Refractive Measurements Research Articles

The Relationship Between Feeding Pattern and Measurements of Refraction in Preschool Children

Objective: To compare the effect of feeding human milk as opposed to formula and human milk on refractive error in preschool children aged 3 to 6 years. Material and Methods: One hundred and seventy six eyes of 88 children were evaluated. According to the feeding pattern, the patients who fed only breast-fed were classified as Group I, and the patients who fed with combination of breast-fed and formula were classified as Group II. Results were retrospectively compared between groups. Results: A total of 88 children undergone detailed ophthalmological examinations, of which 40 (45.5 %) were males and 48 (54.5 %) were females. Maternal birth age of 27.3% (n=24) of the children included in the study was over 30 years and birth weight of 96.6% (n=85) was over 2500 grams. The mean ± standard deviation of the spherical, cylindrical and spherical equivalent (SE) values were 1.61±1.46 D; -0.98 ± 0.69 D and 1.12±1.43 D in group I and 1.00±2.57 D; -0.90 ± 0.81 D and 0.55 ± 2.72 D in group II, respectively (p=0.507 for spherical; p=0.299 for cylindrical and p=0.799 for SE). Although myopic refraction was less common in the breastfed group, there was no significant difference in myopic refraction between the groups (p= 0.507). Conclusion: In conclusion, mean refractive error were different according to feeding pattern, but this study did not show significant differences between groups (p<0.050). There is a need to confirm this finding by performing more studies with a larger sample sizes.

Knowledge, attitude, and practice of childhood myopia among Indian optometrists: A questionnaire-based study.

To investigate the knowledge of myopia and its natural history including complications and clinical approaches for management adopted by optometrists across India. An online survey was distributed to Indian optometrists. A pre-validated questionnaire was adopted from previous literature. Respondents provided information about their demographics (gender, age, practice location, and modality), myopia knowledge, self-reported practice behaviors relating to childhood myopia, the information and evidence base used to guide their practice, and perceived extent of adult caregiver engagement in making management decisions for myopic children. A total of 302 responses were collected from different regions of the country. Most respondents demonstrated knowledge of the association between high myopia and retinal breaks, retinal detachment and primary open-angle glaucoma. Optometrists used a range of techniques to diagnose childhood myopia, with a preference for non-cycloplegic refractive measures. The most common approaches to management were single-vision distance despite most optometrists identifying orthokeratology and low-dose (0.01%) topical atropine as two potentially more effective therapeutic interventions for controlling childhood myopia progression. Almost 90% of respondents considered increasing the time spent outdoors to be beneficial for reducing the rate of myopia progression. The main sources of information used to guide clinical practice were continuing education conferences, seminars, research articles, and workshops. : Indian optometrists appear to be aware of emerging evidence and practices, but are not routinely adopting measures. Clinical guidelines, regulatory approval, and sufficient consultation time may be of value for assisting practitioners in making clinical decisions based on the current available research evidence.

Risk Factors Associated with Keratoconus in an Iranian Population.

To determine associated factors for keratoconus (KCN) in the Iranian population. In this retrospective case-control study, 100 KCN patients and 200 age- and sex-matched individuals, who were either candidates for photorefractive keratectomy or healthy referrals from the Torfeh Eye Hospital, were included as the case and control groups, respectively. KCN patients were all registered at the Iranian National Registry of Keratoconus (KCNRegⓇ). Demographic characteristics, patients' symptoms and their habits, as well as systemic and ocular disorders were documented. Clinical examinations included best corrected visual acuity (BCVA) and refractive error measurements, biomicroscopic examination, and corneal imaging. In this case group, the frequency of mild, moderate, and severe KCN was 38%, 28%, and 34%, respectively. Parental consanguinity (odds ratio [OR] = 1.758, P = 0.029), positive familial history in patients' first degree (OR = 12.533, P 0.001) and second degree (OR = 7.52, P 0.001) relatives, vernal keratoconjunctivitis (OR = 7.510, P = 0.003), severe eye rubbing (OR = 10.625, P 0.001), and systemic diseases including migraine, hypertension, and thyroid disease (OR = 6.828, P = 0.021) were found as associated factors for KCN. Lesser frequency of KCN was observed in patients with Fars ethnicity (OR = 0.583, P = 0.042), with higher levels of wealth indices (OR = 0.31, P 0.001) and higher levels of education (OR = 0.18, P = 0.024). Severe eye rubbing, vernal keratoconjunctivitis, parental consanguinity and positive familial history of KCN, low socioeconomic status, and low levels of education were significantly associated with KCN in our study population.

