Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Más filtros











Intervalo de año de publicación
1.
Int Ophthalmol ; 44(1): 60, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38345707

RESUMEN

PURPOSE: To analyze higher-order aberrations (HOAs) and their visual impact in a pediatric blepharokeratoconjunctivitis (PBKC) cohort compared with healthy controls. METHODS: Prospective case-control study of pediatric patients (≤ 16 years old). Subjects underwent wavefront aberrometry analysis to compare HOAs and their impact on visual quality. RESULTS: 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. CONCLUSIONS: 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).


Asunto(s)
Astigmatismo , Opacidad de la Córnea , Aberración de Frente de Onda Corneal , Humanos , Niño , Adolescente , Estudios de Casos y Controles , Agudeza Visual , Córnea , Refracción Ocular
2.
Graefes Arch Clin Exp Ophthalmol ; 262(5): 1545-1552, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38095689

RESUMEN

PURPOSE: To assess the accuracy of intraoperative wavefront aberrometry (IWA) versus modern intraocular lens formulas in post-myopic laser vision correction (LVC) patients undergoing cataract surgery with capsular tension ring placement. METHODS: This is a retrospective chart review conducted at an academic outpatient center. All post-myopic LVC eyes undergoing cataract surgery with IWA from a single surgeon from 05/2017 to 12/2019 were included. All patients received a capsular tension ring (CTR). Mean numerical error (MNE), median numerical error (MedNE), and percentages of prediction error within 0.50D, 0.75D, and 1.00D were calculated for the above formulas. RESULTS: Twenty-seven post-myopic LVC eyes from 18 patients were included. In post-myopic LVC, MNE with Optiwave Refractive Analysis (ORA), Barrett True K (BTK), Haigis, Haigis-L, Shammas, SRK/T, Hill-RBF v3.0, and W-K AL-adjusted Holladay 1 were + 0.224, - 0.094, + 0.193, - 0.231, - 0.372, + 1.013, + 0.860, and + 0.630 (F = 8.49, p < 0.001). MedNE were + 0.125, - 0.145, + 0.175, + 0.333, + 0.333, + 1.100, + 0.880, and + 0.765 (F = 7.89, p < 0.001), respectively. BTK provided improved accuracy in both MNE (p < 0.001) and MedNE (p = .033) when compared to ORA in pairwise analysis. If the ORA vs. BTK-suggested IOL power were routinely selected, 30% and 15% of eyes would have projected hyperopic outcomes, respectively (p = 0.09). CONCLUSIONS: Our study suggests that in post-myopic LVC eyes undergoing cataract surgery with CTRs, BTK performed more accurately than ORA with regard to accuracy and yielded a lower percentage of eyes with hyperopic outcomes. Haigis, Haigis-L, and Shammas yielded similar results to ORA with regard to accuracy and percentage of eyes with hyperopic outcomes. On average, Shammas and Haigis-L suggested IOLs that would yield outcomes more myopic than expected when compared to BTK.

3.
Clin Ophthalmol ; 16: 4281-4291, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36578668

RESUMEN

Purpose: InstaRef R20 is a handheld, affordable auto refractometer based on Shack Hartmann aberrometry technology. The study's objective was to compare InstaRef R20's performance for identifying refractive error in a paediatric population to that of standard subjective and objective refraction under both pre- and post-cycloplegic conditions. Methods: Refraction was performed using 1) standard clinical procedure consisting of retinoscopy followed by subjective refraction (SR) under pre- and post-cycloplegic conditions and 2) InstaRef R20. Agreement between both methods was evaluated using Bland-Altman analysis. The repeatability of the device based on three measurements in a subgroup of 20 children was assessed. Results: The refractive error was measured in 132 children (mean age 12.31 ± 3 years). The spherical equivalent (M) and cylindrical components (J0 and J45) of the device had clinically acceptable differences (within ±0.50D) and acceptable agreement compared to standard pre- and post-cycloplegic manual retinoscopy and subjective refraction (SR). The device agreed within ± 0.50D of retinoscopy in 67% of eyes for M, 78% for J0 and 80% for J45 and within ± 0.50D of SR in 70% for M and 77% for cylindrical components. Conclusion: InstaRef R20 has an acceptable agreement compared to standard retinoscopy in paediatric population. The measurements from this device can be used as a starting point for subjective acceptance. The device being simple to use, portable, reliable and affordable has the potential for large-scale community-based refractive error detection.

