Comparison of Corneal Tomography Measurements Using Galilei, Orbscan II, and Placido Disk–based Topographer Systems

Purpose: Ocular features of Alport syndrome include anterior lenticonus, posterior polymorphous corneal dystrophy, and fleck-and-dot retinopathy in most cases. Keratoconus in such patients has been rarely mentioned in previous studies. To our knowledge, this is the first report of corneal cross-linking for halting the progression of keratoconus in a patient with Alport syndrome. Case report: A 22-year-old male was referred for his initial corneal topography, after he was already prescribed with rigid gas-permeable contact lenses. Alport syndrome was diagnosed in his infancy and gene COL4A5 mutation was confirmed. Ophthalmological evaluation confirmed keratoconus. One-year follow-up showed a progression on his right eye and standard corneal cross-linking was performed. Stabilization of the disease marked by normalization in visual function and corneal tomography values was noticed 1 year after the procedure. Conclusions: When diagnosing ocular clinical findings of Alport syndrome, keratoconus should be considered. Standard corneal cross-linking protocol can halt its progression.

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Surface and Orbscan II slit-scanning elevation topography in circumscribed posterior keratoconus

Journal of Cataract & Refractive Surgery ◽

10.1016/j.jcrs.2004.06.087 ◽

2005 ◽

Vol 31 (3) ◽

pp. 636-639 ◽

Cited By ~ 12

Author(s):

Nicolás Charles ◽

Martin Charles ◽

Oscar J. Croxatto ◽

Daniel E. Charles ◽

Diego Wertheimer

Keyword(s):

Orbscan Ii ◽

Slit Scanning ◽

Posterior Keratoconus

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Correction Factor in Orbscan II in the Assessment of Corneal Pachymetry

Cornea ◽

10.1097/01.ico.0000240089.26467.dc ◽

2006 ◽

Vol 25 (10) ◽

pp. 1158-1161 ◽

Cited By ~ 10

Author(s):

Arthur C K Cheng ◽

Emily Tang ◽

Shaheeda Mohamed ◽

Dennis S C Lam

Keyword(s):

Correction Factor ◽

Orbscan Ii

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Outcomes of a 320-degree intrastromal corneal ring segment implantation for keratoconus: Results of a 6-month follow-up

European Journal of Ophthalmology ◽

10.1177/1120672118818018 ◽

2018 ◽

Vol 30 (1) ◽

pp. 139-146 ◽

Cited By ~ 3

Author(s):

Guilherme Andrade do Nascimento Rocha ◽

Paulo Ferrara de Almeida Cunha ◽

Leonardo Torquetti Costa ◽

Luciene Barbosa de Sousa

Keyword(s):

Visual Acuity ◽

Spherical Equivalent ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

Intrastromal Corneal Ring ◽

Corrected Distance Visual Acuity ◽

Ring Segment ◽

The Mean ◽

Corneal Tomography

Importance: This study shows that a newer long-arc length intrastromal corneal ring segment is efficient and safe for keratoconus treatment. Background: To evaluate visual, tomographic results and complications of a 320-degree intrastromal corneal ring segment implantation with the femtosecond laser for keratoconus treatment. Design: A prospective, nonrandomized, and interventional study. Participants: A total of 34 eyes of 31 patients diagnosed with keratoconus were enrolled. Methods: Patients were divided into two groups based on the strategy used for 320-degree intrastromal corneal ring segment thickness selection. In one group, this selection was based on spherical equivalent (SE group) and in the other on the mean asphericity (Q group). The uncorrected and corrected distance visual acuities, spherical equivalent, K1, K2, Km, Kmax, and mean asphericity ( Q) on corneal tomography were evaluated preoperatively and at 3 and 6 months postoperatively. For astigmatism improvement, we analyzed the corneal tomographic vectorial astigmatism change preoperatively and at 6 months postoperatively. The mean follow-up period was 6.63 ± 0.96 months. Results: The mean uncorrected distance visual acuity and corrected distance visual acuity improved with a significant spherical equivalent improvement ( p < 0.05), with no differences between the 320-degree intrastromal corneal ring segment groups. All corneal tomographic parameters improved significantly ( p < 0.05) between the preoperative and postoperative intervals, with a significant better performance when we used spherical equivalent for the 320-degree intrastromal corneal ring segment thickness selection. Finally, the mean vectorial corneal tomographic astigmatism significantly improved after 6 months, again with no differences between groups. Conclusion: This study suggests that implanting a 320-degree intrastromal corneal ring segment is a safe and effective procedure for treating patients with keratoconus. It also suggests that for thickness selection spherical equivalent is the better strategy.