A Proposed Method for Estimating Refractive Error in Primary School Children.

Background This study aimed to evaluate consecutive measurements of biometric parameters, age, and refraction in a cohort of Turkish primary school-age children and to assess the correlation between biometric changes and refraction. Methodology The study population was seven and 12-year-old children (n = 197). The retrieved data consisted of three consecutive measurements with a one-year interval for each subject. Data from one eye (right) were used. Age, gender, body mass index, spherical equivalent (SE), axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), keratometry (K), and lens thickness (LT) were analyzed. The onset and final data were retrieved from the database in 2013 and 2016, respectively. Statistically, logistic and Cox regression models of all parameters were analyzed, and the significance level was set at 5%. Results The median of the onset and final SE values were -0.00 D (0.00-0.00) and 0.50 D (0.19-1.00), respectively. The onset AL (hazard ratio (HR) = 5.82, 95% confidence interval (CI) = 3.45-9.76, β = 1.76, p < 0.001), Kmean(HR = 2.28, 95% CI = 1.67-3.11, β = 0.82, p < 0.001), and age (HR = 0.77, 95% CI = 0.59-0.99, β = -0.26, p = 0.046) were correlated with myopia progression. To calculate the estimated SE, the onset data were included in the logistic regression model. The onset SE (β = 0.916, p < 0.001), AL (β = -0.451, p < 0.001), ACD (β = 0.430, p = 0.005), and K (β = -0.172, p < 0.001) were correlated with the mean final SE. An equation was generated using the regression model analysis. Conclusions The onset parameters of SE, AL, ACD, and K were confirmed to correlate with the final SE values in the proposed model. To confirm the use of the refractive calculator, a cross-validation analysis is needed to estimate three-year subsequent refractive error among seven and 12-year-old children.

Calcipotriol Attenuates Form Deprivation Myopia Through a Signaling Pathway Parallel to TGF-β2–Induced Increases in Collagen Expression

To determine the role of calcipotriol, a vitamin D3 analogue, in myopia development and altering the expression of scleral α1 chain of type I collagen (Col1α1) in mice. We also aimed to identify if the signaling pathway mediating the above changes is different from the one involved in transforming growth factor β2 (TGF-β2)-mediated increases of COL1A1 in cultured human scleral fibroblasts (HSFs). C57BL/6J mice were either intraperitoneally injected with calcipotriol and subjected to form deprivation (FD) or exposed to normal refractive development for 4weeks. Scleral vitamin D receptor (Vdr) expression was knocked down using a Sub-Tenon's capsule injection of an adeno-associated virus-packaged short hairpin RNA (AAV8-shRNA). Refraction and biometric measurements evaluated myopia development. A combination of knockdown and induction strategies determined the relative contributions of the vitamin D3 and the TGF-β2 signaling pathways in modulating COL1A1 expression in HSFs. Calcipotriol injections suppressed FD-induced myopia (FDM), but it had no significant effect on normal refractive development. AAV8-shRNA injection reduced Vdr mRNA expression by 42% and shifted the refraction toward myopia (-3.15 ± 0.99D, means ± SEM) in normal eyes. In HSFs, VDR knockdown reduced calcipotriol-induced rises in COL1A1 expression, but it did not alter TGF-β2-induced increases in COL1A1 expression. Additionally, TGF-β2 augmented calcipotriol-induced rises in COL1A1 expression. TGF-β receptor (TGFBRI/II) knockdown blunted TGF-β2-induced increases in COL1A1 expression, whereas calcipotriol-induced increases in VDR and COL1A1 expression levels were unaltered. Scleral vitamin D3 inhibits myopia development in mice, potentially by activating a VDR-dependent signaling pathway and increasing scleral COL1A1 expression levels.

Accounting for speckle-scale beam bending in classical ray tracing schemes for propagating realistic pulses in indirect drive ignition conditions

We propose a semi-analytical modeling of smoothed laser beam deviation induced by plasma flows. Based on a Gaussian description of speckles, the model includes spatial, temporal, and polarization smoothing techniques, through fits coming from hydrodynamic simulations with a paraxial description of electromagnetic waves. This beam bending model is then incorporated into a ray tracing algorithm and carefully validated. When applied as a post-process to the propagation of the inner cone in a full-scale simulation of a National Ignition Facility (NIF) experiment, the beam bending along the path of the laser affects the refraction conditions inside the hohlraum and the energy deposition, and could explain some anomalous refraction measurements, namely, the so-called glint observed in some NIF experiments.