4.
BMC Ophthalmol ; 22(1): 498, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36536321

RESUMEN

BACKGROUND: Refraction is one of the key components of a comprehensive eye examination. Auto refractometers that are reliable and affordable can be beneficial, especially in a low-resource community setting. The study aimed to validate the accuracy of a novel wave-front aberrometry-based auto refractometer, Instaref R20 against the open-field system and subjective refraction in an adult population. METHODS: All the participants underwent a comprehensive eye examination including objective refraction, subjective acceptance, anterior and posterior segment evaluation. Refraction was performed without cycloplegia using WAM5500 open-field auto refractometer (OFAR) and Instaref R20, the study device. Agreement between both methods was evaluated using Bland-Altman analysis. The repeatability of the device based on three measurements in a subgroup of 40 adults was assessed. RESULTS: The refractive error was measured in 132 participants (mean age,30.53 ± 9.36 years, 58.3% female). The paired mean difference of the refraction values of the study device against OFAR was - 0.13D for M, - 0.0002D (J0) and - 0.13D (J45) and against subjective refraction (SR) was - 0.09D (M), 0.06 (J0) and 0.03D (J45). The device agreed within +/- 0.50D of OFAR in 78% of eyes for M, 79% for J0 and 78% for J45. The device agreed within +/- 0.5D of SR values for M (84%), J0 (86%) and J45 (89%). CONCLUSION: This study found a good agreement between the measurements obtained with the portable autorefractor against open-field refractometer and SR values. It has a potential application in population-based community vision screening programs for refractive error correction without the need for highly trained personnel.


Asunto(s)
Errores de Refracción , Selección Visual , Humanos , Adulto , Femenino , Adulto Joven , Masculino , Estudios Prospectivos , Aberrometría , Reproducibilidad de los Resultados , Refracción Ocular , Errores de Refracción/diagnóstico , Pruebas de Visión , Selección Visual/métodos
5.
Curr Eye Res ; 47(8): 1200-1208, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35502999

RESUMEN

PURPOSE: To highlight the magnitude of ocular higher order aberrations (HOA) and lower order aberrations (LOA), including component contributions from corneal and internal planes in Primary Congenital Glaucoma (PCG) patients. METHODS: Consecutive treated PCG patients co-operative for ocular examination and aberrometry, were enrolled over two years for this cross-sectional, comparative, single-center, unmasked study. Best-corrected visual acuity, refraction, IOP, wavefront aberrometry and topography (iTrace) were performed and results were compared with unaffected fellow eyes of unilateral glaucoma patients as well as age and sex-matched controls with no ocular anomalies other than treatable refractive error. RESULTS: Both eyes of 32 consecutive PCG patients (17 unilateral, 15 bilateral) and 39 controls were enrolled. The median LogMAR corrected distance visual acuity of PCG eyes was 0.68 (IQR: 0.2-1.8). Total ocular (Root mean square (RMS) 1.7 µm vs 0.3 µm, p = 0.014), corneal (RMS 1.1 µm vs 0.3 µm, p = 0.004) and internal (RMS 1.1 µm vs 0.2 µm, p = 0.013) aberrations, as well as HOAs and LOAs at each plane, were significantly higher in PCG eyes than in controls. Component HOAs from corneal and internal planes were positively correlated with each other (p < 0.001; rs: 0.7). Total aberrations were greater in the affected eyes of PCG compared to the rest. The predominant subtype of HOAs in PCG was coma and trefoil. PCG with corneal opacity/Haab's striae had significantly higher astigmatism than the affected eyes with clear corneae at the corneal plane (p = 0.02). The aberrations were not statistically associated with the corneal diameter or refractive error in PCG eyes. CONCLUSIONS: Significantly greater aberrations (Total, HOAs and LOAs, at corneal as well as an internal plane) were seen among eyes affected with PCG. Though the exact impact of these aberrations on the final visual outcome is difficult to determine, these could play a pertinent role in compromising visual function, thus impacting the management of visual rehabilitation in these patients.


