Measurements Of Ocular Aberrations Research Articles

Large-Dynamic-Range Ocular Aberration Measurement Based on Deep Learning with a Shack-Hartmann Wavefront Sensor.

The Shack-Hartmann wavefront sensor (SHWFS) is widely utilized for ocular aberration measurement. However, large ocular aberrations caused by individual differences can easily make the spot move out of the range of the corresponding sub-aperture in SHWFS, rendering the traditional centroiding method ineffective. This study applied a novel convolutional neural network (CNN) model to wavefront sensing for large dynamic ocular aberration measurement. The simulation results demonstrate that, compared to the modal method, the dynamic range of our method for main low-order aberrations in ocular system is increased by 1.86 to 43.88 times in variety. Meanwhile, the proposed method also has the best measurement accuracy, and the statistical root mean square (RMS) of the residual wavefronts is 0.0082 ± 0.0185 λ (mean ± standard deviation). The proposed method generally has a higher accuracy while having a similar or even better dynamic range as compared to traditional large-dynamic schemes. On the other hand, compared with recently developed deep learning methods, the proposed method has a much larger dynamic range and better measurement accuracy.

Ocular aberration measurement with and without an aperture stop using a Shack–Hartmann wavefront sensor

Pupil size is an important parameter since it governs the magnitude of ocular aberrations. The pupil size of a human eye has significant individual differences and varies with light level and accommodation. In order to accurately measure ocular aberrations under different pupil sizes using a Shack–Hartmann wavefront sensor (SHWFS), two types of relationship matrices R(1) and R(2) were proposed, which corresponded to wavefront reconstruction with and without an aperture stop, respectively. The numerical and experimental results indicated that matrix R(2) can significantly improve the accuracy of wavefront restoration when the incident beam size is inconsistent with the wavefront reconstruction aperture. Meanwhile, the impact of the aperture stop on the reconstruction accuracy will become smaller and smaller as the ratio ρ of the outer area to the detection aperture decreases. This study not only can be used for accurately measuring ocular aberrations under different pupil sizes, but also for other variable aperture aberrations measurement in other applications.

Ultra-High Resolution Optical Aberrometry in Patients with Keratoconus: A Cross-Sectional Study.

This study performs optical aberration assessment in patients using a novel ultra-high-resolution device. The objective of this study is to analyze optical aberrations, especially the very high order wavefront (more than 10th order of Zernike coefficients), and compare between keratoconus and healthy patients. In this cross-sectional study, we analyzed 43 eyes from 25 healthy patients and 43 eyes from 27 patients with keratoconus using corneal tomography and a very high-resolution (8.55µm) aberrometer prototype (T-eyede) outfitted with a sensor originally developed for use in the field of astrophysics. Corneal aberration values were assessed using an optical model built with Zemax optical software, while ocular aberrations were assessed using T-eyede. In addition, image-processing analysis was performed of the wavefront phase, creating a high-pass filter map. We found lower values for ocular aberrations than corneal aberrations in both groups (p < 0.001). Specifically, we found a reduction in primary astigmatism (0.145µm) and primary coma (0.017µm). Also, the keratoconus group showed significantly higher wavefront aberration values compared with controls (p < 0.001). An analysis of the high-pass filter map revealed 2 contrasting results: one smooth or clear, while the other presented a banding pattern. Almost all in the control group (95%) showed the first pattern, while 77% of the keratoconus group showed a banding pattern on the filtered map (chi-squared test, p < 0.001). This device provides reliable, precise measurements of ocular aberrations that correlate well with corneal aberrations. Furthermore, the extraordinary high-resolution measurements revealed unprecedented micro changes in the wavefront phase of patients with keratoconus that varied with disease stage. These findings could lead to new screening or follow-up methods.

Comparison of Ocular Wavefront Aberration Measurements Obtained Using Two Hartmann-Shack Wavefront Aberrometers.

