International Journal of Keratoconus and Ectatic Corneal Diseases

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2017 | July-December | Volume 6 | Issue 2

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ORIGINAL ARTICLE

Paulo Ferrara, Leonardo Torquetti, Guilherme Ferrara

Intrastromal Corneal Ring Segments in Children with Keratoconus

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:4] [Pages No:45 - 48]

   DOI: 10.5005/jp-journals-10025-1142  |  Open Access |  How to cite  | 

Abstract

Purpose

To evaluate the long-term follow-up of Ferrara intrastromal corneal ring segments (ICRSs) (Ferrara Ophthalmics, Belo Horizonte, Brazil) implantation for the management of keratoconus in children.

Study design

Paulo Ferrara Eye Clinic, Belo Horizonte, Minas Gerais, Brazil.

Materials and methods

A total of 58 eyes of 37 children with keratoconus were included. One or two ring segments were inserted into the cornea, embracing the keratoconus area. Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), asphericity, pachymetry, and keratometry.

Results

Ferrara ICRS implantation significantly improved the mean UDVA and CDVA. Corneal tomography (Pentacam®) showed corneal flattening in all eyes implanted with the Ferrara ring. The mean K decreased, and the corneal asphericity and pachymetry increased in all cases.

Conclusion

The Ferrara ICRS improved all parameters after 2 years of implantation in children with keratoconus. There was significant corneal flattening after ring implantation with improvement of the UDVA and the CDVA. All studied parameters remained stable over time.

How to cite this article

Ferrara G, Ferrara P, Torquetti L. Intrastromal Corneal Ring Segments in Children with Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):45-48.

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ORIGINAL ARTICLE

Maksim V Sinitsyn, Nadezhda A Pozdeyeva, Nikolai P Pashtayev

Comparative Analysis of the Intrastromal MyoRing Implantation performed with the Femtosecond Laser

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:9] [Pages No:49 - 57]

   DOI: 10.5005/jp-journals-10025-1143  |  Open Access |  How to cite  | 

Abstract

Purpose

To comparatively analyze the intrastromal MyoRing implantation with femtosecond laser (FL) using the standard and optimized technologies in the experiment and based on the long-term clinical-functional results of the patients with keratoconus (KC) at stages II and III.

Materials and methods

The experimental work was performed on 24 eyes of rabbits. All eyes were divided into six groups according to the method of operation. In the clinical part of the research, the surgical treatment of 70 patients (76 eyes) with KC at stages II and III was done. Depending on the technology of the operation, all patients were divided into two groups. Group I consisted of 29 patients (32 eyes) with KC, in which MyoRing implantation was performed according to the standard, group II consisted of 31 patients (32 eyes) with KC, in which MyoRing implantation was performed according to the optimized technology.

Results

Higher voltage was required for stretching samples of the second group in comparison with the third and the sixth group in comparison with the fifth group. In group I, during the period of 6 to 36 months the surgery reverses keratometry, corneal thickness above the MyoRing, and posterior corneal elevation. In group II, 12 months after surgery the clinical and functional parameters remained stable throughout the period of observation.

Conclusion

Greater reduction in corneal biomechanical stability was observed after formation of the intrastromal pocket in comparison with an intrastromal tunnel; a more pronounced increase in the strength characteristics of the cornea was observed after implantation of the ring in intrastromal pocket, compared with implantation intracorneal segments in intrastromal tunnel, and with increasing depth of intrastromal ring implantation. Application of optimized MyoRing implantation technology compared with standard allows more biomechanical parameters of the cornea to improve and reduce the risk of the ring protrusion.

How to cite this article

Sinitsyn MV, Pozdeyeva NA, Pashtayev NP. Comparative Analysis of the Intrastromal MyoRing Implantation performed with the Femtosecond Laser. Int J Kerat Ect Cor Dis 2017;6(2):49-57.

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ORIGINAL ARTICLE

Alfredo Vega-Estrada, Jorge L Alio, Pablo Sanz, María J Prieto, Antonio Cardona, Miguel Maldonado, Ramon Gutierrez, Rafael I Barraquer, Luis M Sádaba

Distinction between Early Keratoconus with Normal Vision and Normal Cornea based on Pattern Recognition Analysis

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:9] [Pages No:58 - 66]

   DOI: 10.5005/jp-journals-10025-1144  |  Open Access |  How to cite  | 

Abstract

Aim

To find the profile that differentiates most normal corneas from early keratoconus with normal vision.

Materials and methods

Multicentric, comparative study including a total of 995 eyes and divided into two groups: 625 eyes suffering from early keratoconus but with normal vision [spectacle corrected distance visual acuity (CDVA) of 0.9 decimal or better] and 370 normal control eyes with same normal vision level. To ascertain the main differences that would allow the identification of the keratoconic eyes from normals, a pattern recognition analysis was performed combining two statistical methods: Principal component analysis (PCA) and discriminant analysis. Visual and refractive parameters, corneal topography, aberrometry, and PCA were evaluated in both groups.

