were used to induce positive defocus (+2 diopters [D] and +4 D), negative defocus (-2 D and -4 D), or astigmatism (+1.75 D and -3.75 D, axis 45 degrees) in the periphery. Feet trajectories were analyzed, and several gait assessment parameters were obtained. Statistical tests were conducted to determine significant performance differences between the lenses. Peripheral refraction in each subject was measured using a scanning Hartmann-Shack wavefront sensor to assess the impact of intrinsic peripheral refraction on the experiment.
RESULTS
Statistically significant differences in performance appeared when peripheral errors were superimposed. Crossing time with respect to plano lenses increased by 6.2%, 7.6%, 19.2%, and 29.6% for the -2 D, +2 D, -4 D, and +4 D lenses, respectively (P < 0.05 in the last 3 cases). Subjects exhibited slower walking speeds, increased step count, and adopted precautionary measures. High-power positive defocus lenses had the biggest impact on performance, and differences were observed in distance to steps between induced positive and negative defocus.
CONCLUSIONS
In this laboratory-based study without an adaptation period, peripheral refractive errors affected stair negotiation, causing cautious behavior in subjects. Performance differences among types of peripheral defocus may result from magnification effects and intrinsic peripheral refraction. These results highlight the importance of understanding the effects of induced peripheral errors by myopia control and intraocular lenses.
Topics: Humans; Male; Female; Adult; Refraction, Ocular; Refractive Errors; Young Adult; Eyeglasses; Visual Acuity; Gait; Walking
PubMed: 38940761
DOI: 10.1167/iovs.65.6.42 -
Journal of Cataract and Refractive... Jun 2024To assess corneal sensitivity and the ocular surface in patients undergoing primary femtosecond laser in situ keratomileusis (FS-LASIK) and those undergoing FS-LASIK...
PURPOSE
To assess corneal sensitivity and the ocular surface in patients undergoing primary femtosecond laser in situ keratomileusis (FS-LASIK) and those undergoing FS-LASIK retreatment under the same flap due to residual refractive error.
SETTING
Ekol Eye Hospital, Izmir, Turkey.
DESIGN
Prospective case series.
METHODS
Nineteen patients with previous FS-LASIK who had myopic and astigmatic refractive error were included in the study group, and 19 age- and sex-matched patients undergoing FS-LASIK for the first time as the control group. Corneal sensitivity, Schirmer test, tear film break-up time (TBUT), Oxford grading scheme for ocular surface staining, and Ocular Surface Disease Index (OSDI) were measured preoperatively and at postoperative 1 week and 1, 3, and 6 months.
RESULTS
The mean refractive correction in the study and control groups respectively was 2.18±0.78 D (range: 1.00-3.50) and 2.76±1.20 D (range: 1.00-4.50; p=0.07). Corneal esthesiometry results in the study and control groups respectively were 6.10±12.55 vs. 9.90±11.50 mm at 1 week (p=0.001), 41.95±6.98 vs. 45.09±5.88 mm at 1 month (p=0.004), 56.09±3.37 vs. 56.19±2.52 mm at 3 months (p=0.8), and 58.60±2.01 vs. 58.80±1.39 mm at 6 months (p=0.5). Significant difference between the two groups in Schirmer test score that disappeared at postoperative 3 months and in TBUT and ocular surface staining that disappeared at 6 months, whereas the statistically significant difference in OSDI score persisted at 6 months (p=0.03) was detected.
CONCLUSION
Corneal surface sensitivity and ocular surface health are more impaired in patients undergoing FS-LASIK retreatment due to residual refractive error.
PubMed: 38940469
DOI: 10.1097/j.jcrs.0000000000001511 -
Nature Communications Jun 2024Optical spatiotemporal vortices with transverse photon orbital angular momentum (OAM) have recently become a focal point of research. In this work we theoretically and...
Optical spatiotemporal vortices with transverse photon orbital angular momentum (OAM) have recently become a focal point of research. In this work we theoretically and experimentally investigate optical spatiotemporal vortices with radial and azimuthal quantum numbers, known as spatiotemporal Laguerre-Gaussian (STLG) wavepackets. These 3D wavepackets exhibit phase singularities and cylinder-shaped edge dislocations, resulting in a multi-ring topology in its spatiotemporal profile. Unlike conventional ST optical vortices, STLG wavepackets with non-zero and values carry a composite transverse OAM consisting of two directionally opposite components. We further demonstrate mode conversion between an STLG wavepacket and an ST Hermite-Gaussian (STHG) wavepacket through the application of strong spatiotemporal astigmatism. The converted STHG wavepacket is de-coupled in intensity in space-time domain that can be utilized to implement the efficient and accurate recognition of ultrafast STLG wavepackets carried various and This study may offer new insights into high-dimensional quantum information, photonic topology, and nonlinear optics, while promising potential applications in other wave phenomena such as acoustics and electron waves.