To assess agreement between measurements of ocular wavefront aberrations obtained using the Pentacam AXL Wave (Oculus Optikgeräte GmbH) (Aberrometer A) and KR-1W (Topcon Corp) (Aberrometer B), both of which are based on the Hartmann-Shack principle. In this prospective case-control study, ocular wavefront aberrations measurements were obtained using both aberrometers in patients with keratoconus (KC) and control participants. Ocular wavefront aberrations were measured through the natural pupil without dilation using both devices in a dark room. For both aberrometers, accommodation was inhibited by automatically adding fogging. The individual Zernike coefficients from the second to fourth order were compared between the two aberrometers for a 4-mm pupil diameter. Twenty-six KC and 29 control eyes were assessed. Statistically significant correlations ( P <0.05) were observed for all Zernike coefficients, except for Z 4-2 in the control group. Bland-Altman analysis indicated good agreement between aberrometers and no statistically significant differences in the control group. However, in the KC group, patterns of proportional error were observed in vertical coma Z 3-1 (r=0.338, P =0.008), trefoil Z 4-4 (r=0.701, P =0.003), secondary astigmatism Z 4-2 (r=0.348, P =0.025), and spherical aberrations Z 40 (r=0.407, P =0.012). The Zernike coefficient values measured by the two aberrometers were well correlated in the control and KC groups. However, in eyes with KC, Aberrometer B tended to present greater values in several Zernike coefficients than Aberrometer A, suggesting that wavefront measurements obtained using the two aberrometers are not interchangeable in patients with KC.

Advanced Optical Wavefront Technologies to Improve Patient Quality of Vision and Meet Clinical Requests

Adaptive optics (AO) is employed for the continuous measurement and correction of ocular aberrations. Human eye refractive errors (lower-order aberrations such as myopia and astigmatism) are corrected with contact lenses and excimer laser surgery. Under twilight vision conditions, when the pupil of the human eye dilates to 5-7 mm in diameter, higher-order aberrations affect the visual acuity. The combined use of wavefront (WF) technology and AO systems allows the pre-operative evaluation of refractive surgical procedures to compensate for the higher-order optical aberrations of the human eye, guiding the surgeon in choosing the procedure parameters. Here, we report a brief history of AO, starting from the description of the Shack-Hartmann method, which allowed the first in vivo measurement of the eye's wave aberration, the wavefront sensing technologies (WSTs), and their principles. Then, the limitations of the ocular wavefront ascribed to the IOL polymeric materials and design, as well as future perspectives on improving patient vision quality and meeting clinical requests, are described.

Comparison of ocular aberrations and retinal image quality provided by a validated aberrometer and a new open field aberrometer for VEMoS project

AbstractPurpose: The aim of this observational study was to compare the retinal image quality and ocular aberrations provided by a validated aberrometer and by a new open field aberrometer.Methods: This is an observational and comparative study composed by healthy eyes not presenting cataract or ocular pathologies affecting media transparence or visual function. Patients underwent a measurement of ocular aberrations by a closed field aberrometer (Osiris, CSO) and by an open field aberrometer developed for VEMoS European project (OFA, CSO). Both measurements were performed by a qualified optometrist and the pupil size selected for the analysis was 4 mm. SPSS program was applied for the statistical analysis, particularly Wilcoxon test was used to compare both devices considering a significance of 0.05.Results: The study included 20 eyes of 20 patients with a mean age of 36.2 ± 9.7 years. The sphere was significantly more negative with Osiris in comparison with OFA (−0.33 ± 2.17 diopters vs. 0.29 ± 2.17 diopters, p &lt; 0.001), the spherical aberration was also slightly lower with Osiris (0.02 ± 0.03 microns vs. 0.03 ± 0.03 microns, p: 0.045). The rest of aberrometric coefficients including the cylinder, coma, trefoil, quadrefoil and secondary astigmatism showed no significant differences between devices (p &gt; 0.05). Moreover, the point spread function did not presented statistical differences, but a trend to obtain higher values was observed in Osiris (0.219 ± 0.127 vs. 0.189 ± 0.126, p: 0.370).Conclusions: The sphere provided by an open field aberrometer was significantly more positive comparing with a close field aberrometer probably associated to an accommodative response induced in close field aberrometers. Similarly, the spherical aberration assumed small changes between devices, which would be generated also by accommodation. The rest of parameters showed no differences between devices indicating a suitable agreement between devices for these coefficients.