Efficacy of custom-made soft keratoconus lenses on corneal aberrations and photic phenomena in patients with keratoconus: a corneal topography imaging based study.

To evaluate the efficacy of custom-made soft keratoconus (KC) lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC. Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone (Toris K) soft silicone hydrogel lenses. Best spectacle-corrected visual acuity (BSCVA) and contact lens-corrected visual acuity (CLCVA) were recorded. Lower- and higher-order corneal aberrations (LOAs and HOAs) were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones. Mesopic pupil diameter and subjective photic phenomena were also assessed. Mean CLCVA was significantly improved compared to BSCVA (P<0.0001). Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses, except for posterior corneal curvature values. In the 4.5 mm central optical zone, all wavefront aberrations decreased significantly after lens fitting (P<0.0001). In contrast, in the 7 mm (peripheral) optical zone, values for HOAs, spherical and residual aberrations, and optical path differences were increased, while LOAs, trefoil, and quadrifoil coefficients were decreased. The rate of photic phenomena was significantly higher in participants with a pupil size >6.00 mm (85.7%). Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations. This practical and nonsurgical approach appears to be an effective method for the visual management of KC.

Non-Miotic Improvement in Binocular Near Vision with a Topical Compound Formula for Presbyopia Correction.

The aim of this case series was to examine the association between unaided binocular visual acuity for near vision and pupil change after the instillation of a special topical formulation for presbyopia treatment. This was acase series consisting of consecutive participants with presbyopia aged 40-70years who were tested for visual acuity and pupil diameter before and 2 h after instillation of a formulation of pilocarpine and phenylephrine drops (FOV Tears) for presbyopia. Participants underwent subjective refraction, photopic and scotopic pupil diameter measurement and unaided monocular and binocular visual acuity testing by logMAR for distance and near vision both pre- and post-instillation of eye drops. The study enrolled 363 subjects (n = 176 women, 48%) with a mean (± standard deviation) age of 50.4 ± 5.8years. Mean spherical equivalent (SE) changed significantly (- 0.17 Diopters) after instillation of the FOV Tears formulation (p < 0.001). Post-instillation of eye drops, the scotopic pupil diameter decreased by 0.97 ± 0.98mm, and the near visual acuity by logMAR improved significantly by nearly two lines (p < 0.01). In the linear regression analyses, age (p < 0.001) and SE pre-drop instillation (p < 0.001) were associated with unaided binocular visual acuity. The changes in photopic pupil diameter and the scotopic pupil diameter were not associated with unaided binocular visual acuity. The use of the pilocarpine and phenylephrine formulation (FOV Tears) improved binocular visual acuity for near vision in presbyopic patients, and the effect was independent of pupil change.

Prevalence of Meibomian Gland Dysfunction and Its Determinants in a Deprived Rural Population of Iran: A Population-Based Cross-Sectional Study

To investigate the prevalence of Meibomian gland dysfunction (MGD) and its relationship with some determinants in underserved villages of Iran. This population-based cross-sectional study was conducted on 3850 subjects that were randomly selected from the villages of two underserved districts in the north and southwest of Iran using multistage cluster sampling. All participants underwent complete ophthalmic examinations, including visual acuity and refraction measurement. Then, slit-lamp biomicroscopy was done by an ophthalmologist to investigate MGD. Of 3850 subjects that were invited, 3314 participated in the study (participation rate=86.07%), of whom 1834 (55.34%) were women. The mean age of the participants was 37.7±21.4 years (range=2-93 years). The prevalence (95% CI) of MGD in at least one eye was 29.20% (27.35 to 31.06). According to the results of multiple regression analysis, MGD had a positive association with the male sex (OR: 1.75; CI 95%: 1.44 to 2.13), age 61-70 years (OR: 7.15; CI 95%: 3.65 to 14.01), and living in southern villages (OR: 1.82; CI 95%: 1.48 to 2.22) and an inverse association with education level (OR: 0.89; CI 95%: 0.80 to 0.98). The results of this study showed a lower prevalence of MGD even in Iranian rural regions compared to other Asian countries. This study found that older age, male sex, and low education level served as MGD risk factors. It seems that improved health conditions are an important factor in preventing MGD.