PubMed: 38937504
DOI: 10.1038/s41467-024-49819-4 -
Life (Basel, Switzerland) May 2024This study aimed to investigate the impact of the cornea's biomechanical properties, corneal hysteresis (CH), and corneal resistance factor (CRF) on postoperative...
This study aimed to investigate the impact of the cornea's biomechanical properties, corneal hysteresis (CH), and corneal resistance factor (CRF) on postoperative astigmatism after cataract surgery and determine the other factors that influence it. Forty eyes of 40 patients (13M/27F; the median age of 74) were included in this prospective study, underwent 2.75 mm incision cataract surgery, and were followed for 30 days. Visits were scheduled at baseline before surgery (V0), the 1st (V1), the 7th (V2), and the 30th (V3) postoperative days. The main parameters estimated and analyzed with Statistica 14.0.1 were CH, CRF, astigmatism diopter, and axis. Following the cataract surgery, the CH did not significantly change during the study visits ( = 0.109). However, there was a significant change in the CRF from baseline during the study visits (per protocol set) ( = 0.002). After a slight but insignificant increase from V0 to V1, post hoc analysis found a significant decrease in the mean CRF from V1 to V2 ( = 0.049) with no substantial change from V2 to V3. According to the post hoc analysis, the median astigmatism diopter increased significantly only from V0 to V1 ( = 0.001) and slightly but not significantly decreased to the end of the study with the achievement of a near-baseline value. The main predictors for the final astigmatism diopter (R = 0.898) obtained by stepwise regression analysis were its values at V0, V1, and V2 ( < 0.001). The CRF at V1 was marginally significant, with a negative parameter estimate of -0.098303 ( = 0.0623). In conclusion, there was no correlation between preoperative CH and CRF and postoperative astigmatism using 2.75 mm incision cataract surgery. However, the final astigmatism diopter's main predictors were its baseline values before cataract surgery, the first, and the seventh postoperative days.
PubMed: 38929639
DOI: 10.3390/life14060655 -
Medicina (Kaunas, Lithuania) May 2024Different techniques for artificial iris implantation with or without an intraocular lens, depending on lens status, are described in the literature. We describe a...
Different techniques for artificial iris implantation with or without an intraocular lens, depending on lens status, are described in the literature. We describe a surgical technique for a custom-made artificial iris and toric-intraocular lens intrascleral flange fixation. We modified the "Backpack" artificial iris implantation surgical technique to facilitate an accurate alignment of the toric-intraocular lens in a patient with aphakia, aniridia, and high asymmetric astigmatism secondary to blunt trauma. Two months after the surgery, uncorrected visual acuity was 20/30, corrected to 20/25 with a refraction of -2.00 in the diopter sphere with no residual astigmatism. The artificial iris implant and toric-intraocular lens were well-centered. The patient was satisfied with the visual and cosmetic outcomes. This procedure, however, is not complication-free as our patient developed uveitis and increased intraocular pressure during the postoperative period, which was treated successfully.
Topics: Humans; Iris; Lenses, Intraocular; Sclera; Lens Implantation, Intraocular; Visual Acuity; Astigmatism; Male; Aniridia; Female
PubMed: 38929482
DOI: 10.3390/medicina60060865 -
Current Opinion in Ophthalmology Jun 2024To discuss available premium intraocular lenses (IOLs), patient selection, and important considerations for each premium IOL.
PURPOSE OF REVIEW
To discuss available premium intraocular lenses (IOLs), patient selection, and important considerations for each premium IOL.
RECENT FINDINGS
We review important topics and considerations for premium IOL selection: specifically, toric, extended depth of focus (EDOF), multifocal/trifocal, light adjustable lenses (LALs), and small aperture IOLs. Toric lenses are an excellent option for patients with astigmatism. However, to achieve optimal patient satisfaction, it is critical to account for the ATR astigmatism contribution from the posterior cornea and high angle alphas. Additionally, examining the ocular surface prior to placement of EDOF/multifocal IOLs is important, yet the significance of HOAs on outcomes after implantation still must be elucidated more. Finally, recent studies reveal that the small aperture lens is a good alternative for those with corneal irregularities, and second generation LALs are a great option to achieve target refractions in those with less predictable refractive outcomes, such as in Fuchs' dystrophy or in eyes with previous refractive surgery.