Measurement of Monochromatic Ocular Peripheral Aberrations in Type 1 Diabetes and Age-Matched Controls—a Pilot Study

This pilot study characterised peripheral aberrations over 42° × 32° of right eye visual fields for 5-mm diameter pupils. Peripheral refraction shifted negatively in diabetes and in the control groups relative to the field centre, but there was greater asymmetry for the former group. There was but little variation in spherical aberration co-efficient but horizontal coma changed more rapidly with field angle in the diabetes group (mean rate of change −0.012 deg/μm) than in the control group (−0.006 deg/μm). Consistent with other investigations of ocular optics and biometry, the results indicate that the eyes of people with diabetes act as older eyes than those of people of the same age without diabetes.

Clinical utility of irx3 in keratoconus

ABSTRACT 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.

Measuring Ocular Aberrations Sequentially Using a Digital Micromirror Device.

The Hartmann–Shack wavefront sensor is widely used to measure aberrations in both astronomy and ophthalmology. Yet, the dynamic range of the sensor is limited by cross-talk between adjacent lenslets. In this study, we explore ocular aberration measurements with a recently-proposed variant of the sensor that makes use of a digital micromirror device for sequential aperture scanning of the pupil, thereby avoiding the use of a lenslet array. We report on results with the sensor using two different detectors, a lateral position sensor and a charge-coupled device (CCD) scientific camera, and explore the pros and cons of both. Wavefront measurements of a highly aberrated artificial eye and of five real eyes, including a highly myopic subject, are demonstrated, and the role of pupil sampling density, CCD pixel binning, and scanning speed are explored. We find that the lateral position sensor is mostly suited for high-power applications, whereas the CCD camera with pixel binning performs consistently well both with the artificial eye and for real-eye measurements, and can outperform a commonly-used wavefront sensor with highly aberrated wavefronts.

Reliability of Ocular Aberration Measurements in Children with Moderate and Low Myopia under Scotopic Conditions.

Purpose To investigate the reliability of ocular aberration measurement in myopic children under scotopic conditions and to validate the mathematical Zernike pupil scaling-down technique. Methods Ocular aberrations of 45 myopic children were examined under scotopic conditions via iTrace aberrometer. The intra- and intersession repeatability was evaluated for both the measured values with the true pupil sizes and the estimated ones that were determined by scaling down the pupil sizes to the largest integer value across all measurements. Results The intra- and intersession difference of clinically measured aberration was generally insignificant, and the ICCs for each aberration component exhibited good to excellent reliability (ICCs > 0.4). Similar results were found for the estimated aberration using the scaling-down technique. Although the majority of the estimated Zernike components were comparable with the corresponding measured one, the estimated values of defocus, coma, and the corresponding total aberrations were found significantly smaller than the measured values (all P < 0.01). Conclusions The ocular aberration measurements in myopic children under the circumstances described are reliable. The scaling-down technique is a useful option for comparing the results obtained from different pupil sizes, but the estimated Zernike coefficients were not always comparable with the corresponding measured values.

Repeatability of a Commercially Available Adaptive Optics Visual Simulator and Aberrometer in Normal and Keratoconic Eyes.

