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Takefumi Yamaguchi - One of the best experts on this subject based on the ideXlab platform.
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the contribution of the posterior Surface to the corneal aberrations in eyes after keratoplasty
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kazuno Negishi, Kazuo Tsubota, Takefumi Yamaguchi, Kazuhiko Ohnuma, Daisuke Tomida, Kenji Konomi, Yoshiyuki Satake, Jun ShimazakiAbstract:PURPOSE To investigate the contribution of posterior corneal Surfaces to higher-order aberrations (HOAs) of the cornea, optical quality, and visual acuity after keratoplasty. METHODS Corneal topography of Anterior and posterior Surfaces and pachymetry were conducted using Anterior segment optical coherence tomography (AS-OCT) in 40 eyes (10 eyes after penetrating keratoplasty [PK], 10 eyes after deep Anterior lamellar keratoplasty [DALK], 10 eyes after Descemet's stripping automated endothelial keratoplasty [DSAEK], and 10 normal eyes). Anterior, posterior, and total corneal HOAs were calculated using ray-tracing and decomposition into Zernike polynomials and were evaluated as root mean square values. Modulation transfer functions (MTFs) were also evaluated. RESULTS Topography maps of the Anterior and posterior Surfaces showed reverse patterns in the normal, PK, and DALK eyes, but not in DSAEK eyes. In the normal, PK, and DALK eyes, the total corneal HOAs were significantly smaller (~10%) than were the HOAs of the Anterior Surface (P < 0.01), whereas there was no significant difference between total and Anterior HOAs in the DSAEK eyes (P = 0.483). In the normal, PK, and DALK eyes, the MTFs of the total cornea were slightly better than those of the Anterior Surface. In the DSAEK eyes, the MTFs of the total cornea were lower than those of the Anterior Surface. Visual acuity was significantly correlated with total and Anterior Surface HOAs (P < 0.05). CONCLUSIONS Posterior Surfaces compensate for Anterior aberrations in normal, PK, and DALK eyes. In DSAEK eyes, the posterior Surface increased total corneal HOAs and had a negative influence on MTFs.
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comparison of Anterior and posterior corneal Surface irregularity in descemet stripping automated endothelial keratoplasty and penetrating keratoplasty
Cornea, 2010Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Murat Dogru, Kazuko Yamaguchi, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:PURPOSE To evaluate the irregularity of the Anterior and posterior cornea after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). METHODS This clinical study comprised 39 eyes: 13 consecutive eyes after DSAEK, 13 consecutive eyes after PK, and 13 age-matched normal eyes. Corneal elevation data were acquired using a rotating Scheimpflug camera 1 and 3 months after DSAEK and PK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to eighth order. Total higher-order root mean square (RMS) and RMS from third to eighth order were calculated. The astigmatism and irregularity of the Anterior and posterior Surfaces were compared between DSAEK and PK. RESULTS The regular astigmatism and tilt components of the Anterior Surface were significantly lower after DSAEK than after PK at 1 and 3 months (P < 0.001), whereas there was no difference in astigmatism of the posterior Surface between the groups (P = 0.07, 0.22). The higher-order RMS and RMSs of third- to eighth-order components of the Anterior Surface were significantly larger after PK than those after DSAEK at 1 and 3 months (P < 0.01), whereas there were no significant differences between DSAEK and PK in higher-order aberration RMS and RMSs of third- to eighth-order components of the posterior Surface. CONCLUSIONS Postoperative corneal irregularity of the Anterior Surface was greater after PK than after DSAEK, whereas there was no significant difference in posterior Surface irregularity. DSAEK is superior to PK in terms of the higher-order irregularity of the Anterior Surface.