Estimation of Moist Atmospheric Profiles from Refraction and Attenuation Measurements by Using Centimeter and Millimeter Wave Links between LEO Satellites

Microwave occultation using centimeter and millimeter wave links between low Earth orbit (LEO) satellites provide a potential way to estimate the moist atmospheric profiles based on refraction and attenuation measurements, which is called the LEO-LEO microwave occultation (LMO) technique. It has not yet been implemented in orbit. In this paper, we analyzed the attenuation properties at different heights of centimeter and millimeter waves based on simulations. The observing capabilities with different frequency combinations at the X, K, and M bands were analyzed. The results show that LMO may improve the retrieval accuracy of bending angles above 35 km. By using several appropriate frequencies at the X+K+M band, water vapor profiles from the near-surface to the lower stratosphere (~24 km) can be obtained. When the M-band frequencies were added, the temperature retrieval accuracy does not change obviously, but the accuracy of water vapor retrieval can significantly improve above 15 km, especially at about 17–24 km, and the RMS errors decrease from over 20% to less 10%. For promoting the LMO mission in the real world, a frequency combination at the X+K band is proposed, which can provide the potential to observe the temperature profiles at about 2.5–50 km and water vapor profiles at about 2.5–15 km accurately under clear and cloudy conditions. This study demonstrates that LMO can greatly extend the capabilities of the radio occultation technique and improve our ability to measure the moist atmospheric profiles globally.

FIAT: A Device for Objective, Optical Measures of Accommodation in Phakic and Pseudophakic Eyes.

To present FIAT, a novel optical instrument and analysis package that is designed to elicit and optically record accommodation in human eyes. FIAT employs a Shack-Hartmann wavefront sensor and a retro-illumination pupil camera that records from a single eye at video rates. It is effective at eliciting accommodation by offering the subject a full-field binocular view of an alternating distant target and a near-eye display. FIAT analysis software computes wave aberrations for each video frame over full- or subpupil sizes and computes accommodative dynamics and accommodative range. The system is validated by showing accurate refraction measurements in model eyes and human eyes with trial lenses. Robust accommodative responses are shown for young eyes, and a lack of accommodative response is shown for a known presbyopes. Accommodative stimulus-response curves from five phakic subjects over a range of ages show expected results. Results from two individuals with monofocal intraocular lenses are shown. FIAT is an effective instrument for making accurate, objective measures of accommodation in phakic and pseudophakic eyes. We present a device that can play an important role in the development and testing of accommodating intraocular lenses.

Association between whole-grain intake and myopia in chinese children: a cross-sectional epidemiological study

BackgroundNutritional status influences the growth and development of the eyes. However, there are few studies on the association between diet, especially whole grains (WG) consumption, and myopia. The study aimed to evaluate the association between WG intake and myopia prevalence among primary school-age children in China.MethodsThis cross-sectional epidemiological study conducted between November 2019 and December 2019 included 586 children, aged 6–12 years, attending primary school in Binhai district, Tianjin, China. Ophthalmologic examinations and optometric cycloplegic refraction measurements were conducted. Information was collected on known risks and protective factors for myopia and the consumption of WGs, vegetables, and fruits. This association between the probability of myopia and the proportion of WG consumption (WG proportion was calculated as the mean intake from WG sources divided by total grain intake), adjusted for protective and risk factors, was analysed using crude and multivariable logistic regression.ResultsAmong the study participants, 226/586 (38.57%) children had myopia in at least one eye. WG intake was inversely correlated with the prevalence of myopia. Furthermore, in the multivariate analysis, WG intake of > 50% was identified as a protective factor against myopia after subsequent adjustment for children’s age, sex, parental myopia, near-work activity, screen time, reading and writing habits, visual fatigue, outdoor time, and classroom light environment (all P < 0.05).ConclusionWG intake (> 50%) was an independent protective factor against myopia. Modifying the form of grains consumed (whole versus refined) could be one of the targets of future public health measures.

Refractive index dispersion measurement in the short-wave infrared range using synthetic phase microscopy.

Refractive index is an optical property explored in the light scattering measurement of micro- and nano-particles as well as in label-free imaging of cells and tissues. Because the refractive index value is a major input to the characterization and quantification of the analyzed specimens, various methods have been developed targeting at different sample types. In this paper, we demonstrate a technique for the refractive index measurement of homogeneous microspheres and liquids in the short-wave infrared (SWIR) range. We use synthetic phase microscopy (SPM), which records a scattering-corrected projection of the 3D refractive index distribution, in combination with a least-squares fitting to a theoretical model of a sphere. Using the method, we determine the refractive index dispersion of two polymer microspheres (polymethyl methacrylate and polystyrene), two glass microspheres (silica and soda lime), and three microscopy mounting media (glycerol, FluorSave, and Eukitt) in the SWIR range of 1100-1650 nm.