To evaluate the repeatability of aberration measurement obtained by a Hartmann-Shack aberrometer combined with a visual adaptive optics simulator in normal and keratoconic eyes. One hundred fifteen normal eyes and 92 eyes with grade I and II keratoconus, as per the Amsler-Krumeich classification, were included in the study. To evaluate the repeatability, three consecutive measurements of ocular aberrations were obtained by a single operator. Zernike analyses up to the 5th order for a pupil size of 4.5 mm were performed. Statistical analyses included the intraclass correlation coefficient (ICC) and within-subject standard deviation (SD). For intrasession repeatability, the ICC value for sphere and cylinder was 0.94 and 0.93 in normal eyes and 0.98 and 0.97 in keratoconic eyes, respectively. The ICC for root mean square of higher order aberrations (HOARMS) was 0.82 in normal and 0.98 in keratoconic eyes. For 3rd order aberrations (trefoil and coma), the ICC values were greater than 0.87 for normal eyes and greater than 0.92 for keratoconic eyes. The ICC for spherical aberration was 0.92 and 0.90 in normal and keratoconic eyes, respectively. Visual adaptive optics provided repeatable aberrometry data in both normal and keratoconic eyes. For most of the parameters, the repeatability in eyes with early keratoconus was somewhat better than that for normal eyes. The repeatability of the Zernike terms was acceptable for 3rd order (trefoil and coma) and spherical aberrations. Therefore, visual adaptive optics was a suitable tool to perform repeatable aberrometric measurements. [J Refract Surg. 2017;33(11):769-772.].

Comparison of Higher-Order Aberration Values between Different Aberrometry Technologies in Preoperative Laser Refractive Surgery Patients

Introduction: Purpose of this study was to evaluate the inter-device agreement of ocular and corneal higher-order aberration measurements using various aberrometers. Materials and method: Ocular and corneal higher-order aberrations were measured from 57 eyes. For ocular aberration, the measurements were obtained from WASCA Analyzer (Carl Zeiss Meditec, Jena, Germany), i-Profiler Plus (Carl Zeiss Meditec, Jena, Germany) and OPD-Scan III (NIDEK Co. Ltd., Tokyo, Japan). Whereas for corneal aberration, an additional measurement was obtained from Atlas Corneal Topographer 9000 (Carl Zeiss Meditec, Jena, Germany). All the measurements were displayed by the Zernike algorithm. Root mean squares of total, 3rd and 4th order of higher-order aberrations were compared between any three devices using repeated measured analysis of variance. The Bland-Altman analysis and Pearson's correlation were employed to assess agreement and strength of relationship between measurements. Results: For ocular aberrations, there were no significant difference (P &gt; 0.05) in all comparisons except for total higher-order aberration, oblique and horizontal trefoil. Whereas for corneal aberrations, vertical coma, spherical aberration and with-therule/against-the-rule secondary astigmatism between devices were found to be significantly different (P &lt; 0.05). The most agreeable device pairs for ocular and corneal aberrations were demonstrated by i-Profiler Plus - OPD Scan III (95% limit of agreement: -0.340 to 0.730) and Atlas Corneal Topographer 9000 - i-Profiler Plus (limit of agreement: 0.196 to 0.520) respectively. The r-values are stronger than 0.70. Conclusion: There were differences in the value of higher-order aberrations between different aberrometry technologies. Clinical impact due to the differences in wavefront measurement between skiascopy, Placido-based and laser technologies need to be investigated further.

Ocular, corneal, and internal aberrations in eyes with keratoconus, forme fruste keratoconus, and healthy eyes.

The purpose of this study is to evaluate ocular, corneal, and internal aberration parameters in eyes with keratoconus (KC), forme fruste keratoconus (FFKC), and normal eyes. In a prospective study, one eye of 110 patients with KC, 60 FFKC patients, and 150 healthy participants was evaluated using OPD-Scan II. Ocular, corneal, and internal higher-order aberrations were measured through a sixth-order Zernike polynomial decomposition. Receiver operating characteristic analysis was performed to evaluate the diagnostic ability of the aberration parameters in discriminating KC and FFKC from normal eyes. The root mean square of the all ocular aberration measurements was significantly higher in the KC and FFKC patients than that of normal participants (p<0.05). All of the corneal aberration measurements were significantly higher in KC patients than those of normal patients (p<0.05); however, only corneal total higher-order aberration (HOA), vertical and total coma, and higher-order astigmatism were significantly higher in the FFKC patients than normal participants (p<0.05). The results also showed that internal aberration lower-order astigmatism, total trefoil, and total higher-order spherical aberration were significantly different between KC and normal groups (p<0.05). In comparison, internal total HOA, lower and higher-order astigmatism, total trefoil, and vertical coma were significantly different between FFKC and normal groups (p<0.05). Ocular vertical and total coma had the highest ability in discriminating keratoconic from normal eyes. Ocular total higher aberration and total coma had the highest diagnostic ability in discriminating FFKC from normal eyes. The diagnostic ability of internal aberration, on the other hand, was moderate to poor in discriminating KC and FFKC from normal eyes. Ocular aberration especially vertical and total coma and total HOA were found to be suitable parameters to discriminate KC and FFKC from normal patients. These two parameters could be used as discriminating factors in evaluating the patient for refractive surgery in an attempt to avoid iatrogenic ectasia.