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effect of Anterior and posterior corneal Surface irregularity on vision after descemet stripping endothelial keratoplasty
Journal of Cataract and Refractive Surgery, 2009Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Kazuko Yamaguchi, Dogru Murat, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:Purpose To evaluate irregularity of the Anterior and posterior cornea before and after Descemet-stripping endothelial keratoplasty (DSEK) and its effect on visual acuity. Setting Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. Methods Corneal data were acquired using a rotating Scheimpflug camera before and 1 month and 3 months after DSEK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to the 8th order within a 4.0 mm diameter region. Total higher-order root mean square (HO-RMS) and RMS from the 3rd to 8th order were calculated. The effects of Anterior and posterior Surface irregularity on visual acuity were evaluated. Results This clinical study comprised 13 consecutive eyes of 12 bullous keratopathy patients. The mean best corrected visual acuity (BCVA) was 1.11 logMAR ± 0.5 (SD) preoperatively, 0.49 ± 0.49 logMAR 1 month postoperatively, and 0.27 ± 0.32 logMAR at 3 months. The HO-RMS of the Anterior Surface 1 month ( P = .040) and 3 months ( P = .048) postoperatively was significantly lower than preoperatively. There were no significant differences in posterior Surface HO-RMS between preoperatively and 1 month ( P = .45) and 3 months ( P = .054). The postoperative BCVA was significantly correlated with HO-RMS ( P P = .354). Conclusion Postoperative BCVA correlated with irregularity of the Anterior Surface but not the posterior Surface. In addition to corneal transparency, regularity of the Anterior Surface is an important factor in visual acuity after DSEK.
Kazuo Tsubota - One of the best experts on this subject based on the ideXlab platform.
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the contribution of the posterior Surface to the corneal aberrations in eyes after keratoplasty
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kazuno Negishi, Kazuo Tsubota, Takefumi Yamaguchi, Kazuhiko Ohnuma, Daisuke Tomida, Kenji Konomi, Yoshiyuki Satake, Jun ShimazakiAbstract:PURPOSE To investigate the contribution of posterior corneal Surfaces to higher-order aberrations (HOAs) of the cornea, optical quality, and visual acuity after keratoplasty. METHODS Corneal topography of Anterior and posterior Surfaces and pachymetry were conducted using Anterior segment optical coherence tomography (AS-OCT) in 40 eyes (10 eyes after penetrating keratoplasty [PK], 10 eyes after deep Anterior lamellar keratoplasty [DALK], 10 eyes after Descemet's stripping automated endothelial keratoplasty [DSAEK], and 10 normal eyes). Anterior, posterior, and total corneal HOAs were calculated using ray-tracing and decomposition into Zernike polynomials and were evaluated as root mean square values. Modulation transfer functions (MTFs) were also evaluated. RESULTS Topography maps of the Anterior and posterior Surfaces showed reverse patterns in the normal, PK, and DALK eyes, but not in DSAEK eyes. In the normal, PK, and DALK eyes, the total corneal HOAs were significantly smaller (~10%) than were the HOAs of the Anterior Surface (P < 0.01), whereas there was no significant difference between total and Anterior HOAs in the DSAEK eyes (P = 0.483). In the normal, PK, and DALK eyes, the MTFs of the total cornea were slightly better than those of the Anterior Surface. In the DSAEK eyes, the MTFs of the total cornea were lower than those of the Anterior Surface. Visual acuity was significantly correlated with total and Anterior Surface HOAs (P < 0.05). CONCLUSIONS Posterior Surfaces compensate for Anterior aberrations in normal, PK, and DALK eyes. In DSAEK eyes, the posterior Surface increased total corneal HOAs and had a negative influence on MTFs.
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comparison of Anterior and posterior corneal Surface irregularity in descemet stripping automated endothelial keratoplasty and penetrating keratoplasty
Cornea, 2010Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Murat Dogru, Kazuko Yamaguchi, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:PURPOSE To evaluate the irregularity of the Anterior and posterior cornea after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). METHODS This clinical study comprised 39 eyes: 13 consecutive eyes after DSAEK, 13 consecutive eyes after PK, and 13 age-matched normal eyes. Corneal elevation data were acquired using a rotating Scheimpflug camera 1 and 3 months after DSAEK and PK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to eighth order. Total higher-order root mean square (RMS) and RMS from third to eighth order were calculated. The astigmatism and irregularity of the Anterior and posterior Surfaces were compared between DSAEK and PK. RESULTS The regular astigmatism and tilt components of the Anterior Surface were significantly lower after DSAEK than after PK at 1 and 3 months (P < 0.001), whereas there was no difference in astigmatism of the posterior Surface between the groups (P = 0.07, 0.22). The higher-order RMS and RMSs of third- to eighth-order components of the Anterior Surface were significantly larger after PK than those after DSAEK at 1 and 3 months (P < 0.01), whereas there were no significant differences between DSAEK and PK in higher-order aberration RMS and RMSs of third- to eighth-order components of the posterior Surface. CONCLUSIONS Postoperative corneal irregularity of the Anterior Surface was greater after PK than after DSAEK, whereas there was no significant difference in posterior Surface irregularity. DSAEK is superior to PK in terms of the higher-order irregularity of the Anterior Surface.
