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Kazuo Tsubota - One of the best experts on this subject based on the ideXlab platform.
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corneal higher order aberrations and visual improvement following corneal transplantation in treating herpes simplex keratitis
American Journal of Ophthalmology, 2017Co-Authors: Kazuo Tsubota, Takefumi Yamaguchi, Daisuke Tomida, Yoshiyuki Satake, Eisuke Shimizu, Yukari YagiyaguchiAbstract:Purpose To examine corneal higher-order aberrations (HOAs) and visual improvement following corneal transplantation in treating corneal scar caused by herpes simplex keratitis (HSK). Design Retrospective consecutive case series. Methods This study included a total of 52 eyes: 18 eyes of normal subjects, and 34 eyes of consecutive patients with corneal scar owing to HSK who underwent penetrating keratoplasty (PKP, 17 eyes) or deep anterior lamellar keratoplasty (DALK, 17 eyes). HOAs of the anterior, Posterior Surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. The correlations between corneal HOAs and visual improvement were also analyzed. Results Mean logarithm of the minimal angle of resolution (logMAR) visual acuity significantly improved from 1.40 ± 0.70 to 0.46 ± 0.45 after corneal transplantation ( P P = .035, DALK: from 0.94 ± 0.57 μm to 0.37 ± 0.18 μm, P = .004). Visual acuity following corneal transplantation was correlated with the corneal HOAs at 12 months (r = 0.53, P = .01). Visual improvement at 3, 6, and 12 months was positively correlated with preoperative HOAs of the total cornea and Posterior Surface (all P Conclusions Preoperative corneal HOAs were associated with the visual improvement in treating corneal scar caused by HSK. Thus, the preoperative assessment of corneal HOAs, especially of the Posterior Surface, is important in the decision to perform corneal transplantation in eyes with HSK.
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decreased visual acuity by an irregular corneal Posterior Surface after repeat descemet stripping automated endothelial keratoplasty
Eye & Contact Lens-science and Clinical Practice, 2017Co-Authors: Hiroyuki Yazu, Murat Dogru, Kazuo Tsubota, Takefumi Yamaguchi, Yoshiyuki Satake, Jun ShimazakiAbstract:Purpose To investigate the impact of higher-order aberrations (HOAs) on visual acuity after repeat Descemet stripping automated endothelial keratoplasty (DSAEK) in the same eyes. Methods This retrospective comparative case series includes 23 patients who underwent DSAEK twice in the same eyes (46 DSAEK in total). We evaluated the HOAs of the anterior and Posterior corneal Surfaces, and total cornea using the Fourier analysis data from anterior segment optical coherence tomography. Eyes were divided into one of the following groups, based on the improvement and decline in the best-corrected visual acuity (BCVA) after repeat DSAEK; group A: 12 eyes with an improvement ≥ 2 lines, group B: 12 eyes with a decline ≤ 2 lines, and group C: 11 eyes with no change or change within 1 line. Results The HOAs of the Posterior Surface in group B were significantly greater than those of group A (P=0.028), whereas there were no significant differences in the anterior Surface and total corneal HOAs between groups A and B (P=0.12 and 0.08). There were no significant differences in the anterior and Posterior Surface as well as total cornea HOAs between initial DSAEK and repeat DSAEK in group C (P=0.87, 0.65, and 0.42). The postoperative BCVA had a significant correlation with the HOAs of the anterior and Posterior Surfaces as well as the total cornea (R=0.40, 0.46, and 0.53; P=0.01, 0.002, and 0.001). Conclusions Posterior corneal HOAs can have a negative influence on the visual acuity after endothelial keratoplasty.
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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.
Takefumi Yamaguchi - One of the best experts on this subject based on the ideXlab platform.
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corneal higher order aberrations and visual improvement following corneal transplantation in treating herpes simplex keratitis
American Journal of Ophthalmology, 2017Co-Authors: Kazuo Tsubota, Takefumi Yamaguchi, Daisuke Tomida, Yoshiyuki Satake, Eisuke Shimizu, Yukari YagiyaguchiAbstract:Purpose To examine corneal higher-order aberrations (HOAs) and visual improvement following corneal transplantation in treating corneal scar caused by herpes simplex keratitis (HSK). Design Retrospective consecutive case series. Methods This study included a total of 52 eyes: 18 eyes of normal subjects, and 34 eyes of consecutive patients with corneal scar owing to HSK who underwent penetrating keratoplasty (PKP, 17 eyes) or deep anterior lamellar keratoplasty (DALK, 17 eyes). HOAs of the anterior, Posterior Surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. The correlations between corneal HOAs and visual improvement were also analyzed. Results Mean logarithm of the minimal angle of resolution (logMAR) visual acuity significantly improved from 1.40 ± 0.70 to 0.46 ± 0.45 after corneal transplantation ( P P = .035, DALK: from 0.94 ± 0.57 μm to 0.37 ± 0.18 μm, P = .004). Visual acuity following corneal transplantation was correlated with the corneal HOAs at 12 months (r = 0.53, P = .01). Visual improvement at 3, 6, and 12 months was positively correlated with preoperative HOAs of the total cornea and Posterior Surface (all P Conclusions Preoperative corneal HOAs were associated with the visual improvement in treating corneal scar caused by HSK. Thus, the preoperative assessment of corneal HOAs, especially of the Posterior Surface, is important in the decision to perform corneal transplantation in eyes with HSK.