Results

The application of the PCA with Varimax rotation offered a total of five factors which explains the 85.51% of the total variability. Discriminant analysis indicated that factors 1 and 3 were at the greatest discriminating capacity. From a total of 318 cases, the newly identified abnormal pattern profile allowed the recognition of 275, which presents a sensitivity and specificity of 71.6 and 97.3% respectively.

Conclusion

In eyes with normal CDVA, those factors related to the nonorthogonal shape irregularity of the cornea and the refractive power are the ones that showed more discriminating capabilities between normal and early keratoconic eyes.

Clinical significance

Principal component analysis allows to correctly discriminate between normal and mild keratoconus patients; additionally, this method is not restricted to a particular corneal topography technology and is available to any normally equipped ophthalmology office.

How to cite this article

Alio JL, Vega-Estrada A, Sanz P, Prieto MJ, Cardona A, Maldonado M, Gutierrez R, Barraquer RI, Sádaba LM. Distinction between Early Keratoconus with Normal Vision and Normal Cornea Based on Pattern Recognition Analysis. Int J Kerat Ect Cor Dis 2017;6(2):58-66.

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ORIGINAL ARTICLE

Parmod Guleria, Vikas Sharma

To evaluate the Role and Efficacy of Collagen Cross-linkage with Ultraviolet Therapy following Riboflavin Drops with Orbscan in Cases of Progressive Keratoconus

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:6] [Pages No:67 - 72]

   DOI: 10.5005/jp-journals-10025-1145  |  Open Access |  How to cite  | 

Abstract

Aim

To evaluate the role and efficacy of collagen cross-linkage with riboflavin (C3R) in cases of progressive keratoconus.

Study design

Prospective, nonrandomized, single-center clinical study.

Materials and methods

The C3R was done in 32 eyes of 21 patients with at least 6 months of documented progression. Outcome of the procedure was measured by means of uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), corneal topography with Orbscan changes in posterior best fit sphere (PBFS), ratio of anterior and posterior best fit sphere (ABFS/PBFS), astigmatic changes in central 3- and 5-mm zone, central endothelial count postcorneal C3R.

Results

Thirty-two eyes with a follow-up of 6 months were analyzed. The mean age was 19.8 years. The preoperative values on the day of treatment were compared with postoperative values after the 6-month examination. The improvement in UCVA and BSCVA was statistically significant (p = 0.02 and 0.01 respectively). The change in power for PBFS was not statistically significant (p = —0.08). There was no significant difference in corneal endothelial counts pre- and post-C3R (p = 0.058). Mean value pre-C3R for ratio of ABFS/PBFS was 1.25 ± 3.7 and post-C3R was 1.22 ± 1.8 (p = 0.00). Mean value of astigmatism in 3-mm zone pre- and post-C3R was —4.3 ± 0.98 and —3.9 ± 0.66(p = 0.046) respectively. Mean value pre-C3R for astigmatism in 5-mm zone was —4.9 ± 1.91 and post-C3R was —4.0 ± 0.82 (p = 0.02).

Conclusion

The results show a stabilization and improvement in keratoconus after C3R in Indian eyes.

How to cite this article

Guleria P, Sharma V. To evaluate the Role and Efficacy of Collagen Cross-linkage with Ultraviolet Therapy following Riboflavin Drops with Orbscan in Cases of Progressive Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):67-72.

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RESEARCH ARTICLE

Guillermo Rocha, Victor Penner, Kylee Lewis

Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:5] [Pages No:73 - 77]

   DOI: 10.5005/jp-journals-10025-1146  |  Open Access |  How to cite  | 

Abstract

Purpose

To demonstrate clinical outcomes of epithelium-off corneal cross-linking (CXL) in combination with wavefront-guided photorefractive keratectomy (PRK) for the treatment of keratoconuns.

Materials and methods

Total, 28 keratoconic eyes of 21 patients were included. The Sirius Wavefront Analyzer (SCHWIND eye-tech-solutions GmbH and Co. KG) was used to evaluate the high-order aberrations (HOAs). The coupled Amaris 750S excimer laser then performed a PRK of no more than 40 μm using the measured HOA. The CXL was then carried out respecting the standard of 400 μm of corneal thickness.

Results

The average age was 32 (15—48) years. Uncorrected distance visual acuity (UDVA) improved from 0.58 to 0.31 logMAR (p < 0.001), with best corrected distance visual acuity (CDVA) improving from 0.03 to 0.02 logMAR (p = 0.7).

On manifest refraction, the average spherical component decreased from –1.87 to –1.40 D (0.47 ± 2.12, p = 0.4). Cylinder decreased from 2.18 to 0.87 D (1.31 ± 1.14 D, p < 0.001).

