Kiliç A. Corneal Physiology and Responses to Cross-Linking and Intracorneal Rings in Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):1-6.

Gordon-Shaag A, Millodot M, Shneor E. The Epidemiology and Etiology of Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):7-15.

Nowadays, ICRS are a step in the treatment of keratoconus. The purpose of this study was to evaluate the refractive effect and the tomographic and biomechanical parameters in keratoconus patients implanted with Ferrara ICRS, and their stability after 18 months.

Twenty eyes of 20 keratoconus patients implanted with ICRS were evaluated. The average follow-up was 18 months. UDVA, CDVA, biomicroscopy, tomography (Pentacam) and biomechanics (ORA) of the cornea were evaluated before and after surgery. For the comparison of groups, the Wilcoxon test was used.

The mean UDVA improved from 1.00 to 0.30 and the mean CDVA improved from 0.51 to 0.12; both were statistically significant (p = 0.0001). The average keratometry decreased from 50.7D to 47.5D (p = 0.0003), and the average astigmatism decreased from 5.5D to 3.5D (p = 0.0058). The mean CCT did not change significantly after surgery, but the mean TPP increased from 441.2 to 455.2 µm (p = 0.004). There was a significant reduction in the anterior cornea elevation, both the central (from 16.2-8.8; p = 0.0066) and the minimum (from–43.2 to −57.1; p = 0.0228). No significant change was found for posterior corneal elevation and for biomechanical parameters (hysteresis or CRF).

There was a significant improvement of UDVA and CDVA after ICRS implantation, in keratoconic eyes. There was a significant and stable corneal flattening, and a decrease of the astigmatism. Corneal biomechanic parameters did not change.

Salgado-Borges JM, Costa-Ferreira C, Monteiro M, Guilherme-Monteiro J, Torquetti L, Ferrara P, Ambrósio R Jr. Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients. Int J Keratoco Ectatic Corneal Dis 2012;1(1):16-21.

To determine the long-term alterations of corneal thickness, along with topographic outcomes, after corneal collagen cross-linking treatment (CXL) for keratoconus.

In this retrospective case series, 46 patients (52 eyes), 32 males and 14 females, with progressive keratoconus were included. All eyes underwent CXL in accordance with the standard protocol (Dresden) for the treatment of their ectatic corneal disorder between January 2006 and June 2007. Pachymetric and topographic outcomes were evaluated preoperatively and at 1, 3, 6, 12, 24 and 36 months postoperatively.

Mean follow-up was 28.08 ± 8.39 months (range, from 12 to 36 months). A statistically significant decline in corneal pachymetric values (at the thinnest location) when compared with preoperative values (467.65 ± 41.08 µm) was demonstrated at 1 (437.63 ± 50.57 µm), 3 (439.08 ± 52.27 µm), 6 (449.37 ± 52.73 µm), 12 (449.63 ± 83.53 µm) and 24 (459.97 ± 47.32 µm) months after CXL (p < 0.05, for all mentioned time intervals). Return to preoperative pachymetric values (469.52 ± 40.52 µm) was revealed 36 months post-CXL (p > 0.05). With respect to topographic (flat and steep keratometric values, keratoconus index), no statistically significant differences between preoperative and all postoperative intervals were found (p > 0.05, for all values for all time intervals).

Corneal pachymetric values reduce significantly up to 24 months after CXL treatment, while a return to preoperative values was revealed 36 months after the procedure. No significant changes’ concerning topographic outcomes was demonstrated after CXL, indicating stability of these parameters.

Zotta PG, Almaliotis DD, Kymionis GD, Diakonis VF, Moschou KA, Karampatakis VE. Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):22-25.

To evaluate the influence of age and severity of keratoconus in the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS).

A total of 1,073 eyes of 810 patients, consecutively operated from January 2006 to July 2008, were evaluated. Two independent analysis were made according to the age of patients and keratoconus staging. Four groups were created according to the age of patients: < 20 years old, 20 to 30, 30 to 40 and >40 years old. The patients were also evaluated according to the keratoconus stage (I to IV). The outcome analysis included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry (K), asphericity (Q), corneal volume (CV) and pachymetry. All patients were evaluated using the Pentacam.

