To analyze and define the possible errors that may be introduced in keratoconus classification when the keratometric corneal power is used in such classification.

Retrospective study including a total of 44 keratoconus eyes. A comprehensive ophthalmologic examination was performed in all cases, which included a corneal analysis with the Pentacam system (Oculus). Classical keratometric corneal power (P_k), Gaussian corneal power (P_c^Gauss), True Net Power (TNP) (Gaussian power neglecting the corneal thickness effect), and an adjusted keratometric corneal power (P_kadj) (keratometric power considering a variable keratometric index) were calculated. All cases included in the study were classified according to five different classification systems: Alió-Shabayek, Amsler-Krumeich, Rabinowitz- McDonnell, collaborative longitudinal evaluation of keratoconus (CLEK), and McMahon.

When P_k and P_kadj were compared, differences in the type of grading of keratoconus cases was found in 13.6% of eyes when the Alió-Shabayek or the Amsler-Krumeich systems were used. Likewise, grading differences were observed in 22.7% of eyes with the Rabinowitz-McDonnell and McMahon classification systems and in 31.8% of eyes with the CLEK classification system. All reclassified cases using P_kadj were done in a less severe stage, indicating that the use of P_k may lead to the classification of a cornea as keratoconus, being normal. In general, the results obtained using P_kadj, P_c^Gauss or the TNP were equivalent. Differences between P_kadj and P_c^Gauss were within ± 0.7D.

The use of classical keratometric corneal power may lead to incorrect grading of the severity of keratoconus, with a trend to a more severe grading.

Llorens DPP, Camps V, Caravaca-Arens E. Errors Associated to Keratoconus Grading using Systems based on Corneal Power. Int J Kerat Ect Cor Dis 2015;4(2):41-46.

Raiskup F, Hillen M. Corneal Crosslinking can halt the Progression of Keratoconus, but what is the Best Approach to Treatment? Int J Kerat Ect Cor Dis 2015; 4(2):47-51.

The purpose of this review is to outline the etiology, clinical features, and management of acute corneal hydrops (CH) in cases of keratoconus (KC).

The advent of newer investigative modalities like ultra biomicroscopy, anterior segment optical coherence tomography and confocal microscopy has contributed toward the diagnosis, treatment planning and following the course of therapy in cases of acute hydrops.

Corneal hydrops is an acute complication of keratoconus which in most instances resolves spontaneously. However, prolonged corneal edema can lead to complications, such as corneal neovascularization which can jeopardise a future corneal graft. Hence, timely intervention is required in most cases to prevent such complications as well as for early visual rehabilitation. Intracameral gas injection is the most commonly performed surgical procedure for hydrops. Modifications in surgical technique can help to tackle difficult situations.

Maharana PK, Nagpal R, Sharma N. Corneal Hydrops in Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):52-55.

Llorens DPP. Fitting of a New Design of Full Scleral Contact Lens in Advanced Keratoconus with Previous Implantation of Intracorneal Ring Segments. Int J Kerat Ect Cor Dis 2015;4(2):56-59.

To describe and report long-term outcomes of a surgical technique in advanced pellucid marginal degeneration (PMD) combining conventional central penetrating keratoplasty (PK) with an additional crescentic inferior keratoplasty, using a single corneal transplant.

We report the case of a 55-year-old male patient, who underwent a customized sizing PK in his right eye for an advanced PMD, which combined a central PK with an additional crescentic inferior keratoplasty. The 1 year postoperative results show very good clinical outcomes, including visual acuity and biomechanical parameters, as well as tectonic outcomes, documented with high resolution optical coherence tomography (OCT) at the junction site between the two grafts.

Advanced PMD is a specifically challenging condition for keratoplasty due to an extreme peripheral corneal thinning. This surgical technique may facilitate inferior suturing and optimize the postoperative tectonic outcomes.

Saunier V, Smadja D, Touboul D. Simultaneous Penetrating Keratoplasty with Crescentic Inferior Keratoplasty in Advanced Pellucid Marginal Degeneration. Int J Kerat Ect Cor Dis 2015;4(2):60-62.

Abbondanza M, Guidobaldi M. Corneal Collagen Cross-linking in a Prepubescent 10-Year- Old Girl with Aggressive Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):63-65.

To report the clinical course of a typical young patient presenting with asymmetric keratoconus (KC), that demonstrates that stabilization of the ectatic process is possible without cross-linking (CXL) procedure.

Case report and review of the literature.

A 17-year-old male patient was referred due to the diagnosis of keratoconus. Patient complained of loss of vision in the left eye (OS). Uncorrected distance visual acuity (UDVA) was 20/25+ in the right eye (OD) and 20/80 in the left eye; wavefront-assisted manifest refraction gave best corrected distance visual acuity (CDVA) of 20/20 in OD and 20/40 in OS. The diagnosis of keratoconus was confirmed with Placido disk-based topography (Oculus Keratograph 4), and Pentacam HR corneal tomography (Oculus Optikgeräte GmbH, Wetzlar, Germany). Femtosecond laser-assisted intracorneal ring segment (ICRS) implantation was performed in the left eye and treatment for allergy was prescribed for both eyes, along with patient education and advice not to rub the eyes. After 3 months, significant improvement was observed on UDVA (20/30) and CDVA (20/20) in the left eye. Topometric and tomographic stability of ectasia was observed in the right eye in a 4-year follow-up.

Intracorneal ring segment caused significant regularization of the corneal shape and improvement on visual acuity. Ectasia stability was achieved with no need for CXL, despite the patient's young age. This case raises the point that the indication of CXL for every keratoconic patient should be reconsidered.

de Oliveira Corrêa R, Canedo ALC, Beildeck R, Salomão MQ, de Politis PB, Ambrósio R Jr. Longterm Stability of Ectasia in a Young Patient with Asymmetric Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):66-68.

Barbara A, Barbara R. A Special Design of Intacs SK and Collagen Corneal Cross-linking for the Treatment of Pellucid Marginal Degeneration in a 74-Year-Old Male. Int J Kerat Ect Cor Dis 2015;4(2):69-75.

Daxer A. MyoRing Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):76-83.