All HOAs decreased: total HO 0.94 to 0.58 (0.36 ± 0.42, p = 0.05); spherical aberration: 0.142 to –0.018 (0.160 ± 0.160, p < 0.001); secondary astigmatism: 0.21 to 0.11 (0.10 ± 0.11, p = 0.02); coma: 0.80 to 0.42 (0.38 ± 0.47, p = 0.03); trefoil: 0.33 to 0.29 (0.04 ± 0.17, p = 0.7).

Conclusion

Utilizing HOA to guide the laser treatment in combination with CXL resulted in a significant decrease of HOA at 6 months postprocedure. This is a small case series, but demonstrates a promising trend of improved HOA. Considering that keratoconic eyes have very irregular surfaces with significant HOA, reducing these aberrations should improve best corrected quality of vision. Having longer follow-up and greater numbers may demonstrate a clearer improvement.

How to cite this article

Penner V, Lewis K, Rocha G. Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):73-77.

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REVIEW ARTICLE

Adel Barbara, Yumna Busool

Post Laser-assisted in situ Keratomileusis Ectasia: A Systematic Review

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:9] [Pages No:78 - 86]

   DOI: 10.5005/jp-journals-10025-1147  |  Open Access |  How to cite  | 

Abstract

Purpose

To provide a comprehensive overview of ectasia development following laser-assisted in situ keratomileusis (LASIK).

Materials and methods

Literature review of relevant studies dealing with corneal ectasia associated with refractive surgery, keratoconus (KC), and cross-linking.

Results

Post Laser-assisted (PLE) involves histopathologic, clinical, and topographic characteristics similar to KC. Several risk screening indices were developed to enhance the detection of KC suspect and mild KC cases prior to the laser procedure. A grading system of PLE was developed, based on risk factors for the severity of ectasia, primarily measured by visual loss. The aims of the treatment are halting ectasia progression and restoring visual acuity.

Conclusion

Familiarity with the highly sensitive and specific indices for ectasia screening, in addition to procedure parameters that increase the likelihood of ectasia development following the refractive procedure, is essential for minimizing the risk of PLE. However, when ectasia develops, early recognition and proper management are essential to prevent progression and improve visual rehabilitation.

How to cite this article

Busool Y, Barbara A. Post Laser-assisted in situ Keratomileusis Ectasia: A Systematic Review. Int J Kerat Ect Cor Dis 2017;6(2):78-86

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REVIEW ARTICLE

Abdelsattar N Farrag, Ahmed A Hussein, Shiji Ummar

Treatment of Pellucid Marginal Degeneration

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:5] [Pages No:87 - 91]

   DOI: 10.5005/jp-journals-10025-1148  |  Open Access |  How to cite  | 

Abstract

Purpose

To summarize the recent trends in the treatment of pellucid marginal degeneration (PMD) based on available published data.

Method and literature search

A PubMed search was conducted with combinations not limited to the following search terms: Pellucid marginal degeneration, Corneal ectasia, Corneal collagen cross-linking (CXL), Intracorneal ring segments (ICRS), Contact lens, Keratoplasty in corneal ectasia. A review of the search results was performed and relevant articles to the topic were included.

Summary

Ophthalmologists have got a wide array of therapeutic modalities for the management of PMD. However, the key to optimal treatment is careful clinical assessment of patients and their visual requirements and tailoring the treatment to individual patients.

How to cite this article

Farrag AN, Hussein AA, Ummar S. Treatment of Pellucid Marginal Degeneration. Int J Kerat Ect Cor Dis 2017;6(2):87-91.

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REVIEW ARTICLE

Aylin Kiliç

Corneal Cross-linking in Combination with Intracorneal Ring Segments

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:5] [Pages No:92 - 96]

   DOI: 10.5005/jp-journals-10025-1149  |  Open Access |  How to cite  | 

Abstract

How to cite this article

Kiliç A. Corneal Cross-linking in Combination with Intracorneal Ring Segments. Int J Kerat Ect Cor Dis 2017;6(2):92-96.

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CASE REPORT

Roberto Soto-Negro

Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:4] [Pages No:97 - 100]

   DOI: 10.5005/jp-journals-10025-1150  |  Open Access |  How to cite  | 

Abstract

How to cite this article

Piñero DP, Soto-Negro R. Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):97-100.

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CASE SERIES

Jorge S Haddad, Eliza Barnwell, Karolinne M Rocha, George O Waring IV

First Clinical Impressions on the Integrated Corneal Tomography and Corneal Deformation with Scheimpflug Imaging

[Year:2017] [Month:July-December] [Volume:6] [Number:2] [Pages:9] [Pages No:101 - 109]

   DOI: 10.5005/jp-journals-10025-1151  |  Open Access |  How to cite  | 

Abstract

How to cite this article

Haddad JS, Barnwell E, Rocha KM, Waring IV GO, Ambrosio Jr R. First Clinical Impressions on the Integrated Corneal Tomography and Corneal Deformation with Scheimpflug Imaging. Int J Kerat Ect Cor Dis 2017;6(2):101-109.

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