Subjective Refraction Research Articles

Myoring implantation with and without cross-linking: Comparative study of pre and postoperative visual outcomes and pentacam indices.

Comparing the visual, topographic, and aberrometric changes following Myoring implantation alone or combined with corneal cross-linking (CXL). This retrospective, comparative study was conducted on keratoconus (KC) patients with moderate, central KC who sought medical advice at Watany Eye Hospital, Cairo, Egypt. Group 1 patients performed femtolaser-assisted Myoring implantation, while group 2 patients performed Myoring implantation with CXL. Group 1 included 44 eyes, and group 2 comprised 40 eyes. The mean follow-up interval was 2.34 years ± 2.25. There was a significant postoperative improvement in subjective refraction for both groups. Patients of group 1 showed statistically significant reductions in postoperative topographic astigmatism, K readings, Index of Surface Variance, horizontal coma, and spherical aberrations. In contrast, patients of group 2 only showed statistically significant improvements in K readings and horizontal coma. Patients of group 1 developed higher improvements in topographic astigmatism and K max compared to group 2. Although the combined technique was non-inferior to implanting the Myoring alone regarding visual, refractive, and keratometric improvements, Myoring implantation alone showed better results, mainly in topographic astigmatism. Hence, our study leans in favor of Myoring implantation without the need for additional CXL.

Case Report: Front surface eccentricity of scleral lens: Its impact on visual quality in eyes with higher-order aberrations induced by refractive surgery

Purpose To report the impact of front surface eccentricity (FSE) of scleral lenses (SCLs) on the visual performance of eyes exhibiting refractive surgery-induced higher-order aberrations (HOAs) Method A female teenager presented to the clinic with blurring of vision and dependency on spectacles even after undergoing Small Incision Lenticule Extraction (SMILE) in both eyes (BE). Her presenting uncorrected high contrast distance visual acuity (HCDVA) was 20/60 in the right eye (RE) and 20/40 in the left eye (LE). On examination, the cornea showed a ring-shaped area of ablation with faint scarring and a well-apposed lenticule-extraction site. Subjective refraction improved the HCDVA to 20/20p in RE and 20/25 in LE but the patient was not happy with the quality of vision. Ocular aberrometry revealed an increase in total HOAs as the underlying cause of unsatisfactory vision. Result A contact lens trial was recommended for BE to enhance visual quality. Rigid corneal lenses (RCLs) were tried, but the patient was intolerant to them. Large diameter SCLs of different FSEs (0, 0.6, and 0.8) were tried to reduce these aberrations. SCL with FSE 0 yielded the most favourable visual outcome, which was confirmed subjectively on ocular aberrometry. Conclusion With this case report, we hypothesize that the eccentricity of SCL can be selected according to the asphericity (at 6 mm) of the posterior corneal surface. This case also re-emphasizes the impact of SCL with varying FSEs on reducing HOAs and enhancing visual quality in eyes where conventional RCLs yield suboptimal results.

Repeatability and agreement of multispectral refraction topography in school children before and after cycloplegia

BackgroundThe purpose of this study was to evaluate the repeatability and agreement of multispectral refraction topography (MRT) in measuring retinal refraction before and after cycloplegia in children. The results of this study will provide valuable insights into the accuracy and reliability of MRT as a tool for assessing retinal refraction in pediatric patients.MethodsChildren aged 7 to 18 years old were recruited for this prospective research. The central and peripheral retinal refraction was measured three times using multispectral refraction topography (MRT) before and after cycloplegia. The retinal deviation value (RDV) was used to describe the average peripheral refractive error of the retina. In addition, objective refraction (OR) and subjective refraction (SR) measurements were also performed.ResultsA total of 60 children with a mean age of 10.50 ± 1.81 years were enrolled. Before cycloplegia, all the central and peripheral retinal refraction parameters showed good repeatability with the lowest intraclass correlation coefficient (ICC) being 0.78 in the retinal deviation value from 45° eccentricity to 53° of the retina (RDV 45–53). After cycloplegia, the repeatability of MRT was significantly enhanced (lowest ICC = 0.91 in RDV-I). The 95% limits of agreement (LoA) of the central refraction and OR ranged from − 2.1 to 1.8 D before cycloplegia, and from − 1.69 to 0.27 D after cycloplegia. The 95% LoA of the central refraction and SR ranged from − 1.57 to 0.36 D after cycloplegia. All the 95% LoA demonstrated high agreement.ConclusionsThe MRT shows high agreement with autorefractometry and experienced optometrist in measuring central refraction. Additionally, the MRT provides good repeatable measurements of retinal peripheral refraction before and after cycloplegia in schoolchildren.