Intrasession repeatability of refractive and ocular aberrometric measurements obtained using a multidiagnostic device in healthy eyes.

PurposeTo evaluate the intrasession repeatability of refractive and ocular aberrometric measurements obtained using a new multidiagnostic device in healthy eyes.Patients and methodsA total of 107 eyes of 107 patients, age ranging from 23 to 65 years, were enrolled in this study. A complete eye examination was performed in all eyes, including an ocular examination using the VX120 system. Three consecutive measurements were obtained using this device to assess the intrasession repeatability of different refractive and ocular aber-rometric parameters. The within-subject standard deviation (Sw), intrasubject precision (1.96×Sw), and intraclass correlation coefficient (ICC) were calculated.ResultsSw and intrasubject precision for refractive data were below 0.12 and 0.20 D, respectively, in all cases. The ICC ranged from 0.947 for the J45 power vector component to 0.997 for the sphere. Concerning aberrometric measurements Sw and intrasubject precision values were below 0.05 µm and 0.10 µm, respectively. Likewise, the ICC ranged from 0.805 for the quadrafoil root mean square to 0.954 for the primary spherical aberration. Poor correlations were found between most of the refractive parameters and their Sw (–0.033≤r≤0.053, p≥0.064). Moderate and significant positive correlations were found between the magnitude of the aberrometric parameters evaluated and their Sw (r≥0.446, p<0.001).ConclusionThe new multidiagnostic device evaluated is able to provide consistent measurements of refraction and ocular aberrations in healthy eyes. Future studies should confirm if this consistency is also observed in highly aberrated eyes.

Comparison of the Adaptive Optics Vision Analyzer and the KR‐1 W for measuring ocular wave aberrations

BackgroundThe aim was to assess the agreement in the measurement of ocular aberrations between a new Adaptive Optics Vision Analyzer (AOVA, Voptica, Murcia, Spain) and a commercial aberrometer (KR‐1 W, Topcon, Tokyo, Japan), both based on the Hartmann–Shack technique.MethodsOne experienced examiner measured 29 healthy right eyes nine consecutive times with the two instruments. The individual Zernike coefficients and the root mean square (RMS) of each order from the second to the fifth order, the higher‐order RMS (RMSHOA), the total RMS (RMSTOT) and the values of the spherical equivalent (M) and Jackson cross‐cylinder (J0 and J45) were compared. All aberrations were computed for a 4.0 mm pupil diameter.ResultsBland and Altman analysis showed good agreement between instruments and most of the parameters showed no statistically significant differences. Although the largest mean differences were obtained for the defocus coefficient C(2,0) and the spherical equivalent (M) with a mean difference (and standard deviation) of 0.190 ± 0.099 µm and −0.150 ± 0.188 D, respectively, they were clinically acceptable and significant correlations were found between the AOVA and KR‐1 W for the major refractive components such as spherical equivalent (r = 0.995, p < 0.001), J0 (r = 0.964, p < 0.001), J45 (r = 0.901, p < 0.001) and C(4,0) (r = 0.575, p = 0.001).ConclusionThe results suggest good agreement between instruments. Accommodation and misalignment of the measurements may play a role in some of the statistically significant differences that were obtained, specifically for defocus C(2,0), vertical coma C(3,−1) and spherical aberration C(4,0) coefficients; however, these differences were clinically irrelevant.

