To assess the clinical outcomes in ectatic corneas following accelerated transepithelial cross-linking (CXL) over 1 year of follow-up.

Twenty-one eyes diagnosed with progressive corneal ectasia (19 keratoconus, 2 post-laser in situ keratomileusis ectasias) in 14 patients aged between 26 and 69 years were enrolled. All cases were treated with accelerated transepithelial CXL using the Avedro KXL^® system (Waltham, MA, United States). Changes at visual, refractive, corneal topographic, and corneal aberrometric level were evaluated over a 12-month follow-up period. The demarcation was also determined using optical coherence tomography (OCT).

The mean depth of the demarcation line measured by OCT was 202.72 µm, varying between 153 and 230 µm. One month postsurgery, a change was noted at the limit of statistical significance in sphere (p = 0.05) and in spherical equivalent (p = 0.05). Likewise, a statistically significant difference was observed in corrected distance visual acuity (CDVA) (p = 0.01). There were no significant changes in either visual acuity or refraction between 1 and 6 months (p ≥ 0.35). Although changes in trend were observed in corneal topographic and aberrometric parameters after surgery, none reached statistical significance (p ≥ 0.08). A significant change was observed only in astigmatism of the posterior surface between 1 and 12 months (p = 0.02).

Accelerated transepithelial CXL may be a useful technique for the management of progressive corneal ectasia, as it is able to maintain the topographic and aberrometric profile of the cornea with no significant changes. Longer-term studies are required to confirm this finding

Piñero DP, Artola A, Ruiz-Fortes P, Soto-Negro R, Pérez-Cambrodi RJ. Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking. Int J Kerat Ect Cor Dis 2016;5(3):93-98.

To propose a new system of keratoconus staging using a set of parameters describing the keratoconic cone.

Retrospective case series study of 101 keratoconic eyes of 58 patients was undertaken. They all had complete eye examination including corneal topography (Oculus Pentacam). K_mean, K_max, higher order aberrations (HOAs) root mean square (HOARMS) value, pachymetry at thinnest point and steepest corneal meridian were obtained from Pentacam. Apex to thinnest pachymetry distance (D) was calculated using trigonometry. Pearson correlation coefficients between K_max and HOARMS, between D on the one hand and the adjusted angle of steepest meridian, K_mean and K_max respectively on the other, were calculated.

There is a statistically significant positive correlation between K_max and HOARMS (p < 0.00001). There is a negative correlation, a “horizontalization,” of the steep meridian with D increase, although it fell short of statistical significance (p = 0.07). D and K_mean (p = 0.003), and D and K_max (p = 0.005) are significantly negatively correlated.

K_max correlates with significant changes in HOAs. D correlates with corneal astigmatic meridian change and has a divergent path to K_mean and to K_max. We propose a new keratometry, decentration, and thinnest pachymetry staging using the parameters K_max (K), distance from the corneal apex to the thinnest pachymetry point (D), and corneal thickness at its thinnest point (T) to give a better, detailed description of a keratoconic cornea which could lead to improvements in assessment of its severity and treatment outcomes.

Tu KL, Tourkmani AK, Srinivas S. Keratoconic Cone using its Keratometry, Decentration and Thickness as Staging Parameters. Int J Kerat Ect Cor Dis 2016;5(3):99-104.

To evaluate anterior chamber indices including anterior chamber depth (ACD) and anterior chamber volume (ACV) with the progression of keratoconus using a rotating Scheimpflug camera to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes.

After full ophthalmological examination in the Memorial Institute of Ophthalmic Research, the patients are divided into two groups: Group I consisting of 50 eyes of normal control. Group II consists of 50 eyes of moderate keratoconus. All the subjects were evaluated with a Pentacam Scheimpflug camera (Oculus, Wetzlar, Germany). Keratoconic eyes were evaluated by vertical asymmetry (VI), keratoconus index (KI), thinnest corneal thickness (TCT) with front elevation at thinnest location (F.Ele.Th) and back elevation at thinnest location (B.Ele.Th) and then divided into three groups according to mean keratometer (K) readings: Mild (K = less than 47.0 D), moderate (K = 47.0 to 52.0 D), and severe (K = 52.0 D or higher), and ACD and ACV were obtained after exclusion of mild and severe cases.