Asunto(s)
Aberración de Frente de Onda Corneal , Glaucoma , Aberrometría , Topografía de la Córnea , Aberración de Frente de Onda Corneal/diagnóstico , Estudios Transversales , Glaucoma/diagnóstico , Humanos , Refracción Ocular
6.
J Optom ; 15 Suppl 1: S22-S31, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35431181

RESUMEN

PURPOSE: To assess the performance of machine learning (ML) ensemble models for predicting patient subjective refraction (SR) using demographic factors, wavefront aberrometry data, and measurement quality related metrics taken with a low-cost portable autorefractor. METHODS: Four ensemble models were evaluated for predicting individual power vectors (M, J0, and J45) corresponding to the eyeglass prescription of each patient. Those models were random forest regressor (RF), gradient boosting regressor (GB), extreme gradient boosting regressor (XGB), and a custom assembly model (ASB) that averages the first three models. Algorithms were trained on a dataset of 1244 samples and the predictive power was evaluated with 518 unseen samples. Variables used for the prediction were age, gender, Zernike coefficients up to 5th order, and pupil related metrics provided by the autorefractor. Agreement with SR was measured using Bland-Altman analysis, overall prediction error, and percentage of agreement between the ML predictions and subjective refractions for different thresholds (0.25 D, 0.5 D). RESULTS: All models considerably outperformed the predictions from the autorefractor, while ASB obtained the best results. The accuracy of the predictions for each individual power vector component was substantially improved resulting in a ± 0.63 D, ±0.14D, and ±0.08 D reduction in the 95% limits of agreement of the error distribution for M, J0, and J45, respectively. The wavefront-aberrometry related variables had the biggest impact on the prediction, while demographic and measurement quality-related features showed a heterogeneous but consistent predictive value. CONCLUSIONS: These results suggest that ML is effective for improving precision in predicting patient's SR from objective measurements taken with a low-cost portable device.


Asunto(s)
Errores de Refracción , Humanos , Aberrometría/métodos , Errores de Refracción/diagnóstico , Refracción Ocular , Pruebas de Visión , Aprendizaje Automático , Reproducibilidad de los Resultados
7.
Graefes Arch Clin Exp Ophthalmol ; 259(3): 673-683, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33471202

RESUMEN

PURPOSE: To evaluate the effect of visual axis positioning on the optical performance of the Tecnis MIOL and the Diff-aA MIOL. METHODS: In this prospective, randomized comparative study, 70 eyes of 35 subjects with senile cataract were implanted with the spherical aberration-correcting diffractive, bifocal Tecnis ZLB00 IOL and 60 eyes of 30 age-matched subjects with the spherical aberration neutral, diffractive, bifocal Diffractiva IOL. Observation procedure was performed 1, 3, and 6 months postoperatively. Main outcome measures included uncorrected and corrected distance and near visual acuity, manifest refraction, ocular aberrations, and visual quality metrics with 2 mm and 4 mm pupil and the position of visual axis. RESULTS: At the 6-month visit, no significant difference was found in monocular and binocular uncorrected (UDVA) and corrected (CDVA) distance and near (UNVA, CNVA) visual acuity between the groups. Spherical and coma-like aberrations were similar measured with a 2-mm pupil, but with a 4-mm pupil, the SA was significantly larger (in negative direction) in the Diffractiva group. The higher-order Strehl ratio and MTF was significantly larger in the Diffractiva group measured at 2 mm entrance pupil; however, this difference disappeared by the 4-mm pupil measurements. Postoperative angle alpha distance had a significant influence on HO Strehl value. CONCLUSIONS: The size of angle alpha is a predictive factor of image quality by multifocal IOL patients. TRIAL REGISTRATION: Trial registration number and date of registration: NCT04274088, 14.02.2020.


Asunto(s)
Lentes Intraoculares , Lentes Intraoculares Multifocales , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Estudios Prospectivos , Diseño de Prótesis , Seudofaquia , Refracción Ocular
8.
Curr Eye Res ; 46(3): 333-340, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32935593