Comparison of Subjective and Wavefront-Measured Refractions by InnovEyes Platform in Myopic Patients.

To compare the subjective refraction and Innov-Eyes (Alcon Laboratories, Inc) wavefront-measured refraction in patients with myopia and astigmatism before refractive surgery. Consecutive myopic patients planning to receive refractive surgery with ages between 18 and 50 years old were retrospectively enrolled. The subjective and wavefront-measured refraction (InnovEyes platform) were compared, and the influential factors for the measurement difference were analyzed. Of the 500 eyes enrolled, the mean age was 29.3 ± 6.8 years. Mean wavefront-measured refraction was 0.58 ± 0.62 diopters (D) more myopic and 0.10 ± 0.27 D more astigmatic than subjective refraction (P < .001). Wavefront-measured refraction exhibited excellent consistency and significant correlation with subjective refraction. Linear regression demonstrated that age (P = .008) and wavefront-measured sphere standard deviation (P < .001) were positively correlated with spherical measurement difference, and total quality score (P < .001) and accommodative response (binocular cross-cylinder) (P = .011) demonstrated a negative correlation with spherical and cylindrical measurement difference. The patients with low wavefront measurement quality had significantly greater spherical differences than those with high-quality measurement (P < .001). The patients with accommodative lead had greater spherical equivalent differences than other participants (P = .047). Wavefront-measured refraction had excellent consistency with subjective refraction, although it measured more myopia and astigmatism than subjective refraction. The spherical measurement difference was greater in older patients and those with accommodative lead. More stable and higher quality repeated measurements will yield closer results between wavefront-measured and subjective refraction. [J Refract Surg. 2024;40(11):e836-e844.].

Vision Screening and Detection of Ocular Abnormalities in School Children by Teachers in Jordan.

To evaluate the accuracy of vision screening and detection of ocular abnormalities conducted by teachers in school children in Jordan compared with vision testing by optometrists and ocular disease identification by ophthalmologists. A non-random, purposive sampling strategy where 6-year-old and 15-year-old school children from three schools in Amman, Jordan were included. Twenty-two teachers were trained to conduct visual acuity screening using the 0.2 logMAR line of the distance visual acuity (DVA) chart at 10 feet and near visual acuity (NVA) chart at 16 inches, in addition to detecting ocular abnormalities. An optometrist assessed the visual acuity and conducted objective and subjective refraction, while an ophthalmologist examined the ocular health of all children. A total of 542 children (51% female) were included in the study, of which 47% were 6 years old and 53% were 15 years old. Teacher screening had sensitivities of 76.92% for DVA, 68% for NVA, and 37.50% for abnormality detection. The specificities of DVA, NVA, and ocular abnormalities were 98.22%, 98.48%, and 99.24%, respectively. The positive predictive value for DVA, NVA, and ocular abnormalities were 83.33%, 99.00%, and 60%, respectively. The negative predictive value for each procedure was 98.22% for DVA, 98.48% for NVA, and 98.12% for ocular abnormalities. Teachers were able to conduct vision screening with a high level of accuracy compared to the gold standard of testing by optometrists, which would be useful for the early detection and referral of refractive errors in school children. However, they were unable to detect ocular abnormalities compared with the gold standard for disease identification by ophthalmologists. Further training and monitoring, or different training approaches should be implemented to enable teachers to identify ocular abnormalities at acceptable levels.

Evaluation of Long-term Rotational Stability and Functional Performance of Two Toric Multifocal IOL Models Beyond 5 Years.