The postoperative increase in UDVA and CDVA was statistically significant in all groups (p < 0.05). The magnitude of improvement of CDVA was larger for patients between 21 and 30-year-old (CDVA = 20/40) and patients with keratoconus grade I (CDVA = 20/35) (p < 0.05). There was a statistically significant increase in CV and pachymetry postoperatively in all groups. The keratometry (3.95D) and asphericity (–0.77) reduction were larger in patients younger than 20-year-old and in patients with keratoconus grade IV (p < 0.05).

The best clinical outcomes are seen in patients between 20 and 30-year-old and initial cases of keratoconus (grade I). The more advanced the keratoconus, the larger magnitude of K and Q reduction after ICRS implantation.

Torquetti L, Ferrara G, Ferrara P. Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation. Int J Keratoco Ectatic Corneal Dis 2012;1(1):26-30.

Belin MW, Kim JT, Zloty P, Ambrosio R Jr. Simplified Nomenclature for describing Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):31-35.

Gatinel D, Saad A. The Challenges of the Detection of Subclinical Keratoconus at Its Earliest Stage. Int J Keratoco Ectatic Corneal Dis 2012;1(1):36-43.

To calculate and compare cone location and magnitude index (CLMI), Kmax and other corneal measures derived from three different technologies, Placido, Scheimpflug, and a combination dual Scheimpflug-Placido device, from the same group of eyes with keratoconus and postrefractive surgery corneal ectasia.

Keratoconus (n = 26) eyes of (n = 19) subjects and postrefractive surgery ectasia (n = 5) eyes of (n = 5) subjects were selected to have measurements performed using the Keratron Scout, Pentacam HR and Galilei Dual Scheimpflug Analyzer. Device-generated SimK's and device-specific CLMI and Kmax indices as well as map data, were exported from each device. Index values for multiple exams were averaged. The map data were processed using The Ohio State University Corneal Topography Tool (OSUCTT) to calculate CLMI parameters, Kmax and SimK values using consistent algorithms on all three devices. Maps were averaged before calculation for multiple examinations. Repeated measures analysis of variance and post- hoc analysis were used to identify differences between devices.

The anterior axial CLMI calculated from the Keratron data was significantly higher than CLMI for the Galilei (p = 0.0443) or Pentacam (p < 0.0004) with keratoconus, 12.23 compared with 11.20 and 11.00 diopters, respectively. Kmax was also significantly higher in the Keratron than the Galilei (p = 0.0063) or the Pentacam (p < 0.0002). Galilei and Pentacam were not significantly different from each other in either CLMI (p = 0.6287) or Kmax (p = 0.2115). The anterior CLMI values for the postrefractive surgery ectasia eyes were not significantly different between devices. Posterior CLMI values were calculated from the Galilei and Pentacam data and were −2.60 and −2.46 diopters (p = 0.1173) for keratoconus and −2.66 and −3.04 diopters (p = 0.2242) for postrefractive surgery ectasia.

The small cone Placido measured dioptric values that were greater than the pure Scheimpflug system, but the difference was only about 1 diopter, which is not relevant clinically in evaluating and managing ectasia. The combined dual Scheimpflug-Placido system produced measured dioptric values between the other two technologies. The anterior CLMI calculations accurately predicted keratoconus with all three devices. The posterior CLMI in ectasia may be a potentially valuable calculation in demonstrating asymmetric steepening.

Mauger TF, Mahmoud AM, Roberts CJ, Chheda LV, Kuennen RA, Hendershot AJ, Lembach RG. Comparison of Placido, Scheimpflug and Combined Dual Scheimpflug-Placido Technologies in Evaluating Anterior and Posterior CLMI, SimK's as well as Kmax, in Keratoconic and Postrefractive Surgery Ectasia. Int J Keratoco Ectatic Corneal Dis 2012;1(1):44-52.

• C Roberts is a Consultant for Oculus Optikgerate GmbH and Ziemer Ophthalmic Systems AG, and has an interest in the GALILEI.

• A Mahmoud has an interest in the GALILEI.

• T Mauger, L Chheda, R Kuennen, A Hendershot, and R Lembach have no financial interests.

To assess the effect of corneal cross-linking on progressive keratoconus in children.