RESUMEN

PURPOSE: To compare the visual performance after implantation of three aberration-correcting aspherical intraocular lens (IOL). MATERIALS AND METHODS: Seventy-seven eyes of 77 cataract patients were divided into three groups: 26 eyes implanted with a non-constant aberration IOL (LUCIA 601P IOL, Zeiss Company, Germany); 26 eyes implanted with a spherical aberration -0.18µm IOL (CT ASPHINA 509M, Zeiss Company, Germany) and 27 eyes implanted with a spherical aberration -0.27µm IOL (AMO Tecnis ZCB00, Johnson & Johnson Surgical Vision, USA). Three months after operation, the distance visual acuity, wavefront aberrometry, contrast sensitivity, intraocular stray light, IOL decentration, and tilt were evaluated. RESULTS: Three months postoperatively, no statistically significant differences were found in uncorrected distance visual acuity and corrected distance visual acuity (p≥.83). The RMS for total ocular coma was statistically significantly lower in the Lucia group (p=.03) and spherical aberration was statistically significantly lower in the Tecnis group (p<.01). No statistically significant differences were observed among the three lenses in higher order aberration (p=.85) and in contrast sensitivity under both photopic and mesopic lighting conditions (p≥.05). The intraocular stray light was statistically significantly better in the Lucia group (p=.04). No statistically significant differences were observed with respect to IOL decentration (p=.75) and tilt (p=.89). CONCLUSIONS: Cataract surgery with non-constant aberration IOL resulted in lower coma and better intraocular stray light than with the spherical aberration -0.18µm and -0.27µm IOLs despite equivalent postoperative levels of visual acuity and contrast sensitivity.


Asunto(s)
Implantación de Lentes Intraoculares/métodos , Lentes Intraoculares , Agudeza Visual , Anciano , Femenino , Humanos , Masculino , Facoemulsificación/métodos , Periodo Posoperatorio , Diseño de Prótesis , Estudios Retrospectivos
9.
Clin Exp Optom ; 104(1): 107-114, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32924191

RESUMEN

CLINICAL RELEVANCE: Diagnosis and monitoring of keratoconus is increasingly being conducted with the aid of imaging equipment such as corneal aberrometry. There is a need to also know the confidence with which ocular aberration measurements can be made. BACKGROUND: To assess the repeatability of lower- and higher-order aberration measurements in patients with keratoconus using the irx3 wavefront aberrometer (Imagine Eyes, Orsay, France) and evaluate correlations with corneal curvature. METHODS: The irx3 wavefront aberrometer was used to measure bilateral lower- and higher-order ocular aberrations on 33 participants with keratoconus. Three measurements were taken from each eye to determine the repeatability of lower-order aberrations (quantified as sphere and cylinder in dioptres) and higher-order aberration co-efficients (up to eighth order in micrometres), coma, trefoil and total higher-order aberration root mean square (in micrometres). Corneal curvature was measured using the Pentacam HR system (OCULUS, Wetzlar, Germany). RESULTS: Repeat measurements for lower-order aberrations resulted in larger co-efficients of repeatability than higher-order aberrations. Similarly, larger co-efficients of repeatability between repeated measures across all Zernike co-efficients were observed in eyes with severe keratoconus (that is, corneal curvature > 52-D) compared to eyes with flatter corneas. The difference between repeated measures tended to be significant for the lower-order aberrations regardless of corneal curvature. The highest correlations with corneal curvature for right and left eyes respectively, were identified for total higher-order aberration root mean square (r = 0.92, p < 0.001 and r = 0.91, p < 0.001), followed closely by coma (r = -0.93, p < 0.001 and r = -0.86, p < 0.001) and the Z (3, -1) co-efficient (r = -0.92, p < 0.001 and r = -0.86, p < 0.001 for right and left eyes, respectively). CONCLUSIONS: Lower-order aberrations tended to be less repeatable, indicating that instrument variability must be considered when monitoring progression. Total higher-order aberration root mean square and third-order aberrations, in particular the vertical coma Z (3, -1) co-efficient, demonstrated a stronger correlation with corneal curvature than the lower-order aberrations.


Asunto(s)
Aberración de Frente de Onda Corneal , Queratocono , Topografía de la Córnea , Aberración de Frente de Onda Corneal/diagnóstico , Proteínas de Homeodominio , Humanos , Queratocono/diagnóstico , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Transcripción
10.
BMC Ophthalmol ; 20(1): 450, 2020 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-33198718