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effect of Anterior and posterior corneal Surface irregularity on vision after descemet stripping endothelial keratoplasty
Journal of Cataract and Refractive Surgery, 2009Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Kazuko Yamaguchi, Dogru Murat, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:Purpose To evaluate irregularity of the Anterior and posterior cornea before and after Descemet-stripping endothelial keratoplasty (DSEK) and its effect on visual acuity. Setting Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. Methods Corneal data were acquired using a rotating Scheimpflug camera before and 1 month and 3 months after DSEK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to the 8th order within a 4.0 mm diameter region. Total higher-order root mean square (HO-RMS) and RMS from the 3rd to 8th order were calculated. The effects of Anterior and posterior Surface irregularity on visual acuity were evaluated. Results This clinical study comprised 13 consecutive eyes of 12 bullous keratopathy patients. The mean best corrected visual acuity (BCVA) was 1.11 logMAR ± 0.5 (SD) preoperatively, 0.49 ± 0.49 logMAR 1 month postoperatively, and 0.27 ± 0.32 logMAR at 3 months. The HO-RMS of the Anterior Surface 1 month ( P = .040) and 3 months ( P = .048) postoperatively was significantly lower than preoperatively. There were no significant differences in posterior Surface HO-RMS between preoperatively and 1 month ( P = .45) and 3 months ( P = .054). The postoperative BCVA was significantly correlated with HO-RMS ( P P = .354). Conclusion Postoperative BCVA correlated with irregularity of the Anterior Surface but not the posterior Surface. In addition to corneal transparency, regularity of the Anterior Surface is an important factor in visual acuity after DSEK.
George Asimellis - One of the best experts on this subject based on the ideXlab platform.
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clinical correlation between placido scheimpflug and led color reflection topographies in imaging of a scarred cornea
Case Reports in Ophthalmology, 2014Co-Authors: Anastasios John Kanellopoulos, George AsimellisAbstract:This case report aims to evaluate safety, efficacy and feasibility of Anterior Surface imaging by a novel point-source reflection topographer, in comparison to four other corneal imaging modalities. A 17-year-old female patient, clinically diagnosed with chronic herpetic keratitis in her left eye was imaged by a novel multicolored-spot reflection topography system. We comparatively investigated elevation and curvature maps between the novel topographer and established Placido disk topography and Scheimpflug tomography systems. Pachymetry maps were compared between the Scheimpflug system and Anterior-segment optical coherence tomography system. The Placido system failed to properly register the abnormal Anterior Surface due to incomplete mire registration, while the Scheimpflug topometry device imaged the Anterior Surface properly, but not the posterior (due to media opacity), and thus pachymetry was highly irregular and erroneous in this case. Imaging of corneas infected with herpes simplex virus keratitis has been rare; we have not identified any such documentation in the peer review literature in the last 10 years. This novel multicolored-spot reflection topography imaging may offer successful corneal imaging in cases where established clinical topography systems may fail to produce accurate reconstruction of the corneal shape. This is an important case demonstrating exceptional clinical feasibility in such rare cases offered by a newly introduced technology in ophthalmic imaging.
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corneal refractive power and symmetry changes following normalization of ectasias treated with partial topography guided ptk combined with higher fluence cxl the athens protocol
Journal of Refractive Surgery, 2014Co-Authors: Anastasios John Kanellopoulos, George AsimellisAbstract:Purpose To investigate preoperative and postoperative Anterior and posterior keratometry and simulated corneal astigmatism in keratoconic eyes treated with collagen cross-linking combined with Anterior Surface normalization by partial topography-guided excimer ablation (the Athens Protocol). Methods Anterior and posterior corneal keratometry were measured by Scheimpflug imaging for 267 untreated keratoconic eyes. Following treatment, they were assessed 1 year postoperatively. Results Before treatment, average Anterior keratometric value was 47.06 ± 6.02 diopters (D) for flat and 51.24 ± 6.75 D for steep. The posterior keratometric values were -6.70 ± 0.99 D (flat) and -7.67 ± 1.15 D (steep). Anterior astigmatism was on average with-the-rule (-1.97 ± 6.21 D), whereas posterior astigmatism was against-the-rule (+0.53 ± 1.02 D). The posterior and Anterior astigmatism were highly correlated (r(2) = 0.839). After treatment, Anterior keratometric values were 43.97 ± 5.81 D (flat) and 46.55 ± 6.82 D (steep). Posterior keratometric values were -6.58 ± 1.05 D (flat) and -7.69 ± 1.22 D (steep). Anterior astigmatism was on average with-the-rule (-1.56 ± 3.80 D), whereas posterior astigmatism was against-the-rule (+0.45 ± 1.29 D). The statistically significant (P .05). Conclusions Before treatment, there was a strong correlation between posterior and Anterior corneal astigmatism. After treatment, statistically significant Anterior keratometric values flattened. The posterior Surface keratometric values did not demonstrate statistically significant postoperative change: there was minimal posterior change, despite the significant Anterior Surface normalization.