In this retrospective study we enrolled nine eyes of nine consecutive children aged 11 to 17 years old who underwent corneal riboflavin-UVA induced cross-linking for progressive keratoconus at the Department of Ophthalmology at Assaf Harofeh Medical Center. They were followed for 6 to 24 months (average 16 ± 8.1 months). Evaluated parameters were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, pachymetry, slit lamp examination and corneal topography.

Cross-linking resulted in stability of visual acuity in seven of the nine (77.8%) treated eyes. We found a nonsignificant improvement in UCVA and BSCVA with a small reduction of manifest cylinder. Furthermore, there was an improvement in spherical equivalent that was close to statistical significance (p = 0.07). There was 0.86 D reduction of average Kmax value postoperatively (p = 0.36). Most patients (7 of 9, 77.8%) showed a long-term stability or reduction in Kmax.

In this study, we demonstrated the efficacy of corneal cross-linking in arresting the progression of keratoconus in children. We believe that larger scale studies in this age group should be performed to further establish the relevance of this technique in children.

Bakshi E, Barkana Y, Goldich Y, Avni I, Zadok D. Corneal Cross-Linking for Progressive Keratoconus in Children Our Experience. Int J Keratoco Ectatic Corneal Dis 2012;1(1):53-56.

To evaluate the efficacy of corneal cross-linking on keratoconic eyes in the pediatric age group.

Private laser center, Haifa, Israel, affiliated to Hadassah Hospital, Jerusalem.

This is a retrospective study of 29 eyes of 20 children treated with corneal cross-linking with aim to arrest the progression of keratoconus. We preformed collagen corneal cross-linking using riboflavin 0.1% and UVA irradiation. Follow- up ranged between 6 and 46 months (mean 25.5 months). Evaluation included uncorrected visual acuity, best spectacle corrected visual acuity, manifest refraction, slit lamp examination and corneal topography. Ocular response analyzer was used to assess the corneal resistance factor, corneal hysteresis and cornea compensated intraocular pressure.

The results show improvement in uncorrected visual acuity and best spectacle-corrected visual acuity and reduction in astigmatism. There was no statistically significant change in sphere, keratometry, corneal resistance factor, corneal hysteresis or cornea compensated intraocular pressure.

Corneal cross-linking demonstrates efficacy in arresting the progression of keratoconus as well as improving uncorrected and best corrected visual acuity and reducing astigmatism.

Barbara R, Pikkel J, Garzozi H, Barbara A. Collagen Cross-Linking and Keratoconus in Pediatric Patients. Int J Keratoco Ectatic Corneal Dis 2012;1(1):57-60.

To demonstrate the effectiveness of UVA/riboflavin cross-linking (CXL) in the treatment of therapy resistant corneal melting of different etiology.

This paper describes a series of four cases presenting severe ulcerative keratitis with infectious and noninfectious causes. In spite of intensive medical treatment, corneal melting did develop in all four eyes. CXL was performed to avoid imminent corneal perforation.

After CXL, there was a rapid improvement in two eyes which healed completely within a month. In the other two eyes, an emergency keratoplasty had to be performed.

This case series highlights the effectiveness of CXL in the treatment of corneal melting as an addition to our current therapeutic armamentarium. Improvement can be expected in a few days after treatment. CXL can be considered as an adjunct therapy as soon as melting appears in severe corneal ulcers not responding to conventional, intensive treatment.

Al-Sabai N, Koppen C, Tassignon MJ. UVA/Riboflavin Cross-Linking as an Alternative Treatment for Therapeutic Keratoplasty in Corneal Melting. Int J Keratoco Ectatic Corneal Dis 2012;1(1):61-65.

Bahar I, Bialer O. Cataract Extraction and Toric Intraocular Lens Implantation for the Management of Pellucid Marginal Degeneration and Cataract. Int J Keratoco Ectatic Corneal Dis 2012;1(1):66-67.

Barbara R, Zadok D, Pikkel J, Marcovich A, Garzozi H, Nasser O, Abdelaziz L, Barbara A. Collagen Corneal Cross-Linking followed by Intac Implantation in a Case of Post-PRK Ectasia. Int J Keratoco Ectatic Corneal Dis 2012;1(1):68-72.

Mortensen JN. Corneal Ectasia after PRK. Int J Keratoco Ectatic Corneal Dis 2012;1(1):73-74.