RESUMEN

BACKGROUND: Currently, there is no standard technique for determining corneal astigmatism. The iTrace wavefront aberrometry of cornea calculated steep power and axis based on the best Zernike mathematical fit from all topo data within 4 mm circle. It was supposed to be more accurate than iTrace simulated keratometry which was calculated based on only 4 points on the circle of 3 mm. This aim of this study was to evaluate visual outcomes and rotational stability after toric intraocular lens (IOL) implantation using the wavefront aberrometry of the cornea with iTrace. SETTING: Single site in China, Shanxi Eye Hospital, Shanxi, China. DESIGN: Prospective case series. METHODS: The study included 85 eyes of 63 patients undergoing phacoemulsification and toric IOL implantation. The IOL power and cylinders were chosen with the help of the iTrace toric planning program using wavefront keratometric astigmatism. Astigmatic changes were assessed using Alpins vector method over a 3-month follow-up period. RESULTS: Preoperative mean corneal topographic astigmatism was 1.91 diopters (D) ± 0.69 (standard deviation). Postoperative mean refractive astigmatism decreased significantly to 0.48 D ± 0.34. Surgical induced astigmatism was 1.73 D ± 0.77 and the mean correction index was 0.89 ± 0.22, showing a slight undercorrection. The proportion of astigmatism ≤0.50 D increased from 0 to 71.8% postoperatively. CONCLUSIONS: This is the first study on evaluation of clinical outcomes of toric IOL implantation in corneal astigmatism patients using iTrace wavefront keratometric readings. The findings show that use of iTrace built-in toric calculator is safe and effective for planning toric IOL surgery for wavefront keratometric astigmatism. TRIAL REGISTRATION: Current Controlled Trials ISRCTN94956424 , Retrospectively registered (Date of registration: 05 February 2020).


Asunto(s)
Astigmatismo , Lentes Intraoculares , Facoemulsificación , Aberrometría , Astigmatismo/diagnóstico , Astigmatismo/cirugía , China , Córnea/cirugía , Humanos , Implantación de Lentes Intraoculares , Estudios Prospectivos , Refracción Ocular , Agudeza Visual
11.
Indian J Ophthalmol ; 68(12): 2670-2678, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33229642

RESUMEN

We are in the midst of a shift towards using novel polynomials to decompose wavefront aberrations in a more ophthalmologically relevant way. Zernike polynomials have useful mathematical properties but fail to provide clinically relevant wavefront interpretation and predictions. We compared the distribution of the eye's aberrations and demonstrate some clinical applications of this using case studies comparing the results produced by the Zernike decomposition and evaluating them against the lower degree/higher degree (LD/HD) polynomial decomposition basis which clearly dissociates the higher and lower aberrations. In addition, innovative applications validate the LD/HD polynomial basis. Absence of artificial reduction of some higher order aberrations coefficients lead to a more realistic analysis. Here we summarize how wavefront analysis has evolved and demonstrate some of its new clinical applications.


Asunto(s)
Refracción Ocular , Errores de Refracción , Algoritmos , Topografía de la Córnea , Humanos , Trastornos de la Visión
12.
Diagnostics (Basel) ; 10(8)2020 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-32823769

RESUMEN

Imaging has become indispensable in the diagnosis and management of diseases in the posterior part of the eye. In recent years, imaging techniques for the anterior segment are also gaining importance and are nowadays routinely used in clinical practice. Ocular surface disease is often synonymous with dry eye disease, but also refers to other conditions of the ocular surface, such as Meibomian gland dysfunction or keratitis and conjunctivitis with different underlying causes, i.e., allergies or infections. Therefore, correct differential diagnosis and treatment of ocular surface diseases is crucial, for which imaging can be a helpful tool. A variety of imaging techniques have been introduced to study the ocular surface, such as anterior segment optical coherence tomography, in vivo confocal microscopy, or non-contact meibography. The present review provides an overview on how these techniques can be used in the diagnosis and management of ocular surface disease and compares them to clinical standard methods such as slit lamp examination or staining of the cornea or conjunctiva. Although being more cost-intensive in the short term, in the long term, the use of ocular imaging can lead to more individualized diagnoses and treatment decisions, which in turn are beneficial for affected patients as well as for the healthcare system. In addition, imaging is more objective and provides good documentation, leading to an improvement in patient follow-up and education.

