FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2051299495> ?p ?o ?g. }

• W2051299495 endingPage "110" @default.
• W2051299495 startingPage "106" @default.
• W2051299495 abstract "Purpose: The purpose of this study was to determine which preoperative factors are associated with the presence of high-order aberrations. Methods: A total of 93 eyes of 52 subjects were evaluated preoperatively between 1 January and 31 March 2003, using a Hartmann−Shack-based aberrometer. Age, gender, cycloplegic refraction, pupil size, keratometry readings, anterior chamber depth, white-to-white tests, intraocular pressure and basic secretion tests were evaluated. Results: Factors associated with high-order aberrations included age ≥ 40 years (mean 4.39 ± 2.95 µm; p = 0.03, Mann–Whitney test), higher keratometry values (44.96 ± 1.57 D) (r = 0.447, p < 0.001, Spearman's correlation coefficient), higher degrees of myopia (≥ − 6.1 D) (p < 0.001, Kruskall−Wallis test) and increasing pupil size (p < 0.001, anova). Other factors including anterior chamber depth, white-to-white results, intraocular pressure and basic secretion test results did not correlate with the presence of high-order aberrations preoperatively. Conclusions: Ocular wavefront aberrations varied greatly from subject to subject. Treatment should be customized for each laser based on patient characteristics in order to ensure the optimal treatment profile for the aberration. Refractive surgery continues to be a rapidly growing and evolving field of ophthalmology (Solomon et al. 2004). Recently, wavefront and customized corneal ablation have introduced alternative options in LASIK (laser in situ keratomileusis) surgery (Howland & Howland 1976). Wavefront devices provide a fast, non-invasive method of measuring not only the sphere, cylinder and axis of a patient, but also their higher order aberrations (HOAs) such as coma and spherical aberration (Fernández de Castro et al. 2003; Salmon et al. 2003). The aberrations measured are not just corneal, but represent aberrations of the entire optical system. The aberration is calculated as the difference between the wavefront obtained from an ideal optic system and the wavefront derived from the measured eye. The shape of the wavefront varies according to the refractive error. Techniques for measuring ocular aberrations include Hartmann−Shack (Shack−Hartmann) wavefront sensing, Tscherning aberrometry sensing, Tracey ray-tracing aberrometry, and optical path difference (OPD) scans. Aberrometers based on the Hartmann–Shack principle include the LADARWave (Alcon Laboratories, Fort Worth, TX, USA), the WaveScan (VISX, Santa Clara, CA, USA), and the Zywave (Bausch & Lomb Surgical, San Dimas, CA, USA), among others. Tscherning aberrometry is conducted with the Allegretto WaveLight Analyser (WaveLight Laser Technologie AG, Erlanger, Germany). Ray tracing aberrometry is performed with the Tracey-VFA (Tracey Technologies, Houston, TX, USA). The OPD principle is applied with the Nidek OPD-Scan (Nidek, Tokyo, Japan). The actual derived aberrations are critical issues in terms of designing wavefront-guided refractive surgery treatments. Therefore, basic data regarding corneal wavefront aberrations, such as distribution in the population, changes with age, pupil dilation and refractive error are essential for understanding the nature of each aberration and how to correct it. The purpose of this paper was to determine which ocular and patient characteristics are associated with HOAs. The study protocol adhered to the tenets of the Declaration of Helsinki (1996) and the regulations of the Medical University of South Carolina Institutional Review Board for Human Research and Health Insurance Portability and Accountability Act (HIPAA). All patients provided signed informed consent prior to initiation of any study-related procedures. Inclusion criteria included patients who had been screened for LASIK and in whom wavefront measurements had been taken using the LADARWave aberrometer. The LADARWave aberrometer measures both low- and high- order aberrations using an 820-nm diode laser light source and a lenslet array that captures wavefront data at 200 or more sample points over a 7.0-mm pupil. The entire optical system of the eye is assessed by taking the wavefront measurement with a dilated pupil. The dilated pupil prevents the pupillary aperture from changing in size during wavefront measurement and provides wavefront data for use in the formulation of the customized ablation pattern. The automatic fogging eliminates the effects of patient accommodation on transmission of the laser light. The dynamic range of measurement is − 15 D to + 15 D sphere and up to − 8 D cylinder. Five consecutive measurements are captured; the two most outlying measurements are discarded and the remaining three are used to make an average composite. A total of 93 eyes in 52 patients (87 myopic eyes and six hyperopic eyes) of both sexes, with or without astigmatism