PubMed: 38920096
DOI: 10.1097/ICU.0000000000001067 -
Journal of Cataract and Refractive... Jun 2024To assess the cost-effectiveness of the treatment of low corneal astigmatism (≤1.5 D) at the moment of the cataract surgery.
PURPOSE
To assess the cost-effectiveness of the treatment of low corneal astigmatism (≤1.5 D) at the moment of the cataract surgery.
SETTING
("Masked by journal requirement").
DESIGN
Economic Evaluation.
METHODS
A decision tree was used to assess the cost-effectiveness of implanting spherical versus toric intraocular lenses (IOLs) or the spherical lens combined with the following corneal incisions: limbal relaxing incisions conducted manually (M-LRI) or assisted by femtosecond laser (F-LRI), arcuate keratotomies conducted manually (M-AK) or assisted by femtosecond (F-AK), and intrastromal arcuate keratotomies (F-iAK). Outcomes of cost were selected from a patient's perspective considering the gross cost of each one of the surgeries at European centers, and the effectiveness variable was the probability of achieving a visual acuity of 20/20 after surgery. A sensitivity analysis was conducted to assess the uncertainty considering the evidence retrieved from the transition probabilities of the model, the effectiveness, and the cost.
RESULTS
F-AK or Toric IOLs were the most effective treatments, increasing an 16% or 9%, respectively, in the percentage of eyes attaining 20/20 vision. The M-LRI, F-iAK, and F-LRI procedures were strongly dominated, while the M-AK and toric IOL were weakly dominated by the F-AK. A patient with low corneal astigmatism would need to be willing to pay 360€ [CI 95%: 231-1224] with F-AK and 472€ [CI 95%: 149-4490] with toric IOLs for a 10% increase in the probability of achieving 20/20 vision.
CONCLUSIONS
From the patient's perspective, F-AK was generally the most cost-effective treatment, even though toric IOLs can dominate in some countries.
PubMed: 38915158
DOI: 10.1097/j.jcrs.0000000000001507 -
International Ophthalmology Jun 2024Evaluation of anterior segment parameters using the Scheimpflug corneal topography 1 year after surgery in patients who underwent sutureless scleral fixation...
PURPOSE
Evaluation of anterior segment parameters using the Scheimpflug corneal topography 1 year after surgery in patients who underwent sutureless scleral fixation intraocular lens (SFIOL) implantation using the modified Yamane technique and retropupillary iris-claw intraocular lens (RPIOL) implantation.
METHODS
A total of 60 eyes from 57 patients who underwent sutureless SFIOL implantation and 57 eyes from 52 patients who underwent RPIOL implantation were included. Anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), anterior-posterior corneal astigmatism, and keratometric values were assessed using the Scheimpflug corneal topography (Pentacam HR, Germany).
RESULTS
There was no statistically significant difference in postoperative UCVA and BCVA between the sutureless SFIOL and the RPIOL group (p = 0.236, p = 0.293, respectively). While there was no statistically significant difference in postoperative IOP between the two groups (p = 0.223), a statistically significant decrease in IOP was observed in both groups (p < 0.001). While there was no statistical difference between the sutureless SFIOL group and the RPIOL group in terms of spherical value (p = 0.441) and spherical equivalence (p = 0.237), there was a statistically significant difference in cylindrical value (p < 0.001). While there was a statistical difference in anterior astigmatism (p < 0.001), there was no statistical difference in posterior astigmatism (p = 0.405). There was no statistical difference in terms of ACV, ACD, and ACA between the sutureless SFIOL and the RPIOL group (p = 0.812, p = 0.770, p = 0.401, respectively).
CONCLUSION
In this study, although there was a statistical difference in cylindrical value and anterior corneal astigmatism between the sutureless SFIOL and RPIOL groups, vision was not affected. According to this study, sutureless SFIOL and RPIOL are two successful methods in terms of visual acuity, anterior segment, and keratometry outcomes in aphakic patients after phacoemulsification.
Topics: Humans; Male; Female; Visual Acuity; Sclera; Lens Implantation, Intraocular; Middle Aged; Corneal Topography; Aged; Iris; Sutureless Surgical Procedures; Lenses, Intraocular; Retrospective Studies; Anterior Eye Segment; Adult; Treatment Outcome; Prosthesis Design; Aphakia, Postcataract; Follow-Up Studies; Aphakia
PubMed: 38914871
DOI: 10.1007/s10792-024-03187-6 -
Scientific Reports Jun 2024The Persian Eye Cohort Study, a population-based cross-sectional study from 2015 to 2020, examined refractive error prevalence among 48,618 Iranian adults aged 31 to 70....