To assess visual outcomes and stability of lens alignment more than 3 years after implanting either the AT Lisa Tri Toric (Carl Zeiss Meditec) or the Acrysof IQ Restor Toric (Alcon Laboratories, Inc) intraocular lens (IOL). Patients who had received either the AT Lisa Tri Toric or the Acrysof IQ Restor Toric IOL were included in the study. The average follow-up period was 5.4 years for the AT Lisa Tri Toric group and 7.9 years for the Acrysof IQ Restor group. The examinations covered included: subjective refraction, monocular and binocular corrected and uncorrected visual acuity at far (4 m), intermediate (75 cm), and near (40 cm) distances, binocular best-corrected defocus curve analysis (4 m), contrast sensitivity evaluation, assessment of IOL axial position, and presence of positive dysphotopsia. A total of 42 eyes were evaluated. Both groups exhibited good long-term lens axial stability. The AT Lisa Tri Toric group had a mean misalignment of 4.8 ± 3.2° from the preoperatively determined axis, whereas the Acrysof IQ Restor Toric group had an average misalignment of 5.4 ± 4.5° (no statistically significant difference, P = .578). Mean achieved spherical equivalent was -0.19 ± 0.36 diopters (D) for the AT Lisa Tri Toric group and 0.15 ± 0.39 D for the Acrysof IQ Restor Toric group. In the AT Lisa Tri Toric group, 18 eyes (72%) achieved an uncorrected distance visual acuity of 0.10 logarithm of the minimum angle of resolution (20/25 Snellen) or better, compared to 15 eyes (88%) in the Acrysof IQ Restor Toric group. Overall, 21 eyes (84%) in the AT Lisa Tri Toric group and 14 eyes (83%) in the Acrysof IQ Restor Toric group achieved a postoperative spherical equivalent refraction between -0.50 and +0.50 D. Both the AT Lisa Tri Toric and the Acrysof IQ Restor Toric IOLs showed good long-term stability and functional outcomes. They proved to be effective options for restoring vision at far, intermediate, and near distances, providing a viable solution for presbyopia correction even several years after implantation. [J Refract Surg. 2024;40(11):e845-e853.].

Convergence insufficiency prevalence in attention deficit and hyperactivity disorder children depends on the diagnosis criteria.

Attention deficit and hyperactivity disorder (ADHD) is a neurodevelopmental condition commonly seen in children and adolescents, characterised by an increase in distractibility or inattention. Several studies have noted a higher rate of visual problems in this group, especially convergence insufficiency (CI), but when using different diagnostic criteria. The aim of this study was to evaluate visual function in ADHD children and non-ADHD controls to compare the different signs for diagnosis of CI. In this prospective case-control study, a group of children aged 7-17 years, diagnosed with ADHD before the start of pharmacological treatment and matched for age and gender with non-ADHD controls were examined. Visual acuity (VA), objective and subjective refraction, accommodative amplitude and facility, heterophoria, positive and negative fusional vergences (PFV and NFV) and stereopsis were assessed. Sixty participants (30 ADHD and 30 non-ADHD controls) were evaluated. There was no significant difference between the two groups for VA, refraction and accommodative abilities. There were significant differences in PFV and NFV: PFV break/recovery values for the ADHD and control groups were 18.9/16.2∆ and 26.9/22.1∆, respectively. Respective values for NFV were 15.7/13∆ and 19.3/15.9∆. Using the three signs of receded near point of convergence (NPC), decreased PFV and exophoria 4∆ greater at near than distance, the prevalence of CI was equivalent for the ADHD and controls (p = 0.34) If only two signs were considered for the CI diagnosis, (i.e., receded NPC and decreased PFV), then prevalence was significantly greater for the ADHD group (p < 0.01). These results show a higher prevalence of binocular vision problems in the ADHD group. This suggests a relationship between vergence problems and ADHD, but the direction of this link remains unclear. Further studies with specific samples may be needed to understand fully the association between binocular vision disorders and ADHD.