and screened for LASIK surgery between 1 January and 31 March 2003, were included. The mean age was 40.9 ± 10.3 years; 52% of subjects were male and 48% were female. All eyes had 20/20 best corrected visual acuity (BCVA). The cycloplegic spherical equivalent (SE) range was − 9.00 D to + 3.00 D. Patients were dilated with 1% cyclopentolate hydrochloride (Cyclogyl; Alcon Laboratories). Once the pupil was dilated to > 6 mm, measurements were taken using the LADARWave aberrometer. Trained personnel using the operating procedures recommended by the manufacturer took measurements with the wavefront device. With the pupil standardized at 6 mm, third and fourth order aberrations were analysed and correlated with age, gender, cycloplegic SE, keratometry (flattest, steepest and average), white-to-white, anterior chamber depth (ACD), intraocular pressure (IOP) and basic secretion test (BST). To evaluate variations of third and fourth order aberrations associated with changes in pupil size, a subgroup of 18 eyes were analysed and aberrations were measured at pupil sizes of 5, 6, 6.5 and 7 mm. Orbscan II (Bausch & Lomb Surgical, San Dimas, CA, USA) was used to obtain the keratometry, white-to-white and ACD values for each patient. The BST was attained after installing a drop of proparacaine 1% in each eye, drying the fornix, and placing a sterile standardized Schirmer tear test strip (Alcon Laboratories) in both inferior fornices at the junction of the lateral and middle thirds. It was measured at 5 mins and recorded in mm. Statistical analysis was performed using anova (compares the means of three or more paired groups) for normally distributed data. Statistical methods for data that were not normally distributed included the Kruskall−Wallis test (compares the median between three or more paired groups); Mann–Whitney test (determines whether the medians of two paired groups differ significantly); and Spearman's correlation coefficient (quantifies how well two variables from a population that do not follow a Gaussian distribution vary together). A p-value of < 0.05 was considered statistically significant. All p-values reported are two-sided. Ocular aberrations were measured before LASIK refractive surgery using the LADARWave aberrometer. Table 1 summarizes the overall factors that affected HOAs. There was a significant difference in defocus between women (mean 5.66 ± 2.35 µm) and men (mean 4.22 ± 3.06 µm; p < 0.01, Mann–Whitney test). Patients ≥ 40 years of age (n = 58) tended to have greater total HOAs (mean 0.45 ± 0.16 µm) and spherical aberrations (mean 0.23 ± 0.15 µm) than younger patients (n = 35; means 0.36 ± 0.10 µm and 0.15 ± 0.14 µm, respectively. Younger patients were more likely to have greater defocus (mean 5.79 ± 2.37 µm) than patients ≥ 40 years of age (mean 4.39 ± 2.95 µm; p = 0.03, Mann–Whitney test). Although the correlation illustrated in Fig. 1 appears to be widely scattered, there is a statistically significant correlation between age and total HOA. Figure 2 illustrates a statistically significant correlation between age and spherical aberration. Scatterplot showing a significant correlation between preoperative high-order aberrations (HOAs) and age: the older the patient, the higher the aberrations (r = 0.331; p < 0.001, Spearman's correlation coefficient). Scatterplot showing a significant correlation between preoperative spherical aberrations and age: the older the patient, the higher the spherical aberrations (r = 0.331; p < 0.001, Spearman's correlation coefficient). The mean steepest k-value was 44.96 ± 1.57 D (range 41.9–49.0 D) showing the highest correlation with total HOA among all the studied factors (r = 0.447; p < 0.001, Spearman's correlation coefficient; Fig. 3). The mean flattest k-value was 44.02 ± 1.48 D (range 41.1–47.3 D), and the average k-value was 44.5 ± 1.5 D (range 41.6–48.1 D). Scatterplot showing a significant correlation between preoperative high-order aberrations (HOAs) and steepest k-readings: the higher the k-values, the higher the HOA (r = 0.447; p < 0.001, Spearman's correlation coefficient). The mean cycloplegic SE was − 3.5 ± 2.5 D (range 3.1 D to − 9.2 D). The refractive error was arbitrarily divided into three degrees of ammetropia, as follows: 0.1 D to + 3.0 D, 0.0 D to − 6.0 D, and > − 6.0 D. Table 2 shows the values of HOA grouped by spherical equivalent. Defocus was the only term that showed a significant difference among the groups (p < 0.001, Kruskall-Wallis test). By definition, the higher the degree of myopia, the higher the defocus value. There was an increase in the total root mean square (RMS), total HOA, and each Zernike term when the pupil size was increased from 5.0 mm to 7.0 mm (Table 3,Fig. 4). There was a significant difference (anova test, p < 0.001) in the different aberrations (e.g. total RMS, total HOA, defocus and total coma) measured when comparing the different pupil sizes (5.0, 6.0, 6.5 and 7.0 mm), with the exception of total astigmatism when comparing the 6.0–6.5-mm and the 6.5–7.0-mm pupil sizes, and spherical aberration in the 6.5–7.0-mm pupil size. Graph demonstrating the increase in total preoperative high-order aberrations as pupil diameter increases (p < 0.001). Vertical bars denote 0.95 confidence intervals. Evaluations of BST scores (mean 17.5 ± 9.9 mm, range 3–35 mm), white-to-white values (mean 11.7 ± 0.5 mm, range 10.5–13 mm), IOP values (mean 14.7 ± 2.8 mmHg, range 10–20 mmHg) and ACD values (mean 3.7 ± 0.4 mm, range 2.5–4.6 mm) showed that none of them were found to influence the presence of HOA (p > 0.05, Spearman's correlation coefficient). It is important to understand which ocular characteristics affect HOAs in the normal population. Average aberrations in the human eye tend to change over time with age (1, 2). In young patients corneal aberration predominates and the lens compensates for corneal aberration. This is not the case for older patients, where there is a loss of aberration balance between the cornea and lens (Oshika et al. 1999; Guirao et al. 2000; McLellan et al. 2001; Castejon-Mochon et al. 2002; Kuroda et al. 2002a, 2002b; Wang & Koch 2003a; Wang et al. 2003a). Additionally, the shape of the cornea changes from with-the-rule to against-the-rule astigmatism with age (Oshika et al. 1999). The transparency of the ocular media also differs with age (e.g. lens opacity, vitreous degeneration), contributing to further optical aberrations (Kuroda et al. 2002b, 2002c). Our study found that patients ≥ 40 years of age tended to have greater HOA and spherical aberration than younger patients (p = 0.03, Mann–Whitney test). Astigmatism has been associated with the induction of HOA (Wu 2002). We found that the mean steepest k-value showed the highest correlation with total HOA among all the studied factors (p < 0.001, Spearman's correlation coefficient). Postoperative residual or induced astigmatism may limit uncorrected visual acuity and cause starbursts and glare at night. Additionally, irregular astigmatism can also cause loss of BCVA, monocular diplopia, and ghosting of images (Wu 2002). Conventional LASIK surgery can induce astigmatism, whereas the customized corneal ablation, using wavefront-derived data, reduces it, improving the final outcome for the patient (Wu 2002). Simonet et al. (1999) and Marcos et al. (2000) reported that aberrations increase with increasing myopia. The latter found that this effect applied only to myopia ranging from − 7.0 D to − 13.0 D. We found a relationship between a change in defocus and higher degrees of myopia ≥ − 6.1 D (p < 0.001, Kruskall−Wallis test). Oshika et al. (1999) showed a marked increase in total aberrations and coma-like aberrations when stimulating pupillary dilation from 3 mm to 7 mm. Campbell & Gubisch (1966) and Liang & Williams (1997) demonstrated that image quality is relatively good in medium-sized pupils but deteriorates as pupil diameter increases. Another important feature of aberration maps of normal eyes is the tendency to be relatively flat in the centre of the pupil, with aberrations growing stronger near the pupil margin (Applegate et al. 2001). In this study we found a positive relationship between HOA and pupil size that is consistent with the literature (Oshika et al. 1999; Moreno-Barriuso et al. 2001; Miller et al. 2002; Schallhorn et al. 2003; Wang & Koch 2003a, 2003b); Wang et al. 2003b). Clearly, pupil size plays an important role in the magnitude of wavefront aberrations for both measurement and treatment. Irregularities in the anterior surface of the cornea, specifically tear film (Tutt et al. 2000; Koh et al. 2002), may lead to significant optical aberrations. However, our study did not find a correlation between BST and HOA, which may be a result of good tear volume and tear film stability in our study group. It is important during the preoperative period to remain cautious of ocular surface complaints in order to treat patients properly and avoid the drying of the ocular surface during image capture. Additionally, checking the condition of the tear film during wavefront sensing could be important before the procedure because dry eye is a common finding following LASIK. In conclusion, aberrations are greatly influenced by a number of variables such as age, k-values, SE and pupil diameter. Anatomical and functional variations associated with the cornea, the crystalline lens, the vitreous, the morphology of the retina, and probably other elements can also influence aberrations. It is important that surgeons take all these factors into consideration preoperatively in order to achieve the optimal profile required to improve vision quality. This study was presented in part at the annual meeting of the American Society of Cataract and Refractive Surgery, San Francisco, CA, USA, 12–16 April 2003. The study was supported in part by NIH/NEI EY-014793 and an unrestricted grant to MUSC-SEI from Research to Prevent Blindness, New York, NY, USA." @default.