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decreased visual acuity by an irregular corneal Posterior Surface after repeat descemet stripping automated endothelial keratoplasty
Eye & Contact Lens-science and Clinical Practice, 2017Co-Authors: Hiroyuki Yazu, Murat Dogru, Kazuo Tsubota, Takefumi Yamaguchi, Yoshiyuki Satake, Jun ShimazakiAbstract:Purpose To investigate the impact of higher-order aberrations (HOAs) on visual acuity after repeat Descemet stripping automated endothelial keratoplasty (DSAEK) in the same eyes. Methods This retrospective comparative case series includes 23 patients who underwent DSAEK twice in the same eyes (46 DSAEK in total). We evaluated the HOAs of the anterior and Posterior corneal Surfaces, and total cornea using the Fourier analysis data from anterior segment optical coherence tomography. Eyes were divided into one of the following groups, based on the improvement and decline in the best-corrected visual acuity (BCVA) after repeat DSAEK; group A: 12 eyes with an improvement ≥ 2 lines, group B: 12 eyes with a decline ≤ 2 lines, and group C: 11 eyes with no change or change within 1 line. Results The HOAs of the Posterior Surface in group B were significantly greater than those of group A (P=0.028), whereas there were no significant differences in the anterior Surface and total corneal HOAs between groups A and B (P=0.12 and 0.08). There were no significant differences in the anterior and Posterior Surface as well as total cornea HOAs between initial DSAEK and repeat DSAEK in group C (P=0.87, 0.65, and 0.42). The postoperative BCVA had a significant correlation with the HOAs of the anterior and Posterior Surfaces as well as the total cornea (R=0.40, 0.46, and 0.53; P=0.01, 0.002, and 0.001). Conclusions Posterior corneal HOAs can have a negative influence on the visual acuity after endothelial keratoplasty.
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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.
Jun Shimazaki - One of the best experts on this subject based on the ideXlab platform.
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decreased visual acuity by an irregular corneal Posterior Surface after repeat descemet stripping automated endothelial keratoplasty
Eye & Contact Lens-science and Clinical Practice, 2017Co-Authors: Hiroyuki Yazu, Murat Dogru, Kazuo Tsubota, Takefumi Yamaguchi, Yoshiyuki Satake, Jun ShimazakiAbstract:Purpose To investigate the impact of higher-order aberrations (HOAs) on visual acuity after repeat Descemet stripping automated endothelial keratoplasty (DSAEK) in the same eyes. Methods This retrospective comparative case series includes 23 patients who underwent DSAEK twice in the same eyes (46 DSAEK in total). We evaluated the HOAs of the anterior and Posterior corneal Surfaces, and total cornea using the Fourier analysis data from anterior segment optical coherence tomography. Eyes were divided into one of the following groups, based on the improvement and decline in the best-corrected visual acuity (BCVA) after repeat DSAEK; group A: 12 eyes with an improvement ≥ 2 lines, group B: 12 eyes with a decline ≤ 2 lines, and group C: 11 eyes with no change or change within 1 line. Results The HOAs of the Posterior Surface in group B were significantly greater than those of group A (P=0.028), whereas there were no significant differences in the anterior Surface and total corneal HOAs between groups A and B (P=0.12 and 0.08). There were no significant differences in the anterior and Posterior Surface as well as total cornea HOAs between initial DSAEK and repeat DSAEK in group C (P=0.87, 0.65, and 0.42). The postoperative BCVA had a significant correlation with the HOAs of the anterior and Posterior Surfaces as well as the total cornea (R=0.40, 0.46, and 0.53; P=0.01, 0.002, and 0.001). Conclusions Posterior corneal HOAs can have a negative influence on the visual acuity after endothelial keratoplasty.
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descemet stripping automated endothelial keratoplasty for bullous keratopathy with an irregular Posterior Surface
Cornea, 2013Co-Authors: Takahiko Hayashi, Yumiko Hirayama, Norihiro Yamada, Seika Shimazakiden, Jun ShimazakiAbstract:Purpose To investigate the efficacy and safety of Descemet stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy with an irregular Posterior Surface of the cornea caused by anterior-Posterior radial keratotomy or forceps injury. The results were compared with eyes that had undergone penetrating keratoplasty (PKP). Methods Six eyes of 6 Japanese patients (mean age, 52.0 years) who underwent DSAEK between 2007 and 2012 were analyzed retrospectively. Of the 6 cases, 5 were birth injuries and 1 resulted from anterior-Posterior keratotomy. Five of the 6 cases had mild-to-moderate amblyopia. The clinical results of DSAEK were compared with the outcomes of disease-matched cases treated with PKP [19 eyes of 18 patients (mean age, 58.4 years): 9 cases were birth injuries and 10 resulted from anterior-Posterior keratotomy]. Subjective symptoms, graft clarity, best-corrected visual acuity, corneal astigmatism, postoperative endothelial cell density, Posterior irregularity, and intraoperative and postoperative complications were evaluated. Results All grafts were attached successfully without double chamber formation following DSAEK. The corneas remained clear throughout the observation period, and the subjective symptoms improved in all cases. Significant improvement was observed in the best spectacle-corrected visual acuity and Posterior irregularity in all the patients. No significant difference in corneal astigmatism was observed between the DSAEK and PKP groups. The mean endothelial cell density was 1450 cells per square millimeter 6 months postoperatively in the DSAEK group, which was similar to that in the PKP group. Conclusions DSAEK is considered to be useful, even in bullous keratopathy eyes with an irregular Posterior Surface.
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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.
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.
Thomas Kohnen - One of the best experts on this subject based on the ideXlab platform.
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characteristics of corneal astigmatism of anterior and Posterior Surface in a normal control group and patients with keratoconus
Cornea, 2017Co-Authors: Mehdi Shajari, Stefan Friderich, Miad Pour Sadeghian, Ingo Schmack, Thomas KohnenAbstract:PURPOSE To evaluate and compare power and axis orientation of anterior and Posterior astigmatism in eyes with keratoconus with healthy eyes. METHODS In this retrospective cohort study, we examined 861 eyes of 494 patients diagnosed with keratoconus at the Department of Ophthalmology, University Hospital Frankfurt, and 256 eyes of 256 healthy individuals. Using a Scheimpflug device (Pentacam HR), we measured the magnitude and axis orientation of anterior and Posterior corneal astigmatism, corneal thickness, and conus location. The results were compared between different stages of the disease according to the Amsler-Krumeich classification and the control group. RESULTS Magnitude of corneal astigmatism was 3.47 ± 2.10 diopters (D) on the anterior Surface and 0.69 ± 0.40 D on the Posterior Surface in eyes across all keratoconus stages. We found a significant increase of anterior and Posterior corneal astigmatism with progression of disease (P < 0.01, 1-way analysis of variance) and a significant correlation between anterior and Posterior corneal astigmatism (r = 0.77, P < 0.01). In contrast to eyes of healthy individuals, in which Posterior corneal axis alignment is vertical in most cases independent of anterior alignment, we found in eyes with keratoconus a match between anterior and Posterior alignment when alignment was vertical in 97% of eyes, 46% when oblique and 61% when horizontal (Cohen kappa coefficient κ = 0.55, P < 0.01). With progression of disease, alignment of anterior and Posterior corneal astigmatism became increasingly vertical. CONCLUSIONS In eyes with keratoconus, Posterior axis alignment of corneal astigmatism is in line with alignment of the anterior Surface in the majority of cases. Posterior astigmatism axis alignment could potentially be used in algorithms to support diagnosis and staging of keratoconus.
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detection of subclinical keratoconus by using corneal anterior and Posterior Surface aberrations and thickness spatial profiles
Investigative Ophthalmology & Visual Science, 2010Co-Authors: Jens Buhren, Thomas Kohnen, Daniel Kook, Geunyoung YoonAbstract:PURPOSE. To assess the suitability of corneal anterior and Posterior Surface aberrations and thickness profile data for discrimination between eyes with early keratoconus (KC), fellow eyes of eyes with early KC, and normal eyes. METHODS. Thirty-two eyes (group 1) of 25 patients were newly diagnosed with KC; 17 eyes of 17 patients (group 2) were asymptomatic fellow eyes without clinical signs of KC. One hundred twenty-three healthy eyes of 69 patients were negative control eyes (group 3). Zernike coefficients from anterior and Posterior Surfaces, data from corneal thickness spatial profiles, and output values of discriminant functions based on wavefront and pachymetry data were assessed by receiver operating characteristic (ROC) curve analysis for their usefulness in discriminating between KC (groups 1, 2) eyes and control eyes. RESULTS. Vertical coma (C(3)(-1)) from the anterior Surface was the coefficient with the highest ability to discriminate between groups 2 and 3 (area under the ROC curve [A(z)ROC] = 0.980; cutoff, -0.2 microm). For Posterior wavefront coefficients and pachymetry data, A(z)ROC values were lower. Constructing discriminant functions from Zernike coefficients increased A(z)ROC values. The function containing first-Surface data reached an A(z)ROC of 0.993; the functions containing Posterior Surface or pachymetry data had lower A(z)ROC values (0.932 and 0.903, respectively). The function with anterior, Posterior, and pachymetry data reached an A(z)ROC of 1.0. CONCLUSIONS. Corneal wavefront and pachymetry data enabled highly accurate distinction of eyes with subclinical keratoconus from normal eyes. Posterior aberrations and thickness spatial profile data did not markedly improve discriminative ability over that of anterior wavefront data alone.