Comparative visual performance of ultraviolet light-filtering and violet light-filtering monofocal intraocular lenses of the same material and basic design

We compared the visual performance of ZCB00 ultraviolet light-filtering and ZCB00V violet light-filtering monofocal intraocular lenses (IOLs) (both Johnson & Johnson Surgical Vision) with the same materials and basic design in cataract patients treated from 2011 to 2020. The evaluations were performed 10 weeks after the last surgery for implantation of bilateral lenses ≤ 3 months apart. The ZCB00 and ZCB00V groups included 904 eyes from 452 patients (age 72.3 ± 6.8 y; women/men, 268/184) and 1374 eyes from 687 patients (age 73.0 ± 7.4 y; women/men, 415/272), respectively. Statistical validity was confirmed using a linear mixed-effects model with binocular data and adjustments for age, sex, subjective refraction cylinder, subjective refraction spherical equivalent, corneal astigmatism, axial length, pupil diameter, and corneal higher-order aberrations. ZCB00 showed slightly but significantly better results (p < 0.05, Wald) for uncorrected intermediate/near visual acuity, corrected near visual acuity, and components of the 25-item Visual Function Questionnaire (VFQ-25) (Role_Limitation, Mental_Health, Social_Function, Distance_Vision, Color_Vision). Additionally, ZCB00V showed significantly better contrast sensitivity with glare (visual angle of target: 6.3°/4.0°/0.7°; p < 0.00068, Wald); slightly but significantly better contrast sensitivity without glare (4.0°/2.5°/1.6°) and with glare (2.5°/1.6°/1.0°), VFQ-25 General_Health scores, and near spectacle independence; and slightly but significantly smaller higher-order aberrations (internal, scaled to a 6-mm pupil; Wavefront_6_post_I_Trefoil) (p < 0.05, Wald).

Refractive error and ocular alignment in school-aged children from low-income areas of São Paulo, Brazil

BackgroundUncorrected refractive errors and amblyopia are reported as the two main causes of childhood visual impairment and blindness worldwide. Our purpose was to evaluate refractive status, ocular alignment and effective refractive error coverage (eREC) of school-aged children from low-income areas of Sao Paulo city, Brazil.MethodsData from the “Ver na Escola” Project were used for the current study. Children enrolled in the selected schools had an ophthalmic exam including eye alignment assessed by cover test, automatized and subjective dynamic and static refraction. The associations of demographic variables with occurrence and magnitude of refractive errors and eREC were investigated by multiple logistic regressions and multilevel mixed effect models.ResultsA total of 17,973 children (51.12% females) with mean ± sd age 8.24 ± 3.54 years old examined from July 2018 to July 2019, were included in the study. Most of the participants (73%) showed orthoposition of the visual axis for both distance and near. Heterophoria was found in about 25% of participants (N = 4,498), with 71.7% of them (N= 3,222) classified as exophoria. Less than 2% (N = 232) showed strabismus, most of them (N = 160) esotropia. Overall, 1,370 (7.70%) of participants had myopia and 577 (3.24%) had hyperopia. Age was found to be significantly associated with increasing static subjective refraction spherical equivalent (Coefficient: -0.18; 95% Confidence Interval (CI): -0.21 to -0.16; p < 0.001). Female sex (Odds Ratio (OR) = 1.13; 95%CI: 1.01–1.27; p = 0.027) and older age (OR = 1.17; 95%CI: 1.16–1.19; p < 0,001) were significantly associated with myopia diagnosis. Older age decreased the odds of hyperopia (OR = 0.95; 95%CI: 0.93–0.98; p < 0.001). The overall effective refractive coverage was 51.76% and was significantly associated with age group, ranging from 32.25% in children aged 3 to 7 years to 61.35% in children aged 8 to 12 years.ConclusionsMost children have shown eye alignment for both distance and near assessments and no refractive error. Myopia was observed in 7.70% of the population and it was associated with older age and female sex. Hyperopia was observed in 3.24% and was associated with younger age. The overall eREC was 51.76%, significantly associated with age.

Non-orthogonal spectacle correction for irregular astigmatism.

To investigate the potential improvement in visual acuity and subjective perception of image quality in patients with keratoconus using non-orthogonal correction (NOC) cylinder trial lenses where the steep and flat power meridians are set at angles less or greater than 90°. A set of NOC plano/cylindrical trial lenses, where the axes between the power meridians were set at a range of non-orthogonal angles, were used to refract 18 participants with keratoconus in whom 23 eyes were used for testing. Corneal elevation data were processed by bespoke MATLAB code from Pentacam Scheimpflug tomographer scans. Each participant first underwent subjective refraction using standard orthogonal cylinder trial lenses, and the monocular best-corrected visual acuity (BCVA, logMAR) was recorded for each eye. They then underwent a second subjective refraction using NOC cylinder trial lenses created for the study and completed a questionnaire to elicit their subjective appraisal of letter clarity and ghosting. Fourteen (61%) eyes demonstrated an increase in objective BCVA with the NOC versus the orthogonal correction; seven (30%) eyes showed no change and in two (9%) eyes, the BCVA was slightly worse. Further, 87% and 79% experienced an increase in letter clarity and a reduction in ghosting, respectively, independent of changes in BCVA. The majority of non-orthogonal angles were in the range of 80°-85°, and it was possible to refine the cylinder and axis of the NOC further compared with the orthogonal correction. All but one of the participants said they would be interested in trying non-orthogonal spectacles if the opportunity arose. Correcting irregular astigmatism in keratoconic individuals with non-orthogonal spectacle correction may provide benefit in terms of increased visual acuity, improvements in letter clarity and a reduction of ghosting effects. This type of correction has the potential to improve the overall quality of life for patients with keratoconus.

KeraRing Implantation with Femtosecond Laser in Keratoconus Treatment at Different Stages

Objective: To investigate the reliability and effectiveness of femtosecond laser-assisted KeraRing (Mediphacos, Belo Horizonte, Brazil) implantation in treating keratoconus. Methods: Intrastromal corneal ring segments (KeraRing, Mediphacos, Brazil) were implanted in 15 eyes of 14 patients unable to tolerate contact lenses. Femtosecond laser (Intralase, 60 Hz) was used for corneal tunnel creation. Based on the distribution of ectatic area on the cornea, dual segments were implanted in 9 eyes, while single segments were implanted in 6 eyes. Preoperative and postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), objective and subjective refraction, and topographic corneal curvature (K) values of the cases were compared using the Wilcoxon test. Results: The mean age of patients was 25±7.46 (range: 15-39) years, with a mean postoperative follow-up period of 10.8±7.37 (range: 1-24 months). BCVA improved in all eyes during the follow-up period, increasing from a mean of 0.12±0.1 to 0.38±0.24 (p

Subjective quasi-vector-based refraction with a conventional phoropter.

To introduce a novel methodology for subjective refraction based on power vectors with a conventional phoropter. A conventional phoropter was used to measure power vector components of refraction (M, J0 and J45) directly by using the sphere power (for M measurement) and the cylinder power combined with the Jackson cross-cylinders (for J0 and J45 measurements). Conventional subjective refraction was also performed, and this result was mathematically transformed into power vector notation for comparison purposes. Visual acuities with the conventional prescription and the quasi-vector-based prescription were compared. Refractive error from 40 healthy participants was measured by conventional and quasi-vector-based subjective refraction. No differences were found between methods for any of the power vector components of refraction (p > 0.21 in all cases). The visual acuity achieved with the prescriptions yielded similar values (p = 0.85). Subjective refraction can be measured directly in power vector notation using a conventional phoropter without any additional adaptation and computation.

Effect of Monofocal, Wavefront-Shaped, and Diffractive Trifocal Intraocular Lenses on Scanning-Slit Automated Refraction

PurposeTo compare scanning-slit retinoscopy automated refraction spherical equivalent (ARSE) to subjective manifest refraction spherical equivalent (MRSE) in normal eyes with four different types of intraocular lenses (IOLs). DesignRetrospective cross-sectional study Methods279 pseudophakic eyes that underwent lens extraction at a private center with implantation of either a wavefront shaped IOL (Acrysof® Vivity, DFT015), a nonapodized diffractive trifocal IOL (Acrysof® Panoptix), or a monofocal IOL with negative spherical aberration (Tecnis ZCBOO) or aberration-free (Envista Mx60E). Patients who had an automated refraction measurement with retinoscopy refractometer and aberrometer (NIDEK OPD Scan III, Nidek Technologies) and subjective refraction data 1-2 months postoperatively were included in the study. Main outcome measured was the difference between automated refraction and subjective refraction. ResultsSixty-one eyes implanted with a DFT015 IOL, 78 eyes with a TFNT00 IOL, 40 with a ZCBOO IOL and 100 with a Mx60E IOL were enrolled in this study. Statistically significant myopic results were observed when using ARSE compared to MRSE in the DFT015 (-0.95±0.64, -0.33±0.65, p < .001), TFNT00 (-0.43±0.36, -0.2±0.35, p <.001), ZCBOO (-0.81±0.63, -0.4±0.69, p = .008) and Mx60E (-0.75±0.65, -0.45±0.52; p <0.05) IOL groups. The absolute difference between the 2 methods was statistically significant in the DFT015 IOL group (0.65±0.49; p< 0.05). ConclusionAutomated refraction yields myopic results in pseudophakic eyes with monofocal and presbyopia correcting IOLs and may be used with caution. Manifest refraction “push-plus” technique should be used in all pseudophakic eyes to avoid over-minus prescriptions, especially in patient with residual refractive error following cataract surgery.