13.
Clin Ophthalmol ; 13: 1807-1813, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31571819

RESUMEN

PURPOSE: To compare the accuracy, speed and repeatability of the voice assisted subjective refractor (VASR) to traditional refractive methods. METHODS: Fifty healthy adult subjects were examined by autorefractor, followed by subjective phoropter refinement. Subjects were then evaluated using the VASR (Vmax Vision) to obtain an objective and subjective result. Three total assessments were performed for each subject using each of the methods described. Corrected visual acuity was recorded for each eye after each procedure. The total time was measured for both the traditional and VASR refraction. RESULTS: A comparison of the results obtained by traditional refraction and VASR revealed no statistically significant difference from the mean in equivalent sphere measurements (P=0.1383), and the datasets were highly correlated (r=0.993). The data comparisons for cylinder power and axis were similar (cylinder: P=0.6377, r=0.864) (axis: P=0.6991, r=0.738). VASR, on average, required 71 additional seconds to complete when compared to traditional phoropter refraction. In terms of repeatability, the average difference noted upon repeat of equivalent sphere power was 0.01 D for the phoropter (P=0.98) and 0.10 D for the VASR (P=0.23). For sphere power, the average difference was 0.02 D for the phoropter (P=0.55) and 0.07 D for the VASR (P=0.58). For cylinder power, the average difference was 0.02 D for the phoropter (P=0.11) and 0.03 D for the VASR (P=0.39). For all refractive methods, the differences between measurements amounted to ≤0.10 diopters, which is neither clinically nor statistically significant. CONCLUSION: Refractive error results obtained with the VASR were not statistically different from those achieved using traditional phoropter methods. Time elapsed for the VASR was slightly longer than a more traditional refractive sequence. The VASR demonstrated clinically and statistically significant repeatability of measurement, consistent with traditional refraction.

14.
Indian J Ophthalmol ; 67(7): 1030-1035, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31238402

RESUMEN

Purpose: To evaluate the agreement of selected higher order aberration measurements between aberrometers based on three different wavefront technologies. Methods: Twenty-three eyes of 23 participants were compared between Zywave, OPD-Scan III, and iDesign aberrometers, for total ocular aberrations. Participants were between 19 and 69 years of age, and exclusion criteria were previous ocular surgery or trauma, contact lens wear within the preceding 2 weeks, and ocular or systemic disease. Corneal aberrations were compared between the OPD-Scan III and GALILEI™ G2 aberrometers. Zernike coefficients of vertical and oblique trefoil, vertical and horizontal coma, and spherical aberration were analyzed in R software. Results: In all, 276 scans were captured in total, with a male-to-female ratio of 11:12. Total ocular vertical coma [mean difference (MD) = 0.026 µm, P < 0.005], vertical trefoil (MD = 0.033 µm, P < 0.05), and spherical aberration (MD = 0.022 µm, P < 0.05) differed significantly between the iDesign and OPD-Scan III. Differences in total vertical (MD = 0.072 µm, P < 0.05) and oblique trefoil (MD = 0.058 µm, P < 0.05) were demonstrated between the Zywave and OPD-Scan III, and spherical aberration (MD = 0.030 µm, P < 0.005) between iDesign and Zywave. iDesign corneal horizontal coma (MD = 0.025 µm, P < 0.05) and spherical aberration (MD = 0.043 µm, P < 0.005) measurements were significantly different between the GALILEI™ G2 and the OPD-Scan III. Conclusion: Zywave, iDesign, and OPD-Scan III, and GALILEITM G2 and OPD-Scan III may be used interchangeably for their total ocular and corneal wavefront functions, respectively; however, care must be taken if using these devices for guiding ablation or monitoring corneal disease.


Asunto(s)
Aberrometría/métodos , Córnea/diagnóstico por imagen , Aberración de Frente de Onda Corneal/diagnóstico , Refracción Ocular/fisiología , Agudeza Visual , Adulto , Anciano , Aberración de Frente de Onda Corneal/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto Joven
15.
Acta Ophthalmol ; 94(7): 679-684, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27496244

RESUMEN

PURPOSE: To compare objective refraction using small-zone eccentric laser ray tracing (LRT) wavefront aberrometry to standard autorefraction in keratoconus (KC), and whether the visual acuities achieved with these refractions differ from corresponding values in healthy eyes. METHODS: Twenty-nine eyes of 29 patients with KC and 29 eyes of 29 healthy controls were included in this prospective unmasked case-control study. The uncorrected (UCVA) and spectacle-corrected (SCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuities based on refractions derived from LRT in central and four eccentric zones were compared to those achieved with standard autorefraction. The spherical equivalent (M) and two astigmatic power vectors (C0 and C45) were calculated for all refractions. Pentacam HR® was used to generate keratometry readings of the corresponding zones. RESULTS: In KC, the refraction from the upper nasal zone rendered a higher SCVA than the standard autorefraction more often than in the controls (p < 0.001). There were no significant variation in M between the different LRT measurement points in the control group, but central data provided the best SCVA. The UCVA:s and SCVA:s were worse in KC, and the KC eyes showed inferior myopia and superior hyperopia. Multiple refractions rendered similar SCVA:s in KC. Pentacam HR® showed higher keratometry readings infero-temporally, but also lower readings supero-nasally, compared to controls. CONCLUSION: In KC, eccentric LRT measurements gave better SCVA than standard autorefraction more often than in healthy eyes. Eccentric LRT may become a valuable tool in the demanding task of subjective refraction in KC.