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keratoconus management long term stability of topography guided normalization combined with high fluence cxl stabilization the athens protocol
Journal of Refractive Surgery, 2014Co-Authors: Anastasios John Kanellopoulos, George AsimellisAbstract:PURPOSE: To investigate refractive, topometric, pachymetric, and visual rehabilitation changes induced by Anterior Surface normalization for keratoconus by partial topography-guided excimer laser ablation in conjunction with accelerated, high-fluence cross-linking. METHODS: Two hundred thirty-one keratoconic cases subjected to the Athens Protocol procedure were studied for visual acuity, keratometry, pachymetry, and Anterior Surface irregularity indices up to 3 years postoperatively by Scheimpflug imaging (Oculus Optikgerate GmbH, Wetzlar, Germany). RESULTS: Mean visual acuity changes at 3 years postoperatively were +0.38 ± 0.31 (range: -0.34
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evaluation of visual acuity pachymetry and Anterior Surface irregularity in keratoconus and crosslinking intervention follow up in 737 cases
International Journal of Keratoconus and Ectatic Corneal Diseases, 2013Co-Authors: Anastasios John Kanellopoulos, Vasiliki Moustou, George AsimellisAbstract:Purpose: To investigate visual acuity, corneal pachymetry, and Anterior-Surface irregularity indices correlation with keratoconus severity in a very large pool of clinically-diagnosed untreated keratoconic eyes, and in keratoconic eyes subjected to crosslinking intervention. Materials and methods: Total of 737 keratoconic (KCN) cases were evaluated. Group A was formed from 362 untreated keratoconic eyes, and group B from 375 keratoconic eyes subjected to partial normalization via topography-guided excimer laser ablation and high-fluence collagen crosslinking. A control group C of 145 healthy eyes was employed for comparison. We investigated distance visual acuity, uncorrected (UDVA), best-spectacle corrected (CDVA), and Scheimpflug-derived keratometry, pachymetry (central corneal thickness, CCT and thinnest, TCT), and two Anterior-Surface irregularity indices, the index of Surface variance (ISV) and the index of height decentration (IHD). The correlations between these parameters vs topographic keratoconus classification (TKC) were investigated. Results: Keratometry for group A was K1 (flat) 46.67 ± 3.80 D and K2 (steep) 50.76 ± 5.02 D; for group B K1 44.03 ± 3.64 D and K2 46.87 ± 4.61 D; for group C, K1 42.89 ± 1.45 D and K2 44.18 ± 1.88 D. Visual acuity for group A was UDVA 0.12 ± 0.18 and CDVA 0.59 ± 0.25 (decimal), for group B, 0.51 ± 0.28 and 0.77 ± 0.22, and for group C, 0.81 ± 0.31 and 0.87 ± 0.12. Correlation between ISV and TKC (r2) was for group A 0.853, and for group-B 0.886. Correlation between IHD and TKC was for group A r2 = 0.731, and for group B 0.701. The ROC analysis ‘area under the curve’ was for CDVA 0.550, TCT 0.596, ISV 0.876 and IHD 0.887. Conclusion: Our study indicates that the traditionally employed metrics of visual acuity and corneal thickness may not be robust indicators nor provide accurate assessment on either keratoconus severity or postoperative evaluation. Two Anterior Surface irregularity indices, derived by Scheimpflug-imaging, ISV and IHD, may be more sensitive and specific tools. Precis: Visual acuity, Scheimpflug-derived pachymetry and Anterior-Surface irregularity correlation to keratoconus severity in untreated cases (A), treated with crosslinking (B), and in a control group (C) reveals that visual acuity and pachymetry do not correlate well with keratoconus severity.
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revisiting keratoconus diagnosis and progression classification based on evaluation of corneal asymmetry indices derived from scheimpflug imaging in keratoconic and suspect cases
Clinical Ophthalmology, 2013Co-Authors: Anastasios John Kanellopoulos, George AsimellisAbstract:PURPOSE To survey the standard keratoconus grading scale (Pentacam®-derived Amsler-Krumeich stages) compared to corneal irregularity indices and best spectacle-corrected distance visual acuity (CDVA). PATIENTS AND METHODS Two-hundred and twelve keratoconus cases were evaluated for keratoconus grading, Anterior Surface irregularity indices (measured by Pentacam imaging), and subjective refraction (measured by CDVA). The correlations between CDVA, keratometry, and the Scheimpflug keratoconus grading and the seven Anterior Surface Pentacam-derived topometric indices - index of Surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, index of height asymmetry, index of height decentration, and index of minimum radius of curvature - were analyzed using paired two-tailed t-tests, coefficient of determination (r(2)), and trendline linearity. RESULTS The average ± standard deviation CDVA (expressed decimally) was 0.626 ± 0.244 for all eyes (range 0.10-1.00). The average flat meridian keratometry was (K1) 46.7 ± 5.89 D; the average steep keratometry (K2) was 51.05 ± 6.59 D. The index of Surface variance and the index of height decentration had the strongest correlation with topographic keratoconus grading (P < 0.001). CDVA and keratometry correlated poorly with keratoconus severity. CONCLUSION It is reported here for the first time that the index of Surface variance and the index of height decentration may be the most sensitive and specific criteria in the diagnosis, progression, and surgical follow-up of keratoconus. The classification proposed herein may present a novel benchmark in clinical work and future studies.
Leonard Bielory - One of the best experts on this subject based on the ideXlab platform.
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allergic inflammation of the Anterior Surface of the eye
Allergy and Asthma Proceedings, 2020Co-Authors: Leonard BieloryAbstract:Background: Ocular allergies affect an estimated 40% of the population, 98% of which are because of allergic conjunctivitis and includes tear film dysfunction. With the current advent of both repurposed drugs for ocular allergies, as well as novel drugs, lubricants and methods of administration, there is a need to update new treatments to optimize the care of ocular allergy patients. Methods: An overview of mediators, clinical characteristics and management is provided in a summary format. Results: Lubricants (best when refrigerated provide immediate relief that is short lived (several minutes) due to its dilutional effect on mediators and pollen in the tear film. Immediate and longer-term benefit occurs from different topical and oral medications - primarily histamine receptor agonists. Conclusion: The newest prescription topical ophthalmic histamine H1 receptor antagonist (an inverse agonist) to be approved by the U.S. Food and Drug Administration in the past 10 years (U.S. NDA approved May 30, 2017) is cetirizine ophthalmic solution for the treatment of ocular itching with allergic conjunctivitis in adults and in children more than 2 years old.
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allergic diseases of the eye
Medical Clinics of North America, 2006Co-Authors: Leonard BieloryAbstract:The prevalence of allergies continues to rise due to multiple factors that include variations in pollen production due to climatic variables, epigenetics of plants, and sensitization from environmental adjuvants (“hygiene hypothesis”). The eye is the most exposed target organ to the environment with Anterior inflammatory reactions of the Anterior Surface being the most common comprising of ocular allergy, infection, and dry eye syndromes. These conditions can vary from mildly irritating to progressive ocular inflammatory disorders that can have major effects on the ocular that can be sight threatening. This chapter provides an overview of the noninfectious Anterior Surface ocular conditions that affect the conjunctiva and the periocular tissue. It presents some updated potential interventions and treatments and summarizes the various conditions of importance to the practicing physician.
Kazuno Negishi - One of the best experts on this subject based on the ideXlab platform.