Axial length acquisition success rates and agreement of two swept-source optical biometers in eyes with dense cataracts.

Swept-source optical coherence tomography-based (SS-OCT) biometers have been used in different clinical studies with the aim of assessing the accuracy of the technique, specifically in eyes with dense cataracts. Our objective is to evaluate the axial length acquisition success rates and agreement of two SS-OCT biometers when measuring axial length and biometric parameters in eyes with dense cataracts. 46 eyes (46 patients) with dense cataracts (LOCS III grade ≥ 4) were measured 3 consecutive times using the Eyestar 900 and Argos SS-OCT biometers. Keratometry (K1, flat and K2, steep), central corneal thickness (CCT), white-to-white (WTW), anterior-chamber-depth (ACD), lens-thickness (LT), and axial length were measured using both biometers. The percentage acquisition success rate and a Bland-Altman analysis to determine the agreement between the biometers were calculated. Corrected and uncorrected distance visual acuity, subjective refraction, and axial length (to assess preoperative axial length accuracy) were measured 1-month post-cataract surgery. The mean LOCS III score was 4.37 ± 0.68. The acquisition success rates for both biometers was 100%. There were statistically significant differences between the two SS-OCT biometers for all parameters evaluated (p < 0.05). The mean differences for K1, K2, CCT, WTW, ACD, LT and axial length were 0.106 D, 0.128 D, -6.347 μm, -0.054 mm, 0.095 mm, 0.110 mm, and -0.036 mm, respectively. The mean pre- and post-surgery axial length difference was -0.036 mm for the Eyestar 900 and -0.020 mm for the Argos. This difference was ≤ 0.1 mm in 97.82% of eyes with the Eyestar 900 and in 100% of eyes with the Argos. SS-OCT biometry successfully measures axial length in dense cataracts. The differences between biometers in some parameters may have a clinically significant impact but should be judged individually. The pre- and post-surgery axial length differences for each biometer can be considered clinically negligible and should not affect the IOL power calculation.

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

To compare the clinical and aberrometric outcomes obtained with a new diffractive pentafocal intraocular lens (IOL) and a diffractive trifocal IOL. 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. 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. 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.].

Comparison of the accommodative amplitude measured with and without the use of a specialised accommodative rule in children

ObjectiveTo determine the agreement between measurements of accommodative amplitude (AoA) in children using a specialised accommodative rule and measurments without it.MethodsA total of 502 children underwent optometric examinations, including the...

Influence of Capsular Tension Rings on the IOL-Capsule Complex in Patients With Long Axial Length: A Clinical Observation Based on SS-OCT.

To evaluate the influence of a capsular tension ring (CTR) on the intraocular lens (IOL)-capsule complex after cataract surgery in patients with long axial length. This was a prospective study. Patients underwent phacoemulsification and IOL implantation, with or without CTR implantation. Swept-source optical coherence tomography was performed at 1 day, 1 week, 1 month, and 3 months postoperatively to determine the postoperative aqueous depth (PAD), capsular bend index (CBI), and IOL tilt and decentration. Spherical equivalent values were obtained through subjective refraction and autorefraction. Root mean square was adopted to evaluate the indices listed above. Forty-three patients (56 eyes) were included in the study. Generalized estimating equation analysis of PAD showed a statistical difference between groups (P = .031). The RMS of the change in PAD was smaller in the CTR group than in the non-CTR group during the 3 months after surgery (P = .015). CBI in the CTR group increased more from 1 to 3 months after surgery than that in the non-CTR group (P = .025). The RMS of the change in vertical decentration was smaller in the CTR group than in the non-CTR group during the 3-month follow-up (P = .009). CTR implantation can stabilize the axial position of the IOL within the capsular bag after cataract surgery in patients with long axial length without affecting the refractive stability. The formation of capsular bend may be slightly delayed in the early stage after CTR implantation, but it accelerates from 1 to 3 months after surgery. [J Refract Surg. 2024;40(9):e654-e661.].