Visual acuity and quality of life in dry eye disease: Proceedings of the OCEAN group meeting

Dry eye disease (DED) results in tear film instability and hyperosmolarity, inflammation of the ocular surface and, ultimately, visual disturbance that can significantly impact a patient's quality of life. The effects on visual acuity result in difficulties with driving, reading and computer use and negatively impact psychological health. These effects also extend to the workplace, with a loss of productivity and quality of work causing substantial economic losses. The effects of DED and the impact on vision experienced by patients may not be given sufficient importance by ophthalmologists. Functional visual acuity (FVA) is a measure of visual acuity after sustained eye opening without blinking for at least 10 s and mimics the sustained visual acuity of daily life. Measuring dynamic FVA allows the detection of impaired visual function in patients with DED who may display normal conventional visual acuity. There are currently several tests and methods that can be used to measure dynamic visual function: the SSC-350 FVA measurement system, assessment of best-corrected visual acuity decay using the interblink visual acuity decay test, serial measurements of ocular and corneal higher order aberrations, and measurement of dynamic vision quality using the Optical Quality Analysis System. Although the equipment for these methods may be too large or unaffordable for use in clinical practice, FVA testing is an important assessment for DED.

Changes of ocular aberration stability after correction with adaptive optics system

Background The use of adaptive optics (AO) system in ophthalmic clinic and basic studies has increased in recent years.However, there are few reports on the stability of ocular aberrations after correction. Objective This study was to analyze the stability of aberration after correction by observing the repeatability of ocular aberration measurements. Methods Forty-one postgraduate school students and volunteers who meet the conditions were included from February to April 2014.The Zernike aberration coefficients including astigmatism (Z2-2, Z22), defocus (Z20), trefoil (Z33, Z3-3), coma (Z3-1, Z31), spherical aberration (Z40) and the value of root mean square (RMS) including 3rd-order to 7th-order aberrations, total higher-order aberrations (HOAs) and total ocular aberrations (TOAs) were measured by using AO system.The repeatability and stability of these data after corrected with AO system were analyzed.The repeatability was evaluated by ANOVA, within-subject standard deviation (Sw), repeatability (r) and intra-class correlation coefficients (ICC). The stability was evaluated by the nonparametric Friedman's rank test. Results AO system showed excellent repeatability on Z2-2, Z22, Z20 and TOA RMS (ICC>0.9), good repeatability on Z31, Z33, Z3-3, Z40, 3rd-order RMS, 4th-order RMS, HOA RMS (ICC>0.75), poor repeatability on Z3-1, 5th-order RMS, 6th-order RMS, 7th-order RMS (ICC<0.75). Repeatability (2.77 Sw) values ranged from 0.009 mm (7th-order RMS) to 0.163 mm (Z31). After low-order ocular aberrations were corrected, It was founded that Z2-2, Z22 reached stable state at the 4th second; Z20 was stable at the 6th second; Z3-3and Z33 reached stable state at the 4th second and third second, separately; Z31 was stable from 3rd-second to 9th-second, Z3-3 was stable at the 4th-second.Z40 and HOA RMS were stable at the third second and fifth second, respectively.The Z2-2, Z20, Z22, Z3-3, Z3-1, Z33, Z40 and HOA RMS were significantly different among different time points before and after low-order aberrations correction (all at P<0.05). Z2-2, Z22, Z20 reached stable state at the 4th-second, 3rd-second and 5th-second, respectively; Z3-3, Z33reached stable state at the 2nd-second and 3rd-second, respectively; Z3-1and Z40 reached stable state at the 2nd-second; HOA RMS reached stable state at the 5th-second. Conclusions After correcting the human ocular aberration, different aberrations can reach stable state at different time.The time of Z20, Z22, Z3-3, Z3-1, Z40 reaching stable state after 2nd-order to 5th-order ocular aberrations correction was earlier than those of lower-order aberrations correction. Key words: Adaptive optics; Wavefront aberration; Repeatability; Correction; Stability