With the progression of the disease, there was statistically significant differences in ACD and ACV measurements between the normal and moderate keratoconus eyes with progressive increase in the ACD and ACV with disease progression.

Anterior chamber parameters including depth and volume showed significant increase with moderate keratoconus than control.

Ali NH, AbdElKhalek MO, El Ghonemy HM. Comparison of Anterior Chamber Parameters between Normal and Keratoconus Eyes using Scheimpflug Photography. Int J Kerat Ect Cor Dis 2016;5(3):105-108.

To simplify and enhance safety in the generation of a stabilizing intracorneal scar by circular keratotomy (CKT). A femtosecond laser was used to perform individually sized intraparenchymal cuts.

As equipped, the Ziemer Z6 femto-second laser cuts a 400-µm-deep incision with a diameter of 7.0 mm around the optical axis. The epithelium, Bowmann's membrane, the internal borders of Descemet's membrane, and the endothelium are not affected.

The 3-, 6-, and 12-month postoperative values were compared with the 1-month postoperative keratometric readings and astigmatism. The preoperative best corrected visual acuity (BCVA) with glasses was compared with the values found at the same time points as noted above.

Statistical evaluation indicated that keratometry within ±1.5D remained in 96.6, 93.1, and 96.6% of cases at the 3-, 6-, and 12-month time points respectively.

Astigmatism was stable at the same time points in 100, 95.8, and 92.3%.

The BCVA improved in 12 cases throughout the first post-operative year (48%, n = 25); however, 11 cases did not change (44%) and 2 cases lost at least one line (8.0%).

Femto CKT halts the progression of keratoconus for at least 1 year in 96.6% of cases. This treatment provides keratometric and refractive stability for over 1 year. This result, in conjunction with the significant improvement in BCVA, demonstrates the potential of this method for patients with stage I and II keratoconus.

Krumeich JH, Hirnschall N, Breyer D, Laufer F. Femto Circular Keratotomy to Halt the Progression of Keratoconus I and II. Int J Kerat Ect Cor Dis 2016;5(3):109-113.

Torquetti L, Sandes J, Ferrara G, Ferrara P. Ferrara Intrastromal Corneal Ring Segments. Int J Kerat Ect Cor Dis 2016;5(3):114-127.

Hefner-Shahar H, Erdinest N. Highorder Aberrations in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(3):128-131.

This observational clinical case series examined patients with keratoconus (KC) fit with keratoconic bi-aspheric (KBA) lenses to assess visual acuity (VA), wavefront aberrations, physiological fitting, subjective comfort, and manufacturer's fitting guidelines.

Seven adult patients (11 eyes, four females, mean age: 34.15 ± 14.12) with nipple cones from the Hadassah Academic College contact lens clinic (Jerusalem, Israel) were fit with KBA lenses by modifying the initial base curve (BC) to obtain an acceptable physiological fit. The uncorrected and corrected distance (D) and near (N) Snellen VA and the ocular wavefront measurements, and responses to a self-administered five-point scale questionnaire were compared after 2 weeks of wear using paired two-tailed t-test or Mann-Whitney U test, as appropriate.

Visual acuity and total root mean square (RMS) improved significantly with the lenses (DVA_uncorrected = 0.04 ± 0.02, DVA_corrected = 0.66 ± 0. 22, NVA_uncorrected = 0.34 ± 0.30, NVA_corrected = 0.95 ± 0.12). Subjects reported an average of 7.0 ± 2.7 hours of wear daily, with good scores in visual stability, satisfaction with VA and quality of vision, improvement of mood and quality of life, and low scores in foreign body sensation, pain, red eye, and itching during wear, and difficulty with lens removal. An average of two BC modifications from the diagnostic lens were necessary (0.16 mm steeper in nine eyes, 0.27 mm flatter in two eyes).

Keratoconic bi-aspheric lenses can provide 7 hours of comfortable wear, significantly improved VA and total RMS aberrations, alongside subjective satisfaction. Base curve modifications can be reduced by fitting a diagnostic lens 0.75 mm steeper than the flattest keratometry reading.

Gantz L, Gordon-Shaag A, Gideon-Abousaid A, Serero G, Fine P. Keratoconic Bi-aspheric Contact Lenses. Int J Kerat Ect Cor Dis 2016;5(3):132-138.