Distribution and associated factors of keratometry and corneal astigmatism in an elderly population

To determine the distribution of keratometry and corneal astigmatism (CA) and their association with demographic factors, systemic parameters, anthropometric measures, ocular biometric indices, and refractive errors in people aged 60 years and above. In this cross-sectional study, 160 clusters were randomly selected from Tehran city (Iran) using the multi-stage cluster sampling method. All participants underwent optometric examinations including testing uncorrected and best-corrected distance visual acuity, non-cycloplegic autorefraction, and subjective refraction. Pentacam imaging for all participants was carried out using Pentacam AXL. Keratometry and CA were reported based on Pentacam’s data. The average, standard deviation (SD) and 95% confidence interval (CI) of flat keratometry (Kf), steep keratometry (Ks), mean keratometry (mean K), and CA were 44.02 ± 1.58 D (95% CI 43.94–44.1), 44.86 ± 1.67 D (95% CI 44.78–44.94), 44.44 ± 1.58 D (95% CI 44.36–44.52), and 0.84 ± 0.74 D (95% CI 0.81–0.87), respectively. The 95% and 99% percentiles of mean K were 47.1 and 48.6 D, respectively. According to the multiple generalized estimating equation model, the mean K was significantly higher in males, in myopes, and in those with higher systolic blood pressure. Moreover, the mean K was inversely related to the axial length, height, anterior chamber depth (ACD), corneal diameter, and central corneal thickness (CCT). The prevalence of various types of CA based on a cut-off > 0.50 D was as follows; with-the-rule: 32.5% (95% CI 30.6–34.4), against-the-rule: 18.2% (95% CI 16.7–19.7), and oblique: 10.0% (95% CI 9.1–11.0). The present study investigated the normal distribution of keratometry and CA in individuals ≥ 60 years, and results can be used in clinical matters, especially in intraocular lens power calculation. Sex, systolic blood pressure, height, and some biometric components such as ACD, corneal diameter, and CCT were significantly related to keratometry and should be considered.

Comparison between a new transepithelial PRK vs. conventional alcohol-assisted PRK: Corneal densitometry and aberrometry study.

To describe and compare corneal densitometry, subjective refraction, visual acuity, and corneal higher order aberrations (HOA) after corneal refractive surgery using either alcohol-assisted photorefractive keratectomy (aaPRK) or single-step transepithelial PRK (tPRK). We conducted a retrospective and observational study. We analyzed 120 right eyes from 120 healthy consecutive myopic patients who underwent aaPRK or tPRK to correct myopia of up to 6 diopters and astigmatism of up to 2 diopters. The WaveLight EX500 excimer laser (Alcon Laboratories, Inc.) was used in all cases. Visual acuity, subjective refraction, and Pentacam AXL® measurements were performed at the preoperative visit and at 6-months follow-up visit. Pentacam AXL® software was used to assess corneal optical density in various annuli for different corneal depths and anterior corneal HOA (6 mm area of analysis). Preoperative spherical equivalent values were similar between groups preoperatively (-3.07 ± 1.52 and -3.38 ± 1.46 in the aaPRK and tPRK groups, respectively). There were no statistically significant differences in visual acuity and postoperative refraction between groups. Postoperative corneal densitometry did not show statistically significant differences in any of the areas studied and both surgical procedures obtained similar results. However, analysis of HOA showed statistically significant differences between the techniques (1.42 ± 0.39 and 1.80 ± 0.62 for the aaPRK and tPRK groups, respectively; p = 0.000). Both aaPRK and single-step tPRK gave comparable visual, refractive, and corneal density outcomes. Some differences were observed in HOA but were not clinically relevant.

Distributions of non-cycloplegic subjective refractions at Sekororo Hospital in Limpopo province, South Africa

Distributions of non-cycloplegic subjective refractions at Sekororo Hospital in Limpopo province, South Africa