K eratoconus is a bilateral, asymmetric, chronic, initially progressive ectasia of the cornea characterized by steepening, distortion, and thinning of the apical cornea as well as corneal scarring. Intrastromal corneal ring segments (Intacs; Addition Technology Inc, Sunnyvale, California) is 1 treatment option available for patients with keratoconus, especially those with contact lens intoleran...

PURPOSE Corneal collagen cross-linking (CXL) is a method for modifying the natural history of keratoconus and other corneal ectatic diseases. The authors evaluated the use of collagenase for generating an experimental model of ectasia to evaluate the topographic effects of CXL interventions. METHODS Nine human corneoscleral specimens unsuitable for transplantation were used. After epithelial ...

The aim of this study was to evaluate the long-term safety and efficacy of photorefractive keratectomy (PRK) for patients with myopia and thin corneas. In this retrospective case series, we included 74 eyes of 38 patients with myopia and central corneal thickness (CCT) < 550 µm who underwent PRK and had a mean postoperative follow-up period of four years. The following factors were evaluated: C...

OBJECTIVE It is to study the pattern of corneal diseases (including injuries) in paediatric population in a tertiary eye care center. MATERIALS AND METHODS A descriptive, cross sectional study was carried out in a tertiary eye care center which included 176 cases. RESULTS Out of 176 cases studied, 6 cases (3.4%) presented with congenital causes, 4 cases (2.27%) were of dystrophy and ectasia...

Undetected subclinical keratoconus (KC) is the main risk factor for iatrogenic ectasia. Many parameters have been proposed to help differentiate normal from subclinical KC corneas. Linear discriminant analysis is a technique that models the difference between different classes of data by looking for linear combinations of variables which best explain the data. The association of surfaces elevat...

An integrated model for keratectasia risk assessment has received much attention over many years. The objective of this article is to propose a more complete, conceptual model by which high risk individuals can be screened, even with no topographic irregularity or corneal thinning. In this model, corneal ectasia results from the fatigue effect of cyclic shear stress and tensile stress, caused b...

Keratoconus is a common corneal ectasia that leads to progressive visual impairment. Numerous studies have shown abnormal protein expression patterns in keratoconic corneas. However, the specific mechanisms causing this disease remain ambiguous. This review aims to provide an update on morphological studies of the keratoconic cornea, relate these early studies with current findings from proteom...

ow should we screen our patients for postoperative ectasia risk prior to excimer laser corneal refractive surgery, or laser vision correction, in 2013? This has been debated in the literature1-4 and remains a “hot topic” at most meeting venues. The challenge we face as refractive surgeons in daily practice is to most accurately identify individuals who have increased susceptibility for developi...

Implantation of phakic refractive lenses PRL® (Phakic Refractive Lens; IOLTech/Carl Zeiss Meditec AG, Jena, Germany) is one of the options available for the correction of moderate to high myopia, although there are few reports on the outcomes. In those cases where a corneal laser-assisted surgical procedure is not indicated because of the great amount of tissue to be removed, small optical zone...

PURPOSE To review outcomes of corneal collagen cross-linking (CXL) for keratoconus (KC) or ectasia in a cornea subspecialty practice. METHODS Results from controlled clinical trials at a single site cornea subspecialty practice, including 104 eyes (66 KC and 38 ectasia). Outcomes and the natural course of changes in postoperative parameters including maximum keratometry (KMax), uncorrected vi...