Clinical Effects and Safety of 3% Diquafosol Ophthalmic Solution for Patients With Dry Eye After Cataract Surgery: A Randomized Controlled Trial

To compare the efficacies and safety profiles of 3% diquafosol and 0.1% sodium hyaluronate in patients with dry eye after cataract surgery. Randomized controlled trial. setting: Soonchunhyang University Hospital, Seoul, South Korea. In all, 130 eyes of 86 dry eye patients who had undergone cataract surgery between January 2014 and January 2015 were enrolled and randomly divided into a diquafosol group and a sodium hyaluronate group. The diquafosol group used diquafosol 6 times a day and the hyaluronate group used sodium hyaluronate 6 times a day after cataract surgery. Evaluations of efficacy were conducted based on an Ocular Surface Disease Index questionnaire, tear breakup time (TBUT), Schirmer I test, corneal fluorescein and conjunctival lissamine green staining scores, serial measurement of ocular higher-order aberrations (HOAs), corneal HOAs, and uncorrected distance visual acuity test. Safety evaluations were based on anterior chamber inflammation and discontinuation of the eye drops. Objective signs and subjective symptoms were aggravated at 1 week postoperatively and began to recover significantly 4 weeks after surgery. The diquafosol group showed significantly superior TBUT (P < .001), corneal fluorescein (P = .045), and conjunctival staining (P = .001) compared to the sodium hyaluronate group throughout the study period. TBUT (P < .001) and the change in HOAs (P = .018) recovered significantly more quickly in the diquafosol group. The safety evaluations showed no intergroup differences. Eye drops of 3% diquafosol may be an effective and safe treatment for the management of cataract surgery-induced dry eye aggravation in patients with preexisting dry eye.

Wavefront-guided Laser-assisted in situ Keratomileusis

The measurement and treatment of ocular aberrations has been profoundly beneficial to mankind. Over the last several hundred years, correcting errors of refraction with spectacles, and later contact lenses, has provided countless millions of people with good vision. With the advent of wavefront technology, we have entered a new phase in our ability to assess the ocular function of the eye. No longer restricted to measuring sphere and cylinder, wavefront aberrometers can now quantify other types of aberrations that can impair vision, such as coma and spherical aberration. Using these devices, we are gaining a much better appreciation of the optical characteristics of the eye. In addition to this robust diagnostic capability, wavefront technology is now being used to treat ocular aberrations in the form of wavefront-guided laser-assistedin situkeratomileusis (LASIK).

Evaluation of optical quality parameters and ocular aberrations in multifocal intraocular lens implanted eyes.

PurposeWe investigated the correlations between optical quality parameters obtained from the double-pass system and ocular aberrations obtained from the ray-tracing aberrometer in multifocal intraocular lens (IOL) implanted eyes.Materials and MethodsTwenty eyes from 20 patients were enrolled in this study. Modulation transfer function cutoff frequency, The Strehl ratio, objective scatter index, and objective pseudo-accommodation obtained from the double-pass system were compared with root mean square (RMS) total aberration, RMS higher-order aberration, and spherical aberration obtained from the ray-tracing aberrometer. Additionally, parameters of the double-pass system and ray-tracing aberrometer were compared with manifested refraction values and subjective visual acuity, respectively.ResultsThere was no statistically significant correlation between optical quality parameters obtained from the double-pass system and ocular aberrations, except between the Strehl ratio and RMS total aberration (r=-0.566, p=0.018). No significant correlations were found between the parameters of both devices, and manifested refraction values or subjective visual acuity.ConclusionOptical quality parameters, especially the Strehl ratio, in multifocal IOL implanted eyes were affected by RMS total aberration. Further studies based on accurate measurements of ocular aberrations and additional optical quality parameters are needed to delineate relationships between optical quality parameters and ocular aberrations in multifocal IOL implanted eyes.