The Persian Eye Cohort Study, a population-based cross-sectional study from 2015 to 2020, examined refractive error prevalence among 48,618 Iranian adults aged 31 to 70. The study encompassed six centers in Iran, employing random cluster sampling for demographic, medical, and socioeconomic data collection through interviews. Ophthalmic exams included visual acuity, automated and manual objective refraction, subjective refraction, slit lamp, and fundus examinations. Using the spherical equivalent definition, the sample population was categorized into groups. Results indicated a mean age of 49.52 ± 9.31 and a mean refractive error of 0.26 diopters (D) ± 1.6 SD (95% CI - 0.27 to -0.24), ranging from -26.1 to + 18.5 SD. Prevalence of myopia (< -0.5D) and hyperopia (> + 0.5D) was 22.6% (95% CI 22.2-23%) and 12.5% (95% CI 12.1-12.8%), respectively. Regarding different age groups, the prevalence of hyperopia and astigmatism exhibited a steady and significant rise with increasing age (p-value < 0.001 for both). The prevalence of Myopia, however, showed a distinctive pattern, initially increasing in adults under 45, declining in those aged 55-64, and rising again among individuals aged 60 and older. Female gender, older age, urban residency, higher education, higher income, and Fars ethnicity were significantly related to a higher prevalence of myopia (p-value < 0.001 for all). Female gender (p-value < 0.001), aging (p-value < 0.001), urban residency (p-value = 0.029), and lower-income (p-value = 0.005) were significantly related to higher prevalence of hyperopia. Astigmatism (> 1D) was prevalent in 25.5% of participants (95% CI 25.1-25.9%) and correlated with male gender, aging, urban residency, illiteracy, and higher income (p-value < 0.001, < 0.001, < 0.001, < 0.001, 0.014, respectively). The study's comparison with regional and international surveys highlighted the increase in myopia among those over 65 due to higher nuclear cataract rates in older adults. Myopia positively related to education, income, and urban residency, while hyperopia did not exhibit such associations.
Topics: Humans; Iran; Middle Aged; Male; Female; Adult; Prevalence; Aged; Refractive Errors; Cross-Sectional Studies; Cohort Studies; Myopia; Hyperopia
PubMed: 38914645
DOI: 10.1038/s41598-024-65328-2 -
International Ophthalmology Jun 2024To evaluate the effect of pregnancy on the anterior chamber, corneal parameter, and intraocular pressure measurements; and compare the results between trimesters,...
PURPOSE
To evaluate the effect of pregnancy on the anterior chamber, corneal parameter, and intraocular pressure measurements; and compare the results between trimesters, postpartum and non-pregnant healthy age-matched women.
METHODS
This prospective study included 41 pregnant women and 53 non-pregnant women. Four measurements were taken from the pregnant women, in each trimester and postpartum third month, and once from the control group. Of the individuals included in the study, anterior chamber depth (ACD), anterior chamber volume (ACV), K1 (flat keratometry), K2 (steep keratometry), Kmean (mean value of K1 and K2), anterior chamber angle (ACA), central corneal thickness (CCT), thinnest corneal thickness (TCT), astigmatism value (AST), corneal volume (CV), biometry, axial length (AL), spherical equivalent (SFEQ), intraocular lens power (ILP), VA (visual acuity) datas were recorded.
RESULTS
We observed a statistically significant decrease in K2, CCT, ACD, AL and CV in the postpartum period (p = 0.025, p < 0.001, p = 0.029, p = 0.005, p = 0.004 respectively) and a statistically significant increase in ACV, CCT, and TCT as the gestational week progressed in the pregnant group (p = 0.007, p < 0.001, p = 0.025, respectively). A statistically significant decrease in IOP towards to the third trimester, and an increase in the postpartum period was observed (p < 0.001). We did not observe statistically significant changes in K1, Kmean, AST, ACA, VA, ILP, and SFEQ values.
CONCLUSION
It is important to investigate the physiological changes that may occur during pregnancy, distinguish them from pathological changes, and avoid unnecessary treatment. We consider that it's also important to guide the timing of anterior segment surgeries such as cataract and refractive surgery and to prescribe glasses/contact lenses.
Topics: Humans; Female; Prospective Studies; Pregnancy; Adult; Postpartum Period; Pregnancy Trimesters; Intraocular Pressure; Anterior Eye Segment; Young Adult; Visual Acuity; Biometry; Cornea; Anterior Chamber
PubMed: 38913127
DOI: 10.1007/s10792-024-03173-y