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A New Pre-descemetic Corneal Ring (Neoring) in Deep Anterior Lamellar Keratoplasty for Moderate-Advanced Keratoconus: A Pilot 2-Year Long-Term Follow-Up Study

Frontiers in Medicine ◽

10.3389/fmed.2021.771365 ◽

2021 ◽

Vol 8 ◽

Author(s):

Belén Alfonso-Bartolozzi ◽

Carlos Lisa ◽

Luis Fernández-Vega-Cueto ◽

David Madrid-Costa ◽

José F. Alfonso

Keyword(s):

Spherical Aberration ◽

Lamellar Keratoplasty ◽

Deep Anterior Lamellar Keratoplasty ◽

Anterior Lamellar Keratoplasty ◽

Corrected Distance Visual Acuity ◽

Long Term Follow Up ◽

The Mean ◽

Corneal Tomography

Purpose: To assess the outcomes of implanting a new polymethylmethacrylate (PMMA) ring (Neoring; AJL Ophthalmic) in pre-descemet deep anterior lamellar keratoplasty (PD-DALK) procedure for moderate-advanced keratoconus.Methods: This prospective study included 10 eyes of 10 patients with moderate-advanced keratoconus who underwent PD-DALK with Neoring implantation. Neoring was implanted in a pre-descemetic pocket. The post-operative examination included refraction, corrected distance visual acuity (CDVA), corneal tomography, and endothelial cell density (ECD). The root mean squares (RMSs) for coma-like aberrations and spherical aberration were evaluated for a pupil size of 4.5 mm. The junctional graft (Tg) and host (Th) thicknesses were measured. The post-operative follow-up was 24 months.Results: Post-operative CDVA was 0.82 ± 0.14 (decimal scale), 100% of the eyes achieved a CDVA of 0.7 (decimal scale). The refractive cylinder was −2.86 ± 1.65 2-years after surgery. No eyes had a post-operative refractive cylinder ≥5.00 D and in five eyes (50%), it was ≤2.50 D. At the last visit, the mean keratometry was 45.64 ± 1.96 D, the RMS for coma-like aberrations was 0.30 ± 0.15 μm and spherical aberration was 0.22 ± 0.09. The mean ECD remains without changes over the follow-up (P = 0.07). At the last visit, Tg and Th were 679.9 ± 39.0 and 634.8 ± 41.2 μm, respectively. The thickness of the complex (host-Neoring) was 740.6 ± 35.6 μm. In all cases, this thickness was thicker than Tg.Conclusion: The results of this study suggest that PD-DALK along Neoring implantation is a viable, effective, and safe option to optimize the post-operative results for moderate-severe keratoconus.

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Pentacam – A Corneal Tomography System

Delhi Journal of Ophthalmology ◽

10.7869/djo.581 ◽

2020 ◽

Vol 31 (1) ◽

Author(s):

Abhishek Upadhyaya

Keyword(s):

Tomography System ◽

Corneal Tomography

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Group Analysis of Q Values Calculated with Tangential Radius of Curvature from Human Anterior Corneal Surface

Journal of Ophthalmology ◽

10.1155/2018/7263564 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5

Author(s):

Zheren Xia ◽

Chengmin Lin ◽

Xueping Huang ◽

Jinglu Ying ◽

Mingguang Shi ◽

...

Keyword(s):

Linear Regression ◽

Group Analysis ◽

Radius Of Curvature ◽

Linear Regression Equation ◽

Adult Group ◽

Corneal Surface ◽

Power Maps ◽

Adults And Children ◽

The Mean ◽

Orbscan Ii

Objective. To calculate the Q values from the human anterior corneal surface with the tangential radius of curvature and analyze its distribution characteristics in different age and refractive status groups. Methods. Tangential power maps of the anterior cornea from Orbscan II were acquired for 201 subjects’ right eyes. They were divided into groups of adults and children and then divided further into subgroups according to the refraction status. The Q values of each semimeridian were calculated by the tangential radius with a linear regression equation. The Q value distribution in both the nasal cornea and temporal cornea were analyzed. Results. The mean temporal Q values of the emmetropia group of adults and all children’s groups were significantly different from the mean nasal Q value. The mean nasal corneal Q values were more negative in children. The adult group showed differences only in the low myopia group. The mean Q value of the nasal cornea among different refractive groups of children was significantly different, and so was the temporal cornea between the adult myopia and emmetropia group. Conclusion. The method using the tangential radius of curvature combined with linear regression to obtain anterior surface Q values for both adults and children was stable and reliable. When we analyzed the anterior corneal Q value, area division was necessary.

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Comparison of Corneal Tomography: Repeatability, Precision, Misalignment, Mean Elevation, and Mean Pachymetry

Current Eye Research ◽

10.1080/02713683.2018.1441873 ◽

2018 ◽

Vol 43 (6) ◽

pp. 709-716 ◽

Cited By ~ 12

Author(s):

Simon Schröder ◽

Stephanie Mäurer ◽

Timo Eppig ◽

Berthold Seitz ◽

Kathrin Rubly ◽

...

Keyword(s):

Corneal Tomography

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