Comparison of Intraocular Lens Power Calculation between Standard Partial Coherence Interferometry-Based and Scheimpflug-Based Biometers: The Importance of Lens Constant Optimization.

To compare the intraocular lens (IOLs) power calculated with Haigis, Hoffer Q, Holladay 1, and SRK/T formulas between the IOLs Master 500 and Pentacam AXL according to the lens status. In this cross-sectional study, sampling was done in subjects above 60 years living in Tehran using multi-stage cluster sampling. All participants underwent optometric examinations including the measurement of visual acuity and refraction as well as slit-lamp biomicroscopy to determine the lens status. Biometric measurements and IOLs power calculation were done using the IOL Master 500 and Pentacam AXL. The order of imaging modalities was random in subjects. IOL power calculation was done according to optimized ULIB constants for the Alcon SA60AT lens. The IOL power was calculated according to a target refraction of emmetropia in all subjects. After applying the exclusion criteria, 1865 right eyes were analyzed. The mean IOL difference between the two devices was -0.33 ± 0.35, -0.38 ± 0.39, -0.41 ± 0.43, and -0.51 ± 0.43 according to the SRK/T, Holladay, Hoffer Q, and Haigis formulas, respectively. The Pentacam calculated larger IOL power values in all cases. The 95% limits of agreement (LoA) between the two devices for the above formulas were -1.01 to 0.35, -1.14 to 0.39, -1.25 to 0.43, and -1.35 to 0.33, respectively. The best LoA were observed in normal lenses for all formulas. The difference in the calculated IOL power between the two devices using the four formulas had a significant correlation with axial length, mean keratometry reading, and anterior chamber depth. According to the results of the four formulas, mean keratometry reading had the highest standardized regression coefficient in all formulas. Although the difference in the calculated IOL power between IOL Master 500 and Pentacam AXL is not significant clinically, the results of these two devices are not interchangeable due to the wide LoA, especially for the Haigis formula; therefore, it is necessary to optimize lens constants for the Pentacam.

Temperature, Refractive Index, and Corrosion Simultaneous Monitoring Using Raman Anti-Stokes Reflectometric Optical Fiber Sensor

Optical sensors that can measure multiple parameters is a promising area of research. This can also be attributed to the fact that monitoring two or more measurands at the same time is crucial in embedded systems, especially when they are interconnected, as is the case of temperature and corrosion, or temperature and refractive index. In this work, an optical fiber sensor based on Raman scattering in single-mode optical fibers to simultaneously monitor temperature, refractive index and corrosion is proposed and experimentally demonstrated. This sensor consists of a distributed temperature detection system based on Raman scattering with additional sensor heads: for multipoint corrosion monitoring and multipoint refractive index variation measurement. The multiparameter sensor was evaluated for solutions with refractive indices in the range of 1.3370 – 1.3840 RIU (Refractive Index Unit), for temperatures between 30 °C and 100 °C, and for aluminum thin-film corrosion in acid solution. The experimental results show that the sensor presents sensitivities of 0.5 dB/10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> RIU to refractive index variations, of 0.43 dB/nm for corrosion, and of 0.243 dB/°C for temperature, with resolution of 2 °C. The sensor system can also provide the corrosion rate and operate in fiber links several kilometers long.

The optical fiber refractive index profile measurement based on phase-correct quantitative phase microscopy

The optical fiber refractive index profile measurement based on phase-correct quantitative phase microscopy

Permittivity measurements for raw and boiled quinoa seeds versus temperature, bulk density, and moisture content

Quinoa is a nutrient-rich pseudocereal that is gaining popularity in European countries since it is gluten-free and an interesting source of fat, proteins, minerals, and amino acids. However, up to date, the electric permittivity of quinoa seeds has not been measured and, therefore, this hampers the possibility of designing optimized recipes for its microwave processing. In this work, the permittivity of both raw and boiled quinoa seeds is measured around 2.45 GHz at several conditions for temperature, moisture content, and bulk density. The grain kernel permittivity is also estimated from the Complex Refractive Index (CRI) mixture equation and different bulk density measurements. The obtained results show different temperature behaviours for raw and boiled seeds, whereas the permittivity of quinoa seeds versus moisture content and bulk density was as expected: the permittivity (both the dielectric constant and loss factor) levels increased as the observed variables did. From the measured data, it can be concluded that both raw and boiled quinoa can be processed with microwave technology, although care must be taken with raw quinoa grain kernels since the permittivity increases significantly with temperature, and a thermal runaway may occur.