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the contribution of the posterior Surface to the corneal aberrations in eyes after keratoplasty
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kazuno Negishi, Kazuo Tsubota, Takefumi Yamaguchi, Kazuhiko Ohnuma, Daisuke Tomida, Kenji Konomi, Yoshiyuki Satake, Jun ShimazakiAbstract:PURPOSE To investigate the contribution of posterior corneal Surfaces to higher-order aberrations (HOAs) of the cornea, optical quality, and visual acuity after keratoplasty. METHODS Corneal topography of Anterior and posterior Surfaces and pachymetry were conducted using Anterior segment optical coherence tomography (AS-OCT) in 40 eyes (10 eyes after penetrating keratoplasty [PK], 10 eyes after deep Anterior lamellar keratoplasty [DALK], 10 eyes after Descemet's stripping automated endothelial keratoplasty [DSAEK], and 10 normal eyes). Anterior, posterior, and total corneal HOAs were calculated using ray-tracing and decomposition into Zernike polynomials and were evaluated as root mean square values. Modulation transfer functions (MTFs) were also evaluated. RESULTS Topography maps of the Anterior and posterior Surfaces showed reverse patterns in the normal, PK, and DALK eyes, but not in DSAEK eyes. In the normal, PK, and DALK eyes, the total corneal HOAs were significantly smaller (~10%) than were the HOAs of the Anterior Surface (P < 0.01), whereas there was no significant difference between total and Anterior HOAs in the DSAEK eyes (P = 0.483). In the normal, PK, and DALK eyes, the MTFs of the total cornea were slightly better than those of the Anterior Surface. In the DSAEK eyes, the MTFs of the total cornea were lower than those of the Anterior Surface. Visual acuity was significantly correlated with total and Anterior Surface HOAs (P < 0.05). CONCLUSIONS Posterior Surfaces compensate for Anterior aberrations in normal, PK, and DALK eyes. In DSAEK eyes, the posterior Surface increased total corneal HOAs and had a negative influence on MTFs.
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comparison of Anterior and posterior corneal Surface irregularity in descemet stripping automated endothelial keratoplasty and penetrating keratoplasty
Cornea, 2010Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Murat Dogru, Kazuko Yamaguchi, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:PURPOSE To evaluate the irregularity of the Anterior and posterior cornea after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). METHODS This clinical study comprised 39 eyes: 13 consecutive eyes after DSAEK, 13 consecutive eyes after PK, and 13 age-matched normal eyes. Corneal elevation data were acquired using a rotating Scheimpflug camera 1 and 3 months after DSAEK and PK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to eighth order. Total higher-order root mean square (RMS) and RMS from third to eighth order were calculated. The astigmatism and irregularity of the Anterior and posterior Surfaces were compared between DSAEK and PK. RESULTS The regular astigmatism and tilt components of the Anterior Surface were significantly lower after DSAEK than after PK at 1 and 3 months (P < 0.001), whereas there was no difference in astigmatism of the posterior Surface between the groups (P = 0.07, 0.22). The higher-order RMS and RMSs of third- to eighth-order components of the Anterior Surface were significantly larger after PK than those after DSAEK at 1 and 3 months (P < 0.01), whereas there were no significant differences between DSAEK and PK in higher-order aberration RMS and RMSs of third- to eighth-order components of the posterior Surface. CONCLUSIONS Postoperative corneal irregularity of the Anterior Surface was greater after PK than after DSAEK, whereas there was no significant difference in posterior Surface irregularity. DSAEK is superior to PK in terms of the higher-order irregularity of the Anterior Surface.
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effect of Anterior and posterior corneal Surface irregularity on vision after descemet stripping endothelial keratoplasty
Journal of Cataract and Refractive Surgery, 2009Co-Authors: Takefumi Yamaguchi, Kazuno Negishi, Kazuko Yamaguchi, Dogru Murat, Yuichi Uchino, Shigeto Shimmura, Kazuo TsubotaAbstract:Purpose To evaluate irregularity of the Anterior and posterior cornea before and after Descemet-stripping endothelial keratoplasty (DSEK) and its effect on visual acuity. Setting Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. Methods Corneal data were acquired using a rotating Scheimpflug camera before and 1 month and 3 months after DSEK. Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to the 8th order within a 4.0 mm diameter region. Total higher-order root mean square (HO-RMS) and RMS from the 3rd to 8th order were calculated. The effects of Anterior and posterior Surface irregularity on visual acuity were evaluated. Results This clinical study comprised 13 consecutive eyes of 12 bullous keratopathy patients. The mean best corrected visual acuity (BCVA) was 1.11 logMAR ± 0.5 (SD) preoperatively, 0.49 ± 0.49 logMAR 1 month postoperatively, and 0.27 ± 0.32 logMAR at 3 months. The HO-RMS of the Anterior Surface 1 month ( P = .040) and 3 months ( P = .048) postoperatively was significantly lower than preoperatively. There were no significant differences in posterior Surface HO-RMS between preoperatively and 1 month ( P = .45) and 3 months ( P = .054). The postoperative BCVA was significantly correlated with HO-RMS ( P P = .354). Conclusion Postoperative BCVA correlated with irregularity of the Anterior Surface but not the posterior Surface. In addition to corneal transparency, regularity of the Anterior Surface is an important factor in visual acuity after DSEK.