• W2051299495 created "2016-06-24" @default.
• W2051299495 creator A5006303592 @default.
• W2051299495 creator A5034151982 @default.
• W2051299495 creator A5034386605 @default.
• W2051299495 creator A5062585001 @default.
• W2051299495 creator A5064815297 @default.
• W2051299495 date "2006-09-20" @default.
• W2051299495 modified "2023-09-25" @default.
• W2051299495 title "High-order aberrations and preoperative associated factors" @default.
• W2051299495 cites W146726056 @default.
• W2051299495 cites W1514797584 @default.
• W2051299495 cites W1979736425 @default.
• W2051299495 cites W1983091781 @default.
• W2051299495 cites W1991954284 @default.
• W2051299495 cites W1993400116 @default.
• W2051299495 cites W2003198209 @default.
• W2051299495 cites W2006751222 @default.
• W2051299495 cites W2023734694 @default.
• W2051299495 cites W2024536806 @default.
• W2051299495 cites W2031010001 @default.
• W2051299495 cites W2034749295 @default.
• W2051299495 cites W2042033299 @default.
• W2051299495 cites W2098692202 @default.
• W2051299495 cites W2105102125 @default.
• W2051299495 cites W2128721648 @default.
• W2051299495 cites W2149917223 @default.
• W2051299495 cites W2151084406 @default.
• W2051299495 cites W86986330 @default.
• W2051299495 doi "https://doi.org/10.1111/j.1600-0420.2006.00757.x" @default.
• W2051299495 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/17244221" @default.
• W2051299495 hasPublicationYear "2006" @default.
• W2051299495 type Work @default.
• W2051299495 sameAs 2051299495 @default.
• W2051299495 citedByCount "22" @default.
• W2051299495 countsByYear W20512994952012 @default.
• W2051299495 countsByYear W20512994952013 @default.
• W2051299495 countsByYear W20512994952014 @default.
• W2051299495 countsByYear W20512994952016 @default.
• W2051299495 countsByYear W20512994952017 @default.
• W2051299495 countsByYear W20512994952018 @default.
• W2051299495 countsByYear W20512994952020 @default.
• W2051299495 countsByYear W20512994952021 @default.
• W2051299495 countsByYear W20512994952022 @default.
• W2051299495 crossrefType "journal-article" @default.
• W2051299495 hasAuthorship W2051299495A5006303592 @default.
• W2051299495 hasAuthorship W2051299495A5034151982 @default.
• W2051299495 hasAuthorship W2051299495A5034386605 @default.
• W2051299495 hasAuthorship W2051299495A5062585001 @default.
• W2051299495 hasAuthorship W2051299495A5064815297 @default.
• W2051299495 hasConcept C118487528 @default.
• W2051299495 hasConcept C119767625 @default.
• W2051299495 hasConcept C165788157 @default.
• W2051299495 hasConcept C2778257484 @default.
• W2051299495 hasConcept C71924100 @default.
• W2051299495 hasConceptScore W2051299495C118487528 @default.
• W2051299495 hasConceptScore W2051299495C119767625 @default.
• W2051299495 hasConceptScore W2051299495C165788157 @default.
• W2051299495 hasConceptScore W2051299495C2778257484 @default.
• W2051299495 hasConceptScore W2051299495C71924100 @default.
• W2051299495 hasIssue "1" @default.
• W2051299495 hasLocation W20512994951 @default.
• W2051299495 hasLocation W20512994952 @default.
• W2051299495 hasOpenAccess W2051299495 @default.
• W2051299495 hasPrimaryLocation W20512994951 @default.
• W2051299495 hasRelatedWork W2059294092 @default.
• W2051299495 hasRelatedWork W2382574795 @default.
• W2051299495 hasRelatedWork W2411461630 @default.
• W2051299495 hasRelatedWork W2427732479 @default.
• W2051299495 hasRelatedWork W2473894363 @default.
• W2051299495 hasRelatedWork W3028626267 @default.
• W2051299495 hasRelatedWork W3030114235 @default.
• W2051299495 hasRelatedWork W3216739921 @default.
• W2051299495 hasRelatedWork W4252614341 @default.
• W2051299495 hasRelatedWork W4296807208 @default.
• W2051299495 hasVolume "85" @default.
• W2051299495 isParatext "false" @default.
• W2051299495 isRetracted "false" @default.
• W2051299495 magId "2051299495" @default.
• W2051299495 workType "article" @default.