Analysis for Clinical Refraction by Optometrists

A total 136 cases of refraction examinations performed between the year 2015 and 2018 by korean optometrists were analyzed based on 16 items to assess the errors observed during these examinations. The results of the analysis showed that history were not administered in 50.7% of the cases. Further, dominant eye testing was not performed in 72.8% of cases; uncorrected visual acuity testing in 86.8%; refractive power measurements of the current prescription in 54.4%; corrected visual acuity testing with the current prescription in 91.9%; subjective refraction test using a phoropter in 45.6%; fogging before refraction testing in 72.1%; maximal visual acuity testing in 80.9%; fogging before astigmatism testing in 72.8%; astigmatic fan chart testing in 49.3%; astigmatic refining testing in 39.0%; maintenance of meridian balance during astigmatic refining testing in 66.2%; binocular balance testing in 29.4%; and spherical end-point testing in 12.5%. The most preferred test for measuring binocular balance was the alternating cover test, which was performed in 27.4% of the cases, and the most preferred method to the measure end-point of refraction was the maximum plus to maximum visual acuity (MPMVA) procedure, performed in 43.4% of the cases. In 45.0% of the cases, optometrists performed the binocular balance test without the dominant eye test, and in 26.5% of cases, they conducted the astigmatic fan chart test without fogging. In 27.2% of the cases, astigmatic refining tests were conducted without the maintenance of the meridian balance; 23.5% of the binocular end-point refraction measurements were conducted without the binocular balance test, and 35.3% of astigmatic tests were conducted with unchanged autorefractometer (AR) values. Such inaccuracies during the examination process could lead to inability in obtaining a complete correction of the refractive errors in the participants and cause various deviations in the refraction test-based binocular visual function findings.

Development and Testing of a Compact Autorefractor Based on Double-Pass Imaging

Autorefraction is an objective way to determine the refractive error of the eye, without the need for feedback by the patient or a well-educated practitioner. To make refractive measurements more accessible in the background of the growing prevalence of myopia, a compact autorefractor was built, containing only few optical components and relying on double-pass imaging and the physical properties of the point-spread function and digital image processing instead. A method was developed to analyze spherical defocus as well as the defocus and angle of astigmatism. The device was tested using calibrator eye models in a range of ± 15 D spherical defocus and -3 D astigmatic defocus. Reliable results could be achieved across the whole measurement range, with only a small increase in deviation toward high values of refractive errors, showing the feasibility of a PSF-based approach for a compact and low-cost solution for objective measurements of refractive error.

Comparison of Visual and Aberrometric Outcomes in Suture-Free Scleral Fixation: Three-Piece Lenses versus Carlevale Lenses.

Purpose: To compare the refractive results between sutureless scleral fixation intraocular lens (IOLs) (Carlevale, Soleko) and suture-free scleral fixation three-piece IOLs (Sensar AR40, Johnson & Johnson) for secondary implantation in patients with IOL dislocation or aphakia. Methods: This is a monocentric retrospective study on 28 patients (28 eyes) with sutureless scleral fixation Carlevale IOL and 25 patients (25 eyes) with suture-free scleral fixation three-piece IOL. Best-corrected visual acuity (BCVA) evaluation, refractive measures and IOL tilt evaluation with anterior segment optical coherence tomography were conducted at one, three, six and twelve months after surgery. Point Spread Function (PSF) was measured using a total ocular aberrometer. Results: BCVA in both groups improved since the postoperative visit at 1 month and reached a stable value at 3 months At month 12, mean BCVA was 0.23 logMAR in group one and 0.32 logMAR in group two. Mean IOL tilt angle at 12 months was 2.76° ± 1.87 in group one and 2.51° ± 1.80 in group two. PSF at 12 months was 0.18 ± 0.09 in group one and 0.15 ± 0.05 in group two. There were no statistically significant differences (p > 0.05) for all comparisons. The post-operative complications were similar within the two groups. Conclusions: Our results show that secondary IOL implantation has similar visual and surgical outcomes when a sutureless Carlevale lens scleral fixation and a suture-free scleral fixation three-piece IOL are used.