Asunto(s)
Aberrometría , Aberración de Frente de Onda Corneal/fisiopatología , Queratocono/fisiopatología , Refracción Ocular/fisiología , Agudeza Visual/fisiología , Adulto , Estudios de Casos y Controles , Topografía de la Córnea , Femenino , Humanos , Masculino , Estudios Prospectivos , Pruebas de Visión , Adulto Joven
16.
Case Rep Ophthalmol ; 6(1): 132-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25969687

RESUMEN

PURPOSE: To describe a patient complaining of 'ghosting' and 'shadowing' after bilateral, sequential cataract extraction with toric intraocular lens (IOL) implantation who was found to have significant eyelid ptosis. METHODS: The following is a case report. RESULTS: The patient's complaints arose a few weeks after surgery. By the second postoperative month, the patient's keratometry had changed compared to preoperative measurements. Because of significant ptosis, the patient underwent upper eyelid surgery. Four months later, he was found to have less corneal astigmatism than had been measured prior to cataract surgery. Following 2 stable examinations, a Prevue lens based on Hartmann-Shack wavefront aberrometry was made for each eye, which the patient said significantly improved his quality of vision. Wavefront-guided photorefractive keratectomy (PRK) was performed 6 months after cataract surgery. One year after PRK, the patient's symptoms had disappeared, his uncorrected visual acuity was 20/20 in the right eye and 20/15 in the left, and he was satisfied with his quality of vision. CONCLUSIONS: Bilateral toric IOLs were implanted in this patient based on measurements of corneal astigmatism that changed after cataract surgery and changed further after ptosis repair. This case demonstrates the importance of evaluating eyelid position in cataract surgical planning as ptosis can contribute significantly to corneal astigmatism. Patient education is important in the setting of higher expectations from purchase of premium lens implants.

17.
Rev. bras. oftalmol ; 73(6): 358-362, Nov-Dec/2014. tab, graf
Artículo en Inglés | LILACS | ID: lil-741914

RESUMEN

Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia), the RA group (24 eyes of 13 children with unilateral refractory amblyopia) and the C group (28 eyes of 14 children with normal visual development). Higher order aberrations were evaluated using an OPD-Scan III (NIDEK). Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism), higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia. .


Objetivo: Alguns estudos levantaram a hipótese de que um perfil aberrométrico de alta ordem desfavorável poderia ser um fator ambliogênico, responsável por certos casos de ambliopia “idiopática” ou refratária ao tratamento convencional. Este trabalho tem como objetivos: 1) comparar o perfil aberrométrico de crianças amblíopes com o de crianças com desenvolvimento visual normal; 2) comparar a aberrometria de olhos amblíopes tratados com sucesso/curados e olhos amblíopes refratários ao tratamento convencional com a aberrometria de olhos saudáveis. Métodos: Estudo transversal com três grupos de crianças: grupo CA (22 olhos de 11 crianças com ambliopia unilateral curada), grupo RA (24 olhos de 13 crianças com ambliopia unilateral refratária) e grupo C (28 olhos de 14 crianças com desenvolvimento visual normal). Avaliou-se a aberrometria ocular total utilizando o OPD Scan-III (NIDEK). Comparou-se o perfil aberrométrico dos três grupos de estudo bem como dentro dos grupos CA e RA, o olho amblíope com o saudável. Resultados: As aberrações de alta ordem com maior impacto na qualidade visual não foram significativamente superiores nos grupos CA e RA, comparativamente ao grupo C. Por outro lado, não se encontraram diferenças estatisticamente significativas entre o perfil aberrométrico de alta ordem dos olhos amblíopes e dos olhos sãos dentro dos grupos CA e RA. Conclusão: Contrariamente às aberrações de baixa ordem (miopia, hipermetropia, astigmatismo primário), as de alta ordem não parecem relacionar-se com a etiopatogênese da ambliopia. É também pouco provável que estas sejam a causa da maioria dos casos de ambliopia refratária. .


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Refracción Ocular , Ambliopía/diagnóstico , Aberración de Frente de Onda Corneal/diagnóstico , Aberrometría , Agudeza Visual , Ambliopía/fisiopatología , Ambliopía/terapia , Estudios Transversales
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA