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Ioannis G Pallikaris - One of the best experts on this subject based on the ideXlab platform.
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simultaneous conventional Photorefractive Keratectomy and corneal collagen cross linking for pellucid marginal corneal degeneration
Journal of Refractive Surgery, 2014Co-Authors: George D Kymionis, Michael A Grentzelos, Argyro D Plaka, Konstantinos I Tsoulnaras, Vardhaman P Kankariya, Mohammad M Shehadeh, Ioannis G PallikarisAbstract:Purpose To present the results after simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration. Methods In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic Keratectomy during treatment (Cretan protocol plus conventional Photorefractive Keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively. Results No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05). Conclusions Simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration.
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management of pellucid marginal corneal degeneration with simultaneous customized Photorefractive Keratectomy and collagen crosslinking
Journal of Cataract and Refractive Surgery, 2009Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Alexandra E Karavitaki, Sonia H Yoo, Ioannis G PallikarisAbstract:A 34-year-old woman had simultaneous Photorefractive Keratectomy and corneal collagen crosslinking with riboflavin–ultraviolet-A irradiation for the treatment of progressive pellucid marginal corneal degeneration in both eyes. No intraoperative or early postoperative complications occurred. Twelve months postoperatively, the uncorrected visual acuity was assessed at 20/40 in both eyes compared with counting fingers preoperatively. The corrected visual acuity also improved from 20/50 and 20/63 to 20/25 and 20/32 in the right eye and left eye, respectively. Corneal topography revealed a significant improvement in both eyes. Despite the encouraging results, longer follow-up is necessary to confirm the stability of the results.
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comparison of corneal sensation following Photorefractive Keratectomy and laser in situ keratomileusis
Journal of Cataract and Refractive Surgery, 1997Co-Authors: Ioannis G Pallikaris, Eric D Donnenfeld, Anastasios John Kanellopoulos, Stathis Detorakis, Konstantina Koufala, Henry D PerryAbstract:Purpose: To evaluate the effect of Photorefractive Keratectomy (PRK) and laser in situ keratomileusis (LASIK) on corneal sensation. Setting: Eye Institute, Medical School of the University of Crete, Heraklion, Greece, and Orasis, Hellenic Eye Center of Athens, Greece. Methods: In a masked study, corneal sensation was measured with the CochetBonnet aesthesiometer in 40 consecutive patients 6 to 12 months following PRK and LASIK (60 mm constitutes normal reading and <40 mm, abnormal). Results: After 6 to 12 months, the mean corneal sensation following PRK was 39.2 mm (range 30 to 55 mm) (mean 9.5 months) and after LASIK, 53.6 mm (range 40 to 60 mm) (mean 9.3 months). The mean correction attempted for PRK was 7.05 diopters (D) (range 2.5 to 12.0 D) and for LASIK, 11.71 D (range 6.0 to 20.0 D). Conclusion: In this group of patients, with correction of primarily severe myopia, corneal sensation was significantly greater after LASIK than after PRK.
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excimer laser in situ keratomileusis and Photorefractive Keratectomy for correction of high myopia
Journal of Refractive Surgery, 1994Co-Authors: Ioannis G Pallikaris, Dimitrios S SiganosAbstract:BACKGROUND: The purpose of this research was to study the visual outcome of excimer laser Photorefractive Keratectomy and laser in situ keratomileusis (LASIK) for the correction of moderate and high myopia. METHODS: Twenty partially-sighted eyes of 20 patients were divided into two groups, LASIK and Photorefractive Keratectomy. Ten eyes underwent LASIK and the other 10 Photorefractive Keratectomy. Follow up was at 1, 3, 6, and 12 months. The LASIK technique included a nasally based, 150 microns thick, 8.0 x 9.0 mm diameter, truncated, disc-shaped corneal flap created with a microkeratome; and the ablation of the stroma with a 193-nanometer ArF excimer laser. The flap was returned to its original position and held in place by apposition. The Photorefractive Keratectomy technique included mechanical removal of the epithelium and ablation of the stroma with a 193-nanometer ArF excimer laser. RESULTS: LASIK series: One eye had a ruptured globe during the second postoperative month and was excluded from the study. The preoperative spherical equivalent refraction ranged from -10.62 to -25.87 diopters (D). The attempted correction ranged from -8.00 to -16.00 D. Postoperative refraction and corneal topography stabilized between 4 and 12 weeks. Spectacle-corrected visual acuity was within 1 Snellen line of preoperative in all eyes. The refraction in six eyes (66.6%) was within +/- 1.00 D of the intended correction, and in eight eyes was within +/- 2.00 D (88.8%) at 12 months. The mean attempted correction (11.40 +/- 2.60 D) was close to the mean achieved correction at 12 months (11.96 +/- 3.10 D). The mean postoperative refractive astigmatism (1.50 +/- 0.97; range, 0.25 to 3.50 D) was close to the preoperative astigmatism (1.70 +/- 1.15; range, 0 to 3.75 D). Endothelial cell density at 12 months showed an average 8.67% of cell loss. All eyes showed a clear interface. Photorefractive Keratectomy series: The preoperative spherical equivalent refraction ranged from -10.75 to -23.12 D. The attempted correction ranged from -8.80 to -17.60 D. Postoperative refraction showed regression throughout the follow-up period, and corneal topography did not stabilize. Spectacle-corrected visual acuity was within 1 Snellen line in eight eyes. Two eyes lost 2 and 3 Snellen lines. One eye was within +/- 1.00 D, and three eyes (30%) were within +/- 2.00 D of the intended correction at 12 months. The achieved correction mean (7.17 +/- 5.29 D) was 61% of the attempted mean (11.72 +/- 2.81 D) at 12 months. The postoperative refractive astigmatism (1.80 +/- 0.95; range, 0.50 to 4.00 D) was very close to the preoperative (1.90 +/- 1.33; range, 0 to 5.00 D). Endothelial cell density showed an average of 10.56% cell loss at 12 months. The mean haze at 12 months was 1.2 (0 to 4 scale). CONCLUSION: LASIK, although more complicated because of the use of a microkeratome, was more effective than Photorefractive Keratectomy in higher myopes. LASIK created less corneal haze. The refraction was more stable with LASIK in the correction of high myopia. Its predictability was three times that of PRK.
George D Kymionis - One of the best experts on this subject based on the ideXlab platform.
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simultaneous conventional Photorefractive Keratectomy and corneal collagen cross linking for pellucid marginal corneal degeneration
Journal of Refractive Surgery, 2014Co-Authors: George D Kymionis, Michael A Grentzelos, Argyro D Plaka, Konstantinos I Tsoulnaras, Vardhaman P Kankariya, Mohammad M Shehadeh, Ioannis G PallikarisAbstract:Purpose To present the results after simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration. Methods In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic Keratectomy during treatment (Cretan protocol plus conventional Photorefractive Keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively. Results No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05). Conclusions Simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration.
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simultaneous topography guided Photorefractive Keratectomy followed by corneal collagen cross linking for keratoconus
American Journal of Ophthalmology, 2011Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Aliki N Limnopoulou, Georgios A Kontadakis, Michael A GrentzelosAbstract:Purpose To present the long-term results after simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking for keratoconus. Design Prospective, interventional, consecutive case series. Methods In this study, 26 patients (31 eyes) with progressive keratoconus were included. All patients underwent customized topography-guided Photorefractive Keratectomy immediately followed by corneal collagen cross-linking with the use of riboflavin and ultraviolet A irradiation. Epithelium was removed by transepithelial phototherapeutic Keratectomy in all cases. Results Mean follow-up was 19.53 ± 3.97 months (range, 12 to 25 months). Mean preoperative spherical equivalent was −2.3 ± 2.8 diopters (D), whereas at the last follow-up examination, it was significantly ( P P P P = .013) at the last follow-up examination. Conclusions Simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking seems to be a promising treatment alternative in our series of keratoconic patients.
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management of pellucid marginal corneal degeneration with simultaneous customized Photorefractive Keratectomy and collagen crosslinking
Journal of Cataract and Refractive Surgery, 2009Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Alexandra E Karavitaki, Sonia H Yoo, Ioannis G PallikarisAbstract:A 34-year-old woman had simultaneous Photorefractive Keratectomy and corneal collagen crosslinking with riboflavin–ultraviolet-A irradiation for the treatment of progressive pellucid marginal corneal degeneration in both eyes. No intraoperative or early postoperative complications occurred. Twelve months postoperatively, the uncorrected visual acuity was assessed at 20/40 in both eyes compared with counting fingers preoperatively. The corrected visual acuity also improved from 20/50 and 20/63 to 20/25 and 20/32 in the right eye and left eye, respectively. Corneal topography revealed a significant improvement in both eyes. Despite the encouraging results, longer follow-up is necessary to confirm the stability of the results.
Michael A Grentzelos - One of the best experts on this subject based on the ideXlab platform.
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simultaneous conventional Photorefractive Keratectomy and corneal collagen cross linking for pellucid marginal corneal degeneration
Journal of Refractive Surgery, 2014Co-Authors: George D Kymionis, Michael A Grentzelos, Argyro D Plaka, Konstantinos I Tsoulnaras, Vardhaman P Kankariya, Mohammad M Shehadeh, Ioannis G PallikarisAbstract:Purpose To present the results after simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration. Methods In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic Keratectomy during treatment (Cretan protocol plus conventional Photorefractive Keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively. Results No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05). Conclusions Simultaneous conventional Photorefractive Keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration.
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simultaneous topography guided Photorefractive Keratectomy followed by corneal collagen cross linking for keratoconus
American Journal of Ophthalmology, 2011Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Aliki N Limnopoulou, Georgios A Kontadakis, Michael A GrentzelosAbstract:Purpose To present the long-term results after simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking for keratoconus. Design Prospective, interventional, consecutive case series. Methods In this study, 26 patients (31 eyes) with progressive keratoconus were included. All patients underwent customized topography-guided Photorefractive Keratectomy immediately followed by corneal collagen cross-linking with the use of riboflavin and ultraviolet A irradiation. Epithelium was removed by transepithelial phototherapeutic Keratectomy in all cases. Results Mean follow-up was 19.53 ± 3.97 months (range, 12 to 25 months). Mean preoperative spherical equivalent was −2.3 ± 2.8 diopters (D), whereas at the last follow-up examination, it was significantly ( P P P P = .013) at the last follow-up examination. Conclusions Simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking seems to be a promising treatment alternative in our series of keratoconic patients.
Amy K Hutchinson - One of the best experts on this subject based on the ideXlab platform.
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Photorefractive Keratectomy for the treatment of purely refractive accommodative esotropia
Journal of Cataract and Refractive Surgery, 2003Co-Authors: Paolo Nucci, Massimiliano Serafino, Amy K HutchinsonAbstract:Abstract Purpose To evaluate the results of Photorefractive Keratectomy (PRK) for the treatment of young adult patients with purely refractive accommodative esotropia. Setting Private practice and university hospital, Milan, Italy. Methods The medical records of consecutive patients who had PRK for hyperopia associated with purely refractive esotropia were reviewed retrospectively. Preoperative and postoperative visual acuity, alignment, and sensory data were recorded and analyzed. Surgical methods and complications were reviewed. Results Sixteen eyes of 8 patients were treated. The mean patient age at the time of treatment was 24.6 years (range 17 to 38 years). All patients were followed for 1 year. At the 1-year follow-up evaluation, the uncorrected visual acuity was 20/40 or better in all eyes. No patient lost a line of best spectacle-corrected visual acuity. The mean spherical equivalent was −3.7 diopters (D) preoperatively and −0.7 D postoperatively. All patients were within ±0.37 D of emmetropia at the 1-year evaluation. Preoperatively, the mean esotropic deviation was 10.75 prism diopters. Postoperatively, all patients were orthophoric without correction. Stereopsis was unaffected by PRK in all patients. There were no intraoperative or postoperative complications. Conclusion Photorefractive Keratectomy was an effective treatment for esotropia associated with mild to moderate hyperopia in young adults with purely refractive accommodative esotropia. These findings should not be widely applied to children with accommodative esotropia.
Dimitra M Portaliou - One of the best experts on this subject based on the ideXlab platform.
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simultaneous topography guided Photorefractive Keratectomy followed by corneal collagen cross linking for keratoconus
American Journal of Ophthalmology, 2011Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Aliki N Limnopoulou, Georgios A Kontadakis, Michael A GrentzelosAbstract:Purpose To present the long-term results after simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking for keratoconus. Design Prospective, interventional, consecutive case series. Methods In this study, 26 patients (31 eyes) with progressive keratoconus were included. All patients underwent customized topography-guided Photorefractive Keratectomy immediately followed by corneal collagen cross-linking with the use of riboflavin and ultraviolet A irradiation. Epithelium was removed by transepithelial phototherapeutic Keratectomy in all cases. Results Mean follow-up was 19.53 ± 3.97 months (range, 12 to 25 months). Mean preoperative spherical equivalent was −2.3 ± 2.8 diopters (D), whereas at the last follow-up examination, it was significantly ( P P P P = .013) at the last follow-up examination. Conclusions Simultaneous Photorefractive Keratectomy followed by corneal collagen cross-linking seems to be a promising treatment alternative in our series of keratoconic patients.
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management of pellucid marginal corneal degeneration with simultaneous customized Photorefractive Keratectomy and collagen crosslinking
Journal of Cataract and Refractive Surgery, 2009Co-Authors: George D Kymionis, Dimitra M Portaliou, George A Kounis, Alexandra E Karavitaki, Sonia H Yoo, Ioannis G PallikarisAbstract:A 34-year-old woman had simultaneous Photorefractive Keratectomy and corneal collagen crosslinking with riboflavin–ultraviolet-A irradiation for the treatment of progressive pellucid marginal corneal degeneration in both eyes. No intraoperative or early postoperative complications occurred. Twelve months postoperatively, the uncorrected visual acuity was assessed at 20/40 in both eyes compared with counting fingers preoperatively. The corrected visual acuity also improved from 20/50 and 20/63 to 20/25 and 20/32 in the right eye and left eye, respectively. Corneal topography revealed a significant improvement in both eyes. Despite the encouraging results, longer follow-up is necessary to confirm the stability of the results.